Ok. Please forgive me if this has been covered 1000 times. I tried the search function, and waded through lots of posts but nothing pertaining to my paticular problem.

I made my first road fixie (been years on a ss mtb though).

The rear wheel is a dedicated ss/fixie flip-flop hub (no name brand off ebay). For the front cog, I'm using middle ring off my 3-ring crankset.

I'm using a Godspeed chain tensioner I got for a couple bucks off eBay.

Chain: Original 3/32 using a 3/32 half-link.
Chainline: Seems pretty dead-on when eyeballing it.

Here's my problem. I can hammer the pedals as hard as I want, and the chain does NOT fall off. The chain DOES fall off when I put some back-pressure on the pedals to slow down. It happens EVERY time.

So I look down to see what's going on, and the chain WARPS (not wraps) and eventually falls off.

Am I stuck? I'm almost considering going to a freewheel, but I have that for my mtb, and I fell in love with fixie.

Here's a pic of the bike.
http://img.photobucket.com/albums/v287/TuksonRider/Bikes/fixxed.jpg

You cannot use the tensioner on a fixed. - TF

Well... that would explain it. :(

Thanks. :)

You've got vertical drops on that frame, but all is not lost. Magic gear, maybe?

Here are a couple calculators. (1) (http://www.peak.org/~fixin/personal/fmu/php/fixmeup.php) (2) (http://www.machinehead-software.co.uk/bike/chain_length/chain_length_calculator.html)

I have a feeling that we live in the same city in SE Arizona, just based on your user name, so if you need a hand, I'd be happy to help.

Can't use a chain tensioner on a fixie. It don't work.

Has anyone ever tried a lock in place tensioner?

There are two types of tensioners.

1. Spring loaded
2. Lock in place

In theory, a lock in place tensioner should work on a fixed. I've never tried one and really don't want to be the test dummy but it should work. As long as you have the ability to lock it both side to side and up and down, the chain will stay put....