FarHorizon

I have a new coaster-brake bike with an aluminum frame and forward-facing slotted dropouts. I'd like to buy an axle tensioner. I purchased an Origin8 brand one, but it won't work There are two flaws:

1. The slot in the rear of the tensioner is not wide enough to fit over the wider aluminum dropout

2. The bolt in the tensioner is not long enough to reach the rear of the longer aluminum dropout

I may modify the tensioner by filing out the rear for sufficient clearance. I may then add a link to the chain so the axle will sit further back in the dropout (this might make the bolt sufficient to reach the rear of the dropout).

Rather than do this, though, I'd rather buy a tensioner that's designed for aluminum frames. Anyone make one?

PS: Note that I do NOT have the rearward-slotted "track" dropouts on this bike.

Thanks - FH

dsaul

They are generally referred to as "chain tugs" or "chain tensioners". Amazon has a great number of different styles. Without a picture of your dropouts, its hard to tell what will work. I've attached a picture of a home made one I made for my Schwinn Prelude when I converted it to single speed.

FarHorizon

Sweet! All hardware store parts?

dabac

Don't think I've ever seen a chain tug for forwards facing dropouts...

Leebo

What about just using a nut and bolt to put in front of the axle? Fit it through the drop out and tighten.

fietsbob

With non QR axles it is pretty straightforward to tighten the left end with the wheel askew, and as you pull the wheel to the right, straightening it, you also tension the chain.


But by post 3 the Idea seemed to be dawning on you that the "Anyone make one?" is in fact, YOU, getting on with a Bit of DIY.

jyl

Why do you need this part?

Can't you position the axle in the horizontal dropouts so that the chain is adequately tensioned, then tighten the axle bolts or quick release?

The chain doesn't have to be taut. it is supposed to have a slight amount of slack. Park Tool Co. » ParkTool Blog » Chain Tension on One Speed Bikes

I think you are over complicating things (ahem, wouldn't be the first time).

FarHorizon

I have seen tensioners for forward-facing dropouts. They do work fine. Since my dropout openings face forward on the frame rather than aft (like track dropouts), putting a bolt in front of the axle won't work.

The convenience of being able to center the wheel while leaving the proper amount of slack in the chain is just that - a convenience. It is not an "overcomplication," nor is it a necessity. It is just that - a convenience. And it's a convenience I'd like to have. My LBS is searching now for an appropriate part. If they find one, I'll buy it. If not, I'll make my own.

hueyhoolihan

i bought a couple of expensive chain tugs for my track bikes. i've subsequently dispensed with them. they were more a bother than a help WRT centering the wheel and adjusting chain tension.

and AFAIK coaster brake hubs use long axles and nuts (my beater bike has the Velosteel one on it) that can be tightened to just about any tightness one wishes. if slippage is an issue i would just tighten the nuts a bit more. good luck.

FarHorizon

Nah - not slippage issue, just a convenience for consistently setting the proper chain slack.

squirtdad

FWIW I used one designed for backward facing dropouts on a forward faceing dropout, by dremeling a little notch in the back side of each drop out

dsaul

I made the one in my picture with a piece of aluminum angle. I drilled a hole for the QR to go through and drilled and tapped a hole for the bolt. The bolt is ground to a point that sits in the old axle adjustment screw hole. It's not pretty, but it solved my problem of the axle slipping forward under load and I made it from stuff I had in my shop. I only have one on the drive side.