The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Russ on 03.09. 2019 10:49

Title: What rims and offset
Post by: Russ on 03.09. 2019 10:49

What Rims should I buy and what is the off-set for my wheels?
OK so you need a few details.
My bike is a 51, A10 Plunger. Front wheel is the half width 8" brake and rear is the 7" Q.D crinkle hub. Both rims are WM2 X 19" X 40 spokes. If I've got that wrong feel free to correct me.
I have the hubs but the old rims were thrown out long ago.  Have researched the usual Devon and Central Wheel Company sites for info and prices and wheel suppliers / builders local to me, "Victoria Australia"
Now my bike, if ever finished, will be a "sunny Sunday rider" so will spend most of its life in the shed. I get great enjoyment from this research and rebuild but I guess I will have to ride it at some stage to justify to the "boss"
the cost and time spent, 11 years at this stage.
So what rims do you recommend and what is the off-set for my wheels?
Thanks Russ

Title: Re: What rims and offset
Post by: morris on 03.09. 2019 21:52

I got my rims from CWC.
The plunger has stainless, but on the SA I have the cheaper chrome rims from them. I find both good quality
For the plunger front and back the rims are 19 X 1.85 (WM2)
Front spokes; 20 of 145mm length (right side) and 20 of 217mm length (left side).
Wheel offset; 17mm measured from brake edge to rim edge
Rear spokes; 20 of 204mm length (right side) and 20 of 202mm length (left side).
Wheel offset; rim centre 13mm to the left of hub centre
Both offsets where a good starting point and needed only minimal correction to get the wheels central to the frame

Title: Re: What rims and offset
Post by: Russ on 04.09. 2019 00:50

Thanks for that excellent information Morris. Appreciated.
Russ

Title: Re: What rims and offset.
Post by: Russ on 07.09. 2019 15:01

Further to my initial post.
My front hub, 8" half width, has larger diameter spoke holes on the brake side. Service sheet 714 shows A Group bikes of 1954 & 1955 had spokes part # 67-5606 being "Butted 8 / 10 size fitted.
It would appear I have a later model front hub for my 51 A10. Does that sound right?  Can I use this hub, is it the same for a 51 and a later 54 model?  Can I use 10 gauge spokes for this application or must I use a "Butted 8 / 10 gauge spokes?  I don't like the look of Butted spokes.
Thanks Russ
 

Title: Re: What rims and offset
Post by: JulianS on 07.09. 2019 16:21

This service sheet may help explain.

Title: Re: What rims and offset
Post by: morris on 07.09. 2019 17:52

Sorry, forgot to mention. My front spokes are butted 8/10 both sides. IMHO, barely noticeable.

Title: Re: What rims and offset
Post by: ironhead on 07.09. 2019 23:33

I split the difference & use 9G. I've also noticed that modern "repro" spokes can vary quite a lot in the head size from originals. (some smaller, some larger.) Depending on who makes them.

Title: Re: What rims and offset
Post by: Russ on 08.09. 2019 00:25

Thanks JulianS and morris for that info.  I might go with ironhead and use 9G.
Cheers Russ