36 tooth crank
 

Visiting here from over in Touring, figuring this to be the place for a gear head question.

I think I want to build out a new touring bike with 36 tooth crankset coupled to a 10 spd cassette, friction shifted. Can this be done and if so, what are the considerations? Do you know where I could buy such a crankset? If not, can a double or triple be sized down to one chainring and work ok with a 10 spd cassette?

99.5% of my loaded touring miles can be done with this combo. I don't mind pushing the rest in the interest of KISS.

Two considerations for a 1x10 setup is chainline and how to get the chain back on if it falls off or how to keep the chain from falling off.
Chainline is pretty easy to achieve if you use a square taper crank. There are several methods to keep the chain from falling off and bashguards and chainkeepers are worth a consideration. Alternatively a FD locked into place should do as well.

It should be pretty easy to find a crankset with a 36T middle and just remove the other two rings.
I've bought a 36T square taper crankset with bashguard already attached for $25 before as well.

Either MTB or compact road crankset can be used, so whichever you can find will do.


Otherwise...
Friction shifting might not be so smooth with a 10sp cassette.
Chain length needs to be two whole links longer than when you are in big-big, instead of the traditional one for double and triple setups.

If it were me, I'd get a square taper crank with 48/36/26 rings, ditch the 48T and replace with a bashguard (basically a pant-saver now) or replace chainring bolts with BMX ones, choose a BB spindle length that puts the 36T about middle of the cassette or slightly outside, and re-adjust the front derailleur. Even if you'll hardly use it, might still be nice to have that bailout gear. The 26T could even be replaced with a 22T for a true bailout.

If you really want that setup, I would recommend using a crank with a 110mm bcd which is common on both touring cranks and mountain bike cranks from the 80s and 90s. One such crank that has proven its reliability is the Sugino XD2. With this crank I would mount the 36t chainring on the the inside of the spider, mount a chainring guard on the outside (to keep the chain from falling off the outside), and use a chain keeper to keep the chain from falling off the inside. (Of course, you could skip the chainring guard and just go with the Paul Chain Keeper *bling.)

Since you would be going with a 1x10 setup, you would be well-advised to use a chainkeeper since the chainline can be so extreme. Btw, I am not a shill for Benscycle.net, they merely came to mind when I was looking for the components above. Good luck!

Cheers
lverhagen

+1

I like this idea a lot. You'll want to run some sort of bashguard/chain keeper anyway, so why not just leave the FD on and have a low double?

Also, why the 10 speed cassette? You'll wear through everything faster, and I bet you'll have a much easier time friction shifting 7, 8, or maybe even 9 speeds. Do you really need the close ratios of a 10S cassette on your touring bike? My guess is no, because if you did you'd keep a triple on there.

cyclocross world . com has some nice chain-guards, . you could make a chainring sandwich with 2.

But the 10 cog cassette is rather a narrow space between chainrings,

So your hand needs to be more finely tuned than if there were just 6 cogs in the same space.

Wow. Thanks for the ideas. Sounds like this can be made to work. Whether it turns out to be practical is another issue. Might involve more pushing than I want. According to Sheldon, 3.7 mph @50 rpm. Wobble, wobble, wobble. 19 mph @80. Fast enough for loaded touring.

Currently running a 9 spd cassette. 10 spd to get ultra low granny needed with 36 t chainring. Shifting precision is not a big consideration. Push/pull 'til it feels right or the limits are reached.

Like the chain-guard suggestion as I usually ride in the winter in either jeans or running pants. Sandwiching is not an option according to Cyclocross World, bolt set length being the killer. They do offer a neat dérailleur-like chain keeper.

Personally I'd go for a 2x5 drivetrain rather than a 1x10. Everything is more robust and will last longer, and with a 5-speed and double crankset, cross-chaining is acceptable in all gears, so you still get 10. Careful selection of sprockets and chainrings will result in a half-step setup.

Well there you go. Being practical and sensible. That's not what this is about:) But hey, good thoughts for sure. There is a double, internally geared crankset out there that sure looks interesting.

No use in going 10s unless you are stuck with a 7800 hub. Do the 9 as you can find cassettes and chains for way cheap.

And yes, I agree with what most have said above. Chainline in the middle of the cluster, chain catcher, adequate tension, etc... If you have a compatible chainring hanging around, you can grind off the teeth and make a nice guard.

If there is a need for a low gear, consider a 2/3 of a triple,
Outer, a toothless chainguard, middle ring, your 36t and a bail out
granny gear, like a 26t or 24t