Thorn Cycles Forum

Technical => Transmission => Topic started by: KvBCycles on April 26, 2021, 10:42:45 pm

Title: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: KvBCycles on April 26, 2021, 10:42:45 pm
Good evening all,

My bike: Nomad MK2
Bottom Bracket: Shimano BB-UN55 73mm (x107mm) English threaded, square tapered bottom bracket.
Mileage: about 20000km´s
Issue: started to creak again
Want to: replace
Problem: cannot find a replacement (or maybe looking for the wrong thing?)

Hope you can help here. As per above, want to replace my BB. I have been searching for a like-for-like replacement, but I simply cannot find a 73mm square tapered BB in the EU (I am in Spain).
I got in touch with Thorn and Robin pointed out 2 possible replacements (TH industries and Tange Seiki) but - delivery to my location is double the price of the replacement, plus, he cannot promise I won´t be slapped with additional customs duties upon delivery.
So I have been looking at European retailers and like I said, I cannot find a 73mm square taper BB - they are all 68mm. Nor can I find either of the 2 suggested by Robin.

So - alternatives, for example, could I replace my BB with the Shimano BB-MT800, a 68/73mm threaded, hollowtech BB?
See here: https://bike.shimano.com/en-EU/product/component/deorext-m8000/BB-MT800.html  (https://bike.shimano.com/en-EU/product/component/deorext-m8000/BB-MT800.html)
As far as I understand it, I can...right?

If so, how does this affect the drive chain and cranks? Can I use my existing ones?
If I am not mistaken - I can right?
And also, if I am not mistaken, the type of tool required to remove/install the different BB´s changes? (but that is no problem as I do not have the tools for either).

My plan is to take it to a local bike shop, but, I want to know what to expect before speaking to them because I am sure they will not have seen an eccentric BB before, language is an issue and I want to be sure nothing is damaged on the bike and I know what I am getting.

Thanks in advance.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: JohnR on April 26, 2021, 11:01:01 pm
See this relevant discussion http://thorncyclesforum.co.uk/index.php?topic=14180.0 .
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: Danneaux on April 26, 2021, 11:03:12 pm
Quote
So - alternatives, for example, could I replace my BB with the Shimano BB-MT800, a 68/73mm threaded, hollowtech BB?
See here: https://bike.shimano.com/en-EU/product/component/deorext-m8000/BB-MT800.html
As far as I understand it, I can...right?
Sadly...no.  :'( The external bottom bracket you listed does not interchange with square-taper cranks intended for use with an internal bottom bracket. You would need to fit matching cranks and convert wholly to an external/outboard bearing system for it to work.

Best,

Dan.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: John Saxby on April 27, 2021, 01:57:55 am
Not in the EU, but German made, expensive, but available here:
https://www.renehersecycles.com/product-category/components/bottom-brackets/ (https://www.renehersecycles.com/product-category/components/bottom-brackets/)

Might be worth a phone call.

I bought a UN55 a couple of months back, and even then they were scarce as hens' teeth. My size, 73 x 118, was one of the few available.

Good luck!
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: Danneaux on April 27, 2021, 02:11:05 am
Over the last 45 years and tens of thousands of miles, I've had good luck with Phil Wood bottom brackets, available in 73mm spacing. See:
https://phil-wood-co.myshopify.com/collections/square-taper-bottom-brackets

Best,

Dan.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: ourclarioncall on April 27, 2021, 02:19:58 am
Over the last 45 years and tens of thousands of miles, I've had good luck with Phil Wood bottom brackets, available in 73mm spacing. See:
https://phil-wood-co.myshopify.com/collections/square-taper-bottom-brackets

Best,

Dan.

