So my 2018 BH MTB experienced a fatal error last week. The rear hanger mount sheared / failed at the linkage. The hanger and derailleur didn't break.
So far BH has been unresponsive as they don't have US ops any more. Fantastic bike, abso loved it.
So it still rides – I had to strider bike it back and the suspension is fine.
I know this is a longshot and only temporary – but is there such a thing as a chain tensioner for turning this into a singlespeed, that mounts other than the rear hanger? This thing actually has a direct mount front.
Also, I've reached out to a few carbon repair places – anyone ever had something like this repaired? I can't even begin to imagine its fixable.
Definitely bike shopping but curious if I can get it rolling for just a few months.
by DickieMcBib
8 Comments
Phantom chainring https://www.sheldonbrown.com/tandem-build2.html#okeefe
eccentric hub https://wheelbuilder.com/white-industries-erics-eccentric-eno-rear-hub/
If you got a trek store near by worth asking if the bash guard with a pulley would work
You may be able to add a udh hanger. Will require a bit of modding.
https://youtu.be/T1NzvWTB6iM?si=3UGI2mXuXIRXNwHc
Redditors are not going to like the solution but I bet it will work. The way you run a single speed is to tension the chain, which if you don’t have horizontal drop outs or some type of eccentric hub or BB, is a pulley set up installed onto the hanger, which you don’t have.
But you do have something which changes the growth of the chain, the rear suspension. I assume with this design the chain is stretched out when the suspension isn’t active, ie when the bike is in the stand.
Deflate the rear shock completely. Move the wheel up slightly so the shock compresses like a millimeter. Shorten the chain so there is almost no play. Reinflate the shock. The wheel returns to its normal position and the chain is stretched.
This solution has some serious problems: you can’t compress your rear shock more than a millimeter or there will be no tension in the chain, and will likely derail and break. You’ll have ride gently probably over smooth terrain; I’d increase the shock PSI so the shock can’t compress from just sitting on the bike.
It’s a bad solution but if you can’t get a new chainstay, well, your bike is shelved.
This isn’t cheap:
https://wheelsmfg.com/collections/ebb
That bike has ISCG tabs at the bottom bracket? I think you can find a tensioner that works off the bottom chain run. Maybe post on r/ Meatengines, they’re into singlespeeds.
Lots of people here are ignoring the chain growth issue of the rear suspension, which is going to require a spring-loaded tensioner.
The most reasonable approach I can think of would be to do a spring-loaded pulley tensioner mounted behind the chainring from the ISCG bolts. Don’t think such a thing exists commerically, though; the two closest I can think of are the Blackspire Stinger (which isn’t spring-loaded), and the YESS ETR-B, which only mounts to old BSA BBs, not ISCG.
If you’re inventive, though, this seems like a solvable problem for ~$100 and a dozen hours of your time.