Hi, I've recently brought a 1978 Sherpa and it's on standard sprockets 13/46 and I think it's a bit too tall for trials. Any suggestions on better sizes? I will need to buy chain and sprocket set, so want to get it right first time. I hope someone can help.

According to haynes manual it should be11/46 It is like it has been gear for the roador trail

13/46 is correct if the bike is a 199

11/39 for 199A and 199B

earlier motors before the internal gearing change are 11/46

Whilst 13/46 sprockets were fitted when the bike was new things have changed, nowadays there are less and dependent on where you ride possibly no road based trials so the higher gearing could now be a disadvantage and reducing the front sprocket to 11 or 12 might be better.

I use 13 / 48 in my 199 bike, it´s perfect for me. You can also go 12 / 46 if you are not a very good rider.

hi why your talking about sprockets i have 11 front 39 rear is this ok? this is on my 199A

Interesting, I'm running 11 Front 46 Rear on my 199A and I'm finding 1st way too low but second just a bit too tall for twisty stuff. Is the better option 39 on the back?

i was told 11 front and 39 rear was made standard on the 199A so ive stuck with it. ive had no problems with this gearing. i was thinking of going biger but to be honest i dont know what would be the best. ive allready got new sprockets so ill stay with what ive got.

ATTENTION: Sprockets for 199 model are diferent that for 199a and 199B !!!!!

The one I use 13 / 48 or the alternative lower 12 / 46 are good for 199 model, NOT for 199a and 199b gear box is not the same.

Original for 199 is 13 / 46

Original for 199a and 199b is 11 / 39

thanks Greeves, I'll go for a 39 rear then.

I think you will find that the 199 and 199A and 199B all have the same gearbox other than the six speed in the 199B and you can use either combination of gearing to get the same result. The gear that concerns most of us is 1st

Using 11/39 1st gear is 37.7:1

Using 13/46 1st gear is 37.6:1

Basically no difference other than you have a much smaller rear sprocket

Earlier models before the 199 series run 11/46 which gives a 1st gear 37.8:1

So all bikes have the same 1st gear ratio with the factory gearing

The 199, 199A and 199B have different internal gears to the previous models, the change was made to give the bikes a higher top speed for events like the Scottish Six Day

Hope this helps Greg

Edited March 14, 201214 yr by sherpa325

I have a 198a bultaco 1979 is has 13/39 is this standard for this model. hightown

I think you will find that the 199 and 199A and 199B all have the same gearbox other than the six speed in the 199B and you can use either combination of gearing to get the same result. The gear that concerns most of us is 1st

Using 11/39 1st gear is 37.7:1

Using 13/46 1st gear is 37.6:1

Basically no difference other than you have a much smaller rear sprocket

Earlier models before the 199 series run 11/46 which gives a 1st gear 37.8:1

So all bikes have the same 1st gear ratio with the factory gearing

The 199, 199A and 199B have different internal gears to the previous models, the change was made to give the bikes a higher top speed for events like the Scottish Six Day

Hope this helps Greg

That is correct sherpa325 !!!!

It is more complicated even, as:

For 198/199 and 198A/199A & 198B = 0,223 / 0,287 / 0,376 / 0,612 / 1

For 199B = 0,223 / 0,287 / 0,361 / 0,512 / 0,739 / 1

I just thought it was more simple to understand to put it like this:

Original for 199 is 13 / 46 if you want more control in the sections go to 13/48 or even slower 12/46 changing front or rear.

Original for 199a and 199b is 11 / 39 the same !!!!

Edited March 14, 201214 yr by Greeves

I think I've got it then guys. That still means 11/46 on my 199A is dead slow which is how it feels and should be better at 11/39.

I think I've got it then guys. That still means 11/46 on my 199A is dead slow which is how it feels and should be better at 11/39.

Go 11 /41 much better control in the sections !!!!!