1961 G12 CSR Front Wheel Offset

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CAB
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Joined: Thu Jul 09, 2009 9:10 pm
Location: CORNWALL UK

1961 G12 CSR Front Wheel Offset

Post by CAB »

Hello
I have decided to rebuild the front wheel on my 1961 G12 CSR (re-chrome the original Dunlop rim, then get the drum trued and oversize linings turned down to suit) in order to try and get the best out of the brake. I was going to just get the drum trued/linings turned to see if it makes any differrence but I don't want to risk a rebuild at a later date pulling the drum out of round.
The bike is kept at my mums (a couple of hours away) and I have just brought the wheel back with me to do the work. I have made a note of the spoke pattern and after removing the tyre I measured the rim offset. With the brake plate off, the wheel parallel to the ground, drum side uppermost, with a straight edge across the drum face there is 3/8" between the under side of the straight edge and the rim (the edge of the hub on the drum side is 3/8" above the rim).
I should have checked that the wheel was central in the forks before I left but I didn't have time. I could rebuild it as it was and re-check between the forks before getting the wheel finally checked by a wheel builder, but that will mean another month before I can get the drum trued.
Does 3/8" sound correct?
Thanks
CAB
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dave16mct
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Re: 1961 G12 CSR Front Wheel Offset

Post by dave16mct »

All heavyweight AMC are supposed to have no offset. So if it's 3/8" on the other side you're OK. I made a Taverner jig as in the Vintage Motorcyclist's Workshop by Radco. I find it isn't too difficult and doesn't take much truing when removed from the jig.
Dave.
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robcurrie
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Re: 1961 G12 CSR Front Wheel Offset

Post by robcurrie »

The spoke pattern works out by itself because of the straight spokes and the holes in the hub. As Dave says, there is no offset.

As a side note, the front and rear rims have opposite hole patterns, hence different part numbers.

Rob C
CAB
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Location: CORNWALL UK

Re: 1961 G12 CSR Front Wheel Offset

Post by CAB »

Thanks for the replies.
I will check for equal offset on the opposite side of the wheel before stripping it.
CAB
CAB
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Posts: 116
Joined: Thu Jul 09, 2009 9:10 pm
Location: CORNWALL UK

Re: 1961 G12 CSR Front Wheel Offset

Post by CAB »

Before stripping the wheel this afternoon I measured the opposite side (cover plate side) at 5/16 compared to the 3/8 on the drum side.
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