sherpa325

The swinging arms were lengthened on the M182/183[1976] by about 10mm. I am pretty confident all the swinging arms from that point on are all the same length. The Comerford bikes could have longer units as some of them had the S/arm pivot moved closer to the engine which would mean a longer arm to keep the same wheelbase. The longer swinging arms have a rectangular bottom shock mount with an additional hole for pillion pegs, whereas the earlier ones have a smaller triangular mount without the extra footpeg mounting holes. PS I think the information on this forum is very honest and put on with the best of intentions, just maybe some people have varying degrees of mechanical & product knowledge. The thing about any restoration on a Bultaco is that the more you can do yourself the cheaper it will be and I personally feel the greater the satisfaction, and keep in mind they are easy to work on and that pretty much everything is available for them. Cheers Greg

There is a diagram in this post showing the two brackets that hold the airbox in place Cheers Greg http://www.trialscentral.com/forums/topic/44249-air-box/?hl=airbox#entry323155

Not sure whether you are talking about the steering or the fork action itself. For me personally getting off my 300 gasser onto one of my Bultacos, the steering and fork action are the least of the differences I find hard to adjust to. I find the slow response of the brakes, clutch and engine and the added weight more of an issue. The overall handling I find to be very stable and predictable, with the bike less likely to be deflected 'off line' like the newer lighter bikes. Cheers Greg

Your triple clamps look correct for the 190. With the 325 bikes the lower triple clamp has a larger more pronounced arch which drops the clamping part further down the leg which means that the knurling on a 325 leg wont line up with your 250 clamps. I would think the easiest way out is to find a complete 325 front end [triple clamps included ,at least the bottom one anyway] and fit that to your bike, however this is going to alter the geometry as the front wheel will be pushed down and forward due to the extra length of the leg. I guess it just depends on what you intend to do with the bike. Cheers Greg

Definitely not cast in position, they are just a neat push fit in Bultacos,however there is no real need to remove them as they can be cleaned up in position. Cheers Greg

The fork tube should slide all the up till it bottoms out on the spigot on the top triple clamp. Assuming the inside bore of the top clamp is clean and free from burrs etc and the fork tube is also clean and free of imperfections, I would use the fork nuts to pull the tube up till it bottoms out on the top clamp,a light smear of oil wouldn't hurt either [leave the springs out while doing this] Cheers Greg Oops, sorry just went and checked in the shed and there is no machined spigot in the top clamp[these are on the later non tapered legs] But I would still use the nuts to pull the tube up as far as it will go into the taper

I don't know of anyone who wants to ride a heavier bike, trials bikes have become progressively lighter over the past 40 years. This continued development has meant we currently have the lightest production bikes ever. This low weight certainly helps younger riders gain skills and move on to full size bikes sooner as well as keeping older riders in the sport. Balancing, hopping, everything is easier on a lighter bike, particularly for lower level riders. Your argument makes no sense at all. Weight limits were bought into other forms of motorsport to stop 'Factory Lightweight Specials' these bikes/cars providing a real advantage for the factory rider/driver over the privateer. All the current production bikes[except Honda] are under the weight limit so no such advantage exists. Since the 1970's Trials bikes have always been the lightest dirt bikes in production. I have seen frames fatigue and develop cracks since I began riding. I have seen cracks in Suzuki, Yamaha[including the mono] Bultaco, Montesa, Italjet, Fantic,Scorpa,Gasgas, Sherco and Beta all over a 40 year period. You are not buying a family car you are purchasing a machine capable of riding a world championship event, what other sport can you do this in. This is where we have ended up because the market has dictated it, the cheaper bikes like the economy gasgas and xispa bikes don't sell.

No I am not bashing Honda but it is very difficult to believe that they have not been the major force behind the addition of the third class On February 28th Ducati confirm they will switch to the Open Class Philip Island testing is from March 3rd through to March 5th - Ducatis finish Day 1 in 2nd, Day 2 in 3rd, Day 3 in 4th. Midway through testing on March 4th Honda are unhappy http://www.autosport.com/news/report.php/id/112760 Rules are changed on March 6th http://www.autosport.com/news/report.php/id/112791

I was originally fairly skeptical that these rules may have been to benefit Honda, but after what has just happened in Moto GP I guess I underestimated the clout HRC really has!

