section swept

Decompressor?only a suggestion. An inch longer kickstart makes a difference with the extra leverage assume cut and weld needed or swap.

Park Ferme .....Car Park ...It was in the Park Ferme ....Car Park, Mr Noble did that one to death!?? Every bike in nearly all the shots looked the same, some mention of manufacturers involved and bike engine capacities would have helped serve the general viewing public and increased awareness. Where were some shots of Dougie as its usual to show the top flight competitor, again the public could have gauged Ross’s efforts more appreciatively. Some of the early 60’s films of this and other trials come across as more entertaining. I suspect anyone watching looking to take up a sport would delete Trials from their list as too difficult and potentially dangerous. Ross bog trotting and falling off again and again showed there was a distinct lack of guidance and advice, only on the last day did we hear James tell Ross to follow other riders tracks and to lift the front to get over the bogs? When I first saw the trailers for the show I waited with baited breath, now I’ve seen all three and I have to own up here; for the last 20 minutes I channel hopped between Ross and Master Chef as I had just about lost interest! Park Ferme ...Car Park etc etc 5/10 for the film 10/10 for Ross’s effort even though he had not prepared in plenty of time.

I have to agree that apart from colour schemes most of the Trials bikes now all tend to mirror each other, bit like all the jelly mold cars we have charging about! Nothing tends to be readily identifiable now unlike in the 80’s and 70’s and before; when bikes had character, then you could tell a make and model from the noise, from the outline and layout of the bike.

Erm, bigger piston equals bigger push down the cylinder bore equals bigger shove from the rear wheel. So a 250 has less shove than a 300. Otherwise what’s the point in the oversize engine? John Shirt when he was developing his 320 Majesty brought it to a weekend event I organised. This thing would go up any hill but the clutch was now the weak link as it developed so much torque. Bigger bore more torque more lugging power to get you through a section!

I’m afraid the internet auction sites make it all to easy to sell the parts stripped off a stolen bike. Anything that can be identified such as engine cases and frames get destroyed or doctored. A few years back a road bike I owned and was never going to part with got stolen from outside my office with security staff watching what they thought was me ( bloke in a crash helmet) fiddling with the chain and lock which went through the back wheel and up and over the seat. He then overcame the ignition/steering lock ( screwdriver I assume) and rode off. The bike an early 1988 Honda XL600V Transalp was worth far more in parts than it’s assembled whole, with just 15000 kilometres showing ( German Impor). Never heard hide nor hare after the event, insurance paid out but it’s not the same, where do you find another like that?☹️

The plug chop will show you how the mixture is under load, just like making the engine work hard in a section. Constant throttle on off as in a section or practising will produce the type of colour you have in the photo. The fuel and oil hangs around longer in the 2T combustion chamber than in a four stroke and this influences the plug colour, the trick is to ensure the jetting, filter and settings are spot on. Altitude and humidity will all have an effect. Rain will give a denser air, hot weather will reduce oxygen content. Riding in a wooded area or forest will usually produce moisture laden air and the bike may feel more responsive. Equally riding at night when the air cools down gives denser air and the bike seems to respond more, your car etc will also react the same. ? You’ll have to advise me what roads you are using as you apparently attract accidents. Maybe put the bike away until you are 100% healed up. ?

No to what? Holding the brakes under pressure after bleeding will cause any tiny bubbles in the fluid to rise.?

Holding the hydraulic brakes on...under pressure... for at least a overnight time will cause the tiny air bubbles to travel up to the highest point...usually the fluid reservoir in this case...and give a more firmer feel to the pedal/ lever. On bikes I’ve had with hydraulic brakes this method works every time. Fairly obviously the system will either have been bled prior to this or after use i.e. putting the bike away.?Bubbles can’t get to the reservoir if the lever is off due to there being no real pressure in the system, any residual pressure is not sufficient to create the effect.??

And the experience/skill level of the rider. Fewer gears means you have to just get on and ride effectively.

Half way through the rebuild stage photo’s when completed. Should look just like a 1972 M80 Sherpa...hopefully! ?