Could you Tell us more if you don’t mind ? Would it be an upgrade in comparison to the un55 or others ?
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: Danneaux on April 27, 2021, 03:39:45 am
Quote
Could you Tell us more if you don’t mind ? Would it be an upgrade in comparison to the un55 or others ?
As a high-mileage cyclist -- 13,000-19,000kms/year at my peak -- I looked for longer-lived solutions early on and found the selection wanting here in the US. I had some pretty good luck with Tange-Seiki sealed units (at one time, they were a supplier for Shimano's branded higher-end units), but nothing has matched the lifespan and trouble-free service of my Phil internal-bearing cartridge bottom brackets; for this reason I consider the Phil units an upgrade. I have several with more then 52,000kms, and a couple more with 45,000+kms and no problems. They spin as smoothly and trouble-free as ever. They have far outlasted a number of Shimano's higher end units for me, but they do command a premium price. The good news is Phil will rebuild older units. I have some really early Phil hubs and BBs dating from the 1970s and they worked on them. They used to make platform pedals and replaced a failed spindle for me free of charge long after they stopped production. See: http://www.bikerecyclery.com/phil-wood-chp-pedals-1970s/

When I got my Nomad, I decided to go with a Shimano Deore crankset and outboard/external bearing bottom bracket (OBB/EBB) because it was a "different" approach that appealed to me. It basically adjusts like a threadless headset. I liked the smaller BCD of the crankset that allowed lower gearing and the large-diameter spindle was lighter, stiffer, and did not require me to carry either a crank puller or fit self-extracting crank bolts to remove and service while on tour. The bearing cups are very easily installed and removed and it is pretty easy/fairly light to carry a spare pair if needed. One drawback is Surly's stainless chainrings are only available in tooth sizes up to 36t for this crank's 104mm BCD and this eliminates compatibility with Hebie's Chainglider.

Unfortunately, in my own experience in harsh conditions, I found the bearings in Shimanos OBB units to be a weak point due to poor weather sealing, little grease supplied at the factory, flexible cups and a less than full complement of ball bearings. OBBs are also extremely sensitive to bearing preload during setup, so be gentle on this if you install one regardless of make. Shimano units can be easily pumped full of more grease which greatly extends their service and it is also possible to press in new bearing cartridges available from aftermarket sources. Having had such good luck with Phil products over the years, I took the plunge and installed a Phil OBB unit in my Nomad. It is heavier, made of billet stainless steel and the bearings are larger, more numerous, and better lubricated and sealed than on many competing models.

These links might be helpful to you as they further describe my experience...
http://thorncyclesforum.co.uk/index.php?topic=4479.msg21711#msg21711
http://thorncyclesforum.co.uk/index.php?topic=12155.msg88741#msg88741
http://thorncyclesforum.co.uk/index.php?topic=11651.msg84942#msg84942
http://thorncyclesforum.co.uk/index.php?topic=4523.msg43173#msg43173
Photos and narrative showing the installation of the Phil OBB unit on my Nomad here...
http://thorncyclesforum.co.uk/index.php?topic=4523.msg43281#msg43281 ...the thumbnails got corrupted in a Forum upgrade, so to see the photos you will have to click on the links to download them for viewing.
http://thorncyclesforum.co.uk/index.php?topic=4523.msg43285#msg43285

So far, the Phil OBB unit has been working just fine on my Nomad, as expected. The Nomad has not seen the mileage of my randonneur bikes because I use it mostly for expeditions, but the BB has been unaffected by the fine, talc-like alkali dust of my desert usage as well as the usual challenges caused by heavy rain, snow, and general usage.

Best,

Dan.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: Andre Jute on April 27, 2021, 10:33:01 am
I got in touch with Thorn and Robin pointed out 2 possible replacements (TH industries and Tange Seiki) but - delivery to my location is double the price of the replacement, plus, he cannot promise I won´t be slapped with additional customs duties upon delivery.

I don't know what the Spanish customs procedure is for low value items. Bear with me just a moment while I explain what it is in Ireland, and may be across the EU though I am sure there will be local variations. Here in Ireland, if the contents of the parcel cost less than Euro 22 including carriage or postage, it passes free of VAT and other taxes, and with no chargeable formalities; if the contents of the parcel cost less than Euro 150 without taking carriage into account, VAT must be paid on the full amount, but there will be no other customs or excise taxes (this doesn't apply to liquor or tobacco products). Note the lower exemption escapes customs inspection: it just passes through in the post. The second exemption can be even more expensive than appears, because the couriers automatically charge a fee for filling in the paperwork and collecting the taxes from you and paying them to the government. A common fee charged by the couriers is a Euro or Sterling Pound minimum sum of 14.50 and rising from there according to the value of the parcel; the Irish post office charges a minimum of Euro 6.50 and rising according to the value of the parcel; you can't escape by buying from Ebay either because the Ebay seller charges you for packaging and postage and then Pitney Bowes, the Ebay customs facilitator, charges you a flat STG 14.50 on top of that, which appears automatically on your Paypal account; in effect you pay for postage twice. As an example of the simplest version, i.e. not involving Ebay's racket, I recently bought a watch for a spot over Euro 130 in Singapore and DHL wanted another 46 or 47 Euro in taxes and fees before they would deliver it; it would have been about the same total cost to buy it in Germany or somewhere else in the EU from a jeweller I've dealt with before and who I know scrupulously honours warranties. Unfortunately, it is actually more complicated than that, but if you're lucky these facts are all you need to know for the next couple of months.