I have two earlier style airboxes, they are from models 159,183,191 - years 1975 to 1977. I was lucky enough to find an original airbox which I removed the sidepanels from and then made a second airbox using the first as a mould. I then made moulds of the original sidepanels and made four new 'blue' sidepanels. I found a dye for the gelcoat that was identical to the bultaco blue, so if I scratch or wear through the paint you see blue not red! I know this sounds like a lot of work, but it was relatively cheap and easy to do, just a little time consuming. Also beware the 250 airboxes, at first glance, look the same but have different sidepanels that to me are not quite as attractive as the 325 ones. I don't know if anyone would make these airboxes as they are very durable and easily repaired if damaged unlike the latter plastic ones. Cheers Greg

I maybe incorrect here, but as far as I am aware there is no 'Professional Trials Riders Association' available for those thirty or so riders who compete in the various classes that make up the World Championship. Every other sport I can think of has such a group/association that acts like a union and negotiates with the relevant governing body for the rights of its members and the sport itself. Golf, Formula 1, Moto GP, Tennis etc all have such an association. If the World Championship riders had been in negotiation with the FIM it would appear that these rules would not have been implemented or maybe some reason behind them may have been forthcoming. I personally don't believe any of these rule changes will increase participation in the World Championship or increase world sales of trials bikes.

Late model 325's can be bored to 340, so there should be several available oversize pistons to use before the liner needs replacing Cheers Greg

Is the motor a bored 250, and if so what piston is used Cheers Greg

First of all you should use C3 clearance main bearings, to provide a little bit of additional clearance. There are two methods of pulling the cases together. A couple friends use the method of gently heating the cases to expand the bearings just enough to allow the crank to slide into place with little force. I have a number of different lengths of pipe that go over the threaded ends of the crank, I then tighten the nut on the end of the crank, as the nut tightens on the pipe the crank is pulled into the bearing at right angles.You have to do both sides separately but I prefer the second method as I can pull the crank exactly as far in as I want without fear of bending the crank out of alignment. Cheers Greg PS It is fairly easy to 'bend' the crank out of alignment

The Boomerang silencer looks like it has had a straight round tube extension welded onto it where it joins the first silencer which has forced it to be mounted further to the rear than it should be, by a couple of inches. Looks like a pretty reasonable purchase- these are a really good looking bike in the original colours and great to ride when set up correctly, well done. Cheers Greg

I use Barnett fiber clutch plates in all of my Sherpas, with the lightest motorcycle gearbox oil you can get hold of [ I have used Maxima and Silkolene] I find the gearbox oils are lighter, ie lower viscosity, than ATF, and only slip for say the first two or three kicks at the start of the day when the motor is cold and never slip again during the day. I assume that as the oil warms up the viscosity would be even lower and as such the dreaded slipping clutch disappears. Cheers Greg

I realize that the private websites do a great job with their reports and the posting of results, but the other official websites for the other disciplines leave trials for dead, they have LIVE FEEDS, LIVE RESULTS,event photos, interviews, practice photos. All we get is what the private websites provide[ which by the way is fantastic considering their resources] - but I don't think it is their responsibility to do so. http://www.motogp.com/

Why is it that the World Championship Website is so difficult to use and rarely is as 'up to date' as other forms of motorsport. It just seems so typical of the way trials is perceived and administered. Moto GP, World Super Bikes, Formula 1 and every other sport that is competing for the consumer interest and dollar/pound has a state of the art website with live feeds etc etc. Just a thought as the day after the Italian round, the results are not on the 'official' website.

Clymer manual says 75 ft/lbs or 10 m/kgs Greg

Basically all the larger bore bikes have the same overall 1st gear ratio using the factory supplied gearing. For the M92 using the 1/2 inch chain its 13/52 [or11/46 for 5/8 chain] interestingly the 250's used 14/52 . The 11/46 gearing was used up until the 199/198 series which went to 13/46[as a result of an internal gearing change to the gearbox] The 199a 198a 199b and 198b used the 11/39 gearing. The 199 and 198 can use the 11/39 and have the same overall gearing. The bottomline is that 4 teeth on the rear sprocket is equal to one on the countershaft and 11/42 would feel very tall as Woody said. Some people run an extra couple of teeth on the rear to get that extra bit of control you are after, but this is personal preference. Cheers Greg

The primary case drain is the centre bottom bolt [basically just rearwards of the B in the bultaco logo] It is supposed to be a large round flat 6mm bolt with an allen head recess. The gearbox drain on a 199A is underneath the counter shaft sprocket and is in the side of the case, not underneath the motor, as in the previous models [Hex head bolt] Cheers Greg

Thats the Kill switch you're pushing

Thanks Paul , do you know what brand they are, some appear to have an advance curve programmed into them, There is not a lot of information about their ignition on the Inmotion siteCheers Greg

I was wondering what brand or brands of electronic ignition people were using and were there any to avoid as a friend has just had to send a faulty Yamaha one back to the UK. This has not been a speedy process and you would assume the reason for installing an electronic ignition would be the reliability issue. Also has anyone noticed the digital one for sale on Todo Trial with the inbuilt advance, for Montesa only at this point. Cheers Greg

I have seen 199A's with bent swinging arms,- usually after you fit one rear shock and then you go to fit the second shock the mounts will not line up, best seen by looking at the bike from the rear, Cheers Greg