woody

This is my old one which had an original 1959 frame and '62 engine. Also considered a special and not allowed back to Scotland after I rode the 2 day on it some years back. Quite how they considered it inelligible when at the time it was parked next to a couple of brand new Cubs using all new parts was lost on me. The term and meaning of replica was also lost on the organiser... 'tis a funny old world we live in

This is the bike. It's in solitary at the back of the shed at the moment as I'm having real trouble getting it to ride as I want.

Yes, tubeless rear rim, bought a used GasGas wheel for about £45 and prayed the rim wasn't rotten. With the exception of the engine, which is a scratch built long stroke 340, the bike was built using mainly stuff from the shed I already had. The frame is a Faber MK3 which was £580, not the best frame available but for that price a pretty reasonable compromise. It is a light frame. Rear hub I had relined £45, rebuilt into the rim with new spokes, about £80. Front wheel is Grimeca and I machined off the fins and rebuilt with new spokes, again about £80. Forks are spare set of Ossa I had. I chose not to run oil in frame and had a mate build the oil tank and the airbox. If I'd run oil in frame and used a foam filter the oil tank and airbox costs wouldn't have been incurred. Originally I used a spare set of Marzocchi yokes I have but wasn't sure about the offset so bought a pair of Alan Whitton's which have some rake built in rather than the usual parallel option The cost of that to get a rolling chassis, no engine, was about £1500. If I'd used the Marzocchi yokes and not had the oil tank and airbox built I could knock £4 - 500 off that. If I'd then used a normal C15 motor, like the type I had in my old bike instead of the long stroke, I could have rebuilt it for around £600, using normal road gears and cam, standard head, iron barrel. Add on ancilliary costs such as tyres, tubes, bars levers (new bars, expensive domino levers) So by using the Faber frame and as many parts as possible from spares in the shed, the bike could actually have been built for under £2000. That's saved over £2000 by not using new hubs, brake plates, rims, fiddle forks And that exercise in economics and practicality makes it a special in some quarters Takes all sorts... As for yours, like I said, I don't think you need worry about anyone picking flies where you'll be using it. 98% of clubs take a more pragmatic view than the odd couple.

Yes, the model 27 was known as the San Antonio and they are a rare bike as they were only produced for a short time before being replaced with the model 49. Rarer than the model 10 thay have the lowest production run apart from the 198b, so a nice find. Has the frame been modified around the footrest area or is it just the angle of the shot that makes it look different

When I said no-one would bat an eyelid I should have maybe qualified it as no-one in his part of the country or from the Midlands southwards which is where he'd most likely be riding it

That should hopefully account for it. I had an engine bolt come loose on my Sherpa once on the road and the rumble was bad enough for me to think the clutch flywheel weight had come loose - or worse. Rumble disappeared when we tightened the bolt.... Also had the same affect on another Sherpa when a badly mis-shaped bashplate was touching the underneath of the engine. The rumble disappeared when the bashplate was removed

I have a Sherpa rear wheel in my BSA which has a Faber frame. I'm assuming the width of the swingarm on that is going to be very much the same as a BSA and Drayton item. The problem you'll face id getting the wheel far enough over to the left for the chain run. With the boss on the Sherpa brake plate it will push the wheel too far to the right and the sprocket will be way off line with the engine sprocket. I machined the boss right down, even taking a bit off the face of the brake plate itself in order to get the sprockets to line up. This meant countersinking the bolt holes in the sprocket to use countersunk bolts as it runs so close to the swingarm normal bolts will foul it. The rim offset had to be moved about 10mm to the right from standard Sherpa offset if I remember correctly due to the wheel sitting closer to the left hand side of the arm than it does in a Sherpa. Next problem was the brake arm as this now fouled the rear of the swingarm if the wheel was forward by a certain amount. In the Sherpa, it sits slightly inboard of the swingarm due to the boss on the brake plate so it's not an issue, but with that machined off it became a problem on the BSA. As the spline exits the brake plate at around 2 o'clock (due to the position of the torque arm stud in the plate) it sits just on the upper rear point of the arm. My solution was to take some metal from the top of the arm above the spindle, angling it down towards the rear to stop the brake arm fouling. Not much room to play with but you have to ensure you can move the wheel forward in the spindle slots and not have an issue. I guess if you're able you could reposition the torque arm stud in the plate to allow the brake arm to be position elsewhere but that was beyond what I can do. You then need to make a torque arm to fit. As there is no spacer on the sprocket side it just needs a spacer made for the other side and that was it. I had thought about fitting a spacer behind the sprocket, moving the sprocket over, not the entire hub which would mean the brake plate wouldn't need shaving down and the brake arm may not be an issue. But I thought it would look odd as there would be a distinct step from sprocket to brake plate, so I never tried that. I have a Grimeca wheel in the front as opposed to a Sherpa but that was a doddle to do compared to the rear, just needed to make spacers and to sleeve the brake plate and bearings for the 12mm spindle as I have Ossa forks. As to whether it's acceptable or whether you'd offend anyone, I doubt anyone would bat an eyelid. Like me you've done it out of practicality and cost and used stuff you already have. There is no real difference in doing what your doing from using new billet machined parts and anyone who thinks there is because they aren't British hubs must have their head stuck far enough up their backside that they've lost touch with reality This is the only picture I have of my back wheel, none of the other side unfortunately. Is it really so different from a billet hub?

