[JRogers]

Hey, guys. I know lots about bikes but not much about SS riding. I just did my first ride today and had some problems with the gear skipping when I put down a decent amount of power. It seemed to get worse as the ride went on. Very disconcerting to be trying to power up a rock-strewn climb and be constantly afraid that my cojones would get mashed.

I'm using an older Surly Singleator, some random SS cog kit (has spacers and aluminum guides on the side of the cog), an 8 speed Shimano chain and RF Turbine LP cranks w/8 speed rings. The Singleator is set to push the chain down. Chainline looks about as good as it can get. Everything is new except for the chainring, but it does not appear to have been used much at all.

The only things I can think of to help are shortening the chain and maybe running it on top of the guide to get more cog wrap and maybe using a non-ramped/pinned ring up front (does the latter make a difference? I don't know.) The tensions seems okay, but I might be able to take another link out.

Any other ideas? What commonly causes this?

 

[peter6061]

What kind of 'wrap' do you have around the rear cog? Could be that because you're using the tensioner pushing down, you're only engaging a few teeth. Try switching the tensioner to push up on the chain to get more wrap.

I don't use ramped rings on my SS, but have in the past without issue.

You can check the chainline pretty easily using a method from the Endless Bikes Website.

 

[MMcG]

Try that Singleator in push up mode if you can as Peter suggested.

 

[JRogers]

Thanks guys. I'll try that and see how it goes. I'd like to try it out today, but it seems as if the skies have other plans.

 

[Wumpus]

I started out with it pushing down, but I wanted more chain wrap:

I didn't have much success with pushing up:

So I got a half link(also need to get a BMX chain -- 1/8"), and the tensioner pushing down. It was very close to not needing the tensioner at all.


Your problem could be that the tensioner isn't quite lined up and since the chain feeds from the tensioner pulley to the rear cog it is causing a skip. One other possibility is that you need more spring tension.

 

[JRogers]

Well, turns out that I don't have a Singleator; I have some crappy generic one that I do not believe can be put under the chain. I tried taking a link out, but it won't work- just a bit short. Plus, the cog I'm using is a bit skinny for my King hub (Al cassette body). Looks like I gotta drag out the credit card again.

I think I might try ordering a Rennen tensioner, new 16T cog, single ring and bashguard. I might try using the 17T on the regular cassette I have in the meantime. That or maybe lengthen the chain and use one of the 4 or 5 sort of working rear derailleurs I have laying around.

 

[peter6061]

Get a quality cog with a wide base. Come brands include Chris King, Surly, Endless, On-One(special Rm deal might still be going on), etc,... You don't want to mar up that cassette body.

A half link may be all you need.

 

[w00dy]

I've had the experience with surly cogs, and you might be seeing the same thing, where the profile of the teeth leads to the chain climbing out of engagement under load. Put on a bike with horizontal drops where the chain had nowhere to go and it worked flawlessly, but the cog was unusable with a spring-loaded tensioner.

I'm a big proponent of the phantom chainring setup. That would do the trick.

edited for clarity.

 

[JRogers]

Bike seems to work fine in the driveway sprint test using the 17T on a 8sp XTR cassette setup as is. I'll probably keep it like this for a bit and upgrade the whole deal whenever. I looked at the cassette body on the hub and it's already a bit nicked up from only 2 rides, so a new cog is in order at least. Thanks for the help, guys!

 

[MMcG]

Get a quality cog with a wide base. Come brands include Chris King, Surly, Endless, On-One(special Rm deal might still be going on), etc,... You don't want to mar up that cassette body.

A half link may be all you need.

As far as I know the free shipping deal on the On-Ones is still in effect.

Brant hasn't written to me to say otherwise!