woody

I've put a 28mm OKO on my 340 199b and it is straight out of the box, no jetting or needle changes were needed, just a small adjustment on the pilot screw. Runs fine. Doubt very much it is any different from how it would run with the original Bing in as new condition, but that wasn't the purpose of fitting it. Like yours, the Bing was worn out and I needed a replacement carb. The OKO cost

Not sure about vague - plain stupid and inconsistent I'd say - Yorkshire Classic for example will allow and overbored/stroked Cub (not possible pre 1965 with the pistons/parts they are using now) to use a Dellorto carburettor, something that is prohibited everywhere else. But you can't even move the shock shock position on a C15 - did no-one own a hacksaw and gas bottles pre 1965..... Why should Cubs be favoured for choice of carburettor? Pre65 Sottish puts a lot of emphasis on the silhouette approach - it has to look period. They don't allow tubeless rims/tyres even though the tyre is still black and round like a tubed type. Tubeless rims look the same as tube type unless you are closer than 5 feet, early ones actually look the same. You can however have 2009 nice light, shiny billet hubs which look just like their pre 1965 counterparts - big, made of steel, black or silver paint and heavy.... Whole thing is a nonsense. The best thing you can do is check with the clubs you are most likely to be riding with as attitudes change from lax to lenient to don't care. Most people are sensible at club level and don't turn up with a Cub/James/whatever with a Sherco front end. It's generally only the pre65 Scottish that causes real arguments. Manx Classic for example are far more pragmatic. The ACU don't govern all of the classic clubs so you won't really find rules on their website - a lot of them are AMCA. At club level the ACU leave it to individual clubs. They govern the two national series, Traditional and Miller and each of those has eligibility guidelines.

You need the continuous tone horn (bicycle will do) and a speedo, doesn't have to work as you say, they just enter 0 or not recorded or something like that for the mielage on the MOT. Chainguard I'm not sure about, I've never had one. That's it legally but, it will depend on your test station. There are one or two that won't do them without lights as they don't know the law. Some also insist on a rear reflector - what use that is in daylight hours is beyond me. Some don't like the 'not for road use in USA and Canada' wording on Michelin tyres and seem to think that it somehow applies to the UK. Some don't like not for road use on a tail pipe but a sticker takes care of that. Try to find a test station in your area that someone else has used for trials bikes (successfully that is....) Once you have the MOT you can get it registered and Bultaco UK, The Vintage Motorcycle Club or Sammy Miller will give you a dating certificate so you can get an age related plate. As it is not a kit or a new vehicle (or manufactured since the SVA regs came in) it is not subject to SVA and all that stuff.

This topic has gone the same way as every other topic on this subject. It ends up with a few balanced views, largely from people who don't care which set of rules is used as it makes no difference to them or the trials they ride in, therefore they can see pros and cons in either. Then there are the strong advocates of 'the rules must be those that I prefer' which inevitably end up in the kind of 'I'm right, you're wrong' posts we have now. Human nature, just like best bike, best football team, best tits... No different from any other forum, whatever the subject matter. To talk of closing the thread just because of this is ridiculous, a forum is to express the opinion of people, right or wrong, just the same as a pointless discussion down the pub after a few beers which is forgotten in the morning. Should people be thrown out of the pub for having a pointless discussion - licencing trade would collapse within a week. Moderaters closing topics is no different from the 'I'm right, you're wrong' opinion in some of the posts, it's effectively saying, my ball, play my way or I'll take it away. If posts get heavily abusive or littered with foul language, that's a different matter, but this one wasn't. This forum is already a lot quieter following the loss of a few characters, people just won't bother posting if heavy 'policing' is in force. There is never going to be a 100% sensible discussion on any topic, especially this one or best bike etc. If people think what is being posted is trolling or has no purpose just ignore the post. If enough feel that way the topic will fizzle out on its own. But people aren't like that are they - that's why we have forums.....

Rarity value and if you want something badly enough. There are very few Model 10 or 27 Sherpas in Spain as most were exported I believe - assuming it has gone to a Spanish buyer. Can't imagine a UK buyer paying that much as they aren't that sought after here. It was the bike that was responsible for the first big change in direction for trials, killing off the competitiveness of British bikes at a stroke, so I guess it is something of an icon in Spain - a bit like an Ariel HT5 here (except that a Model 10 Sherpa still looks like it did in its era....) I was told that there is a series just for Model 10 Sherpas in Spain. It's also the bike that was responsible for the 1965 cut-off for pre65 trials when they were introduced which I'd guess warrants its place in trials history and status as something of an icon.

