tarmenel

Well I've finally come over to the dark side and decided to convert my racing setup to single speed. I bought a conversion kit and replaced the cassette and the deraileur with the chain tensioner. I then removed the smallest and largest chain rings on my XT crank and thought I was aces. As I gingerly set off I was going OK but as soon as I put pressure on the pedals the chain would skip. Please can you guide me as to what the problem may be. The chain is a single speed chain as well as the rear cog. The chainring is a nine speed chainring so this is what I think may be causing the problem but then I thought that the ss chainrings come in the same size 36T and the chainline is straight so that shouldn't be causing the problem, or is it? I've attached some pic's
IMG_6064..jpgIMG_6063..jpgIMG_6062..jpgIMG_6066..jpgIMG_6065..jpg

TejanoTrackie 

Maybe a mix of new and used parts, like new chain but used cog or vice versa.

tarmenel

Everything except the chainring is brand new. The chainring has only had a few rides maybe three or four and nothing longer than an hour and a half. Is it OK to use a regular chainring with the single speed chain?

renton20

Multi speed chainrings are designed to be able to shift well. The teeth are machined very differently from single speed chainrings. I would suggest getting a single speed chainring similar to this https://www.jensonusa.com/store/produ...Chainring.aspx. Other than that your chainline looks straight and it doesn't look like you have a slack chain or anything.

TejanoTrackie 

When you say SS chain, do you mean 1/8? Should be OK, but I've never had a SS or FG setup with a modern ramped and cut tooth chainring, only the old style 3/32 chainrings with full teeth and no ramps. Is it skipping up front on the chainring? You could try a standard 8 or 9 speed chain instead.

tarmenel

I'm leaning more in the line that its the chainring. Will this FSA chainring be compatible on a XT M770:
https://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWAX:IT

tarmenel

Thanks, I have ordered a SS chainring and will try to put a nine speed or eight speed chain on the bike in the mean time.

adriano 

i use a multispeed chainring. its fine.

ismellfish2

I think it's chainline. I see a kink in the chain where it engages the chainring, and with a tensioner inline as opposed to a horizontal dropout setup, it's probably more willing to buck off the chain. My experience with matching worn parts with new parts is that they're just really noisy. The asymmetrical teeth shouldn't cause any problems- nothing has changed from multispeed as far as the front is concerned. FG would be different.

adriano 

the chainline looks fine.

FastJake

You should be able to run multi-speed chainrings on an SS no problem, I've done it on several bikes. The front ring is not the issue.

I had the same problem with my SS mountain bike. I think your chain is too long. See how the chain drops down almost vertically after the rear cog? It isn't engaging enough teeth which is why it only skips when you try to put the power down. Shorten your chain by a link, and then you'll have it wrapped around more of the cog. What gearing do you have on there? If you try to use super small gears this problem will be worse.

November

What FastJake said. Not enough chain wrap. Looks like you're only engaging 7 teeth out back. You may even be able to lose 2 chain links and add a half-link if losing 1 link doesn't do the trick.