Got to get a new rear sprocket for the Bultaco resto project. You wont believe the bodge up that Bodgit & Scarper Motorcycles have done for a rear sprocket So just wondering what is the best combo? 11 x 44, 11 x 46 or 11 x 48 oh yes it's a 520 chain.

Thanks

13x 46 is standard for a 198/199 very close to 11x 39 in the later models, 3.55 -3.54, I like standard sherpa gearing as long as its in good tune. 11x 48 would make 1st very low

http://www.sprocketcalculator.com/ I find this useful in calculating sprockets

Paul I have exactly that model 198 - 250cc. and 13 / 48 is what I use and recommend you.

Paul I have exactly that model 198 - 250cc. and 13 / 48 is what I use and recommend you.

Thanks Javier and mrb505 will ring Talon later and order sprockets. Nothing like whats on me 199b then

Just one other thing mine has an alloy bashplate which looks std from the factory but yours Javier has the frame rails under the motor. Does that make mine a late model or are the UK bikes different from Spanish spec?

Edited April 26, 201214 yr by Old trials fanatic

I have a 198a 1979 blue bultaco with alloy baseplate It is fitted with 11x39 sprockets, the bottom gear works out at 37.7 second gear29.2,that what was on it when I bought it in 1980 Would this be standard On a 198a. Thanking you in advance. Hightown

I got confused by the title of your post Paul, I thought it was a 198 and if yours have an alloy bashplate it must be a 198A; the original sprockets must be then 11 / 39 but I recommend you there 11 / 41 or 11 / 42.

The result is the same, just they changed it when Bultaco changed the model. Some time ago I posted about the same here in TC.

Model 198 and 199 Standard = 13 / 46 I recommend for clubman´s pilots 13 / 48

Model 198a, 198b, 199a and 198b = 11 / 39 I recommend for clubman´s pilots 11 / 41

Although the result is the same, you can go 13 / 48 also.

Edited April 26, 201214 yr by Greeves

I got confused by the title of your post Paul, I thought it was a 198 and if yours have an alloy bashplate it must be a 198A; the original sprockets must be then 11 / 39 but I recommend you there 11 / 41 or 11 / 42.

The result is the same, just they changed it when Bultaco changed the model. Some time ago I posted about the same here in TC.

Model 198 and 199 Standard = 13 / 46 I recommend for clubman´s pilots 13 / 48

Model 198a, 198b, 199a and 198b = 11 / 39 I recommend for clubman´s pilots 11 / 41

Although the result is the same, you can go 13 / 48 also.

Good job i didnt get around to ringing Talon no prob. Thought it was strange the bike had a 11 tooth gearbox sprocket the same as the 340 but i felt it needed gearing down a bit for todays tighter sections. It's currently got a 44 rear on it which has been bodged up so i wanted to fit a good sprocket of the correct size. I will take Javiers advice and order a 41. I havent had chance to ride it yet as it still needs finishing.

I think 11 / 44 will make it too slow, maybe for a real newcomer to trials... but aniway my advice Paul is just try the bike with the 11 / 44 as you are allways on time to order the 41 or 42 sprocket as it is so easy to change. Although I am sure first gear will be too slow with 11/44 and will not push enough when you need some speed in 1st gear.