Scootrs External Disc Brake - Wheel not Central

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Seiotoshi
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Wed Sep 02, 2015 8:46 am

I have recently purchased a new Scootrs anti-dive external disc brake unit. Last night I tried to fit the hub and it would not fit within the distance between my fork links. I replaced the thick nut on the axle with a slightly thinner nut and the hub just about fits. BUT the wheel is now offset from the fork centre line by about 8mm towards the non-disc side. I have new Scomadi forks and Italian hub style links with new springs and buffers. The latest version of Scootrs hubs only have a thick nut on the non-disc side, on the other side it is hard up against the link, so this gives me no scope to play with nut and washer thicknesses as I actually need to move the hub towards the disc side. The only option I can see I have are:-

1) Live with it (I haven't tried riding it yet, it may not have any adverse affect).
2) Machine some thickness off the link on the disc side (not enough meat to take the full 8mm off though).
3) Machine the hub down. I haven't taken the hub apart yet, so I'm not certain this is even possible or safe to do.
4) Buy some more fork links. I could end up spending £140 and it not making a blind bit of difference.

Anyone else had this problem and got any ideas as to how to resolve it?

dennis
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Wed Sep 02, 2015 9:12 am

Had this problem about 5 years ago,can't believe they have not cured the problem,I rode for a little while with the wheel offset with no problem but got so fed up with looking at the offset wheel i changed it for a different hub,plus the offset wheel is a possible MOT failure.

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wack 63
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Wed Sep 02, 2015 2:37 pm

You could try messing about with the internal hub spacers but I can't see you gaining 8 mm.

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wack 63
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Wed Sep 02, 2015 2:44 pm

You could try messing about with the internal hub spacers under the speedo housing but I can't see you gaining 8 mm. Also check your links are around 130 mm apart internally

Seiotoshi
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Wed Sep 02, 2015 2:47 pm

Thanks for the advice. I'd be happy to even get back half of the difference. I'll measure the link distance tonight. I haven't taken an RS hub apart before, presumably not a big job?

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wack 63
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Wed Sep 02, 2015 3:41 pm

Thinking more about it you may not have much scope to alter things as the speedo casing has to be a set distance from the hub so the caliper carrier is correct for the disc.

Seiotoshi
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Wed Sep 02, 2015 4:14 pm

Yes I think you are right. If the speedo housing moves then the caliper and disk have to move as well. That'd mean machining back the hub to move the entire housing/caliper/disc assembly inboard!

Link spacing can vary from scooter to scooter. It seems to me that RS have only provided scope to shim the wheel alignment if you happen to be lucky enough to have link spacing that is over-size. If like me, you are slightly under you are stuffed. Looks like my only option is to run as-is and hope there is no noticeable affect!

Seiotoshi
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Fri Sep 04, 2015 8:24 am

So I have measured the distance between my fork links and it is coming up as 132mm. The new Scootrs disc brake hub measures 136mm across the spindle. I notice from another post on this forum that Frank Sanderson reckons this is the smallest distance you can expect from standard Italian forks and links. There is absolutely no way of fitting the Scootrs unit without changing the spindle nut for a thinner one, and this in turn puts the wheel off centre. Can't really see any way forward other than to send the disc kit back for a refund.

Chris in Margate
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Fri Sep 04, 2015 8:43 am

I fitted mine about 4 months ago and my first impression was that it was never going to fit and I sat and looked at it wondering what to do exactly as you describe. When I'd had time to calm down I went back and "persuaded" it and it sprung in ok.
My fork link bushes and fork internals are about 9 months old.
Be a shame to have to send it back...Lovely kit.

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Adyonekenobi
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Fri Sep 04, 2015 8:04 pm

Think this topic is well known.
I had a similar issue but about 4mm off centre.
I accepted this feature and yes, it is off centre but it is a good powerful disc brake.
I don't find any problems riding straight, hands off the bars if need be! Still rides straight.
Not noticed any uneven tyre wear but only 1400 miles so far.
See if you can reduce the 8mm down a bit and provided all is sound, enjoy the powerful brake with care.
Spanner check the running gear before every outing, like in the Army. You know it makes sense!

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