Author Topic: S/a a10 gearbox sprocket removal  (Read 678 times)

Offline Cleve

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S/a a10 gearbox sprocket removal
« on: 11.07. 2018 21:07 »
Hi, hope you chaps can help, I'm trying to get the gearbox sprocket undone, I'm sure it must undo clockwise? (I'm gearing down from 21 to 19

Thanks

Cleve

Online RoyC

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Re: S/a a10 gearbox sprocket removal
« Reply #1 on: 11.07. 2018 21:16 »
Hi, hope you chaps can help, I'm trying to get the gearbox sprocket undone, I'm sure it must undo clockwise? (I'm gearing down from 21 to 19

Thanks

Cleve

Why not change the engine sprocket instead, that way you won't upset your speedo accuracy.
My bike is a 1958 A7SS
Staffordshire UK

Offline ellis

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Re: S/a a10 gearbox sprocket removal
« Reply #2 on: 11.07. 2018 21:31 »
And you don't need to strip the whole chain case and clutch to do it.

ELLIS

Offline Cleve

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Re: S/a a10 gearbox sprocket removal
« Reply #3 on: 11.07. 2018 21:38 »
Hi Ellis/Roy,
thanks for reply, I've got it all stripped, have a belt drive so clean job, I only put the 21 on last winter, but I can't remember which way the thread goes and can't get it loose, so before I apply more force I hope someone can confirm undo direction 😊 21 is hard work in traffic...

Offline ellis

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Re: S/a a10 gearbox sprocket removal
« Reply #4 on: 11.07. 2018 22:24 »
Hi Cleve.

From what I can remember it was a standard right hand thread.

ELLIS

Offline duTch

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Re: S/a a10 gearbox sprocket removal
« Reply #5 on: 11.07. 2018 22:59 »

 As ellis says they are Right hand thread.

 As Roy says;
 
Quote
...Why not change the engine sprocket instead, that way you won't upset your speedo accuracy.

 If it's a standard speedo it'll already be wrong, so going to a 19T will put it right, but I expect the difference will be extremely noticeable.*eek*
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline Cleve

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Re: S/a a10 gearbox sprocket removal
« Reply #6 on: 12.07. 2018 08:49 »
Thanks again,  I will try undoing it anti clockwise tonight.

Re the speedo, I guess I will have been under reading with the 21 tooth sprocket

Regards

Online Greybeard

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Re: S/a a10 gearbox sprocket removal
« Reply #7 on: 16.07. 2018 22:52 »
You may be able to check your speedo against a SatNav. They are very accurate, (as long as you are not riding up and down hills).

Offline trevinoz

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Re: S/a a10 gearbox sprocket removal
« Reply #8 on: 16.07. 2018 23:04 »
19 is standard so the speedo will most likely be calibrated for it.

Online Butch (cb)

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Re: S/a a10 gearbox sprocket removal
« Reply #9 on: 17.07. 2018 16:58 »
You may be able to check your speedo against a SatNav. They are very accurate, (as long as you are not riding up and down hills).

Either Lincolnshire or the Essex badlands would be best for a calibration run then I guess.
Warning - observations made by this member have a 93% unreliability rating.

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Offline Whipstrut

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Re: S/a a10 gearbox sprocket removal
« Reply #10 on: 01.11. 2018 17:51 »
Quick query, does anyone know the actual thread size of the nut? Thinking of possibly making one from hex stock.

Online RichardL

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Re: S/a a10 gearbox sprocket removal
« Reply #11 on: 01.11. 2018 18:11 »

 As ellis says they are Right hand thread.

 As Roy says;
 
Quote
...Why not change the engine sprocket instead, that way you won't upset your speedo accuracy.

 If it's a standard speedo it'll already be wrong, so going to a 19T will put it right, but I expect the difference will be extremely noticeable.*eek*
 

Dutch,

Did you mean, "...the difference will not be extremely noticeable," meaning the difference in the speedo's report, or did you mean the difference in riding with the 19T sprocket will be extremely noticeable."?

Richard L.
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.


Offline duTch

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Re: S/a a10 gearbox sprocket removal
« Reply #12 on: 01.11. 2018 18:16 »

  I'll be adventurous and guessing at 20 tpi that we would call Cycle thread like most other BSA threads- you obviously don't have sleeve gear handy to measure the threads on that...

 Richard you posted while I was slowly composing...
Quote
.....Did you mean, "...the difference will not be extremely noticeable," meaning the difference in the speedo's report, or did you mean the difference in riding with the 19T sprocket will be extremely noticeable."?......

 No I think I meant what I said (hard to believe I know *smile*), that the difference will be fairly obvious.....
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline coater87

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Re: S/a a10 gearbox sprocket removal
« Reply #13 on: 01.11. 2018 20:52 »
I bought a 5/8 x 20 tap and made my own too.

 Lee
Central Wisconsin in the U.S.

Online chaterlea25

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Re: S/a a10 gearbox sprocket removal
« Reply #14 on: 01.11. 2018 21:32 »
Hi
Quote
Quick query, does anyone know the actual thread size of the nut? Thinking of possibly making one from hex stock.

Lee, I think he is asking about the gearbox sprocket nut??

Whipstrut
If you intend to make one I would include an oil seal as on the SRM product
http://www.shop.srmclassicbikes.com/product/gearbox-sprocket-nut-oil-seal-bsa-pre-unit-swingarm-models

John
1961 Super Rocket
1963 RGS (ongoing)