The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: peecee42 on 11.10. 2014 10:36
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Hi
I'm about to get my hubs relaced with stainless rims, does anyone know the offset measuements
for a 1952 A10 gold flash plunger (I only have the bare hubs) I look forward to your reply
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G'day PC42 *welcome*
I'm pretty sure there is no offset. Center of the spoke ribs on the hub is center of the rim. I'll look at mine in the morning.
Cheers
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According to the data I have rear spokes on the left were 7.8" and spokes on the right 7.9" which suggests there should be a very slight offset to the left, maybe 1/4" or as much as makes no difference! Spoke lengths for other years are as follows.....
1947/48
L 7.9” 10/12GB
R 8.1” 10/12GB
1949
L 7.9” 10/12GB
R 7.9” 10/12GB
1950
L 7.9” 10G
R 7.9” 10G
1951-55
L 7.8” 10G
R 7.9” 10G
1956 on.
L 7.8” 8/10GB
R 7.9” 8/10GB
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Handy info to have beezermacc, those would be for the QD hubs. Would you have the dimensions of the front?
Cheers
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I went through this too, and had the same notion as Musky, but I just now ran a string-line over it and seems I have about 3/16" to the right, which I think even contradicts Beezamaccs info...But not disputing it. .. *conf*
I had the frame straightened as per the factory drawing, and fairly sure as I couldn't find the right offset info, he used the sprockets and chain as reference and I adjusted the rim to centre- I think. ...!.....Well, fairly sure really, it was only a couple of years ago.. *eek*
Keep in mind I have a WM3 rear, but makes no difference to offset anyway.
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File attached gives spoke sizes, not offset. Offset at rear can be calculated using basic geometry and spoke sizes. Off set at front is best set with wheel in situ in the forks as the wheel will be central to the stanchions.
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Thanks mate, very handy chart to have.
Cheers
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The only measurements I trust is the centreline of the frame and forks.
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Spot on wilko, if that's straight. Good to have them wheels right to show that up.
Just looked at mine (51 plunger WM2 rims) The outer edge of rim both sides are in line with the c/l of the spoke rib/holes of the hubs back and front. She runs true, hands off bars any speed, no leaning to keep her straight (cant do that on my rHonda).
Cheers
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Hi
Thanks for the info, will hopefully have a start this week
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got a little question here in a mo
First I won't to say how pleased I am with these SS rims, I've just laced the front one and discovered a "made in England" stamped on the rim, don't think this was mentioned in the advert.
I'm sure someone mentioned using a dial gauge to to true the rims so I did (pic 1), the gauge is incremented in 0.01 of a mm,I think in the UK the run out for steel rims is 4mm, alloy 3mm, these rims were amazingly easy to true, with little hassle I achieved a run out of 0.30 mm max
(apart from the join which has a 0.60 kick)
Now about lacing I studied a many images as I could and found that on (A7/A10 full width hubs) on wheels that had been rebuilt many had both spokes that run the same direction (but on opposite sides of the rim) both would be inside or both outside, whereas rims the were obviously original had one on the inside and one on the outside (pic2) as mine are. Question is does this make much difference, I think probably not.
last pic - the grumpy look I get when the shed comes before a walk
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Looking good bill can't comment on building a wheel but that all looks like you've got it well sorted , BobH
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When I said this....
I had the frame straightened as per the factory drawing, and fairly sure as I couldn't find the right offset info, he used the sprockets and chain as reference and I adjusted the rim to centre- I think. ...!
..... I was referring to this, but only after the straightening did it come together well...(I suggested he use the sprockets and chain as reference), and......
The only measurements I trust is the centreline of the frame and forks.
Bill I'm no wheel expert, but (I think) I read somewhere the obvious, that ideally there be a miniscule gap between the spokes at crossover- I'd say you have that covered...
woofer does look a little disgruntled...!