Once you have bled the hydraulic brake system, use a bungy or cut inner tube elastic band to hold the brake lever in the on position overnight this will cause any tiny (microscopic) air bubbles to rise to the fluid reservoir. Release the bungy etc and operate lever it should now feel more positive. For the rear brake rest a weight on the pedal or tension with some bungy etc and the same effect will be achieved? Brake fluid is hygroscopic which means it absorbs moisture readily from the atmosphere. Keep any spare fluid in an airtight container and avoid shaking the container as this induces air bubbles into the fluid. If possible transfer spare fluid to a smaller container this stops air contaminating the fluid, bit like wine keeping. Fully synthetic brake fluid shouldn’t absorb moisture or attack painted surfaces but take care not to spill any just in case!

False wall. Sounds ridiculous but a blown up photo of the back of your shed, garage mounted on a simple frame will confuse the hell out of pond life thieving scum. Especially if you take the photo with the bike out the way. I get worried when the delivery van drivers are lurking about, no disrespect to the good guys? I get even more worried when I haven’t had chance to cover the bike up. Actually it’s not just bikes they are after but easily disposed of equipment. A bike delivery firm that I use offer a store your bike for a few days/ weeks service in their secure warehouse all fully insured. The driver told me that they have 24/7 security but not how much it cost. So if you are going on holiday, away for whatever reason you might consider moving your bike/s elsewhere. Club members, forum members could get together with one person offering to be custodian of two or three bikes being kept at their location. Just an idea but there may be some worth in the concept.??

Now if they could just fit a hinge in the middle and produce a nice storage bag I could take it on the train as hand luggage. Fit some fizzie pedals on it and ride on the rode as a mountain bike? What a fantastic development and still they get lighter. No ethanol attacking the fuel system issues either. The price is a tad eye watering for me though.?

The bigger, heavier you are the bigger the ‘zap’ and ‘splatter’ when you fall off! ???

Well I wonder what the works riders use or prefer, bike A for rocky trials and bike B for mixed going. Five speed usually means slightly lighter bike, unless the gears are constructed larger for strength. Six speed gives a wider choice of usable ratios to select for different riding conditions. Also consider that the manufacturer may intend at production the engine type to be installed in enduro models not just trials. Obviously tuned differently but still utilising the same engine casing etc. Six gears allows higher road speed or more fuel saving if speed reduced. Lower engine revs equals lower wear rate.

Plug chop needs to be done. Engine hot not warm, ride along a flattish track or on the road at brisk acceleration 4th gear for at least 2/300 yards further if possible, the idea is to put the engine under a constant load making it do work. Pull the clutch in and at some time kill engine and keeping clutch in coast to a halt. Remove plug and check colour, rich tea biscuit colour is good, black is too rich fuel. Too much oil makes fuelling bad and reduces fuels ability to burn effectively. Has this bike been properly set-up by dealer or just unpacked and sold? Carb float level may need to checked. With a duff back and broken wrist I’d not ride until all is back to normal. Just running a two stroke and blipping the throttle is not good for bedding in rings and bearings. Some gentle road work will work wonders for bedding the rings and creating a better seal between cylinder and piston rings. Good way to burn off some of the crap that’s now lurking about in the exhaust. Hope you sort it ?

Not sure about size but knock them out carefully, you may find two on the drive side and just the one on the other side. Measure the inside diameter of the hud where the bearing fits. Measure the outside diameter of the removed bearing/s. Measure the inside diameter of the bearing and the wheel spindle exactly where the bearing will slide to. Google Simply Bearings check the measurements on their easy to use site and order. Every time I have used them they have delivered the next day and very respectsble prices to. There are other bearing suppliers I’m just passing on my experience for you benefit. Change the seals as well and use clean grease. If you buy sealed bearings (they have their own sealing arrangement) and will last longer in the long run. Hope this is useful to you.

