Author Topic: 1947 B33 FRONT WHEEL OFFSET  (Read 245 times)

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ROCKINROD

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1947 B33 FRONT WHEEL OFFSET
« on: 27 December, 2018, 20:18:47 »
Hello, I am new to the Forum, and  in need of some information.
I have a 7" half width front wheel, 19", Type 3
My question, what is the offset  from the outer brake drum,  with the brake removed, to the edge of the rim?
Thanks for any input,
Rod

Keith L

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  • 1946 BSA B31, 1951 Velocette MAC, 1963 LE Velocett
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Re: 1947 B33 FRONT WHEEL OFFSET
« Reply #1 on: 30 December, 2018, 19:53:14 »
Hi. I have a 1946 B31 Rigid. I don't know if the front wheel would be the same as yours? If so would I have to take the wheel off to measure it?

I also have a 1949, I think, front wheel which is not fixed to a bike. Would this also be the same as yours.? If so, I will try to provide the measurement.


Keith L

ROCKINROD

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Re: 1947 B33 FRONT WHEEL OFFSET
« Reply #2 on: 03 January, 2019, 21:21:29 »
Hi Keith,

Devon has a YouTube video showing how to measure offset

https://www.devonrimcompany.com/

So yes wheel would need to be removed.

I think the 49 B31 would be the same as they show the type 3 used from 47 til 55.


If you could get a measurement when possible, that would be great.

I disassembled wheel, and forgot to measure first.

Thanks,

Rod

Keith L

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  • 1946 BSA B31, 1951 Velocette MAC, 1963 LE Velocett
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Re: 1947 B33 FRONT WHEEL OFFSET
« Reply #3 on: 05 January, 2019, 14:43:42 »
Hi Rod.

I found the Devon information and have removed the wheel. It is in poor condition and the measurements moved about a bit but approximately 22.50mm is the answer. Approximately 7/8th" of an inch. Devon also recommend trying the wheel in the forks before final commitment.

Keith L

MALCOLM.JOHNSON

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Re: 1947 B33 FRONT WHEEL OFFSET
« Reply #4 on: 06 January, 2019, 12:44:04 »
The recommendation by Devon would be my take on the subject. I do take a quick check on offset figures, but to be honest I always do the truing of the rim to round, but not tighten the spokes until I fit the wheel and can verify the rim is offset correctly. The rear rim must line central to the frame top tube (headstock bearings) and if you have done a full bike rebuild, then I am presuming that you have checked drive chain sprocket alignment first, just in case incorrect spindle spacers etc. are fitted. The front wheel just has to be central to the headstock. If the offset does need changing it is easier to do on the bike, by loosening nipples to one side and tightening by an equal amount to the opposite nipples. then do a progressive final tensioning.