New Raven build -- advice sought

[Andre Jute]

Don't forget a Chaingliger if you go for a Rohloff hub.
Best bit of extra kit I have fitted to my own Raven.

I know John Saxby has been singing the praises of the chainglider but I had no idea it even existed until I started perusing the forums.  I think the older models had issue scratching the hubs but I think the newer models are ok.  Can these be used on long distance tours?  Any real negatives using one?

Buy the Rohloff model.

Yes.

No.

Yes, I would actually like to know peoples thoughts on the Chainglider.  I did a search yesterday but didn't find anything compelling one way or the other.  I did notice that it works best with a thinner chainring and I am not sure it would work well with the White Industries Eno 38 tooth that I have already purchased.   There is also the question of it marring the frame or hub but I think Hebie has that issue resolved.

The problem with Chaingliders eating Rohloff shells is long since solved. The minor difficulty with Chaingliders not fitting some Thorn frame sizes is solved by shaving a clearance in the Chainglider for the stay it interferes with, as and when you discover any interference. The purpose of my original experiments with a whole set of chaincases, including the eventual winner, the Hebie Chainglider, was not making the chain last longer, but simply towards reduced maintenance with greater cleanliness. A later experiment confirmed that a common mid-level chain (KMC X8) can be run inside the Chainglider for the entire life of the chain on only the factory lube, making the setup zero-maintenance, fit and forget. In addition I fitted steel or stainless steel chainrings, which showed no undue (indeed zero) wear. Several members of this forum have reported the same. I would call our experience here "compelling". What I wouldn't call it is "conclusive"; we don't quite have the numbers for that. It's a question of whether you want to spend your time cycling or repeatedly cleaning the transmission. As Matt has already done, I would describe the Chainglider as the top convenience component to be fitted to any touring/utility/recreation bike; in short, I would rank it right after decent lighting and locking.

[djd828]

Andre, yes I have read your post and I agree that your findings are indeed compelling. Enough for me to give it a fair shake.  It is inexpensive enough to try...I'm all for the set it and forget it potential.

[John Saxby]

Dave, there is a thread which looks at 'gliders mated to various Rohloff sprocket/chainring ratios. If you haven't already seen it, the last two pages of this one cover some of the issues: 

http://thorncyclesforum.co.uk/index.php?topic=4412.180

If you're happy with your 38 x 17 ring/sprocket ratio, then the 38T 'glider should do the business for you.  I decided to change to a smaller (36T) ring, and modified my 38T 'glider, with so-far-so-good results.

The 'glider part of this discussion also plays out in another thread, started by Andre to chart his low-maintenance chain experiment (described above), using only 'glider + manufacturer's lube:

http://thorncyclesforum.co.uk/index.php?topic=6813.120

The last couple of pages in that thread include devil-in-the-detail discussions about getting the best results from 'gliders. (Casual readers might think we're mildly obsessive about this stuff, but then, they're casual readers, so how would they know, and why would we care?)

Gliders are reasonably inexpensive, as you note, esp if purchased as part of a shipment from Deutschland, along with other pricier bits like tires and hubs.

One or two people in this forum have been seriously bummed out by the 'glider.  For most of the others, it seems to come down to the tradeoff between reduced/minimal chain maintenance vs. slightly increased (but barely noticeable, if at all) drag -- so long as you have a sprocket/ring ratio that's compatible with a 'glider. 

I don't know the thickness of your ENO ring, but if you want to try the Surly stainless item, they're fairly cheap at ~USD 30. (I have a used one which is surplus to requirements - send me a PM if you're interested.)

Cheers,  John

[mickeg]

For some reason I just think a chainglider would not look right on a bike in this location.  But if you are staying in civilization, then maybe it would look ok.

Sometimes I run a 44T chainring, sometimes a 36T.  In the photo, I have both chainrings mounted, am using the 36 at the time that photo was taken.  I would rather not give up my ability to easily switch sizes of chainrings.

[Matt2matt2002]

Don't forget a Chaingliger if you go for a Rohloff hub.
Best bit of extra kit I have fitted to my own Raven.

