smokey125

Insulation, walls and roof and keeping the worst of the bad weather out, brush/draught excluder strip on doors and windows can all help keep the worst of the damp out. No need to go too mad, no ventilation could cause it the sweat which is just as bad. With the best will in the world your bike will have a certain amount of moisture on it after its cleaned which will end up in the atmosphere in the shed. A dehumidifer is the only way to get the moisture out of the atmosphere in a shed or garage. As a bonus the water you get out of a dehumidifer is perfect for the cooling system on your bike and the iron!

Thanks for the comments, got a lot more than I was expecting! Summary of comments seems to be there was a big change around 2000, and either side of that its been continuous small improvements. The comment I find most interesting is the improvements in brakes. Another very objective question do people feel this is due to the reduction in bike weights or are the 4 pot calipers a big improvement?

I realise they have got a lot better over the years. What I was really think about was years ago the lightweight Spanish bikes were a massive change, more recently we’ve had the mono, which also saw the start of disc brakes, then water cooled with hydraulic clutches. Has there been anything like that over recent years? For example Beta went from the Zero, to the Techno, Rev 3 and now EVO. Looking at them they are obviously different. GasGas the engines appear to be largely the same from the first water cooled bikes through to early, mid 2000’s but there were a series of what look like relatively small frame mods. Was there anything where one make suddenly moved the goal posts and everyone else followed or was it just all of them making small improvements year on year? micm, I might bump into you in the next few months. I was thinking of joining Normandy or Hookwood club.

Having not ridden regularly in trials for the past 20 years I was wondering what people’s thoughts are on when and what the biggest changes in bike design/technology have been? I continued to follow the sport so I’ve seen the bikes change but having not ridden them I have no idea of what impact these changes have actually made to the way the bikes ride. During one of my odd rides a few years ago I was talking to the dad of one of the guys I started riding with and he commented about how much better the bikes were, easier to ride and easier to do more on. I’ve read a lot of the posts on here about which bikes of various ages is best etc which are very interesting but I was wondering if there have been any step changes in the last 20 years. Has suspension technology suddenly jumped forward or has it been a gradual improvement. I notice everything runs 4 pot brakes now are they a lot better than the older 2 pot ones? Based on the main advantages of bigger brakes in road racing I struggle to see where they are of benefit in trials! Have there been any big changes in makes/models, where they got smaller, lighter or easier to ride? I know these are almost unanswerable questions but I thought I would ask anyway!

Wow where do you start with this. Additive manufacturing (3D printing in its industrial form) is a real industrial process used by a lot of industries including the aircraft industry, F1 and many others. It's even used to print waxes for investment casting. We’ve used it at work for low volume tooling and machine fixtures. In its simplest form you start with a 3D CAD model of what you want to 3D print or build with additive manufacturing this model is then split into thousands of thin slices. Each slice is printed one on top of another, building up the as it goes. You can build any shape and any feature or detail as you split it in a series of individual slices, hollow shapes or shapes within shapes are easy. Mounting lugs would be easy. If it has any metal inserts for threads you would need to build it with a hole that you could then fit something like a Tapex insert in. This is a link to an additive manufacturing company the videos will give you a rough idea of the process. http://www.3trpd.co.uk/video-gallery.htm I should add that this is all dependent upon the CAD model. With something like this how well the part is scanned and reverse engineered into CAD will dictate how good the printed part is.

Depending on how bad your airbox is and how complicated the shape is you might be able to make a mould from the airbox and make a composite one. Probably not much cheaper than an ali one to start with but you be able to make several airboxes the cost comes own with each one you make.

It’s not so much an easy fix more it was quite a new thing when I was last riding regularly. Only Fantic (who I think were the first) and Beta had the option of changing flywheel weights so it was something most people didn’t have a view on. Having come from a TY250 mono the Fantic felt like the engine flew. Since the Fantic manual recommended using the weights for muddy conditions and a lot of the events I did back then were real mud plugging efforts I just left it as it was. I’m happy to take the advice of people who have tried it since I was last riding regularly. That was over 20 years ago, having spent that time racing GP bikes where you have more things to adjust and play with than you can keep track off or developing our own bikes I have learnt how important getting things right can be. I’m coming back to trials for “fun” and something to do since I can’t afford to race at the moment but I will be bringing all that racing/setup experience with me so I will definitely spend more time than I did getting the bike setup right for me and perhaps getting me better in the process! Fantic’s aren’t the work of the devil (well not until they ruined them with the K-Roo), I really enjoy riding it. Not the best bike out there but I’m not the best rider either!

Thank you for the advice.

I've got to admit I never took the weight off my Fantic, but you make a compelling case Nigel, I will be giving it a try.