Now we come to the point of this post. All of that changes on 1 July 2021. The EU to punish Britain for looking after herself, and the Chinese for maliciously creating a pandemic by letting a million people fly out of Wuhan airport to destinations all over the world while they tried to suppress information about virus being shared by scientists, have made a regulation that all customs and excise taxes and duties and penalties (anti-dumping levies and suchlike) must be raised and collected, no matter how small the amount. This automatically adds the further cost of the courier or post office's fee for running the packet past customs and collecting the taxes on behalf of customs. There will also be a delay of several days to many weeks (months!) in customs and then at least another day while the courier emails you demanding online payment before they will even put your parcel on the truck.

In short, in the special case presented in this thread, if you're going to buy the bottom bracket from SJS, it must be delivered to you before 1 July or you will be up for further costs on top of double the price of the UN-55 or equivalent for carriage.

In the case of everyone else not in the UK, it will be smart to start investigating alternative EU-based sources of supply for the smaller items on which these malicious extra costs will be especially punishing.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: PH on April 27, 2021, 01:42:36 pm
My plan is to take it to a local bike shop, but, I want to know what to expect before speaking to them because I am sure they will not have seen an eccentric BB before, language is an issue and I want to be sure nothing is damaged on the bike and I know what I am getting.
Thanks in advance.
I haven't a lot to add to the previous linked thread on BB's and life is too short to get involved with correcting Andre's inaccurate politicking.
But I'd have no qualms about taking it to a bike shop, as far as changing the BB is concerned, doing so in an EBB insert or directly into a frame are no different.  Even if they'd never seen one, a glance would be enough for them to access that there's nothing unusual about it.
The LBS would be my first port of call, they'll know what's available locally.  The UN55 has been discontinued for a while now, they're getting hard to impossible to find and any old stock is selling for a premium.  The replacement UN300 is reported to be of inferior quality, but then people said that about the UN55 when it superseded the UN72, time will tell.  A couple of points on axle length - 107 and 110 offer the same chainline, the 113 (Which I think is the shortest UN300) pushes it out a bit, but if that's all you can get there's ways of bringing it back or there's probably no real harm in being that little bit out (Assuming it was perfect to start with)
if the bike shop can't help, Tange Seiki lists a Spanish distributer who might be able to point you at one than can.

Quality and longevity of bottom brackets does seem to have an element of randomness about it, at least with the mass produced units. I think the cartridge bearing suffer from inconsistency.  I've had UN55's fail after a few thousand miles and I have a real cheapie that's seen off a few chainrings and still runs sweet.   
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: KvBCycles on April 27, 2021, 08:48:56 pm
Well, guys, thank you all for your input - a lot of food for thought  :o

At this point it is clear what I need to do: learn about BB´s  ;D and get to a local bike shop. PH - you are right thinking about what you said, the EBB should not make a difference.
Fingers crossed there is something in stock somewhere. I don´t think I mentioned this but I am in Melilla, the Spanish city on the coast of Africa. We are in fact not part of the EU customs union which makes it really hard to get stuff here - many dealers do not ship to Melilla (or Ceuta, Canaries or Belearics). We have a handful of bike shops here and spare part variety is limited to the basics, but hopefully a square tapered BB falls into that category. SJS sent me a replacement part on warranty last year before the pandemic, it arrived after 2 or 3 weeks, and the import agents here asked for 10 euros to release it.

Out of interest - how could I future proof myself here?
Do I need to buy a handful of square tapered BB´s or, like Dan, go external (OBB/EBB) despite the disadvantages he mentions?

Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: Aleman on April 27, 2021, 09:08:51 pm
If you really want to completely furture proof yourself go with the Phil Woods Square Taper.