Is this definitely correct as DVLA have always maintained that even with the registrations they hold on computer, they cannot (I've always taken that as will not) trace a registration number from the chassis number. I've had this argument with them many times in the past, even when I know a bike is registered, they wouldn't tell me. V62 is generally used to apply for a V5 when the registration is known. Maybe things have changed.. There will be Pre-84 records IF at the time they computerised their system owners sent in the old log book and applied for the then new V5. This would have been done automatically when tax was renewed. If a vehicle was left untaxed and the log book not sent in, then the registration didn't get computerised.

As Lorenzo says, the correct length spokes have to cross 3 times. The spokes on the brake side probably look as though they cross twice as you only see them cross twice when facing them. The 3rd cross (actually the first) is hidden behind the flange but they still cross 3 times

The 198 spoke set - ie: for the later front wheel - from In Motion fits the later wheel correctly as I've used them, so have you definitely got the correct set. Just measure the spokes you have and check the length with them

Later rear Early rears

Which model? Which wheel? There are different hubs fitted to early and later models. This is what I THINK Later type front wheel crosses three times Early front wheel crosses three times Rear wheels cross twice Early front Later front

242 is a very good bike with power not unlike the 240 Fantic but a bit smoother off idle. Chassis and suspension perform well, gear selector mechanism suffers from the common Mont problem of chipping the ends off the pawls if the gear lever catches a rock or suchlike. Clutch is the weak point as typically Montesa - can be a bit grabby and erratic, but most classic events would mean you can ride without worrying too much about having to use the clutch a lot in sections. Dutch rider Eddy Moreman developed some after-market plates which eliminated the grabby action Monts generally aren't as favoured as the spares situation isn't as good as Bultaco or Ossa but they are available usually, just may take a bit longer to find certain parts. Definitely one of the best twinshock bikes

It's an assumption to say it's a bottomless pit in terms of money. What's the objective, to make useable to ride? Or restore to as new condition? The former could possibly be done quite cheaply, the latter is the bottomless pit route, but that applies to any bike. Aside from the piston, from what I can see, the major missing components are the front pipe, seat, kickstart and gear lever. I've seen M92 / 125 / 151 front pipes come up on ebay USA a few times, so if the original can't be found it should be able to get a replacement used item. At worst, they're available new. Kicker and gear lever are no problem. Hugh's does a seat base and a local firm could cover with foam and vinyl - not too expensive but seat is not essential to get it running. Just because the piston has been removed doesn't mean the bottom end is trashed. It could have been something like a snagged ring that caused it's removal, or a mild heat seizure. The cylinder liner should give clues. Mains and big end condition can be gauged by spinning the motor and listening for dry or scored bearings. Mains can be checked for vertical movement in the crank, big end checked for play in the crank. The bottom end of the motor could be quite sound. If so, a new piston is the biggest single expenditure to try and get it running at about $180? Plus the rebore. I don't know if that's expensive to you guys or not. The gamble is, spending that much and then finding that despite the bottom end checks, it does turn out to have unacceptable wear when running. If the bottom end is shot it's another $350 - 400 for a complete rebuild? So something like $600 to sort the engine worst case. Plus some used parts. So for $600 and a bit you could have a useable runner but whether it's worth it depends upon what you want to do with it. If you keep it you just absorb the cost as with any bike. If you come to sell it you have to consider that outlay plus what you paid for it and whether you could at least break even. I don't know what those bikes fetch in the US.And whatever the bike cost to buy. In the end, although it's just an old dirt bike, it's a Bultaco and in the history of trials they have a bit of 'provenance' and status, probably moreso than any other marque. And if you want more oomph than the TY, this will certainly give it you. The TY will be far easier to ride, but it's not a 'taco....

That end to the pipe is not something that was ever crafted in the Bultaco factory... This is the original set up

Compared to the TY175 it will feel bigger, heavier and the engine will pull your arms out. The bike isn't as nimble as a TY175 and won't be so easy to ride, but it is, ultimately, a more capable bike. They were aimed more at expert level riders in their day, not novices. Only you can decide which you prefer once you've ridden them back to back. Your exhaust silencer box is a Sammy Miller aftermarket period alternative and they were used without a back box. The standard silencer was the same shape effectively but steel. As mentioned above, they had the small triangular back box from the factory but they were generally removed before the bike got used as they stifled the motor.