I know John Saxby has been singing the praises of the chainglider but I had no idea it even existed until I started perusing the forums.  I think the older models had issue scratching the hubs but I think the newer models are ok.  Can these be used on long distance tours?  Any real negatives using one?

John certainly helped me decide.
As for using them on long tours....
Mine had never been off since I fitted it 12+ months ago and I toured Tajikistan and Kyrgyzstan for 2 months on rough dirty and dusty roads.
No issues at all.
I rode with a Spaniard who taped his rear ' gaps' shut but I think that was over kill.
Chain looked great at end of the tour.

A pal of mine won't use one since he says he likes to see any slack developing in the chain.
But once you have fitted and removed the Chaingliger a few times its very easy to take a quick peak whenever you want.
Changing the rear wheel requires the end pieces unclipped but adds no more than 5 mins to total change time.

[Matt2matt2002]

Some of us do not use chain gliders, so don't jump to the conclusion that it is a necessity.

Just saw this quote.
Quite right.
I'm a fan but would never bang on and on about it. I had my Raven 2 years before I fitted a Chaingliger. A happy 2 years.
It's a personal thing.
I happen to like them.

[geocycle]

Some of us do not use chain gliders, so don't jump to the conclusion that it is a necessity.

Just saw this quote.
Quite right.
I'm a fan but would never bang on and on about it. I had my Raven 2 years before I fitted a Chaingliger. A happy 2 years.
It's a personal thing.
I happen to like them.

I don't use the  chainglider because it doesn't fit the Raven sport tour frame very well as Andre mentioned above. I also had real problems getting the surly chain ring to seat properly, possibly as it wasn't quite spherical. I did use it on my Raven tour which had bigger clearances and was reasonably happy with it. I did get some minor surface rust but it was generally a success. If I could get it to work on the Raven sport tour I would and I would imagine you would be OK on the new Raven.

[djd828]

Good morning all,

I have been thinking more about my rim choices and my original plan to use the Andra 30 rims.  They are still very much on the top of my list but the new Velocity Cliffhangers have recently caught my attention....particularly the polished silver version.  These seem to come only in non-machined sidewalls so, of course, my first question is if there is any disadvantage to this type of sidewall.

My second question concerns spoke count. The Thorn folks say that a 32 spoke count wheel is more than sufficient for touring...even for tandem bikes.  However, it seems that most folks think 36 is the magic number.  What are you folks using?  Again, I don't plan on being on many dirt/rough roads but I would still like to be prepared for it if I can't avoid it.

Lastly, does anyone know of a good spoke length calculator.  I have it all figured out for the Andra but now I need to get the spoke specs for the Cliffhangers.

Thanks again,

Dave

[mickeg]

Good morning all,

I have been thinking more about my rim choices and my original plan to use the Andra 30 rims.  They are still very much on the top of my list but the new Velocity Cliffhangers have recently caught my attention....particularly the polished silver version.  These seem to come only in non-machined sidewalls so, of course, my first question is if there is any disadvantage to this type of sidewall.

My second question concerns spoke count. The Thorn folks say that a 32 spoke count wheel is more than sufficient for touring...even for tandem bikes.  However, it seems that most folks think 36 is the magic number.  What are you folks using?  Again, I don't plan on being on many dirt/rough roads but I would still like to be prepared for it if I can't avoid it.

Lastly, does anyone know of a good spoke length calculator.  I have it all figured out for the Andra but now I need to get the spoke specs for the Cliffhangers.

Thanks again,

Dave

I have no idea if a non-machined side means it is for a disc or not.  Did it say anything on that topic?

For your rim choice, you need to decide what tire widths you want to use.  I think Sheldon's data on inner (not outer) rim width and tire width is a good place to start.

http://www.sheldonbrown.com/tire-sizing.html#width

Once you know what tire widths you are likely to run, using the chart you can find an ideal rim inner width you want, then start rim selecting and shopping.

I use tires on my Sherpa that range from 40mm to 50mm wide, I suspect for a Raven you would too.  My rims on the Sherpa have an inner width of 21mm which works very well for that range of tire widths.