Robin and Andy chose the Square Taper UN55 BB because it was available pretty much worldwide, it's a PITA that time has marched on though.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: Danneaux on April 27, 2021, 10:34:17 pm
Quote
If you really want to completely furture proof yourself go with the Phil Woods Square Taper.
Agreed with Aleman here. The only Phil OBB/EBB I have is on my Nomad; my Enduro-Allroad bike uses the original Shimano but pumped full of Phil Waterproof Grease.

My square-taper Phil BBs on my other bikes have lasted ages and would surely get you through the next 48,000kms at least based on my own experience (I hope they're still made as well!).

One other possibility to consider is the availability of chainrings. There is still an abundance of 5-arm 110mm BCD chainrings out there, but stateside the number available new seems to be dwindling; same for the cranks that support them. I think you'd still be good for a long while if you go with this size. Things are fashion driven to a degree in cycling; what goes around comes around and standards become obsolete only to return with great popularity. When I started touring the 27in wheel was the road touring standard, replaced by 700C which is still popular in the same rim size but with oversized tires now known as "29ers" for their larger outside diameter. For ages the European touring standard was the 650B, then it went extinct (at least in the US) for about 30 years and now seems to have currently eclipsed the former MTB/Trekking standard 26in. Wait a few years and we'll see these formerly popular sizes return. I'm not ready to sound the death knell for rim brakes and a number of custom builders still favor 1in steerers and 22.2mm quill stems over threadless 1-1/8in  for their clients who want them.

Best,

Dan.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: PH on April 27, 2021, 11:18:47 pm
Out of interest - how could I future proof myself here?
The IRD linked in the other thread comes with a ten year warranty, that's a long enough future for me. But more than that, it has replaceable cartridge bearings which are not IRD, or even cycle, specific.
I don't know anything about Phil Woods stuff, in the UK Royce might be the equivalent, i don't know anything about them either, except for the prices and the need for specialist tools to fit them.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: Andre Jute on April 28, 2021, 02:21:22 am
The contra with the aspirational Phil and Royce bottom brackets is that at best they merely put off the day when they have to be replaced and cause extra expense because a different standard axle must be fitted, with at a minimum new cranks of that standard. Perhaps for a cyclist who rides a couple of thousand miles a year these bottom brackets will outlive him. But for a high-mile tourer -- perhaps even in hostile environments -- they just put the evil day off. Here's a workable-spec Royce on sale at SJS for only 180 quid incl VAT; the landed price for a Phil of comparable spec would be around there too:
https://www.sjscycles.co.uk/bottom-brackets/royce-titanium-bottom-bracket-with-73-mm-shell-red-all-weather-seals-and-stainless-royce-crank-bolts-110-mm

My own instinctive advice to a high-miler keen to future proof his bike would be to lay in a stock of 73mm square taper bottom brackets, and not only to look at brands with big names.

SJS for instance carries a VP bottom bracket with suitable spec for about eighteen pounds.
https://www.sjscycles.co.uk/bottom-brackets/vp-bc73-107mm-bc13724t-unit-price-us304pc
VP is a wonderful Taiwanese firm which makes hight quality cycle gear built around their very high quality bearings and I wouldn't be surprised if the UN55 was made by them for Shimano; I have their headset, with a pricey German brand name on it, and for years I've been recommending their VP 191 block pedals with sealed bearings; one pair of VP 191 was given to me by Trek when I complained about the quality of the expensive boutique pedals that came on an expensive prototype bike: that was twenty-odd years ago and those pedals, which were off their general manager's bike and so pre-loved when they came to me, are still on my daily bike, in perfectly smooth condition.

Another generally available bottom bracket I saw on the SJS site, the Stronglight JP400, which is a Czech-made bottom bracket of impeccable quality found with a lot of famous names on it, and fitted as OEM gear on upmarket European bikes. It's available with plastic, alloy or steel threaded cups (pro tip, as they say: get the one with the plastic cups, which is also the cheapest, to give your Rohloff a bit of protection by flexing as required -- https://www.sjscycles.co.uk/bottom-brackets/107-stronglight-jp400-plastic-cups-sealed-bearing-square-taper-bottom-bracket -- £15!). Some of the unbranded generic versions of this BB made in its millions are amazingly cheap.

SJS also has a Tange in your size; the Tange looks like a big bargain too.

