Which 110mm BCD crank for Rohloff 54mm chain line, and WIDE Q factor (tread)?

[Andre Jute]

I want a crankset for my Kranich. Rohloff 38x16 setup, 60mm Schwalbe Big Apples on 32mm wide 700C rims, so the chain stays are pretty wide, but that doesn't bother me as I prefer a wide stance and use vintage NOS Phillips platform pedals to get the widest stance possible.

Desired crank spec:

Five arm
BCD 110mm (to fit Surly 38t x 110BCD stainless chainring)
Widest possible Q factor (tread)
Square taper fitting
Black preferred

If I have to buy a chain set to get the cranks, it doesn't matter, I'll sell the chainrings on and keep the fitting hardware.

I use a Hebie Chainglider (a very neat enclosing chain case that rides on the chain), and the setup must allow space for it.

I looked at the Middleburn, because I like their shape and the simplicity of the Uno, but their tread is probably too narrow, and they're pricey for a bike that is used a maximum of 2000km per year.

I also looked at Sugino's RD2/Stonglight Impact which is still available from SJS, Spa and a vendor in France I've dealt with before, XX Cycles.

Opinion? Other suggestions.

If I could find something like the TA Cyclotouriste or the Stronglight 48 with a wide tread, I can probably get a stainless chainwheel cut to suit the 52mm BCD of the spider.

Andre Jute

[Danneaux]

Hi Andre,

I'll be happy to keep my eyes open for you.  Can you provide some specifics regarding your current crank's "Q-factor" or "tread"?  If I know what you have, it will be easier to find something that wide or wider.

It may well be the hardest part is finding a spider design to work with the Hebie chainglider.  Do you have measurements of the opening?  A deciding factor may be the offset between chainring face and the backside of the crankarm.

Do you have a preferred arm length?

As for tread, don't forget it is possible -- perhaps even desirable, in the case of wanting wider -- to adjust tread using a different length bottom-bracket spindle.  Phil Wood make spindles of different length in square-taper, and their cartridge design and retaining rings allow the cartridge to be offset, perhaps making for a better fit with the Hebie.  They are certainly reliable; I have more than 35,000 miles on one unit, and well over 28,000 on another, all in pretty tough conditions.  They are also factory-rebuildable.  SKF also make a really nice cartridge (All-stainless!  Double- or triple-sealed!  Roller-bearing on the drive side!  Guaranteed for 10yr/~65,000mi use!), so that might be worth considering as well.

What is wrong with the present model?  What are you looking to address?

Let us know, and we'll start the hunt for candidates....

Best,

Dan.

[Andre Jute]

Thanks for volunteering, Dan.

To summarise the required spec:

INFO

Rohloff gearbox with 38x16, so 54mm chain line

60mm Big Apples, so chain stays are wide

With 131mm axle bottom bracket, current Amar crankset has 54mm chain line and 192mm trade/Q-factor (to outside of cranks) and 23mm clearance between back of crank and chain stay.

Bike is a recreation of the Locomotief Crossframe de Luxe of 1936, not modern at all -- see http://coolmainpress.com/AndreJute'sUtopiaKranich.pdf -- and the cranks should be in keeping.

CRANKS required

Chainset or crank arms (don't mind if I have to throw off chainrings)

Square taper JIS fitting

170mm crank length

Five arm, 110mm BCD, single ring to be fitted, no chain guard

Intend fitting 38T Surly stainless chainwheel

Hebie chain runner 14mm wide, allow 10mm minimum clearance between outside of chain and back of crank wheel at 38T radius

Wide Q factor (tread) preferred

Black preferred

***

I'm familiar with Phil's bottom brackets, and even know someone on the net who as a teenager knew Phil, but I don't think I need a better bottom bracket. I like the Kinex bottom bracket that's fitted to quite a few European bikes. (Commonly available as a Stronglight 400, supplied with steel, ali and plastic cups.) My bike was designed to use it with a plastic cup each side, with a little built-in flex. If I need to change the BB because a different axle length is required, I'll fit another Kinex with twin plastic cups.

BTW, almost anything but a Phil BB will not be available in the required axle length. (Possibly a Royce, which is the British equivalent of Phil, because they essentially custom-make each BB they sell. But I'd be laughed off the forum if I fitted a Royce bottom bracket to a bike which in a bad-weather year like last year I rode just over 1000km.)

***

So far I have looked at these, simply because they aren't featureless flat bars:

Stronglight Impact/Sugino RD2 Double with 118mm BB gives tread 169.5mm, triple with 123mm BB gives tread 171mm

Middleburn RS-7, with ATB spider and 113mm BB gives 169mm tread (Uno who knows, no info, will probably need a wider BB)

Shimano Deore M590, XT 770 & similar, not 110mm BCD but 104mm BCD (requires custom-cut stainless chain wheel) but all with good wide tread in the 170-176mm range

***

I'd like to hear what cranks people actually use with their Rohloff-geared bikes.