200 Cota is a cracking bike - very underated and it seems, overlooked. Haven't seen one in a trial for many years

Why do people ride twinshocks? It's because, generally, they have some sort of affinity with the bikes. They are the bikes they rode when they were younger, or the bikes they would like to have ridden but couldn't afford. Or maybe just because they like the look of the older bikes and even if they weren't riding in that era, they would like to turn the clock back and enjoy trials as they were on the type of bikes that were used then. They ride a Bultaco, Ossa, Montesa etc. because they like them, not because they are the best twinshock available. If that was the case we'd all be on Fantics. So converting an air cooled mono to twinshocks has nothing to do with reliving years gone by and riding your favoured bike from that era. It can only be about creating something that is more competitive than a genuine twinshock - and there is only one reason for doing that - results. The bike never was and never will be a twinshock. As mentioned above the ACU rules for the Sammy Miller and Traditional series are that it has to be a twinshock of original manufacture (needs redifining really as unfortunately, even this has a loophole that people can exploit if they want) However it is up to individual clubs what they want to allow. If our club ran a twinshock championship or gave awards to best twinshock, no way would a converted mono be eligible. They could ride it in the event no problem, I don't care what people want to do to their bikes, but not as a twinshock elligible for awards/points. And yes they do give an advantage. The gap from a Yam mono to the twinshocks was huge. Even with twinshocks on, the chassis design, geometry, weight, engine are all far superior to any genuine twinshock so of course they give an advantage. And once you start throwing Beta TR34, Fantic 305/7 GasGas 330 into the equation where does it end. What chance does a 70s Bultaco or KT stand against those bikes. As for riding for fun, that's true to a point. We all ride for the enjoyment of it but we ride in competitions and everyone wants to do the best they can - on a level playing field and in the fairness and spirit of the class we ride in. If we only ride for fun, then take the scenario of an aircooled mono that has been converted because the original shock is knackered beyond repair. The owner should have no qualms about continuing to ride it in the aircooled mono class, the fact that they will be slightly disadvantaged now against the other monos won't matter - they are only riding for fun.... The cost issue of twinshock vs aircooled mono isn't really an issue either. There are plenty of twinshocks under

The rims with the flange like the Montesa and TYZ type rim, usually take the car type valves, so the valve is all rubber. Where it seats in the rim, similar to a gromment, it has a groove cut into it which sits in the hole in the rim and the lips either side of the groove seal against the inside/outside of the rim. The only thread is for the dust cap. The GasGas, Sherco type Morad rims use a different valve which is threaded along its entire length and has a rubber seal at the head. When the valve is pushed through from the inside and the nut is tightened it pulls the head and seal against the inside of the rim to seal it. The head sits relatively flush against the inside of the rim to allow the sealing rubber to fit into the well of the rim. Does sound like you have the wrong valve, the Montesa type sticks up inside the rim, not flush, as on the Montesa type rim there is no sealing rubber to seal the spokes as they fit externally on the flange.

look for someone that does vapour blasting in your are as it gives excellent results and is not expensive either. I had a barrell and head done for

Deep part at the back as that is where the scavenge tube is located

Far from an expert on this but how you do it is down to your available abilities and resources. Boring out the standard yokes seems to be the most common way. This is difficult to do whilst retaining the standard offset I am told (by offset I man the angle the forks run at in relation to the stem, not strictly offset but it will do) However I guess you could bore them parrallel to the stem which is easier, as the mono forks are leading axle you could afford to reduce the head angle slightly. You can try pressing out the mono stem and replacing it with the t/s one. You may would have to bore out the mono bottom yolk to do this as the ID on the t/s bearing is much bigger, can't remember about the top bearing but you get the idea of what is involved. I think to fit the mono yokes complete may be difficult due to the odd bearing sizes. You'll have to measure up what you need and then you could phone pyramid parts (they have a website) who stock odd bearing sizes. They actually do taper rollers for the t/s so it's possible they could supply bearings that would fit the mono stem in the t/s. Or you may have to make up sleeves or collars for the bearings to get them to fit. Whichever way you do it it is a bit of a job that is probably going to need engineering skills somewhere along the way.

Don't you believe it.... I lost a GasGas off the back of my Sierra 4x4 years ago from wailing it round a roundabout. Centrifugal force took over and the bike just shot out sideways and got dragged behind the car. I was only 200 yards from the house. The RAC rally was in town that year and a few crews were using the local filling station on the roundabout as a service area so I thought I would impress them with the Sierra's cornering ability. Gave them a good laugh anyway. No way could I have got that bike out manually though, it was well strapped in using the tailgate hinge, towbar etc. Never figured how it came out but that Sierra did corner well... Not learning from this experience I lost an Ossa a couple of years later on the way home from a trial. Feeling hungry enough to eat anything I went into one of the local shopping centres that had a MacDonald's. The place was pretty empty so rather than follow the lanes to Mac's on the farthest side of the carpark I bollocked it accross the middle. Didn't know about the slight elevation change, only spotted it at the last moment, obviously too late, so the car (Mk3 Escort estate this time) launched off the slight ramp at around 30mph. It bounced hard enough to smack my head into the roof, first bottoming the front suspension, then the rear. As the rear rebounded the Ossa catapulted upwards out of view of my rear view mirror before returning with a loud thump on the tailgate and landing on the tarmac, once more resulting in a dragged bike before I brought the whole sorry mess to a stop. Fortunately no damage to the Ossa which was more than enough of a relief to offset the large dent in the tailgate inflicted by the bike on its return to earth. Strap them in tight boys.

