Hi All,

Has anyone removed the rear loop from a 199a frame and if so, what strengthening mods are required. Trying to find a picture of a 199b to see the difference.

Thanks in advance,

Willy.

The following might be of use 

 

1 hour ago, mjwilson said:

Hi All,

Has anyone removed the rear loop from a 199a frame and if so, what strengthening mods are required. Trying to find a picture of a 199b to see the difference.

Thanks in advance,

Willy.

Hi Willy,

 As a 199a owner I think leaving your bike as is the better option, they are a great bike in standard condition. The only changes I have made to mine are slightly larger rear sprocket,26mm Mikuni carb and a todotrial bash plate which is wider than the original. Trials now seem to have more twists and turns than maybe they used to so the changes I have made suit this type of section.

the 199b had a 4mm bracket used fixed onto the bottom of the seat and doubled up as the seat mounting brkts .most of us back in the day moved the footrests back about one inch.

i had both bikes but felt the 199a was the better one.

 I hand formed a piece of flat steel to replace the loop that was impacting my sensitive parts on descents.

17 hours ago, trialsrfun said:

Hi Willy,

 As a 199a owner I think leaving your bike as is the better option, they are a great bike in standard condition. The only changes I have made to mine are slightly larger rear sprocket,26mm Mikuni carb and a todotrial bash plate which is wider than the original. Trials now seem to have more twists and turns than maybe they used to so the changes I have made suit this type of section.

Yes, definitely the Todotrial bashplate a lovely piece of kit. Easy to fit and should have been fitted to the Sherpa 199A & B from day one!

The Mikuni is a very good up grade over the original Bing.

http://todotrial.com/es/tienda-tt/accesorios-y-recambios-para-trial/cubrecarter/placa-cubrecarter-de-aluminio-sherpa-detalle.html

Edited March 14, 20188 yr by model80

the oko carb is just as if not beter than the Mikuni and a fraction off the price. the 199A is better left with the loop on in my option. just restoring another 199b 

Edited March 14, 20188 yr by bondy

i did it in 79...but not as short as one above, i would suggest you strengthen fram some how Reg used to do this on the later bikes so removing the loop would definately be needed

What most people do is add a flat bar which goes across the rear tubes under the seat. It is curved like the seat base. Graham.

they look horrible if not done proper i have seen some nice 199As with the loop removed but i don't see the point n ruing a frame if its not done by some 1 who knows what there doing just my view. i do miss my 199A but i still have the 340 in bits when i can be bothered to rebuild it.

Do an internet search for Puma Bultaco, there you will see in most cases bikes prepared by him have the rear loop removed. What is left is warmed and then lifted to give it a more racing look as he himself says. I think they look good , but not so if its cut too short like some I have seen.  A support is added under the seat to strenghten. He also fits Del Orto carbs 

Hope this helps

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As has already been said here the rear frame loop removal was done at the time, I did it too on a new 199A,  it wasn’t done too ape the later bikes at all, the first time I saw was on one of Mart Lampkin’s 199A’s, the 199b’s which came later of course also adopted it in production. Others makers, I cant remember which came first now, many individuals of the time adopted it too , it certainly saved your gonads in some of the more extreme legging situations. Most people I knew, myself included, who did the mod put a flat curved bar in underneath the mudguard to aid fitting the guard itself, finally I don’t think the blue frame pictured here has any works credentials as ML’s were cut off at a 45 deg angle and had a very nice finish. Chrome frame is a SM by the look of it. 

Edited May 16, 20188 yr by modernistutopia