I used 36 spokes on my build, but that is because I could and I always do.  The Rohloff instructions on page 41 (printed page 41, but Adobe page numbering is different) describes why a 32 spoke undished wheel is stronger than a dished wheel with more spokes.  I think that is why for many years Rohloff only made 32 spoke hubs, they thought it was good enough.

http://www.rohloff.de/fileadmin/user_upload/1_General_use_En_2015_03_web.pdf

I have heard that in some less developed parts of the world, 26 inch rims are easy to find if you need a rim than other rim sizes.  But, I have never seen any specification of which is easier to find, a 32 or 36 hole rim.  So, if you are in part going with a 26 inch bike because you plan to pedal to Patagonia, you might want to try to find out which rims are more likely to be available there, 32 or 36.  Otherwise I think it really does not matter which you choose.

Spoke length calculator, I used the Rohloff chart (see page 42 at above link) for my rear wheel.  I do not remember how I selected spoke length for my front wheel.

My rim criteria is probably quite different than yours, I run tires on my Nomad that range from 40mm to 57mm wide.  Thus, an inner width of about 23 to 25mm (From Sheldon's chart, link above) would be ideal for me.  When I bought my Andra 30 rims, I bought them because the Nomad brochure highlighted that as an outstanding expedition rim along with the 57mm wide Extreme tires I got.  But when I received those rims, I was really surprised how narrow they are.  When I measured them, I found the Andra 30 inner width is 19mm.  Using Sheldon's website data, the Andra 30 is significantly too narrow for me when I use 57mm wide tires.  Thus, I think I need to run a higher minimum air pressure on that rim than I would need if I had a proper rim for my tire width.  So, I am sort of bummed about my rim selection.  But if you plan to run 40mm to 50mm tires on your Raven, that narrower rim might be a good rim width for you.  You do not have to be perfectly in the range that Sheldon's chart lists, but I think you want to be close to it.  I have used 50mm tires on my Andra 30 rims and they worked ok.  See photo, my Marathon Winter tires are 50mm wide on the Andra 30 rims in the photo.

[djd828]

Thanks Mickeg,

I don't anticipate that I will run over 40mm often for the type of riding I plan to do.  I am OK with going with Thorns advice of a 32 spoke un-dished wheel.    I am not a really big guy---around 180 pounds at my riding weight.  I was trying to determine if there was a compelling reason to consider a 36 spoke wheel. 

Concerning machined rims, here is what Rivendell says:

"Machined sidewalls? Nope, and here's why:
A rim starts life as a straight extrusion; and then it is rolled into a circle. Before it's rolled, all's well with the braking surface (sidewalls). But in rolling it round, the sidewalls get wavy. That's because the inner and outer circumference travel a different distance, in the same way as the runner in the inside lane of a track runs a shorter distance than a runner in the outside lane (assuming they start and finish on the same line). If the rim material were stretchy, maybe the outer portion (the part nearest a mounted tire) would stretch and get thin. But it's not stretchy, so instead, the inner portion develops waves, so that despite being on the inside, it still travels the same distance. It's like the runner in the inside lane running a curvy line to make up for his advantage. Is this making sense?

In theory, wavy sidewalls are bad, but only in theory. In fact, the degree of waviness is so small that it hardly matters. However, it is undeniable that perfectly flat sidewalls are the ideal, and have less of a tendency to draw attention to themselves on an initial test-ride. That's the whole deal, right there.

Nobody's happy when a customer applies the brakes and hears a squeal. It doesn't often happen with any rim, machined or not, but statistically it is more likely to happen on a raw sidewall than on a machined one. Because of that, rim makers have "solved" the squeal issue by machining the sidewalls.

You might think, so what's not to like? Well, something.

The side wall thickness starts out even, even as it gets wavy in the rolling. But when you machine the waves flat, you lop off the high spots, and that takes material away from the sidewalls. So although your braking surface may be flat, you end up with sidewalls that are thin here and thick there. Some rims start out extra thick to compensate for the shaving. But in those cases, the low spots that barely get skimmed remain disproportionately thick.

Since the waviness is so small to begin with, we think it's best to leave well enough alone, keep the wall thicknesses even, and let braking itself take care of the high spots, over time. It always does.

