I’m trying to convert the wife’s mtb to singlespeed and am having some problems with the chain jumping/skipping over the teeth of the rear cog under torque. The front chainring is a standard lx middle chainring and the back is a 16 tooth wide base cog from superstar. The chain is a 9 speed SRAM 951 with a chain tensioner device. When I put a cassete on the hub, the jumping of the chain stops, but when I install the cog, the chain skips under moderate moderate cranking. Is this a problem with the 9 speed chain and the 3/32″ rear cog not being compatible? If I get a 3/32″ chain, will it work with the 9 speed front chainring or will this need to be swapped to a singlespeed specific one? Thanks in advance guys!

I Will keep an eye on this thread as I am about to do my first SS convention on a old Marin Palisades Trail

Not enough tension in the chain.

Is the tensioner pushing the chain down, or pulling it up (this is best)?

Yeah you need a wider chain such as a kmc z610….
http://www.charliethebikemonger.com/kmc-z610-hx-chain-332-41-p.asp

And you need to make sure there us tension in the tensioner… Watch this… Sorry about the shirt…. [video]http://m.youtube.com/watch?v=L-n0m6jMOCE[/video]

David… This might be of use to you.

[video]http://m.youtube.com/watch?v=93M9lvl8LM8&feature=relmfu[/video]

Strange i started a new conversion tonight and am having the exact same problem using a sram 9 speed chain too it was fine with the 8 speed chain on

Pulling up is better as you get more chain wrap, more teeth engaged.
But some tensioners are push down only… Which is fine.

I am not a fan of 32:16 with a tensioner, go 36:18. Costs the same but more teeth are engaged and wear is slower.

Yep, a wider chain (or a narrower sprocket!) should sort it 🙂

Thanks for the quick replies guys. I will try the chain and see what happens. Don’t really want to buy anything else on this bike as it is only seeing road work right now. The superstar cog I have on there also has really short teeth kind of like the XT one advised against in Charlies vid so maybe that has something to do with this problem

Yeah you need tall teeth.

Its not cheap but surly single cogs are the best IMO
Although I still prefer my eno freewheel to anything alse but that’s a bit more money and some more still

3/32 chain will be fine on your 9 speed ring

For the sake of balance, i should point out that i’ve never had any trouble with this on my Singlespeed On One 456 (no tensioner needed currently, as it’s fallen upon a magic ratio).

I use a DMR 16t cog, a standard SLX middle ring and whatever old 9sp chain comes off my FS.

Your results may vary, but i’ve never found the need for SS specific items. That said, if i was building a SS properly then i’d buy the correct items.