Any of these is as good as a UN55.

I quote the SJS prices, which we know come with a possible hefty loading for you, because these bottom brackets are in stock at SJS. I made a brisk tour of dealers I know to be reliable in France and Germany --  xxcycles.fr in France, and bike-components.de, roseversand.de, and starbike.de in Germany; all have anglophone sites available. I was looking for a cheaper carriage option within the EU, but discovered not a single square taper 73mm bottom bracket, which is why I suggest laying in a stock.

In the light of the stock situation with 73mm bottom brackets (a portent or a pandemic glitch?), the Royce and Phil options start to seem more attractive.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: martinf on April 28, 2021, 07:25:37 am
TA Axix bottom-bracket units are still available, at least here in France. They have become expensive though.

These are a bit like the old cup and cone system :

- aluminium alloy fixed cup and adjustable cup, the latter with an alu lockring. These can be BSC, the old French standard or the old Italian standard.
- steel or titanium square taper axle, available in a variety of lengths. 
- industry standard replaceable sealed bearings.
- can be spaced 68 or 73 with optional spacers that are placed inside the cups.

There are two types of fixed cup. One is like the Shimano, and has no adjustment, but itis possible to fit a suitable spacer underneath to adjust chainline by 1 or 2 mm. The other type has an alu lockring like the adjustable cup, so allows some adjustment in both directions.

I have these on several bikes. And several years ago I bought a cartridge of about 10 compatible sealed bearings in the correct dimension from an online industrial supplier, not that I have needed to replace bearings often.

I also use V-ring seals kept in place behind the cranks by a stack of O-rings. This more or less prevents water entry, and prolongs the life of old-fashioned cup and cone bearings and "sealed" bearing units. I got nearly 40,000 km of use from a cup and cone bottom bracket set with these external seals.

Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: WorldTourer on April 28, 2021, 09:39:03 am
VP is a wonderful Taiwanese firm which makes hight quality cycle gear built around their very high quality bearings and I wouldn't be surprised if the UN55 was made by them for Shimano

The UN55, at least ones I have bought in recent years, are marked Made in Malaysia (like a few other Shimano components nowadays), so unlikely to have that Taiwanese firm involved.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: KvBCycles on April 28, 2021, 10:51:04 am
I went to the local bike shops this morning and haha had a few great reactions.  The first guy took one look and asked me what´s wrong with me! I had to laugh. The word "antigua" was mentioned a few times, antique. One shop said he had exactly what I needed and for a brief moment I was hopeful but when he brought the part out - the model number was BR73, and the size was 68mm x 110mm.

SJS Cycles seems to be *the only retailer* holding 73mm square tapered BB´s at the moment, well apart from a guy on eBay in the US selling used ones for 50 dollars a pop.
Regarding Phil Woods - they appear to be out of stock. When I try to select the item on their website it shows up "out of stock", so I have sent them an email asking about availability.
In the meantime, my basket on SJS Cycles is holding a couple of Tange BB´s along with an eccentric bb and a chainring, may as well get those extras included in the package. About to hit the order button.
In the meantime, I´m going back to one of the bike shops - I asked if he can service the bottom bracket, remove and clean basically. It could just be a bit of dirt in there again (like I had previously in 2019). There is still some life in the UN55 yet. I can still ride the bike, cranks are not moving, just an annoying click, creak noise.
Karl.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: Andre Jute on April 28, 2021, 01:42:56 pm
VP is a wonderful Taiwanese firm which makes hight quality cycle gear built around their very high quality bearings and I wouldn't be surprised if the UN55 was made by them for Shimano.

The UN55, at least ones I have bought in recent years, are marked Made in Malaysia (like a few other Shimano components nowadays), so unlikely to have that Taiwanese firm involved.

Thanks for hard information, World Tourer.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: martinf on April 28, 2021, 08:43:42 pm
Link to the TA square-taper bottom bracket page in French (couldn't find an English option on the manufacturer's website):

https://specialites-ta.com/68-standard-axe-carre

When sold separately, the spacers needed for a 73 mm bottom-bracket shell are marked "Entretoise - Axix 2,5mm (pour boîtier de 73mm et montage dérailleur type "E") (sachet de 2)" and do not seem to be in stock at the moment. If ordering a complete unit for a 73 mm shell you would have to make sure that these spacers are included when the option 68/73mm is noted.

