ajs 500 gearing

ajayrb · Post by **ajayrb** » Mon Nov 07, 2011 8:42 pm

ajs 500 passed the mot today after its restoration it runs great done about 60 miles only it does seem a little high geared tho its got 23 engine and 18 gearbox sprocket apart from that i had the best ride in ages even more so than riding my yamaha 1000

bjork · Post by **bjork** » Mon Nov 07, 2011 8:46 pm

I think a 22 tooth is standard, and one extra here will make quite a difference. What year is it? and what transmission? (sorry, gearbox)

ajayrb · Post by **ajayrb** » Mon Nov 07, 2011 8:58 pm

its a 1959 with amc gearbox it just seemed to labour a little at 45mph in top mabe its just me .this is the first british bike iv restored and ridden and was made 21 years before i was born

itma · Post by **itma** » Tue Nov 08, 2011 10:56 am

quote: made 21 years before i was born

and that dear boy is half the problem.

Getting your motorcycling mind back 40 years into the state it needs to be in is quite a hurdle.

do not judge your bike, your riding habits, anything at all in the way you regard a modern bike.

As I have preached ad nauseum riding an old bike is a state of mind.
When you get to that happy state you will achieve a state of bliss that can only be realised by riding an old bike.

Of course back then there wasn't always those barstewards in BMW's and Audi's to contend you can't get away from the murderous buggers.

So absorb the wisdom to be found here and ride happily little grasshopper.

and oh, 22T is too high you could even drop one below std if you wanted,....... and join the club soon.

196016 · Post by **196016** » Tue Nov 08, 2011 12:17 pm

http://www.ajsmatchlesseastsuffolk.co.uk/

bjork · Post by **bjork** » Tue Nov 08, 2011 7:43 pm

Good luck with your bike then, and go with what uncle Ken says. 22t is standard on my older rigid G80 and that feels like it could just about pull a 23t. I asked as I was surprised to hear someone say it felt over geared, usually it's the other way round and a feeling of needing another gear on todays bigger wider straighter roads.

zwarts · Post by **zwarts** » Wed Nov 09, 2011 4:35 pm

I am suprised no-one has commented on the gearbox sprocket being too big! The (AMC)500cc singles always pulled a top gear of 5:1. Your sprockets are giving you 4.26:1. No wonder it feels high geared. I like my bikes high geared, but this is going a bit too far. You have an engine sprocket 1 tooth bigger than standard and a gearbox sprocket 2 teeth bigger than std. Even if you change the engine sprocket to 22 teeth, you will still have an overall gear ratio of 4.45:1. This will still be a bit too high. A 20 tooth engine sprocket will give a top gear ratio of 4.9:1 and this will be fine. It will save you the trouble of dismantling the clutch etc. to change the gearbox sprocket.
Bob.

ajayrb · Post by **ajayrb** » Wed Nov 09, 2011 8:08 pm

all sorted now it runs perfect .it has 23 engine 16 gearbox and pulls really well cruising speed is now 60/65mph on flat open road .

Peter Lecompte · Post by **Peter Lecompte** » Thu Aug 09, 2012 11:31 pm

Hi Bob, I am putting together a 1950 G80 with a CP gearbox. The engine sprocket is going to be standard at 21T, but it was suggested I might want to use a 17T as the gearbox sprocket (standard is 16T). What will this do for my ratios and how will a extra tooth on the gearbox sprocket affect the performance? Can I still use a standard legnth chain (67T)? I intend to use the bike mainly on fairly open type roads and not as a commuter. thanks Peter

wilko · Post by **wilko** » Fri Aug 10, 2012 12:59 am

I have a 23T front engine sprocket with 16T gearbox sprocket and still pulls like a train, so a 17T gearbox would be a good compromise for you unless you're American.(sorry Don). The bigger the sprockets the kinder on the chains.