[ianinco]

So, I took an old road bike (about 20 -25 yrs old), took of the shifters, etc and shortend/routed the chain as a single speed. Kept the cassette on. With horizontal drop outs the chain is slightly loose and whenever I torque the cranks hard I mananage to torque the wheel out of true with the frame. Any suggestions

 

[Adirondack Blues]

So, I took an old road bike (about 20 -25 yrs old), took of the shifters, etc and shortend/routed the chain as a single speed. Kept the cassette on. With horizontal drop outs the chain is slightly loose and whenever I torque the cranks hard I mananage to torque the wheel out of true with the frame. Any suggestions

Are you using a quick release? Make it really tight. Also, I've noticed that the old steel QR skewers have more "bite" than newer alloy ones. If that doesn't work, try to rough up the paint on the dropout with sandpaper. Last resort you will have to convert the axle to a bolt-on type.

Also, is your chainline straight?

I have an old roadbike of the same vintage, use the QR, and and mine doesn't slip.