dadof2

Perhaps trials is like a fine wine, only of interest to those who can really appreciate it, whereas DM is supermarket plonk for the masses.

http://www.toolstation.com/shop/Hand+Tools/d10/Punches/sd3302/Letter+Number+Punch+Set+36+Piece/p19757 See above link, can get them at plenty of other places also. Another option is a vibro engraver at about £40. To make the bike less attractive to thieves and more likely to be recovered get it registered, it costs nothing. Then stamp or engrave the reg number on lots of parts, some visible and some hidden. I can't remember the exact figure but doing the above reduces theft by something like 70%

Why do away with the flat sprocket conversion which is superior to the dished sprocket arrangement?

Although the TPI is the same at 26 the thread angle is different. BSF is 55 degrees whereas cycle is 60 degrees, therefore although you may get them to go together they joint will be weak and likely to gall or strip.

Unless someone is psychic you are unlikely to get a reply, Its probably 520 pitch but length (number of links) depends on sprocket sizes. I like DID chain but if you are making do with old sprockets a cheaper make will probably do.

You need mud relief grooves in your sprockets, sometimes new sprockets can be supplied with these already in. Rig up sprocket scrapers for both front and rear sprockets, most MX bikes have these integrated with a chain guide for the rear sprocket.

Contrary to Nigel's interpretation 9 I don't not advise buying a gasser. Gear selector spring Baldilocks # 12. Shercos still do this on the 2014s, only about £5 parts and an hours work fortunately. I often wonder why all trials bike manufacturers especially GG and Sherco do not fit a sprung face cam mechanism to protect the gear change system. I am actually quite sad to criticise GG gearboxes as when working properly a GG is a very very good bike. In my opinion the damage to GGs reputation was done mainly in the period 2004 to 2008 and the faults were made worse by the cost of parts and GG UKs refusal to look favourably on failure on low use bikes not long out of warranty. Quite a lot of the riders affected had various makes of bike dating back to as early as 1970s and never had a gearbox fail before (or after). It was these riders who will never touch a GG again. Beta (J Lamkpin) replaced stators, frames and other parts well out of warranty. Newer GGs the "gang" have had, 2010 125 gearbox "selector chain links" failed, 2011 125 water pump failed, new piston + barrel needed, 2011 125 frame broke, 2012 125 clutch release bearing failed and wrecked £500 of gearbox that ingested rollers. 2012 300 main bearings and kickstart failed. As far as I am aware there has been no design changes to cure the "selector chain link" failures the split needle roller failures (not listed above) nor strengthen the kickstart. The rollers in the clutch release can loosen sufficiently to fall out of their cage after only a few hours running. In theory they are trapped in situ even if their cage wears but in practice they do get out at times.

Bead, vapor blast or acid clean. Coating will greatly reduce surfaces ability to transfer heat to air.

Bit surprised you had to have them reamed. Mine never wore out as I kept pipe full of EP 90 - 140) but I did help some people replace worn ones on bikes the had bought and reaming was never needed.

You cant really check output with a meter when kicking, meter does not respond fast enough. The source coil for the ignition power is the stator coil with the fine windings (Thicker windings are for fan / lights). Trace the wires to the fine windings, connect you meter and spin the engine with power drill. Plug out but earthed Expect between 20 and 30 volts AC. If not source coil is probably faulty. Resistance is not a good guide but expect 200 to 250 Ohms. I think the trigger on your bike is transistorised so checking resistance may not be a good guide. Try connecting meter both way round (opposite polarities) and kick the bike over, if it gives a blip connected in either direction is is probably OK. I am not sure but a fully failed ignition source coil (no volts or infinite resistance) may prevent trigger functioning.

Obviously price will be a factor. We have GG and Beta who have been round for a long time and sell in largest numbers. Sherco numbers seem to be increasing. Then there is Mont / Honda which are rather different and well established. Then we have (or will have) the 4 newcomers Jotagas, Ossa, Vertigo and TRS. My suspicion is that this newcomer group will not prove that attractive to many riders of the longer established 4 and that total sales volume in this group may not be able to support all 4. DLs name may give Vertigo an advantage particularly if he signs a top rider who has success on it. Really there is only one rider likely to challenge Bou, Does anyone know Raga's current contract situation?

There are about 8 or 9 in my immediate area who come practising as a group. All have owned gassers at some time, and 2 currently do the bikes being a late 2013 and a 2014. The 13 is owned by a good clubman rider and has never given any problems. The 14 is so new its too early to comment (bought as one of the recent discounts) With the exception of the above 2 gassers all the other pro engined bikes have had a least one gearbox failure, some very expensive and just out of warranty and several of the group swear they will never buy a gasser again. Several of the gearbox rebuilds have been cheap partswise (about £60) and just a long evenings work. But if you break down in a trial and have to pay for labour it is very displeasing. The shercos have had minor faults - brake problems and one stator under warranty. Mechanically the betas have been 100% reliable but one bike needed 1 stator and another needed 3. 2 of the riders are thinking maybe 4rt next.

https://www.google.co.uk/search?q=yamaha+ty250+sale&espv=2&biw=1366&bih=667&tbm=isch&imgil=utX-JA7SpUTuZM%253A%253BnBL7dI977A4FEM%253Bhttp%25253A%25252F%25252Fwww.classictrial.co.uk%25252Fnewsite.html&source=iu&pf=m&fir=utX-JA7SpUTuZM%253A%252CnBL7dI977A4FEM%252C_&usg=__qP_awZntt6DIk3WR4CW5koDhqPc%3D&ved=0CD0Qyjc&ei=5Z1eVJSJF9PhaIrBgrgB#facrc=_&imgdii=_&imgrc=utX-JA7SpUTuZM%253A%3BnBL7dI977A4FEM%3Bhttp%253A%252F%252Fwww.classictrial.co.uk%252F090908_YamahaTYmodernTwinshock.jpg%3Bhttp%253A%252F%252Fwww.classictrial.co.uk%252Fnewsite.html%3B888%3B503 See above picture, just weld on brackets and take monoshock off

http://www.bbc.co.uk/programmes/b04plphs See above, From comments made at end of last program it sounded as if the vans involved may be same as this forum subject. If you watch last 5 minutes of episode 4 on Iplayer you can see makes involved.