When I started out all ACU licenses were done on the same form and up until quite recently this was still the case. Now the trials registration has been separated completely from the rest of the form. So my question is do I need both? When it was all on the one form you applied and paid for the highest level/most expensive license and that granted you any open licenses of a lower level. I have a road race national/international B that allowed me to get a motorcross novice, grass track etc and a trials license. Does the old system still apply? Would my road race license cover me for trials or do I have to buy a trials registration separately? If I have to do them separately do I need to get two unique numbers or will one cover both? I've been round the ACU web site but can't seem to find an answer! It's probably me being thick but any help would be appreciated!

Agreed, and it will take an amount of force (over an area) to get the tyre off the rim. Personal opinion a stiffer sidewall would deflect over a larger area meaning a bigger side force would be needed to get it off the rim. So if everything else was equal it would be more likely to stay on the rim. Either way the original quote made about the tyre is inaccurate.

Being split between dry and dusty and waist deep in mud I clean the airfilter and airbox after every trial. I also put a very fine smear of grease inside the engine side of the airbox to get anything that gets through the filter.

Nigel, I've seen you make the same comment about flywheel weights before. What is it that you dislike (might not be the best description) about flywheel weights. I understand that if your good enough you should be able to adapt your riding to suit but is there not an argument that for a novice or someone that's not going to throw everything at it they are worth keeping on? The owners handbook for my 309 described using the heavy weight for muddy conditions the light weight and rocks and the middle weight for stuff in the middle!

I can see the logic that a stiffer sidewall might be better/less likely to come of the bead if it punctured but agree the only thing that matters is it staying on the rim. I've looked around the prices don't seem all that different or am I missing something?

The forks/front end always was the weakest thing on the 175 if you started to push it hard. The damping is of a fairly old design (no surprise considering the age of the bike) as such it needs the thicker oil to work. If you have strong enough springs to stop it bottoming out it tends to top out. It might be worth trying different amounts of oil. So long as you put enough in to cover the damper piston then you can use the air gap as a secondary spring. This does require the o ring seal in the top cap to be in good condition. As 2stroke4stroke suggested it would require a fair amount on engineering work to fully upgrade the forks to modern damping and springing. Although I'm sure with some inventive thinking it could be upgraded.

That's exactly how I rebuilt the end silencer on the 309. If the mid section was built in the same way I would of already tried it. It's the fact that it has spot welds at various points along the length that concern me the most. If I cut the whole of the side out in the same way there is no guarantee that it will come away without doing a load of damage. I'm going to cut windows between the welds and see how I get on.

Fair comment, I keep forgetting that the air-cooled mono class is starting to get popular. I remember the Kroo being a real disappointment. I loved the 309 but the Kroo just felt heavy and cumbersome by comparison and the motor didn’t feel as good either. The forks are a straight swap the 309 had the same front end as the first Kroo (launched the same year) and the same frame as the older air-cooled bikes. Not 100% certain about the rear shock but I’m reasonably sure the 309 had the same suspension as the Kroo so it should swap across. The one thing you might need to do is add a bracket for the remote reservoir for the rear shock. I can’t remember when the Fantic’s first got it but the 309 has it mounted front left under the tank.

Are you intending on keeping the 245? Or do you think that is worth more money than the Kroo as a complete bike when you sell it? It just seems like a lot of effort to swap everything over. Why not just pull the forks out of the 245 for the twin shock and get rid of the bits you don’t want?

I noticed that on the link feetupfun put up. I certainly found the irony in a company that started out copying Keihin carbs warning about cheap copies!

When I do mine I'll photo what I do and post it on here.

Having looked at the price of parts and the price of OKO carbs I would be tempted to try one of those first. They seem to get some good reviews as well.

I was hoping somebody had already tried it on one of these exhausts. The Middle section is an S shaped two piece pressed steel part welded along each flange with what look like spot welds holding parts in position inside the exhaust. Due to its shape I’m worried about cutting a big piece out of the back in case it distorts. If I assume that the manufacturing method is the same on the later bikes as the one in fourex’s link then I should be able to cut a series of smaller holes without the risk of any distortion. I’ll be going to my in-laws soon and he has a small set of slip rolls. I’ll take it up with me and try and make some close fitting patches before I cut the pipe open. Thanks for the help.

As the title suggests, has anyone had the mid section of a 305, 307, 309 etc exhaust apart? The front section is solid the end silencer is a normal wool packed effort. The way the middle section is made it appears to have some sort of internal structure. I was wondering what it is and if anybody has ever tried to clean it out?

I would try giving it a full rebuild first. You would be amazed how much of a carbs workings can wear and cause poor running. Get it properly cleaned if you can get it ultrasonically cleaned it's worth it. Then treat it to some nice new part. I would look at all seal, o rings and gaskets, needle and needle jet, possibly slide and air adjustment screw. I've never used them personally but these people have come highly recommended. http://www.motocarb.com

We got this in as a sample at work. Only tried it for debulking as all the materials we use are high temp cures for which we use disposable bags. I'm still trying to figure out the best way to use it with wet layup and my bike moulds.