Don't want these Ads? Why not sign up as a Trials Central Supporter.


  • Content count

  • Joined

  • Last visited

  • Days Won


1 Follower

About dadof2

  • Rank
    Advanced Member
  • Birthday

Previous Fields

  • Bike

Profile Information

  • Location
    Northern UK
  • Gender
  1. This post more to do with practising than entering trials, but the more you practice with friends it seemed to be more likely you would enter a trial at the weekend. What I would describe as the local group of riders live several miles apart, and our practice sections are also grouped several miles apart. What used to happen was that you would ride to someones house to see if they wanted to go practicing, if yes a few others would be phoned and agreed to meet at one of the section groups. All would ride there. Over the evening we would move to other groups of sections then split up to ride home. If it got dark we still rode on the (minor) roads in about 4th gear sitting side saddle so if car lights were seen you would jump off and run alongside the bike in case it was the police. As the bikes were road legal even if it was the police they would just ask what you were doing and when you said you just got caught out when dusk fell they accepted that. Now with dodgy number plates, no horns or speedo and a ridiculously low seat they would give you a hard time and probably a ticket. Also because of high insurance and the new license restrictions many no longer have load legal bikes. This sort of practicing has now nearly died out. Now it means getting the car and trailer out and parking at one area (or inconvenience of reloading bike etc). Small fuel tanks don't help either. The vabove may not seem to be major factors but they have reduced the inclination to ride the bikes as often a we used to. There also may be a slight shift to enduro type bikes because modern trial bikes are no longer so suited to road or trail riding.
  2. No way am I suggesting making a case from P20 (it would be totally unsuitable), I just mentioned it because it has similar machining properties (in some ways) and costs to a tough grade of aluminium billet that would be suitable for a case. From a strength point of view (without looking up exact values) P20 is similar to EN24T except it is much easier to get a good finish when machining than it is with the higher EN number steels. I was boring some bright drawn steel a few days ago, what a pile of s--t, variable hardness and a finish like a bear's a--e as they say.
  3. No - they just shoot them Much of the "ban it" pressure in the national parks is not from the park authorities themselves, it is from the Ramblers Association, organisations like The Friends of The Lake District and last but by no means least the quango Natural England.
  4. The fuel rail plus a length of pipe is filled with fuel then compressed air is used to replicate the pressure from the fuel pump. Running cars on compressed air was a major scam a few years ago, a conman made a fortune because some people were daft enough to invest in it.
  5. I would not copy that design even if I had a CAD drawing. There is too much unsupported length under the teeth, no surprise it has broken.
  6. Gorilla glue seems to be very similar to polyurethane glue, At about £6 to do boots quite a few times its cheap and works fairly well, its what I currently use. I can never understand why soles sometimes come off and sometimes not. I have had boots that the soles have remained in place for years, yet have had boots of the same make and size when the soles have come off after little use in less than 2 years. The tendency of soles to come off seems unrelated to age, amount and type of use. MX soles do seem to be harder and come off more frequently. Fitting a small steel cap round the front of the soles delays sole separation and makes home gluing worthwhile.
  7. If I had an ossa or any other EFI bike I would get a fuel pump and pressure regulator from a scrap car (or even buy new on the bay) Rig up a system so you can feed the injector independently of the bikes fuel system. This means you can easily determine if is fuel or ignition that is the problem. PS - I have used compressed air on the fuel rail to check this in cars.
  8. This mistake (CX 500 engine) is now a sought after classic - truly remarkable
  9. P20 is a tough steel that machines to a good finish and is hardwearing. The machine shop I am familiar with use it for injection moulding dies. Its advantage over other tool steels is that it does not have to be heat treated after machining.
  10. There is a cobblers in Barnard Castle (near Morrisons supermarket) who reglue a pair for about £30 but it does not always last. If you have their soles fitted it costs about another £30 but they are much more likely to stay stuck on. Their soles are like a rough walking boot and a bit softer than typical trials boot soles. I have never used Altberg but I used to hear good things about them (MX and walking boots - not heard of anyone using them for a long time). I think a resole for a pair is about £60 to £90
  11. I am well aware the ignition flywheel cover is less complex that the clutch cover, that is not the point. If jimyam contacts Birks or JS they would probably tell him where they got the castings done and he could get a clutch casing priced. I do not know the price of a new OEM TY casing but I assume it is similar to a TYZ clutch case which was £400 plus before the recent fall in the £. A fabricated cover may not look quite right but it would do the job and be tougher / more repairable than the original, price would probably be around £300. An alternative would be to glue (JB weld) his case together then assuming it fits, get it measured on a CMM and then machined from billet. Considering you can get an 18 inch car wheel machined from billet for under £1000 then a much smaller item like a clutch casing might be a price jimyam considers acceptable. A machine shop I used to use machined items of similar size and complexity to a clutch casing for £60 to £90 (in 316 stainless or P20) On top of that you would have to add a programming charge of about £60, a tooling up cost of about £60, the billet cost and the CMM charge.
  12. Perhaps consider the following. John Shirt and Nigel Birkett both used to get ignition flywheel casings cast for TY monos and the retail price was less than £25. Perhaps you could get a clutch case made. It would not be cheap but a good quality aluminium sandcast case should last a long time and would be weldable. Perhaps using TC or ebay a group of TY owners could get together and have a batch made. There are plenty of companies that can do one off or small batch casting and the TY case is simple to machine. Another option would be to have one fabricated out of aluminium rod and sheet, if you have any interest in this option I can give further details how its done.
  13. "Saying that, I am learning that even though I am not hopping the MAR around, it is overdamped in the rear. With that, I have swapped to a lighter rated fluid, and even have been drilling the pistons for added flow." The original MAR was primarily developed for riding slippery stream beds as that is what many of the sections were then. With the lower grip of tyres at that time too little damping would cause the back end to kick sideways and slide off boulders. The stiff damping was right for the time and the tyres but certainly will feel much less bouncy than modern suspension. Also travel was limited without the benefits of rising rate linkage so stiff damping helped prevent bottoming out.
  14. Have the crankshaft cold and the cases and bearings warm. Pull the crankshaft into the bearings by using tubular spacers and washers and the pinion and flywheel nuts. Do not do anything that transmits assembly force through the ball bearings.
  15. Gearbox output shaft oil seal? rumoured to be an issue on Vertigo