This is a link to the "English" page of a French online retailer that sells these TA units:

https://www.alltricks.com/Buy/TA+axix

I have the 131 mm length steel axle version, with the set of two 2.5 mm spacers, on my Raven Sport Tour.

This is the right length for the Rohloff chain line using my old-pattern TA cyclotouriste cranks, modern cranks use shorter axles.

The TA bottom bracket axles and cranks are supposed to be ISO rather than JIS, but in practice they seem to be different from some other ISO standard components I have had in the past (notably a Campagnolo bottom-bracket unit, which didn't fit satisfactorily on my TA cranks). YMMV, but I have successfully mixed TA ISO cranks with JIS bottom brackets and vice-versa.

________________________________________

Off topic as not for 73 mm shells, but perhaps of interest for someone in the EU looking for a 68 mm UN 55 equivalent, Stronglight's site still shows a reasonably-priced square taper bottom bracket unit in the JIS standard:

http://www.stronglight.com/stronglight/index.php/welcome/afficher_Produit?id=210

This website has some, but only in 2 sizes :

https://www.xxcycle.com/bottom-bracket-stronglight-jp-400-al-bsc,,en.php

I have one of these on my large visitor bike, it has done about 11,000 kms so far and seems to be of comparable quality to the Shimano UN 55 units.

I expect TA and Stronglight retailers in France would supply to other EU countries, but perhaps not to the UK with the current post-Brexit uncertainties.
________________________

On the thorny topic of higher shipping costs and/or delays due to Covid19 and Brexit (I live in France):

- I ordered some of the cheap bifocal "safety glasses" I use for cycling from England for my wife and self. They arrived last week on the date scheduled, from memory perhaps 1 or 2 days slower than my previous order several years ago. Shipping cost was significantly more than pre-Brexit, but not crippling. And the supplier added an extra pair as a gift, which more than compensated for the difference in shipping.

- And I have just received an order of mixed cycling spares/clothing care products from a prominent German on-line retailer. Absolutely no extra delay or cost compared to my pre-Covid orders from this company, and quicker than some orders from France. So, at least for some suppliers, Covid19 problems within the Europe Union have already been sorted out.

As far as SJS cycles are concerned, the shipping costs to France are currently very high. But this has happened before, and they eventually found a way to reduce the costs while at the same time maintaining their excellent packaging standards and prompt deliveries. I am reasonably hopeful that solutions for export deliveries will be found when the double whammy of the Covid19 panic and Brexit settles down.   
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: KvBCycles on May 14, 2021, 11:18:12 am
Morning all, received a package from SJS Cycles this morning.
Sent on the 4th of May, value of just under 150 quid, arrived in Melilla (Spain) 10 days later - not bad at all, was expecting it to take longer.
Customs all in order but had to pay 20 euros to the shipping agents here in Melilla to release.

Update on the BB itself - I had it removed along with the EBB a couple of weeks ago, got it cleaned, greased and re-fitted and the noise disappeared, however, noise is back so it seems as if it is nearing end of life. EBB was in good shape, so while I ordered another, I´ll keep it as a spare for now. I ordered 2x Tangeseiki BB´s and I´ll be installing one of them next week, that should keep me going for a while yet while I decide on a Phil Woods.


Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: mickeg on May 15, 2021, 02:10:30 pm
Does anyone know if you can run a 68mm square taper bottom bracket in the 73mm eccentric on the Mk II Nomad?  My concern would be that the internal threads in the eccentric do not extend far enough inside for the non-drive side bushing to thread in if you used a 68mm cartridge bottom bracket.

Yes, I am aware that the bottom bracket would be centered 2.5mm to the drive side instead of in the center of the bike, but I would not worry about that.  And, in the unlikely situation that I noticed the pedals were shifted a few mm to the right, I could slide the eccentric a bit to the left.

I am guessing that if you tried a 68mm and it did not work because the bushing did not thread in far enough, you could grind or cut off 5mm from the bushing to make it fit.

But maybe something else would go wrong in this case that I have not thought of?  Thoughts anyone?

***

After reading parts of this thread, I decided I should put a spare square taper 73mm UN-55, 122.5mm bottom bracket on my shelf for a spare for the Nomad.  I could substitute a 127mm, looked for that too.  And yesterday I looked on-line, and looked harder, and started looking for substitute brands and models, and ... eventually gave up looking.