Sometimes when rims are machined, the tool isn't super sharp, and the process leaves visible, feelable grooves in the braking surface. While we're splitting hair with waves, we might as well continue it here by saying grooves are bad. They reduced the contact area between your rim and pad, so they make braking worse that way. And they're more likely, than a smooth surface, to trap water.

Machining rims is a way for rim makers to justify a higher price, and the only thing it does is make a rim worse, while making it seem smoother. You can still have a grand old time on machined rims, and they're not likely to cut your tour short. But all in all, we'd rather the rims were normal, and all the rims we sell are. In some cases, we've specifically asked the maker to NOT machine the rims when machining them was the default."

So, it looks like I shouldn't be too concerned with a non-machined rim....I think. 

I'll check out the Rohloff chart for the spoke size.  Thanks again.

[Andre Jute]

Couple of notes:

1. You can trust Grant to have worked it out and spoken to the most knowledgeable guy in the entire world on any bicycling subject. If he says you don't want machined sidewalls to your rims, you don't want machined sidewalls. However, you don't want to take his fashion advice; he dresses grotesquely inelegantly, even for a Californian cyclist.

2. There are serious advantages to balloons and semi-balloons in the 47-55mm range, the fatter the better. On a different sort of bike I use 60mm balloons (the biggest a Thorn can take is 2.15in or 55mm) and have been absolutely bowled over by their speed and comfort; the whole affair is really counterintuitive: for a start, low pressure balloons have lower rolling resistance than thin high pressure tyres...

3. [EDITED, with thanks to the excellent MacSpud] The inside width of your rim across the bead retainer must be no narrower than 0.4x the width of the widest tyre you want to fit but there is benefit in going wider still. Let me say that again: Maximum benefit of wide tyres is achieved with a tyre no wider than 2.5x the width of the rim across the bead retainers inside the rim. That ERTRO now permits a lower multiple for balloons is a wrong decision, nothing to do with engineering, taken because in the growth of wider, lower pressure tyre sales a lot of rim manufacturers would have been stuck with unsaleable stock of outlawed narrow rims, in short a permission hostile to cyclists taken for the profits of component makers. So buy the widest (inside measurement) rims that fit your other specifications, which then allows for future changes of mind on tyre width. Personally, if I were fitting out a bike that could take a maximum 55mm tyre, I wouldn't fit a rim less wide across the beads than 22mm. My current bike has 24mm bead spacing Exal XL touring rims, but they're a bit hard to find in the open market. (I've ridden balloons up to 60mm on rims as narrow as 16mm across the beads, and no disasters befell me, but the tyres were noticeably squirmier, so probably I lost the rolling resistance advantage; on a difficult or even just a loaded tour, that could make a difference.)

4. I don't recollect any complaints being traced to 32 spoke Rohloff wheels, appropriately applied, and I have run the 32 spoke Rolloff on a bike that loaded for a day's painting trip weighs well north of an eighth of a ton for thousands of miles without any problem. However, the choice isn't merely based on engineering. If you intend fitting a hub dynamo up front, a common spoke count is 36. If you're trying to buy a new rim in Outer Grimanddustystan, you will be offered 36 holes or 36 holes, if there even is more than one rim to choose from. Now that 36 spoke Rohloff boxes are available for no or a very small premium, I see absolutely no reason not to choose the common 36 hole version for a touring or utility bike.

[djd828]

Thanks Andre for both the humor and advice.  This is the type of sage advice I need concerning the 32/36 spoke debate.

As for the spoke length chart in the Rohloff guide, I will admit I am a bit confused.  Ryde indicates that the 32 hole 26" Andra rim has an ERD of 535 which, according to the Rohloff guide, requires a 234mm spoke length and a 12mm Polyax nipple.  However, The SJC folks are adamant that this rim should use a 238mm spoke with a 14mm Polyax nipple.  Does that means the Rohloff guide is open to variances or personal preference?

The 32 hole 26" Velocity Cliffhanger I am also looking at has a 533 ERD and, according to the Rohloff guide, should also use a 234mm length spoke.  Can I surmise that since the Cliffhanger's ERD is 2 less than the Andra's that SJC would probably recommend a 236mm spoke with a 14mm Polyax nipple for the Cliffhanger?

