engine sprocket

[greasemonkey62]

Having removed the clutch cover for the first time I notice the engine sprocket on my 1962 model 31 650 AJS has 22 teeth, the reason I counted them was the bike has always seemed low geared and seems to be reving high at 50 to 60mph, is this a standard tooth sprocket for this bike does anyone know?

[dave16mct]

Should be 23 on a 650.

[Samuel]

I've heard of hunting tooth drives but ....

[greasemonkey62]

ok thanks for the reply, I can`t see one tooth on the cog making much difference..... or would it?

[Eric]

Yes

[1608]

I replaced my 16 T gearbox sprocket for 18T because I was dissapointed with the apparent low gearing ( commonly refered to as 'racey engine' syndrome on this forum).However, although relatively happy with a slightly more comfortable cruising speed I have experienced intermittent clutch slip if not judicious with the throttle.And a lack of urgency from standstill. On balance I suggest sticking to the original gearing as this was probably the designed optimum. I do not expect to compete with modern machinery and accept that these old bikes were meant to rev a bit.
G12.

[clive]

one tooth in 22 would mean the bike reving 4.5% higher. I wonder if the gearbox sprocket has also been altered? My thinking is it may have been modified to haul a sidecar in the past.

[wilko]

I had a 24 tooth on mine with 16 gearbox and it could still do with gearing up.

[Eric]

You should check the gearbox sprocket just to check what may have been done to that.

I went up one tooth on my G9 but it was too much. The bike will go faster in third gear because it is able to reach the revs required in the power curve to achieve maximum power.

It may be OK to go one tooth on the 650 but AMC would have made the choice they thought most suitable for the bike if you never have a pillion passenger or go touring with lots of luggage and a tent it may be OK.

Remember the engine is designed to rev and it may sound busy when compared to a single but that's what it was designed to do.

[greasemonkey62]

thanks for the input, I understand that it should be a 23 tooth engine sprocket and not the 22 toothed one as I have, I will check the gearbox and rear wheel sprockets too, thanks to all for the info, much appreciated.