[w8kbrder]

Hey folks,

Got an old mid-90s Cannondale F400 that I've run as a single speed for quite some time. I've always run an Endlessbikes 32t chain ring and 19t cog. Great for trails in the mountains. However I've wanted to swap to a 16 or 17t for flatland around town. Unfortunately since I have verticle dropouts where there is no room for chain adjustment, the chain always ends up too short or too long to run a 16t or 17t. 19t is the only one I can run paired with a singulator.

So I decided to try a Paul tensioner. Everything setup pretty easy. Installed the tensioner vertical exactly how they recommended. Tensioner is perfectly in line with the rear cog and both are in line with the chainring. There is plenty of chain wrap. With that said, I keep having the chain jump a tooth on the 17t cog.

The Endlessbikes chainring has alternating teeth that go from wide to skinny...matching up to the chain itself. This feature prevents you from using any half links to get the proper distance on the chain. I'm trying to keep the chain ring in play so I figured using the Paul Melvin would eliminate the problem.

Question: Do you think it is skipping due to the rear cog being an odd number (17t) vs. the even number chainring (32t) and tensioner cogs (10t)? I run the 32t x 19t all the time with a singulator with no problems. However when I try the Melvin on the 17t...it keeps slipping. Any ideas, thoughts, input, suggestions would be great! I'm baffled.

 

[The STIG]

i had similar issues, remove some links and shorten the chain. once i did this it never had another issue. i ran it closer to horizontal than vertical

 

[Flat Ark]

I had issues like that using a Surly tensioner. I switched to a Surly cog and it hasn't skipped since. Only thing I can figure is that it had something to do with the actual tooth profile. The Surly cog has deeper valleys and more of a square edge on the tooth.

As STIG said though, I would try shortening the chain.

Sent from my HTC One using Tapatalk

 

[Saul Lumikko]

Is it possible that you simply ride in a lighter fashion when using the 19t cog and occasionally mash harder when using the 17t cog? It is possible that your problem isn't Melvin or the cog at all.

I thought my chain was skipping teeth, replaced things in the drivetrain and almost went nuts when the problem didn't go away.

Found out it was the Mavic freehub that had worn pawls slipping under load.

Later my brother had the exact same problem, thought it was a drivetrain thing but we ended up fixing it with new pawls. (Suffice to say I have retired the Mavic hub and the bike now has a Hope Pro II Evo.)

 

[w8kbrder]

Thanks for all of the possibilities. I did check the pawls and there was a bit of wear but not enough to cause it to skip. Finally ended up swapping the rear cog to a 16t and problem solved! I didn't think that the odd numbered tooth cog would cause issues but it did. Been riding for awhile not without a single slip. Thanks again guys.