A few years ago I was in a local bike charity that takes old bikes in, fixes them up and resells them, they try to train underprivileged youth into the world of working while providing discounted bikes to the poor.  They have bins of old used parts.  In a bin I found an old cup and cone 73mm/122.5mm spindle, which I mated to a set of cups and some bearings which I bought.  Got home and cleaned it up, that was when I found that the bearing surfaces on the spindle were badly pitted, bad enough that I think it unusable.   

Yesterday, found a new old stock duplicate of that spindle on Ebay.  I paid the overpriced cost of $17 USD.  So, if my UN-55 goes bad, hopefully I will be able to get home before it goes kaput.  And once home, switch to cup and cone.

When I worked in a bike shop, all the bottom brackets then were cup and cone, so I have no fear of getting a cup and cone square taper bottom bracket functional.  I have re-greased plenty of them over the years.

Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: Andre Jute on May 15, 2021, 05:28:58 pm
A few years ago I was in a local bike charity that takes old bikes in, fixes them up and resells them, they try to train underprivileged youth into the world of working while providing discounted bikes to the poor.  They have bins of old used parts.  In a bin I found an old cup and cone 73mm/122.5mm spindle, which I mated to a set of cups and some bearings which I bought.  Got home and cleaned it up, that was when I found that the bearing surfaces on the spindle were badly pitted, bad enough that I think it unusable.

Ashtabula is alive and well in Madison, WI!
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: Danneaux on May 15, 2021, 07:31:51 pm
Quote
...yesterday I looked on-line, and looked harder, and started looking for substitute brands and models, and ... eventually gave up looking.
The entire bike industry is suffering some pretty severe supply-chain problems at present. I was helping place orders last week for a couple friends who own shops. If components aren't outright unavailable from distributors and suppliers, they're backordered indefinitely. I saw expected delivery dates extending well into 2023 and beyond. One for a car roof rack cargo pod was listed as "2035" -- their proxy for "out of stock, availability unknown". Bikes are pre-sold before they've arrived and the prices of used bikes is ticking upward as the supply of new ones is often nil. Hopefully things will begin to ease toward the start of next year. Until then we may have to make do with whatever's available. For example, I found most of Shimano's derailleur offerings were unavailable until I managed to find a small supply of low-end Tourney rear mechs. We were able to trade some stock with other shops so customer repair needs could be met.

As the supply of higher-end components gets tighter, the counterfeits and closely labeled copies are surging. I've seen three "Shingmano" derailleurs and a couple rear mechs labeled "Toumey" and one called "Alevio" instead of "Alivio" -- all used he expected font and it required a second look to really scope what was "off". Be careful out there, I've even seen some "Tamge-Saiki" bottom brackets. I even saw a "Diant" mountain bike where the "D" was so highly stylized it looked like a "G". If you buy from a reputable source you should be okay but eBay may become a little sketchy in the weeks and months ahead. A guy locally was advertising "Romex" watches with the minute hand at 12 obscuring the "m" in his photos, so it isn't just bikes. Prices were up there, too.  ::)

Best,

Dan.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: mickeg on May 15, 2021, 08:57:39 pm
...
Ashtabula is alive and well in Madison, WI!

?


The entire bike industry is suffering some pretty severe supply-chain problems at present. ...

I am well aware that supply chains are a mess.  But I had no idea that 73mm bottom brackets were being dropped from manufacturers production schedules.

And to think that I went with square taper in large part because you would always be able to get it fixed at just about any bike shop, any time, anywhere.

I have Campy square taper triples on several bikes, I prefer the Origin8 bottom brackets over the Campy, recently I realized that all square taper bottom brackets fell off of the Origin8 website.  I did find someone had one with the Campy taper in the spindle length I wanted, so it is now on my shelf as a spare.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: WorldTourer on May 15, 2021, 09:57:32 pm
And to think that I went with square taper in large part because you would always be able to get it fixed at just about any bike shop, any time, anywhere.