Andre Jute

[Danneaux]

The TA Carmina may fulfill your needs, outfitted with a 110mm BCD spider (the Carmina offers a choice of separate spider assemblies, attachable a la Shimano).

See:  http://www.specialites-ta.com/produits/ped_car_gb.htm

I know Peter White uses the Carmina on the Tout Terrain Silkroad Rohloff frames he builds-up, so the standard 54mm chainline is achievable (he uses a Phil Wood BB, but it should also work with your Kinex).  They are available in satin or polished all-black or with a black spider and silver arms in a variety of lengths including 170mm, and may be outfitted with a 110mm bolt circle spider, which would fit your preferred Surely 38t chainring.  According to http://www.peterwhitecycles.com/carmina.asp , the Carmina uses a JIS taper.  Peter further adds,

Due to a production change TA made in 2006, the Carmina can use different length axles.

That same page has some very helpful tips for selecting the proper length axle to get the desired chainline and Q-Factor for a given application.

There is also a possibility something in the Dotek or Vuelta lines might work.

Some people use Middleburn cranks with their Rohloffs, but I fear they may be problematic when using with a 38t 'ring and the Hebie chainguard; reports indicate smaller 'rings by that maker must be notched to clear the backside of the crankarm when used as a single, so there may be limited clearance for the chainguard.

'Hope this helps,

Dan.

[Andre Jute]

Thanks, Dan. I looked at the T. A. Specialites cranks, of course; who wouldn't. The one suitable for MTB style bikes is the Vega, but the current TA cranks are all ugly, aesthetically quite unsuitable for the style of bike. I also looked at the Stronglights (whose styling I've always preferred) but the only ones that are pretty and would suit don't offer square taper interface or a 110mm spider, or are intended for road use with narrow treads -- the wide tread isn't only preferred, it is essential to clear my ankle-bones from chain stays 130mm wide. The only one that works for me in the Stronglight line is the Impact, which is a badge-engineered Sugino RD2, and it's styling is not overly distinguished, compare for instance the Stronglight Z'Light.

Frankly, the best-looking current Stronglight is the base wearitoutandthrowitaway all-ali 55 S. http://www.stronglight.com/stronglight/page.php?nom=produit&keyProd=55S
And the even cheaper all-steel SL 32 S also looks the business. http://www.stronglight.com/stronglight/page.php?nom=produit&keyProd=SL32
Note that the first mentioned is specifically said to have space for a chain protector, so the tread is clearly not minimised; my Hebie Chainglider will certainly fit.

You'll see I listed the Shimano M590. It doesn't have the 110 BCD (104mm instead) but its styling is excellent (I don't care that everyone else also has it: I'm discriminating, not snobbish). It is however so cheap I can probably get a 104 BCD stainless steel chainring cut to suit and still have change out of the price of T. A.'s ugly cranks. (I'm a big admirer of Shimano and especially the excellent value Deore range.)

Thanks for permitting me to think out loud at this length.

Andre Jute

[Danneaux]

You're welcome, Andre.  

If it helps to know you have company, I specifically chose the Shimano M590 for my Sherpa build, and I like the appearance very much.  My chainguard also nicely clears the backside of the crankarm when sitting atop my 44t, so you should indeed be okay with the Hebie Chainglider.  Your reasons for passing on the TAs sound perfectly reasonable to me, given your needs and preferences.

Aesthetic concerns do have merit, and so does matching appearance of components to the ethos of a bicycle.  I've done it myself, looking high and low for Stronglight 99bis drilled chainrings for an older bike, and finally deciding to get out the drill press and drill-and-countersink the lot myself.  Turned out very nicely, and was worth the effort.

Thanks for permitting me to think out loud at this length.

Not at all!  I run on this stuff, so think aloud further if need be...

Best,

Dan.

[Danneaux]

Just out of curiosity, Andre...perhaps I missed it...but...why do you need to replace the original crankset on your Kranich?

Did it fail in some way?

Best,

Dan.

[Andre Jute]

I hated the Sugino Mightly crank, fat and misshapen and ugly, that came with my Kranich, and had it removed while still in Germany. The dealer fitted an inexpensive Indian Amar crankiest because it was cheap, black, with a thin crank and a steel chain wheel. I was supposed to replace it when the bike reached me, but I spent all the time I should have been on the phone finding a Surly stainless chainring and a crank to suit -- riding the bike. Now it is 5K and three years later, and I'm still riding a Kranich with an inexpensive Indian crank... -- Andre Jute