model B 557 sv gearbox ratio

[charvey]

Hi all, Just got my model B going out for it first long run and its a bit slow in top can I change the front sprocket or what to raise the top speed a bit more than it is ?, it pulls very well up hill surprisingly well for a SV and there is plenty of compression etc., or do I need to change the ratio's in the gearbox, any advice, going by the numbers on the g/box it is a low ratio box, thanks Clive.

[Roger Gwynn]

As standard my B has a 16T engine spkt, I run it with a 21T, which is OK in the low countries but I am taking it to the Black Forest next week and will change to a 19 in deference to the hills. 1st is still not used on the flat unless a quick getaway is required but I suspect that starting in 2nd is quicker as it saves a gear change. But speed is not really the point. Overall ratio is always altered using the engine sprocket, all boxes are 1:1 in top gear. I see in 1927 Ariel quoted 17 or 18, then 21 or 23 in 1928-30.

[charvey]

Hi Roger, thanks for the information on the front sprockets i will sort that and try a bigger sprocket as you suggest and see how she goes and you are right about first gear its very low. regards Clive

[BleiererAndreas]

Hi Guys!

May I ask where I get different sprockets for the Model B?

Regards
Andreas

[Roger Gwynn]

Depends on the year, which is always useful information. The sprockets changed in 1928,29 and 1930. Certainly later 1946 sprockets will fit fro 1930, not sure about earlier models. I was lucky in that my bike came with alternative sprockets.

[JohnnyBeckett]

hi you can try Geoff Brown at the clubs gearbox and clutch parts , or try Drags they may have the sprockets you need