smokey125

Looking very good, you should be pleased. I've been experimenting with this stuff, http://www.diatex.com/-Reusable-membranes,456-.htmlthe Elastibag makes bagging parts a lot easier, especially for low temp cures.

It does sound like an ignition problem now. I don’t know anything about the 240 ignition but as Glen says there are plenty of threads on it in the forum. Since it runs for a bit it does sound more like a component breaking down. Could be any number of things, depending on what ignition you have. You could try Bob Wright he was quite helpful when I had problems with my 309 ignition. http://www.fantictrials.co.uk/ On the plus side once you’ve sorted the problem the bike will run like new.

The finish on the parts looks very good considering how complex some of them are. I’ve not really ventured into tanks too much as we seem to have a much more limited selection of sealants this side of the pond. If you can vacuum bag then you can do RIM. There are minor changes to the bagging process, a couple of extra bits are required and the resin is slightly different, thinner and longer pot life. Having said that personally for small volume parts I don't think it's worth bothering with it and it doesn't work so well with complex shapes.

Since I’ve not been actively involved in recent years, the difference between the different years is something I struggle to follow particularly with GasGas, Sherco and Scorpa. With Montesa/Honda and Beta, the big model changes are obvious with changes in-between seeming to be small detail changes which I assume could largely be retrofitted. With GasGas particularly, there seem to of been a lot of changes to the frames, often only quite minor, but with common engines? Then some much more sweeping changes, where it looks like a major redesign. Information on what changed when seems to be variable depending on source!

Much as people may not like it I think electric bikes may be the only way to reverse the decline in trials riding. As has been said the kids now mainly seem to start out on electric. This has several benefits, get them started younger and hopefully get them hooked for life. I would guess that now days a much larger percentage of parents have no interest and no idea how to maintain a motorbike, where an electric one could be a lot less intimidating. They are quite so you can practice every day without annoying anyone. I would suspect that it would be much easier to get more land approved for use with quiet electric bikes. They are perceived as being “green” unlike those noisy, dirty, smelly motorbikes! If the Torrot purchase of GasGas does lead to a new breed of electric bike this could put GasGas as a market leader in the future. As for now it does still seem a bit optimistic as far as the numbers go!

Have you checked that you’re getting fuel as far as the needle valve? Problems I’ve encountered in the past have included, inlet filter inside the fuel tank being blocked, fuel tap being blocked, fuel tap being broken and not allowing fuel through, fuel pipe delaminating and collapsing on the inside despite the outside looking fine. As suggested water in the fuel can cause problems, modern fuel with ethanol in it, if left will quickly form water in the tank. This can rot your tank blocking filters and causing running problems. My personal experience with water in the carb is that it will run just very badly.

Looking very good, I love the skid plate that is brilliant! What did you use for the carbon parts? Pre-preg, wet lay-up, RIM and what resin? Are you planning on lining it with an ethanol proof coating?

I would start with the basics. Is fuel getting to the carb? Check the fuel tap, disconnect the fuel pipe form the carb hold the end over a bowl and turn the tap on. Does fuel come out? If not check the pipe and the fuel tap itself. There may well be a filter on the tap inside the tank this could be blocked. If fuel is coming out the pipe at a good rate then check the float bowl again. Is the float working properly, or is it sticking. You need to start at the beginning, the tank and work from there until you find where the fuel is not getting to.

Have you had the carb apart and checked it all over? I have had a carb where the needle and needle jet had got very worn and could on occasion hook up and effectively jam the carb. If you are reasonably mechanical and have acces to a lathe you can make a leak test kit quite easily. This will at least answer the question about a leak. No reason why you couldn't fit a CB carb if you changed the jets to suit. Personally I would of thought it would be easier to try a carb off 50 or 100 2 stroke road bike as you could probably go with it straight away.

When you said the plug was dry I thought it sounded more like a fuel problem. Some more fuel might sort it. It could be that in the washing process you've accidentally got some dirt of water or both in the carb. I'd start with fuel and if that doesn't fix it take the carb off and give it a good clean out.

