sprocket sizes

Information relating to the Matchless G5 or AJS Model 8 350cc Lightweight
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Ozmadman
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Re: sprocket sizes

Post by Ozmadman »

ajsm18 wrote:
Ozmadman wrote:I have the standard rear sprocket and a 20 tooth gearbox sprocket and I think that is just about right now. Gives a much more relaxed ride at 50 mph and 1st gear can be used properly now
Ooops! I've just asked you that on a different thread!
Mark
No worries!! :beer:
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
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greasemonkey62
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Re: sprocket sizes

Post by greasemonkey62 »

I have just got myself a G5 Matchless as I had one 48 years ago, strange thing is I don't remember the first gear being so very low, I can pull away in second gear from a standstill without any bother so I do think a 20 tooth gearbox sprocket sounds ideal and would make for riding at 50 to 60 much easier on the bikes engine with using lower revs, maybe its so low to allow for two up riding which I do not do. I wish I could find a 20 tooth gearbox sprocket I can't see any listed anywhere.

Cheers Ray.
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1608
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Re: sprocket sizes

Post by 1608 »

I believe Jaguar used to boast that the E-type could pull away in top gear, but they still fitted four gears! Raising the gearing by a tooth or two seems to suit some people though. But, I found it made little difference to top gear and just made 1,2 and 3 too high. I think its more of a case of us all being a little too used to even the smallest of cars or bikes being much more powerful or efficient these days. Our memories can play tricks too. I don't remember this topic being such an issue in the day. I believe these machines are designed to rev a little more than some people feel happy with. I firmly believe that these machines were fitted with the optimum gearing from the factory. Revving an engine won't hurt it, it just sounds worse than it is. Labouring is far more harmful. These bikes also perform better when spinning quickly. Remember that a too higher gearing can detract from the bikes tractability in the lower gears, cause labouring if not careful and chains may need lengthening. Good luck though with the experimenting.
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Rob Harknett
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Re: sprocket sizes

Post by Rob Harknett »

See if you can pull away in 2nd on a steep hill, in particular at lights or junction. That's when you need that low gear, what ever you ride or drive.
RAY BOWMAN
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Re: sprocket sizes

Post by RAY BOWMAN »

Yes, try some of the passes in the Lake District they will try your bottom gear out.
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greasemonkey62
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Re: sprocket sizes

Post by greasemonkey62 »

okaychokay thats a job I will do tomorrow and post the results.
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Colin F
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Re: sprocket sizes

Post by Colin F »

It also makes the engine less tractible through the gears needing more frequent gear changing.

I am building up a 500 single and bought the correct engine sprocket, for various reasons it has been built up with a 350 barrel and head, but the sprocket has not been changes.

Compared with my 350's this bike will not pull as well from low speeds unless you drop a gear and keep the engine in the "power band", so depending on what you want to use the bike for this might not be the best idea.
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greasemonkey62
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Re: sprocket sizes

Post by greasemonkey62 »

The main problem is safety when travelling to meets and shows, I need to keep up with traffic so this is 50 to 60 and as the first gear is virtually useless I think two more teeth on the gearbox sprocket hopefully will do the trick and the bike will not be reving its nuts off.
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greasemonkey62
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Re: sprocket sizes

Post by greasemonkey62 »

Update, I have now tried several hill starts and it pulls away fine in second gear, so I assume the low gearing is for two up riding which I do not do, I had the same problem with my model 31 and that is now perfect for me also with 2 extra teeth on the gearbox sprocket, I had to get a new longer rear chain but that was not a problem for the gains I have made, both bikes also have 12 volt conversions and an LED rear light inside the original light cluster, I am a believer in modernising these bikes as long as it does not alter their looks if they are to be used on our roads, if possible they need to be able to keep up with the traffic flow on A and B roads (not motorways) and be well lit enough for other road users to see me.

Cheers Ray.
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