Perce #50 wrote "Ride a section on your TY & then flog it round a moor for 1/2 an hour, then ride section again. Repeat process on any modern water cooled bike of your choice. If you still want to ride a TY, you're nuts." Harold Crawford, Alderson Alderson in the Scott did OK TYs but I think PA had gassers suspension in his. I had Ty250s for quite a few years and the suspension improvement from the red framed to the white framed model was significant. I actually found the TY250R a very comfortable bike to ride, more comfortable than modern gassers and Betas but oddly enough I found the TYZ horrible to ride, very uncomfortable. I think it would be on the Wainright trial in about 1993 when it was clear that the Beta rear suspension was a step up from the TYR, such is progress. It is very true that modern bikes are well beyond the capabilities of most riders. Sections that have been in use for close on 40 years still challenge most riders as much as they ever did despite bike improvements. Back to the Vertigo, I wonder what effect it and the TRS will have on other marques sales, Ossa and Jotagas in particular.

The 3 sections look like Whaw Bridge, Surrender and Clapgate. That downhill just after Surrender is a bit steeper than it looks on video and where the rushes are at the bottom is a right soft spot if you are just a few inches to right hand side, usually has a few over the bars. Colley and Lampkin had a good battle that year and both looked tired well before the finish.

Carb jets may be clean but are all the passages in the carb clean? Coujld you have powdery rust in the tank (often forms on a laid up bike) that clogs the in tank filter as soon as the bike runs. Anyone you can borrow a tank and carb off? Disconnect the condenser - bike will rub OK for a while without it until points get dirty due to arcing. Check HT and LT coils for resistance both with bike cold and just after it has run. Points. Where the wire connects the spring they are riveted together. Corrosion can increase the resistance of this joint causing no or intermittent running. I have had this happen with brand new points - because they had laid on dealers shelf for many years.

Probably sub contracted to Gasgas

Not surprised that the French have gone this way, its all the frogs legs and snails in their diet, makes them hop and stop.

Thanks for that. Just thought I would add that is is good practice on any liquid cooled bike, trials, mx or enduro to fit a longer vent tube on the coolant system and position it where you will see steam or water coming out if it starts to overheat. I know several riders who could have saved £several hundred, and one a trip up the road on his backside with this easy mod.

Heavy VS light. All things in engineering are a compromise. It is my view that the best compromise, between weight, performance, cost and reliability, for the majority of riders lies at about 75Kg rather than under 70 Kg. In their quest to reduce weight Gasgas have given us frames that break, kickstarts that are fragile and gearboxes that break, fuel taps that leak and now they are having to discount to get rid of over production. Mont / Honda on the other hand are so confident of sales of their HEAVIER bikes only feel it necessary to have 3 dealers. In addition look at the resale values of HEAVY Monts compared to LIGHT GGs and Ossas. Take a Beta swinging arm spindle nut for example. Quite a nice piece of machined lightweight alloy that is then black anodised BUT it is not even a locknut, occasionally falls off and costs about £7.50. If it were not for the quest to reduce weight a standard thin section M16 x 1.5 nyloc nut could be used, more reliable at about 50 pence. Many of the developments that have taken place such as disc brakes and monoshock rear suspension clearly outperform their predecessors and have few drawbacks but some of the developments taking place to shave the last few grams off or squeeze a bit more power out of the engine are of dubious value, particularly when long term maintenance costs and reliability considerations are taken into account. Only time will tell what price and how reliable the Vertigo is but for me the electronic complexity is already a turn off, but perhaps for rides who can't tune a carb EFI is a big plus (until it goes wrong)

If you filled it to the brim with coolant you can expect some to blow out first time it gets hot. To check you fan is working blank the radiator off and run the bike at a fast idle (in neutral) if it blows more coolant out without the fan coming on either thermostat or fan is probably faulty but it could be a loose wire or electrical supply to them. Running at 50:1 or 60:1 will have virtually no effect on coolant temperature. It is up to the owner to choose what fuel:oil ratio he runs his bike at but I really would like to see an end to the false assertion that rich oil ratios dirty the engine, they do not. Dirty engines are due to poor (or inappropriate) oil, poor petrol or poor carburation. In fact more oil gives a cleaner engine because it seals the piston / rings / bore better and reduces blowby. Blowby carries combustion by products into the crankcase where they settle as deposits, when they should be blown out with the exhaust gases.

http://www.penriteoil.com.au/tech_pdfs/V3_RISE%20AND%20FALL%20OF%20CASTOR.pdf Makes you wonder why Shell still make castor based oils for karts and Castrol make 747 for mx and road racing?

http://twostrokemotocross.com/2012/10/wiseco-2-stroke-tech-tip-piston-ring-gap/

So now we have an electric pump (plus its power supply, monitoring and control circuitry) as well as an electric fan to go wrong, I would have far rather seen a mechanical pump retained and a water powered fan motor. I know I may be called a dinosaur but to me trials should be about tackling rough terrain and rider skill, not technological development. The main cooling system faults on current trials bikes are, lack of water capacity, lack of radiator size, radiator clogging and fan electrical failure. The addition of an electric pump solves none of these. There is no reason why the seals on an electric pump will be any more reliable than those on a mechanical pump and it may be that the pump is an expensive sealed unit.