Some of Thorn’s marketing about what parts to choose for problem-free servicing or replacement around the world years into the future, now needs to be reconsidered. I first noticed this in 2018 in Chile, where replacement rim-brake pads were impossible to find unless special-ordered over the internet – I visited over twenty bike shops in Arica and Santiago and the staff spoke as if disc brakes had superseded rim brakes years ago already. Then here we see the dearth of quality square-taper bottom brackets, so in much of the developed world you may be more likely to get a good, long-life replacement if you had just installed Hollowtech cranks like (they’ll tell you) everyone does nowadays. I’ve heard rumours that Schwalbe may discontinue the 26" size of some of their better tires, etc.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: PH on May 15, 2021, 10:43:05 pm
Some of Thorn’s marketing about what parts to choose for problem-free servicing or replacement around the world years into the future, now needs to be reconsidered.
I think you're right, it's only a thought because I don't have the experience to say otherwise.  Yet I also think, that despite the image, such tourers are a tiny percentage of Thorn customers,  I suspect for most a replacement BB isn't ever going to be needed in a hurry in some exotic part of the World.  They rarely fail in such a catastrophic way that for most replacement could wait till they're back home a thousand miles later.  Where, at least if home is the UK, finding a suitable replacement is ten minutes on google or half an hour at most if you want a decent choice, good price and fast delivery. As ST chainsets become less common so will the choice of BB's and 73 have always been less common than 68, but for most of us, they're not going to disappear in our lifetimes.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: mickeg on May 16, 2021, 12:10:44 am
...
Some of Thorn’s marketing about what parts to choose for problem-free servicing or replacement around the world years into the future, now needs to be reconsidered. ...

Some of Thorn’s marketing about what parts to choose for problem-free servicing or replacement around the world years into the future, now needs to be reconsidered.
I think you're right, it's only a thought because I don't have the experience to say otherwise.  Yet I also think, that despite the image, such tourers are a tiny percentage of Thorn customers,  I suspect for most a replacement BB isn't ever going to be needed in a hurry in some exotic part of the World.  They rarely fail in such a catastrophic way that for most replacement could wait till they're back home a thousand miles later.  Where, at least if home is the UK, finding a suitable replacement is ten minutes on google or half an hour at most if you want a decent choice, good price and fast delivery. As ST chainsets become less common so will the choice of BB's and 73 have always been less common than 68, but for most of us, they're not going to disappear in our lifetimes.

I did not rely very much on Thorn marketing for my component decisions on how to build up my Sherpa or my Nomad Mk II.  The one place where I did rely on their marketing, I found out that I should not have done so, that is why my rims on my Nomad Mk II are much narrower than I would have preferred.

All of my bikes are square taper except one, my road bike is one I bought complete, it came with a Campy drive train.  I built up the rest of my bikes from the frame and fork.

I worked as a mechanic in a bike shop before college, in almost all situations (other than my road bike) I chose the parts based on anticipated longevity, robustness, reliability, ease of replacement and reparability.  And generally I am quite happy with my component choices.  But I am a bit disappointed that some manufacturers have decided to make major component changes that could mean that some of my components will be hard to source in the future, such as parts for quick release hubs and skewers versus through axles.

26 inch tires may be more difficult to find in the future, but that certainly can't be blamed on Thorn.

Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: WorldTourer on May 16, 2021, 12:41:39 am
26 inch tires may be more difficult to find in the future, but that certainly can't be blamed on Thorn.

I certainly don't blame Thorn for anything, I only feel sorry for them that they are at the mercy of an industry that is obsoleting components that they had reasonably hoped would stay around.
Title: Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
Post by: Andre Jute on May 16, 2021, 09:16:22 am
I find it very interesting that through-the-bottom-bracket electric motors for bikes made in China use square taper pedal fitments. We're looking at a very large future market here, in which the dominant producer, the Chinese, will set the parameters of which products returns to production after the pandemic is beaten, not by planning but simply by being such a massive lowest common denominator.

Even if the Chinese suddenly go Hollowtech (a hollow horselaugh here -- they hate the Japanese with a fervour) or one morning decide to invent their own standard (possible and even likely with central planning), the boutique makers will supply, as they now supply a whole Rene Herse bike, or as Orange Velo supply antique parts made yesterday. In the longer term, the worry is not about supply but about costs: boutique prices and carriage from distant international suppliers.

In short, while sympathise with those who have urgent present needs, in the longer term, even in the medium term, I have no fear for my beloved square taper pedal axles and bottom brackets.