powitte

I ride an IGH rig, and have persistent troubles with the axle creeping forward, particularly when pulling my axle-mounted trailer. Yes it is torqued to spec.

How do these sliding dropouts work? For what applications are they useful?

lverhagen

What model do you have, the Hyland? The sliding dropouts work such that the dropouts themselves (the parts to which to the wheel actually bolt) are bolted to the frame and slide forward and backward to allow the chain to be tensioned as it wears or if chainring or sprocket sizes are changed, also it maintains the position of the disc caliper in relation to the disc bolted to the wheel, finally they allow vertical dropouts to be used which simplifies wheel removal and installation when fenders are equipped. They are generally considered to be a good thing as opposed to rear facing horizontal dropouts for the exact reasons stated above.

One poor design move on your bike is the absence of stop bolts to prevent the sliding dropouts from sliding when they shouldn't as seen on these by Paragon Machine Works.

As for preventing the dropouts from sliding on your bike, have you considered adding serrated or split washers to each mounting bolt to allow them to grip the frame more effectively? That would be the first approach that I would take in your situation. Good luck!

Cheers
lverhagen

powitte

Thanks for the reply. I don't have a Civia. I have another aluminum frame bike with semi-horizontal dropouts. The serrated non-turn washers that come with the hub (SRAM S7) are pretty bitey, in comparison with the Shimano ones. The problem looks to be the teeth are actually scoring the dropouts as the axle position shifts bit by bit, and then sliding forward into the most forward position when I try to tighten the axle nuts at a point with proper chain tension. That is, I tighten the nut and the chain goes visibly slack as I tighten it. Frustrating.

I was wondering if this sort of design would fix my problem. But, I wonder about the ability of a few allen head screws to achieve enough friction force to keep the assembly moving under similar forces as I'm putting on it now.

$229 for some dropouts??? Who in the world is buying these things?

lverhagen

Have you considered conventional chain tugs such as these? If I recall correctly, they should work just fine with semi-horizontal dropouts. Of course, there are other options for chain tugs and I would suggest looking around for the best option for you frame since you know what it looks like better than I do. The chain tugs should position the wheel at a the place with the best chain tension and hold it there while you tighten the nuts, avoiding the frustration of slippage. Good luck!

Cheers
lverhagen

powitte

Don't think this will interface well with the S7's clickbox unfortunately

MichaelW

Can you smooth out the dropouts to remove the indexing wear marks?

Most sliding dropouts are tough steel so don't suffer from bitey track nut washers.

powitte

I've already filed them down once, which was a pain, but it worked for a couple months. Now I have the same problem, but thinner dropouts.

fietsbob

My Koga Miyata Rohloff sliding dropouts seem OK, frame and dropouts are Aluminum.

Newer signature line Koga Trekking frames are a bit better, it appears.