As I mentioned once before I never anticipated being this far down into the weeds when I started planning the bike build and my confusion continues with each new part I consider.  Thankfully, I have all of you guys and gals to help me navigate through this madness.

Now Andre has me leaning towards the 36 hole rim (yes I am getting a SON28 for the front) so I have to start these calculations all over again...yikes!

[mickeg]

I used the exact spoke lengths from the Rohoff chart, used Wheelsmith spokes and Sapim nipples, but I do not know the length of the nipples that I used.  I did not know there were different ones.

Since you are now trying to figure out spoke lengths, does that mean you plan to build up your own wheels?

According to this link:

http://www.sjscycles.co.uk/rigida-andra-30-26-559-mtb-css-rim-rohloff-drilling-black-32-hole-prod13269/?geoc=us

- ERD - 541

I looked at a bunch of other Andra 30 pages too, all that I looked at said 541.

Does the Rohloff chart match what SJS says with 541?

[John Saxby]

Dave, my Raven has 32-hole rims both fore and aft, with a SON28 at the front & Rohloff at the rear.

The new (2015) profile Cliffhangers look well suited to the requirements of Rohloff + 26-inch rims.  The older style, with a deep inverted V profile, didn't work so well for me, so I switched to Mavic XM719s. I didn't know about the intricate pro/con/doesitmatter arguments about (non-)machined sidewalls -- I made my choice based on the profile of the rim, and the current Cliffhangers share a similar profile with the Mavics, with the latter being slightly lighter.

The Raven will accept tires up to 50 mm wide.  If you allow for those, then the usual recommendation is for 60mm fenders (10 mm total clearance.)

I have VO alloy fenders, 650B x 52 mm, so I expect that the widest tires I'll fit with those fenders will be 1.75's (44.5 mm). (That rules out 26 x 2.00 Supremes, for example.)  There's always a bit of a judgment call on tire widths, as you probably know -- different brands can show actually-inflated widths at variance with their nominal/listed width.)  The 650B fenders do give rather more vertical clearance than their 26" cousins.  Looks a bit odd, but not weird (to my eye at least), and the extra vertical clearance is helpful for muddy going.

Cheers,

John

[Danneaux]

Hi Dave!

Playing devil's advocate for a moment here...why employ equipment that is much heavier-duty than you are likely to need?

A lighter bike is generally more fun to ride, and if you keep overall cargo weight in check, the need for heavy-duty components is less acute. Famed race car designer Colin Chapman was known for the phrase, "add lightness". It holds for bikes also. The flip side is once you start adding weight, a bicycle's avoirdupois multiplies because each addition is a smaller proportion of the whole on a heavy bike. Eventually, one can add whole kilograms and not notice much difference. This is not always a virtue, but has its place when it comes to true expedition touring where you sometimes need to carry a lot of weight in food and water to be self-sufficient.

Let me offer some perspective here...

I weigh 172lb/78kg and do often tour on really rough roads or cross-country occasionally carrying *lots* of water and food so I can go solo and unsupported. For desert crossings in high summer, I'm carrying 26l/26kg/6.9gal/57lb of water alone on rough surfaces, often unpaved and sometimes on no road at all. My Nomad is a sturdy, heavy bike intended to carry big loads on rough roads and all kitted up weighs 20k/44lb dry and unladen.

All this is carried on 26in wheels made with 32-hole Rigida Andra rims. My SON28 dynohub matches at 32-holes, the idea being I *could* swap rims in an emergency should the more heavily laden rear become damaged. I've never had a problem, thanks to several factors:
• 26in rims are considerably smaller in diameter than 700C. Spoke count can be lower because of better bracing angles and shorter spoke lengths.
• Rohloff hub flange spacing results in dishless wheels, as has been noted.
• Large-section tires ridden at appropriate pressures offer considerable cushioning to rider and wheel alike. Years ago when good 27in and 700C touring tires were largely unavailable in my area, I toured on 23-25mm racing-training tires aired up to 125psi/8.6 on narrow rims. They rode like iron bands and the unmitigated shock took a toll on rider and components alike. Fat tires ease impact loads tremendously and will allow lighter components without penalty.

