trials09 Posted May 17, 2010 Report Share Posted May 17, 2010 Hi Everyone I have a Bultaco M199a Frame which someone has slightly changed. I am after some frame dimnesions. Such as the Wheel base and is that measured with the suspenion loaded or unloaded? Steering head angle. Also to help get things line up I am also after the aluminium skid plate spec's. Doyou know of anybody selling these? Look forward to your help Regards Trial09 Quote Link to comment Share on other sites More sharing options...
feetupfun Posted May 18, 2010 Report Share Posted May 18, 2010 Wheelbase 52.5 inches with both ends suspension topped out and rear axle halfway along slot. Sorry not able to measure steering head angle. Could measure fork tube angle if you are stuck. Quote Link to comment Share on other sites More sharing options...
woody Posted May 18, 2010 Report Share Posted May 18, 2010 A problem with steepening the head angle on the Sherpa is that the front mudguard hits the frame downtube so it is limited how far in the forks can be pulled. If your mudguard doesn't hit the tube with the forks depressed I'd leave it as it is, as although it isn't necessarily needed, if the front has been pulled in it will improve the steering. Quote Link to comment Share on other sites More sharing options...
trials09 Posted May 22, 2010 Author Report Share Posted May 22, 2010 (edited) Thanks for the info feetup. If you could, the fork angle measurment would be grreat. Also do you mean by topped that the front suspension is fully compressed? Hi woody The frame was intended for sidecar use as it appears. I am considering restoring the frame back to standard being a M199a. I know were I can get the chrome molly tubing etc to complete the task However, you make a good point. The wheel base is about 3" shorter and on checking the clearance between the guard and down tube I believe they will miss. I sat the engine in the frame and thought this just might work. So you have me re-thinking my options. Thankyou. The alloy skid plate is missing. I know the hole spacing at back of the plate and I can work out the curve section. But could anyone help with the front two hole spacing measurment. Great forum, thankyou for your help Regards Trials09 Edited May 22, 2010 by Trials09 Quote Link to comment Share on other sites More sharing options...
feetupfun Posted May 22, 2010 Report Share Posted May 22, 2010 OK I'll do a fork angle measurement. Topped out is what the suspension does when you support the bike under the motor with the wheels off the ground. It is called topped out because it is the other end of the stroke to being bottomed out. Are you saying your bike wheelbase is currently 3" longer than standard or 3"shorter than standard? Your story sounds very familiar. I think we have spoken on the phone a couple of times about this Bultaco and your 349. I also posted a few photos of what the Bultaco frame should look like at the front end on this forum or the Aussie forum David Quote Link to comment Share on other sites More sharing options...
woody Posted May 22, 2010 Report Share Posted May 22, 2010 You can buy a new 199a/b skid plate from Todotrial Quote Link to comment Share on other sites More sharing options...
trials09 Posted May 23, 2010 Author Report Share Posted May 23, 2010 (edited) Yes you are correct Dave we have discusssed this prviously and you did post some pictures thankyou. The wheel base is 3" shorter. I understand that there was a factory mod were the engine was raised at the front which meant I thihk the front down tube was shortened slightly. And I am trying to work out if the M199a frame was based on this mod. Ended up selling the 349, I might regret it but I needed to clear the deck a little you how pursuasive the ministry of finance can be. Thanks woody I will check out the site. Regards Trials Edited May 23, 2010 by Trials09 Quote Link to comment Share on other sites More sharing options...
feetupfun Posted May 23, 2010 Report Share Posted May 23, 2010 M198 standard frame, standard forks topped out, standard triple clamps, shockie mount centres 345mm, rear axle in middle of slot, Michelin tyres with riding pressure - fork tube angle 28 degrees from vertical Quote Link to comment Share on other sites More sharing options...
sherpa325 Posted May 24, 2010 Report Share Posted May 24, 2010 198 and 199a frames are different so figures taken from a 198 may not be correct,The swinging arm pivot was moved and the ground clearance increased, wheelbase should be the same, not sure about head angle though. It would be helpful if you posted some photos of your frame because at the moment it is difficult to work out where and what mods have been carried out. Its difficult to see how you can shorten a frame by 3 inches without some serious cutting. Cheers Greg Quote Link to comment Share on other sites More sharing options...
feetupfun Posted May 24, 2010 Report Share Posted May 24, 2010 199A frame has different ground clearance because of the alloy bashplate instead of the frame tubes. As far as I know the steering geometry and wheelbase are the same for both. sherpa325 if you are sure it is different geometry and have a 199A to measure please help out by providing the details required by Trials09. I had an idea why the wheelbase may be so short. I've seen people fit early Sherpa T swingarms to late model frames to shorten the wheelbase. It requires interesting mods to get the rear engine mounting arrangement to work but it is possible. Again photos will reveal all to people who know what Bultacos should look like. Quote Link to comment Share on other sites More sharing options...
big john Posted May 29, 2010 Report Share Posted May 29, 2010 You can buy a new 199a/b skid plate from Todotrial I noticed 199A/198A/199B skid plates available from Bultaco UK, same ones as Todo Trial at Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.