Bicycle Mechanics - chain tensioners. singlespeeds. chain skipping

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geekpunk
06-05-05, 07:55 AM
I posted this in the singlespeed forum also, but no reply. so I thought I'd post it here as well.

I just converted my friend's bridgestone RB-1 to a single speed road bike. He wanted something reliable, simple and cheap. He had vertical dropouts so fixed was out (finding the "perfect" chain length was going to be far too cumbersome and he didn't want to shell out for the eccentric hub).

So I threw on a pyramid chain tensioner (the one that looks like the surly singleator, but is cheaper) and shortened the chain a bit. The tensioner doesn't hang straight down vertically but is angled forward a bit from there. When I rode it up a hill, the chain skipped. My gut reaction is that this is because the chain is to slack and that I should shorten it so that the tensioner is angled much farther forward and the chain is tighter. I'm pretty sure the chainline is OK.

Does this sound right to anybody? If so, does anyone have a recommendation for what angle it should be at?

Other suggestions?

Thanx!

Trogon
06-05-05, 08:45 AM
My Singulator hangs a couple of degrees forward of straight down - the axle of the pulley is exactly in line with the front of the rear cog, looking down at it.

I did a couple of things to guarantee chain smoothness. First, I invested the $4.95 in a Shimano BMX cog. It's beefier than a regular cog and has longer teeth. Second, I spent $9.95 on an SRAM track chain. Deeper recesses and quite robust.

Even with that, I had to screw around a lot with the sideways position of the Singulator pulley axle. It skipped, it rubbed the sides of the pulley cage, etc. Finally got it, and when it became completely silent, it worked flawlessly.