In comparison, I also have a tandem with 26in wheels. It uses 36-hole Sun Metal rims and Suzue hubs, the rear with a solid axle and an Arai drum-drag brake and 1.5in road slicks. Thanks to 145mm OLN spacing, the rear wheel is close to symmetrical even with a freewheel. The previous owners were a team each weighing 170kg/375lb. Atop the 21kg/46lb bike, this made a total weight of 361kg/796lb. They rode it in multiple Seattle-to-Portland 325km/200mi road rides. For me, all-up with two fair-sized riders, a full touring load for two and towing a 57kg/125lb trailer, it weighs 272kg/600lb. Even touring on very poor gravel logging roads, I've not had a problem, but this is an instance where 36 spokes really are indicated by weight and use. Four more per wheel results in closer spacing and better support of the rim.

As another data point, I rode Forum member AndyBG's kindly loaned Raven Tour fully loaded on the roads of Eastern Europe on my double-crossing from Bulgaria to France and back. Bulgaria is stunningly beautiful, but their road surfaces are not. As bad as Belgium's cobbles in a different way, they offer craterlike potholes and "tar blowouts" -- ridges formed when heavy trucks drive over deep asphalt patches before they have dried. Mix in bedrock, riprap, underlayment, dirt, rocks, gravel, and flooding, and there's quite a mix. While I was unable to weigh my load, I often carried up to 8l of water through Serbia's two heat waves and likely hauled about 25kg/56lb of cargo including a fair amount of canned food to see me though unpopulated forest areas and Romania's western "eco-tour" route. Andy's bike employed 32-hole Rigida Andra rims fore and aft and the wheels never went out of true in my use. Depending on size, the Raven Tour was made with larger-diameter tubes and had a slightly higher cargo weight rating than the current Raven you are considering.

You may well intend to tour on really rough roads carrying a lot of cargo. If you do -- and do so often enough to justify the higher unladen weight -- then perhaps it would be best to go whole hog and get a Nomad with sturdier frame as well. If you don't intend to carry such loads, then a Raven with 32-hole rims should be fine. Depending on use (road surface and weight plus riding style), you can easily get away with using a rim lighter than Rigida's Andra and narrower tires also.

Using a Rohloff means you don't have as many options for wheelbuilding as you would on a derailleur drivetrain. Rohloff (and Thorn, in their experience based on field service by buyers and designer Andy Blance) have some very specific recommendations that need to be followed for a successful build. You don't have the freedom to alter spoke crossings, use asymmetrical lacing, or play around with various permutations of spoke gauges, hole counts, and rim weights. On the other hand, you don't need to. A 32-hole Rohloff wheel build is generally "strong enough" for most riders in most usage -- especially if built into 26in rims. 700C rims are a different story, but even then 32-holes have proven to be satisfactory for general touring use, but the margin is slimmer than with 26in.

I feel sure you'd be fine with 32 spokes, but four spokes aren't a lot of added weight. Even as rotating weight, the portion near the rim where it counts isn't much. Viewed that way, it is cheap insurance and the wheels will certainly be sturdy and likely to run truer with one broken spoke, allowing you to continue to camp where you can replace it at your leisure. However, it is unlikely you would really need that extra margin in practice on a Raven. As for rim availability in the back-of-beyond...time seems to have altered selection a bit. Where formerly 36 hole rims were the default to be found, it is now more likely to be 32, overwhelmingly the MTB standard for the last 15-20 years. At least this proved to be true in the out-of-the-way shops in Bulgaria, Romania, and Serbia. 32-hole 26in/MTB rims are far more commonly available in shop inventory here in the Northwestern US than 36 at present.

In conclusion, I think you won't have to worry about sturdy 26in wheels if you use 32 spokes, but 36 won't hurt. Just be careful about spec'ing heavier-duty components than you are likely to need, else the finished bike can easily become heavier than you'd wish for pleasurable, lively riding in general use.

All the best,

Dan.