Author Topic: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)  (Read 4171 times)

KvBCycles

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Good evening all,

My bike: Nomad MK2
Bottom Bracket: Shimano BB-UN55 73mm (x107mm) English threaded, square tapered bottom bracket.
Mileage: about 20000kms
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 wont 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
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 BBs 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.

JohnR

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Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
« Reply #1 on: April 26, 2021, 11:01:01 PM »

Danneaux

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Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
« Reply #2 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.

John Saxby

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Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
« Reply #3 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/

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!

Danneaux

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Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
« Reply #4 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.

ourclarioncall

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Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
« Reply #5 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 dont mind ? Would it be an upgrade in comparison to the un55 or others ?

Danneaux

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Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
« Reply #6 on: April 27, 2021, 03:39:45 AM »
Quote
Could you Tell us more if you dont 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.
« Last Edit: April 27, 2021, 03:46:29 AM by Danneaux »

Andre Jute

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Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
« Reply #7 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 wont 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.
« Last Edit: April 27, 2021, 03:33:38 PM by Andre Jute »

PH

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Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
« Reply #8 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.   

KvBCycles

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Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
« Reply #9 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 BBs  ;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 dont 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 BBs or, like Dan, go external (OBB/EBB) despite the disadvantages he mentions?


Aleman

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Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
« Reply #10 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.

Danneaux

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Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
« Reply #11 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.
« Last Edit: April 27, 2021, 10:41:09 PM by Danneaux »

PH

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Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
« Reply #12 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.

Andre Jute

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Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
« Reply #13 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.

martinf

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Re: Nomad MK2 - bottom bracket replacement (73mm Shimano BB-UN55)
« Reply #14 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.