Have you tried Steve Goode, he may have some NOS decals as he has various parts for old Betas, been a Beta dealer right from the outset. Or he may have a brochure picture you can use

I used to ride my Ossa to school, never in the dark so didn't need lights, but I was 16 then and didn't think twice (about a licence either) My mate also used to ride his TL125 to work and back. However, no way I would even contemplate it now. Traffic is far worse now, the lights on the Sherpa are going to be like 1960s xmas tree fairy lights or candles at best and if it's dark and raining you probably are not going to be seen and get wiped out. On a proper road bike you are at least sitting high enough to see around and over cars, on the Sherpa you will be below roof height, again hiding you from other road users. I don't think the police would like it much either these days. On the plus side I guess in a traffic jam you could do a 'Freebie and the Bean' and ride over the cars instead of sitting in queues.... I'd also suggest buying something purpose made.

I used to ride my Ossa to school, never in the dark so didn't need lights, but I was 16/17 then and didn't think twice. My mate also used to ride his TL125 to work and back. However, no way I would even contemplate it now. Traffic is far worse now, the lights on the Sherpa are going to be like 1960s xmas tree fairy lights or candles at best and if it's dark and raining you probably are not going to be seen and get wiped out.

Have a look here Shows the various TR34 models, maybe you can get a clear cutting of the decal.

I had a ride on some Puma Racing Bultacos recently. These bikes are built and set up almost to perfection, possibly perfection itself even, as everything works as it should, much better than when they were new. The rear brake was no exceptopn. A couple of the bikes had cable operated rear brakes. Perfect feel on the pedal meant I could even use it to steady the bike balancing with clutch in, the pedal action was light, smooth and progressive and responded to the lightest of touches. Not far off the feel of a hydraulic brake by comparison. I guess the secret is a perfectly machined boss that the pedal locates on with correctly bushed pedal with no slop/resistance, quality cable with routing for least resistance (although I think it was normal routing from memory) and then whatever Mr Puma does to the brake shoes and actuator in the hub. The front brake and clutch gave the same superb feel on all the Puma bikes I tried, very close to modern bike hydraulics in lightness and feel (clutch was probably lighter actually - yes, on all three Spanish marques...) These are both cable operated so why shouldn't the rear brake work well by cross over cable. It's all in the set up obviously from someone who knows how (ex factory Montesa and Bulto mechanic) No way I can get my Sherpa rear brake to work like that and I'm just swapping it to left hand pedal/rod this week as it happens... But if you can find a man who can.

Are you sure it isn't a problem with electrics giving a weak spark and giving the impression of running rich. It would be very unusual for a carb that hasn't been touched to start running rich at the next event unless a jet is loose or float needle sticking etc. The 250 Villiers should run fine on an Amal MK1 although it would usually be a 26mm rather than 24mm. Mate of mine has a 37a engine on a MK1 which gives no problem at all. Before you fit a Dellorto I'd check the rules of clubs you ride with. Riding an easy route in a modern event, no-one will care what carb you have but for Pre65 events I can't think of any club that would like a Dellorto fitted, has to be British - the only exception I know of is Yorkshire Classic who allow bored out Cubs to have a Dellorto for some reason

First of all you need to decide what events you want to ride your bike in and with which clubs as this could have a bearing on which forks you fit. If you are going to ride it at local modern bike events on the easy route where they may have a pre65 class, the chances are they won't be bothered about the spec of your bike as they won't know any better, therefore the forks you fit won't matter. Always the chance other riders may whinge though. If it is to be ridden in classic club events then they may be a little more fussy over what you fit. Some classic clubs excercise a certain amount of tolerance with modifications, others go apoplectic if they find you have so much as a metric nut and bolt holding your chainguard on (slight exaggeration as I'm induldging myself...) Most clubs will accept forks doctored to have a period appearance (whatever that is as some that are allowed look anything but) Most forks are 35mm stanchion diameter so you want yokes of that diameter. Montesa Cota 247 yokes (from 1973 - 76 bikes) are a good choice as they are basically the same as the billett yokes manufactured by several specialists and these are all accepted. Most yokes use bearings with an ID of 25mm and OD of around 47/48mm. The OD of the original C15 headstock bearings is obviously imperial measurement but works out at about 49mm so metric taper rollers won't go straight in. What I did was to make a sleeve to fit in each bearing housing in the headstock which sleeves it down to 43mm. Pyramid Parts do taper rollers with ID 25mm, OD 43mm and depth of 11mm (maybe 12, can't remember) This allowed me to use the Montesa yokes. You can then fit any 35mm forks. Ossa yokes are another 35mm option although they take bearings with an ID of 20mm, not 25mm. Gives you a few options, but you really need to decide what events you are going to ride it in as to which direction you go in. Depends also on which part of the country you are in. If you aren't bothered about riding it in a pre65 class, then if the mods aren't acceptable to any given classic club, most have a specials class you can ride it in.