A HPI of the VIN is the way to go if it can be done properly in order to find out if there is an existing reg number. I have heard of instances where the wrong reg has been returned as the VIN number entered just happens to be part of a longer VIN of another vehicle and someone hasn't paid due attention... Even though Montesa are the manufacturing factory of the bike, DVLA will only accept proof of age from an agent on their approved list. Montesa SA aren't on it.

First thing to do is get your chassis number registered on NOVA. You don't need a dating certificate or insurance to do this. Your vehicle details must be on NOVA before you apply to DVLA. Problem with VMCC is that the person who was dedicated to providing the dating certificates and all other dating matters left the organisation and as far as I know, wasn't replaced. She had built up substantial knowledge of off-road bikes over the years which helped with a quick turnaround. Therefore processing dating requests through VMCC is now slow. It may be worth trying the company I mentioned above. Or, paying the £95 for them to do it all for you seems good value to me.

You need a dating certificate from a DVLA approved source in order to get the age related number. Before applying to DVLA your bike needs to be NOVA recorded by HMRC - search this particular forum for NOVA for more info You can try the VMCC in Burton Upon Trent for a dating certificate. They'll want a picture of the bike itself for profile ID plus one showing the frame number. Or you could try these people who will undertake the entire process on your behalf if you require for £95 - not a bad thing if you've not been through it before... Not used them myself in that respect, maybe someone else has who could comment. http://www.dvlaadvice.co.uk/

Yes and no Ross. The grip factor is excellent, just as good as the tubeless. The sidewalls let it down. I have had one or two where the sidewalls were stiffer from new but softened with use, but 95% have been too soft from new. I tried one recently in my Ossa when out running in the bike and could not do a cambered section, the rear tyre rolled down the camber and turned the bike around every time. Swapped the wheel for my tubeless one and section cleaned no problem. If you ride solely on rocks and can afford to run a little more psi than normal, say 5 - 6psi, it goes someway to negating the soft sidewall. If you ride mainly mud, cambers, roots etc, then 5 - 6psi is no use, there isn't enough contact patch for maximum grip. With the tyre at normal pressure of 3 - 4psi the sidewalls give and the tyre rolls on the sidewall on cambers, over the points of rocks. I've even had them roll under hard throttle on flat ground in a straight line when going at steps etc. which rear wheel steers the bike offline. It's not so noticeable for lighter riders and it's not so noticeable if sections are fairly straightforward and on the easy side where grip isn't paramount. So depending on how someone rides and the level at which they ride at, it can make a difference I guess. But once section severity increases and grip is at a premium requiring the lowest pressure, the sidewalls cause problems. Don't know why they don't give them the same construction as the tubeless, It can't be that difficult... .

Yes it's the only tube type worth using, but the sidewalls are soft and the tyre can roll on cambers and rocks. Depends on your weight, the temperature, pressure etc. If you run at 6psi it helps stop it rolling but grip will suffer at that pressure, depending on what you're riding on. The Michelin tubed was useless as it was no longer a tubed version of the X11 You can use the tublis system to keep a tubeless tyre on a rim. I used it on a KT250, which, like the Yam, won't hold a tubeless tyre on it's rim. If you can find someone to show you how to modify the bead of a tubeless tyre to the same profile as a tubed type, that's another solution. I've never done it so can't help.

What's a sense of humour got to do with it? People have really lost the plot as to what 'twinshock' trials is and is about. If it needs explaining any more than it has been it really isn't worth it.

You didn't actually say just what is wrong that needs repair... Just the O ring?

That's the tube type, they've been the same since they were introduced. They're inconsistent and some are better than others but generally they are too soft. For lighter riders it's not so noticeable as they don't load the sidewall so much but once you're over, say around 11 - 12 stones, it becomes noticeable. Especially when the weather is warm. The tubeless IRC has a different sidewall which is stiffer, although I've had a couple which have been too soft in recent times and rolled too much, but that's in over 20 years of using them. The tubeless work fine with a tube on Akront rims but I've never been able to get any tubeless tyre to hold on Japanese rims, they generally drop into the well when the pressure drops below 10psi. I guess altering the profile of the bead of the tyre could get around that, to make it the same as a tube type but I've never tried it.

A bit too quick on the button with the last post, I meant to post this link http://www.classicmechanics.com/news/2012-10/revitalise-worn-out-plastics#.VKc83nsvspd Details of the refurb service for plastic tanks. I think someone I know has had a tank done, can't remember. I'll check and if so I'll post the details