still trying, Unfortunately this isn’t one that we built. My dad brought this from someone in the same industrial units that my dad’s business was in. He had built it for his son to start trials riding. When he outgrew it my dad brought it off him, and I started trials on it. We then sold it onto a friend of ours who also started trials on it. From memory it was based on an S90 sport frame with the back section cut off and a new sub-frame fitted to give better angles for the rear units and to allow longer units. The tank and seat unit (all in one) designed to look like a TLR from that time was in fact a dummy cover. The man that made the bike ran a business that made vacuum formed plastic parts, things like street light covers. So that was how he made the cover. The actual tank was a much smaller item that hid under the cover. It had a C50 engine bored out to 75cc. The reason for this was the C50 had a 4 speed box. Well some of them did and that was the only engine of this type to have a 4 speed box. The guy that built it thought the extra gear was more useful than the extra power. As a bike it was a lot of fun and it got several people stared in trials. The biggest problems with it were that the steering angle was wrong and it wasn’t good on tight turns and it was underpowered. I was 12 in that picture and that was my first event. It was also my brother’s first event he was 9 and riding a Whitehawk TY80. The land consisted mainly of two big gully’s it didn’t matter how much I wound the little Honda up on the downhills I couldn’t get it up the biggest of the climbs. Tried every gear I had but couldn’t get to the top. After we had finished I tried them on the Whitehawk and went straight up. I would love to get that bike back. If nothing else it would be a great run around bike. John b, Thanks for the offer but not at the moment. The reason for asking the question initially was to see if the idea was worth pursuing and if so what of the various bits I have would be worth keeping for it. I'm likely to be relocating in the next 3-12 months so I'm getting rid of stuff and the moment rather than collecting but don't want to get rid of anything I would then replace once I've moved, equally I don't want to move stuff I'm not going to use. Having done a lot more searching over the last few day the most interesting comments I keep seeing is how cheep people seem to think the bikes (twinshock and classic) are yet they are already well into the range of being more costly than an older modern bike. With genuine bikes already being modified beyond all recognition to gain a competitive advantage seemingly at very high cost I wonder how long it will be until it ends up like road racing with classic bikes being significantly more expensive than modern ones! This isn't meant to be an inflammatory comment but more an observation.

still trying, Just looked at the pictures of your build, very impressive. I've got to admit I'd not been thinking that radically but that may be my view tainted by years of classic racing politics!

collyolly, I think we are getting our wires crossed (the joys of the written word!), my plan was to take something fairly mundane and with a little bit of lateral thought turn it into something that keeps to the spirit of the class, is a little bit different and fun. This is the same approach I’m using on my current race bike build where I’m aiming to keep build cost down to about £1000. Unfortunately I think the decline in young riders particularly at a club like Surrey Schoolboys goes way beyond the lack of cheap bikes. Personal opinion if anything is going to turn the fortunes of the sport round it will be improved electric bikes. Even then I don’t think it will ever get back to what it was like in the 70’s. Unfortunately I think the same applies to all other areas of two wheeled motorsport. still trying, That is exactly the type of bike I was talking about. Something that can be built with garden shed technology. Where you have to exercise your brain to solve problems not your wallet! I'm hoping people here will be as receptive to the idea as you have found where you are. lineaway, I'm not likely to ever do that, I never was much of a trials rider! Closest I will get was being given a lesson on how to ride by Sammy Miller years back. It showed technology is no match for skill!

This is what I started on 27 years ago. It was built by someone who lived near to us based on a S90. Excuse the picture it was 27 years ago!!!

b40rt I aware of the sort of arguments people have about what's original after 23 years of road racing classic bikes! I'm not interested in building something that will be way better than something that was genuinely available. I've seen that happen with racing and costs have gone through the roof and in my opinion largely ruined it. It's more about what can be done on a budget with a little imagination and thought but still keep the spirit of a class. If money was no object i'd search for a Whitehawk TY175.

There already seem to be plenty of people radically modifying original twin shocks at what can't be anything less than great expense! To gain an advantage. Have to say I've seen a lot that are about as original as Trigger's broom. There also seem to be plenty of people who have already built a twin shock machine for nothing more that the pleasure of doing so and having something a bit different! I'm an engineer and I love building things. I've got lots of parts around me already if the main criteria is it has to be pre 85 and drum brakes then I have a start for a fun/cheap project. I search fleabay and all I see is bikes with price tags that I think are far too big or basket cases with build cost that will run out of control. The moment you are constrained to something that is either desirable or in relatively short supply cost jump out of all proportion. Start with a cheap plentiful road bike and see where it takes you. If that's not in the spirit of the class or outside of the rules then I'll build something different.

Having seen a bit of the Manx classic/twinshock while I've been at the Manx Grand Prix I'm interested in what basics constitute a twinshock. Other than having two shocks! What brakes, frames, engines etc are allowed, size (as in fork diameter) or age limits. Anything else that should be considered before I start to make something that's not allowed. Even more interested after seeing some of the pit bike engine specials people have made which look very similar to the first bike I ever rode in a schoolboy competition. The rules for classic and twinshocks seem to be even more liberal than those for classic racing. Which I didn't think was possible!

Depends on how your ignition is setup. If the kill switch is a make contact to kill the engine just unplug it. This is how my 309 is setup. If it's a break contact to kill then you need to unplug the switch and fit a jumper wire between the terminals on the loom. Dry plug sounds more like a fuel problem to me.

Wonder what Sherco’s long term plan would be if they got Gas Gas? With both companies supplying a very similar range of bikes to what are very small niche markets, it seems like a strange move!

That has got to be the funniest thing I have heard in a long time. I had a TY250 mono, it was a great bike I would get another one at the drop of a hat if I could afford it but there is no way anyone who's owned one would get dewy eyed and nostalgic about the front brake on them no matter how big the problems were with hydraulics! Not unless they had gone senile! That's the problem with nostalgia people forget quite how bad some things were. You'd spend more time working on the front brake of a TY mono after each event than you would after 6 months of riding with hydraulic discs. I'm still smiling now, that's really brightened up my day!

