SS MTB how to convert w/o chain tensioner
 

my bike has vertical drops and i want to convert without using a chain tensioner. i've seen many SSMTBs in this forum with similar drops and no tensioner so it seems to be possible. any tips or how to advice is appreciated. the more details the better. peace

A lot of the SS mtb's I see have vertical dropouts and eccentric bottom brackets. So they're not conversions, you adjust the chain tension with the bottom bracket(though admittedly i have no idea how an eccentric bb works)

Best option: get a White Eno hub - expensive but will make life easier. And you can use it on any bike if you find another frame you like.
Less best option: you can try to find the 'magic gear' that will give you a perfect chain tension, but it will involve trying lots of cogs and chainrings until you get it right (and you might not), putting a half-link in, etc. Then you're locked into the one gearing. And then as the chain stretches, you will potentially lose the magic.
Those are really the only ways to do it, other than getting horizontal dropouts put on your bike.

Mine tension came out perfect with a 32:18, the ratio i wanted. But soon as the chain stretches i will be screwed.

You could try an eccentric bottom bracket conversion kit.

thanks for the info everyone.

eno...+1.

Converted my 1992 Rockhopper Comp and stumbled on a magic gear. No problems yet. Great way to try it out for cheap. Some of the conversion kits come with a few different rear cogs and one worked for me.

The drop outs allow a tiny bit of play that can keep the tension. Since it's a freewheel I'm not super concerned with perfect tension, if it were fixed, I'd get an Eno which I might do anyway since I know I like it.

This looks interesting. Ever tried one?

FWIW we found a magic combo for a customer who rides aggressive offroad, he was back within 2 weeks with tension loss due to chain stretch and got a tensioner. As mentioned already, an eno hub is the most elegant way IMO.

Magic Gear.

-Rob.

Whats wrong with a chain tensioner? It's a MTB........ Your gonna want to change the gearing pretty often unless you just ride the same trail every time you take it out.

Nope.

I'm using a tensioner. It's not ideal as I've found it just about impossible to set up without the chain occasionally skipping. It's my winter beater so it's not a big deal, but it's still annoying. I don't think I'd run this setup for something intensive like mountain biking.

i never trail ride so i'm thinking of turning my mtb into a ss commuter with track drops and bar top levers.

woot.

Do it.

Which tensioner?

use a half link chain. done and done. one fuill chian, each link is a half link.

when it stretches though, you are not so happy, but
can get by because of the magic of half links.

I would go with road drops, aero levers and interrupter levers for the ultimate bad-ass commuter setup.

Surly Singleator. Chainline is perfect and I've got about 8 teeth connecting with the chain and it still occasionally skips if I put alot of torque on it. If I take another link out of the chain to get even more wrap, the chain is too short and the pedals bind. Basically I'm looking at using a half link, which negates the entire purpose of using a tensioner in the first place

1/2 links will break on you.

spring-tensioned 'tensioners' will allow the chain to derail in the rough stuff.

if you must use a tensioner, use a bolt-on like the rennen rollenganger.

I've used 1/2 links for years on my fixed gear and never had one break.

Run the tensioner in pushup mode. Should take care of the chainskip. Check the surly blog for ways to get it right. The older models needed to have the tensioning spring flipped to work in puchup mode. Once I flipped mine and ran it that way it never slipped.

That was the original plan, however I don't know if the issue is with my drive train length or derailleur placement, but pushup mode won't work for me without a half link. If I set it to pushup mode as it is, I get way too much slack, and if I take a link out, the afformentioned "way too short chain" issue comes up. Like I said, I'm not sure if that's my derailleur placement or what, but the amount of chain slack I can pick up in pushup mode is minimal enough that if that's all the chain slack I had I could probably run it without a tensioner in the first place.

It works at any rate, but for a winter commuter. For a mountain bike I was riding the hell out of and climbing out of the saddle, I wouldn't be happy at all with this setup.