Horizontal rear fork ends and disk brakes

[Mussels]

These don't seem to be the best of friends at the moment on my 906. I'm having a hard time keeping the wheel in position and last night I was braking hard coming down a hill and the wheel twisted causing the back end of the bike to wander across the road, thankfully it realigned when I released the brake. I guess this is similar to problems people get with quick release front wheels and disk brakes, except there are no lawyers lips on the back.
This wasn't a problem with a new chain as the spindle was almost as far forward as it would go, any movement would be slight and not be noticed. Now I've moved the spindle back a few mm it's becoming quite a problem. I'm doing the nuts up pretty tight, I'm not light handed and I'm more likely to cause damage by over tightening things. However it needs to be loose enough that I can get it undone with the 6" adjustable wrench I carry on the bike.
I'm not sure if the nuts are vibrating loose and then the spindle is moving or if the nuts are tight but loosen off when the spindle is wrenched forwards, I suspect the latter.
Is there any way to combat this?
I'm thinking of two options but maybe there's something better I haven't thought of.
1. Have the wheel as far forwards as it will go and use a chain tensioner, I'm not sure where I can fit it to yet.
2. use filler in the gaps for the spindle to rest against.

I have the feeling there should be a better way.

 

[Mussels]

As if by magic there were some bike mechanics in the work car park today doing bike MOTs for people and running maintenance lessons at lunchtime, so I wandered over and asked them. I got told "We don't see many of these" which seems odd as hub geared bikes aren't really rare. One of them knew it was an issue for single speed riders and there were solutions available but wasn't sure himself, fortunately single speed bikes are popular round here and there's a specialist close by. I have alead.

Edit: It looks like I need something called a chaintug, two problems:
1. They are designed to only use on the drive side but the brake is on the other side so I need two.
2. I have a replacement rear rack (I would have got another Wisper one but as usual I needed it yesterday) that attaches just above the hub, I don't think it leaves enough room for the chaintug.
Time for more Google.

 

[Mussels]

I've found a few options, some clever ideas in the link below. My ideal is the chainstay mounted tensioner but the web page says "This type of tensioner may work for you, but they seem to be somewhat problematic compared with other tensioning options."

MTBR.com Single Speed Forum - Single Speed FAQ

The phantom chainring would be fantastic if there's room.

 

[Wisper Bikes]

Hi Andrew, another new one for us!

I have passed the link to the thread to Steve and am awaiting hos reply,

I will get back to you tomorrow.

All the best

David

 

[Mussels]

Hi Andrew, another new one for us!

I have passed the link to the thread to Steve and am awaiting hos reply,

I will get back to you tomorrow.

All the best

David

Thanks, another option I hadn't considered is buying a new chain. I might do that first as it should prolong the life of the cogs and if the adjustment does slip it won't go as far.
Half links seem popular as well to shorten the chain as a way of removing the extra slack.

 

[flecc]

Here's a simple and very cheap solution that was common years ago, and it might solve your problem if you have rear opening slots.

The self locking nuts on the rear enable precise adjustment and prevent the wheel moving forward:

Chain adjusters

 

[Mussels]

Here's a simple and very cheap solution that was common years ago, and it might solve your problem if you have rear opening slots.

The self locking nuts on the rear enable precise adjustment and prevent the wheel moving forward:

Chain adjusters

I had looked at similar but they were bigger and more expensive, those look just the ticket.

 

[flecc]

They do work well and many bikes had them 50 years ago. I've no idea why they dropped out of fashion. Of course on motorbikes they are almost universal.

 

[kitchenman]

Here's a simple and very cheap solution that was common years ago, and it might solve your problem if you have rear opening slots.

The self locking nuts on the rear enable precise adjustment and prevent the wheel moving forward:

Chain adjusters

Nice one Flecc. I think these could be useful when sorting out the chain tension post a split chain mid drive install on a recumbent

 

[Mussels]

Here's a simple and very cheap solution that was common years ago, and it might solve your problem if you have rear opening slots.

The self locking nuts on the rear enable precise adjustment and prevent the wheel moving forward:

Chain adjusters

I've finally got round to ordering them along with 2 new KMC long life chains, I'm not sure what makes them long life but they come with the soft links that I'll need so I don't mind paying a bit extra.

 

[Mussels]

Here's a simple and very cheap solution that was common years ago, and it might solve your problem if you have rear opening slots.

The self locking nuts on the rear enable precise adjustment and prevent the wheel moving forward:

Chain adjusters

I ordered and fitted these, the nuts weren't nylock but a bit of threadlock fixed that. I connected them up on the inside of the frame and they work a treat.

 

[Mussels]

I spoke too soon, on the ride home last night my back end felt a bit vague at times so I stopped to check and found that the chain adjuster was too flimsy and the drive side had moved forwards.
The problem is compunded by the Alfine fixing system, there's a serrated washer outside the frame with a dog that hooks inside the fork end to stop the axle rotating in the frame. The serrations are designed to stop it slipping forward under pressure, this is the inadequate part. Anyway... often when I try to adjust the wheel position I find that the serrations have jammed themselves to the frame so hard that I can't pull it back to allow adjustment, there's nowhere I can apply a lever either.
I'm going to order a more substantial chain adjuster in the hope it solves the issue, the problem there is many of them have a thick piece of metal designed to go outside the frame. That's probably fine on a single speed but not with hub gears as the dog must be engaged for the gears to work. The brake side seems to be OK so I might leave the weaker inside the frame on that side with the dog engaged and then replace the right hand fixing with a more substantial adjuster.
Bikes can be so compicated sometimes, my problems sometimes seem beyond the comprehension of bike shops.

 

[flecc]

Sorry to hear that Mussels, they are usually strong enough, but on a crank drive they do have to cope with much more. Hopefully stronger ones will do the trick since these work well on motorbikes with vastly more power.

 

[Mussels]

Sorry to hear that Mussels, they are usually strong enough, but on a crank drive they do have to cope with much more. Hopefully stronger ones will do the trick since these work well on motorbikes with vastly more power.

I remember the motorbike ones and these are nothing like it, I might be able to fabricate a stronger end cap whilst keeping the slim washer that goes over the axle.