bultoboy Posted April 5, 2012 Report Share Posted April 5, 2012 Hi Guys I have got a 159 325 which i have ridden for years and now i have moved up and i am doing hard routes at local trials i have found i cant make the tighter turns (could be my line). My Dad has a 199 325 with a black engine not the 199a, i find his bike has a much snappier engine and is bloody hard to balance at a dead stop which i can do very easily on my bike. when ridding my dads bike however it has a much tighter turning circle therefore i think a steeper head angle. Although it is easy to almost under steer the bike. (you turn and the front wheel goes straight on) I have a 199a frame which i am building up (possibly with a fantic engine as i have one lying around). it has the rear loop modified to look like the 199b ( i did not do, it i got it like that) i was wondering what you top boys would recomend if i was to get the head angle steepened. what angle should i get it done to???? I knew an old engineer who rather modify the head angle did somthing to the fork clamps however he passed away before i could get him to do the work. Whilst i am at it is it worth changing the rear suspension angles/positions? i was just going to buy some magicals and leave it be but in for a penny in for a pound. cheers james Quote Link to comment Share on other sites More sharing options...
bullylover Posted April 5, 2012 Report Share Posted April 5, 2012 Hello Bultoboy. The best way to make a Bultaco turn tighter is to file or grind the steering stops down. You usually have to shorten the tank bolt as well. You can also put longer shocks on it. Don`t change the steering head angle as the mudguard mounts will hit the frame and the mudguard will hit the exhaust. Bully Lover. 1 Quote Link to comment Share on other sites More sharing options...
digger144 Posted April 5, 2012 Report Share Posted April 5, 2012 putting longer shocks on rear will steepen head angle. i done this on a348 mont & it worked well Quote Link to comment Share on other sites More sharing options...
bultoboy Posted April 5, 2012 Author Report Share Posted April 5, 2012 ok so on the bultaco put 380mm centre to centre shocks on it or even 390 Quote Link to comment Share on other sites More sharing options...
woody Posted April 5, 2012 Report Share Posted April 5, 2012 ok so on the bultaco put 380mm centre to centre shocks on it or even 390 No - way too long. 360mm is all you need. You don't need to alter the shock position, just put decent shocks on it. I jave a pair of Magicals and Falcons for mine. Damping is the same but the Magicals spring rates are better due to multiple springs. You can steepen the head angle without it hitting the frame or exhaust, just depends how it's done. My 199b has been done but I think I prefer it how it was. It's now very skittish and hard to control in a straight line in rock streams especially. A s soon as my standard one is rebuilt I'm going to try them back to back for comparison. I'd leave it as it is. There is nothing in a classic trial that needs the Sherpa head angle altered. You need to plan your lines better. They may have a lot of rake but they still turn tight. It's perception. My old M92 turns just as tight as my modified 340. The head angle on them all is the same as far as I know. If it is any different it's not noticeable riding. There could be a few different reasons why your dad's 325 ploughs the front, it's nothing to do with Bultaco steering. The forks are probably set up incorrectly. You're probably perched a bit higher on the later bikes as well due to increased ground clearance which adds to the feeling of instability when trying to balance (Bultacos were never really designed for stop / start riding and there should be no need for it in classic events) Anoother way of reducing the 'rake' of the front forks is to fit parallel yokes from a Pursang or Alpina from about 1975 as they are parallel, they have no 'rake' like the trials yokes. This will pull the front wheel in but it will also affect the trail and I don't know how this would affect the steering/stability (maybe not at all - don't know) For now, I'd get decent 360mm shocks and magical fork springs (set up with 180cc of 10W oil to start) spend some time on set up and reasses it. If I had to recommend shocks I'd say Falcon as they are (to me) best value for money in terms of performance/cost (ie: they are cheaper but perform better than any of the others costing up to a £200 ceiling. Magicals are very good but I'd say the damping action is equal with Falcons, it's the springs that make the bigger difference. A lot more expensive though and subjective as to whether they're worth the extra cost if your not hammering the bike up big stuff (ie: Lakes 2 day type sections, not classic club trials) 2 Quote Link to comment Share on other sites More sharing options...
bultoboy Posted April 5, 2012 Author Report Share Posted April 5, 2012 As always woody comes up trumps with the advice, Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted April 6, 2012 Report Share Posted April 6, 2012 check the frame is straight aswell. Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted April 6, 2012 Report Share Posted April 6, 2012 Hello Bultoboy. The best way to make a Bultaco turn tighter is to file or grind the steering stops down. You usually have to shorten the tank bolt as well. You can also put longer shocks on it. Don`t change the steering head angle as the mudguard mounts will hit the frame and the mudguard will hit the exhaust. Bully Lover. Take the plastic caps of and grind down the stops till it hits the tank refit for clearence. reduce the nut and head of tank bolt too. 1 Quote Link to comment Share on other sites More sharing options...
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