When I tried to insure the Jumbo, I had the same problem in that Carole Nash didn't have it listed and couldn't do it. I never got as far as you did, even though I had 2 bike policies with them and 1 car policy. As I had another long standing policy with Norwich Union through Swinton brokers I tried them. They were able to insure it but as it was added to my existing policy (which takes up to 4 bikes) there wasn't an actual premium for the Jumbo itself, it was just an add-on fee. Going back to Carole Nash, the policy they operate for bikes also allows multiple bikes. Even though it is one policy, each bike has its own certificate and is insured seperately meaning that if they all get stolen they are all covered. The premium is generally based on the highest rated bike and other bikes are just subject to an add-on fee, similar to Norwich Union (except I don't think NU offer this anymore) Any bike prior to 1984 I think, is regarded as a classic and therefore has a cheaper premium. If memory serves I have 3 bikes on a classic premium which costs about

Friend of mine spoke to secretary a few days ago for entry details and was told already full with about 30 on reserve. Popular event then...

Off Road Only in Llandrindod Wells have (or used to) a fairly large stock of piston pin sizes. If you can find them on the net they used to list all the pin sizes in their catologue, or just ring them with the size.

Someone, somewhere, must know how the kickstart is held onto the shaft..??

Below is the method from STU on one way of fitting the GasGas kickstart to the Cub shaft ################################# To fit Gas Gas kickstart:- The flat on kickstart shaft that takes normal cotter pin needs to be groung back carefully with a hand grinder so the flat now comes right to the end of the shaft, now ream out the steel swivel of the Gas Gas kickstart so its a nice fit on shaft then from a piece of round bar cut a d shaped piece that fits the d shapes space that remains when you have fitted the kick start swivel on to the now reground kickstart shaft, make sure you have it positioned in the right place and then weld this new d shaped piece in place in the kickstart swivel. Now a bit of pub, we make half hard ali kickstarts for cubs along with our new wide ali forged footrest/ali mounting brakets that take ali brake lever and ali chain tensioner..... PS, What is best is to use a dummy kickstart shaft in a vice, to be sure you've got it all set up/dimensionaly correct and it can then be checked at itervals so your not making a cock up.....Gas Gas kickstarts are not cheap and all this work while not complicated needs to be done well/acurately....... ################################# Now, the only thing I can't work out here is how you retain the modified kicker on the shaft without it falling off. The GasGas knuckle/swivel doesn't have a pinch bolt as on the GasGas the end of the shaft is drilled and tapped and a retaining bolt stops the kicker sliding off. This can't be done on the modified Cub (C15 in my case) shaft so how is it held in place on the shaft?

As it was a 2 day trial it was a chance to use 2 bikes, one on each day, so I planned on taking the Ossa and the KT which both fall in the pre77 class. However, I've just got the BSA (C15, not B40) back together after some very lengthy work trying to straighten the tired old frame. So I took that too with the intention of trying it on some sections after the trial as the Manx classic is coming up and it has to be right for that. So did one lap on the Ossa on Saturday, no problems with it apart from the new IRC rear tyre which has sidewalls so soft it was hard enough to ride it in a straight line in the field, never mind sections. They've really gone in the wrong direction with their tyres. So, decided to ride the second lap on the BSA as the sections looked a good test for it and would show up any problems. It performed well with the exception of the chain jumping the rear sprocket on section 15 I think. The rear wheel seems to be pulling out of line so have to look at that, but I decided to use it again on Sunday. All was well until about section 11? up on top of the hill. I stopped to take my rucksack off and it wouldn't restart. 15 minutes of fiddling and it still wouldn't go, I think it had an electical connection problem maybe. Decided to roll down the hill back to the carpark but when I stuck it in gear it fired up. Turned round, went back and rode the section but it misfired towards the ends cards and died. So, rolled back down to the carpark, got the KT out and finished the trial off on that. It's like a barge after the other two so it was like riding a different set of sections that time around...... Great fun though.