Not an issue rob it just amazes me people think like this. I race Vintage, Classic and modern bikes and like all for different reasons. To keep that old stuff running we rely on modern technology, without it we would end up having to stop running them. Nigel, I was aware of this, didn’t want to go too far into the cycling thing and try to explain it. The article does highlight nicely how the UCI works for changes in technology like this. Based on how the UCI normally operate I would be very surprised if you see them being used at any of the grand tours next year. I wait to be proven wrong on that now! I’m looking forward to it happening. I’m hoping there will be a flood of cheap second hand bikes and wheels come onto the market as people upgrade. Doubt I’ll be that luck though.

I’ve never really looked at the general section on the site before. Wow there is some entertaining stuff on here. Having actually read through all the posts on this one here’s my summary based on my experience and opinions, thought I’d get that in before anyone jumped down my neck! I don’t ride trials much these days mainly focus on road racing. A couple of years ago it was the 40th anniversary of the schoolboy club I started at so I pulled my old Fantic 309 out of the shed and my brother got his GasGas Contact out. Unfortunately about half way through the day my Fantic started messing about. Eventually stopping altogether when the coil died. I finished the trial on my brothers GasGas. When we were riding regularly I would never have rated the GasGas over the Fantic, but to jump on having not ridden either bike in 15 years the GasGas was light years ahead of the Fantic. Not surprising considering the age difference of the two bikes and that the rear unit on the Fantic had also blown a seal, but the biggest difference was the clutch. The hydraulic clutch on the GasGas was light, precise and easy to use the Fantic felt heavy, grabby and uncontrolled by comparison. I know that a cable clutch can be made every bit as nice as hydraulic one. Agreed if you get a problem with hydraulic one during an event it can be a show stopper, by the same token it can become quite and engineering exercise to get a cable one right. A well setup drum brake can be an absolute joy to use, but much like a cable clutch it can be a pain to setup and ultimately more work to maintain. As for cable operated discs they were tried in the 60’s and 70’s. They didn’t make it to the 80’s for a reason. Some pedal bikes use cable discs, they are better than rim brakes but not even close to hydraulic discs. I would suspect that by the time you’ve made a drum brake as good as a disc in terms of performance and out of the box reliability it would cost as much as a disc to manufacture. So do you need hydraulics no, are they going to make you a better rider no, are they a general benefit to the masses riding yes. Technology moves on and gets cheaper as it does. Best make the most of it rather than wishing for things to go backwards. If you enjoy doing lots of fiddling and fettling and like the satisfaction of making something work right and are happy riding non stop events and routes stick with old technology and enjoy. Equally if you want to ride the latest bikes and try to bounce up 6 foot rocks then great. Trying/wishing for things to go backwards, or wanting everyone to think the same as you is never going anywhere. As for cycling no bikes used in UCI road events will have disc breaks as the UCI don't allow it. Cycling is one of the most regulated sports going. It took years to get discs allowed in cyclocross. They will be introduced into road events in the next few years. The issue they have is nothing to do with teams experimenting with discs because no one is using them. The Mavic support vehicles already have to carry two different types of rear wheels to accommodate the different gear systems but only one type of front wheel. The issue they are trying to resolve is getting all the teams and manufacturers to agree on a set of rules that will make disc brakes as easily interchangeable as rim brakes. Once they have got that sorted the entire professional peloton will be going to disc brakes.

To be honest the front one is a simple enough shape I could probably model it from scratch without too much effort and we are possible going to be getting a laser scanner at work soon so I might have that option as well. The reason I was going down the composite route is that is something I can do at home. The 3D printing option is fine if you can find someone who has a printer and really knows how to use it. One other problem is when you start looking at the better filaments like the impact modified PLA which the writer was going to try next the choice of colours gets a lot smaller. My daughter keeps going on about getting a 3D printer so this may be the justification!

It’s good to hear that they have got a way forward but I’m still doubtful of there long term future. They have gone for the last few years without making any inroads into the debt they had. This basically means they have not been running at an operational profit. Writing off the debt won’t change that. If they know what the problem is then why haven’t they fixed it already? Unless they can get a big money backer who is prepared to keep going with this risk long term then this bail out is really the last chance saloon, if they get themselves in debt again that will be the end of it.

I've got a 309, unfortunately the front disc guard got broken when my brother borrowed the front end out of the bike! Been looking at the idea of using what I have of the guard to make a mould and make a replacement in carbon or Kevlar. The guard looks to be the same on the 305, 307, 309 and early K-Roo. Question is if I made some would anyone be interested in one? The only reason I'm asking is if there is some interest I will put a bit more effort onto the mould if not I will make it good enough to make me a couple for me and leave it at that. If I do this it's not likely to happen until towards the end of the year, got too many other projects to finish. Please don't think I'm doing this in any way as a business it's just something I'm doing for myself and thought I would ask the question.