Everything costs so much now and a 4 stroke road bike converted to trials trim would probably mean looking at a pre 1960’s bike or earlier as most trials versions of the then road bike were merely versions of the road model. I am looking at obtaining a 1953/4 350 AJS road bike two are advertised at around £3500 but the same machine as a Trials bike is nigh on £9000+. You are probably just as aware of the current state of affairs with older bikes rocketing in value ( perceived or otherwise). As you are coming from scrambling/mx due to ‘it hurting more’ in an off it’ll hurt just as much in spill! The Cub and C15 are a good bet but pricey. Converting a bike from road to trials or even scrambling would be absorbing and rewarding but the cost as others have pointed out wil be restrictive unless you’ve just got 5 numbers and the lucky stars. If you go for a Trials bike check all the mods that have been done and make sure of the legitimacy for acceptance into the various classes. Hope you get what you want. You might also consider a BSA B40 the extra umph may help with the erm body weight? Bear in mind if you get a pre-unit bike it won’t be much lighter if any than a similar scrambles machine.

I’m based near Mansfield and am quite handy with the spanner’s and diagnostics. Throw away any old fuel if it’s still in the tank. Make sure the fuel tap allows fuel to flow, the filter if still there may be blocked. The carb float needs to be free and not stuck in the up position. The float needle needs to be free to allow fuel into the bowl and actually shut the yellow off when raised by the float. This is a bit like the toilet system. Remove the spark plug and ensure there is a gap (thickness of a thumb nail will do for now) refit the plug to the HT (high tension) lead cap and rest with the plug metal body touching the cylinder head fins. Make sure bike is in neutral, use kickstart to spin engine over. You should see a lovely fat spark at the plug gap! If not then the contact breakers may be stuck or not opening, I am assuming the bike has not been upgraded with an after market electronic ignition kit. If you have a spark you nearly there. Fuel, air and a spark, now all you need is compression. Refit the spark plug and press down on the kickstart with one hand, leave the plug lead off! You should feel good resistance, if the kickstart turns the engine easily then compression may be poor or the rings may be stuck in the ring grooves in the piston. Crankcase seals if worn will produce all sorts of starting and running issues. That’s about it for you to try should take 20-30 minutes. Dots had alloy tanks, if yours has a glass fibre tank then you have more issues to consider. If your Villiers engine has an alloy barrel and most did from Dot the you must be really careful that if working on the piston the rings will be plain and NOT chromed. The cylinder in alloy barrel was chrome plated and chrome on chrome will tear itself apart. The Villiers engine may have an iron barrel which can take the chrome top ring no issues. Hop this helps and you have some success.

If you do change the crankshaft oil seals and bearings with non Yamaha parts try to get Viton seals as these can withstand the heat far better than the neoprene type. These may be more costly but worth the investment. Be careful with the main bearings and go for a C3 grade type as these bearings are designed to deal with the heat/expansion and contraction within the engine. Breathers need hoses/ plastic pipes to prevent water and tiny specs of grit getting in the transmission, ignition cases. I run mine back and up inside the main backbone of the TY frame. Make sure all the carb breather pipes are fitted and routed correctly. Blocked breathers in the transmission can allow gas pressure to build up and force oil out through seals and weak gaskets. It’s the heat generated as the gearbox oil gets hot. I’ve had to clear many a blocked breather to cure oil seal leaks, mainly on 4x4’s where they’ve been up to their axles in mud and the poor breathers let the rubbish in and it then bakes hard in the breather. Same applies to fork breathers. Enjoy your TY they are getting thin on the ground.?

Having spent more than a few hours researching different trials bikes and members issues on this site, I have finally taken the plunge and signed up?. I am currently restoring a 1972 Bultaco M80 Sherpa 250 ‘T’ Kit Campeon. This will be my third trials bike that I have restored since taking early retirement from an Automotive Engineering background. Previously a 1980 Bultaco 199a 350 (325) Sherpa ‘T’ and then a 1979 Yamaha TY 250 E. The last time I rode a Trials bike in anger was at the Trade and Press Barons Wazy Goose Trial held at Brands Hatch in 1979. I have always had road bikes (many) my last being a KTM 990 Adventure, a fantastic machine. That went when I decided that it was too dangerous to ride on the roads, far too many white van’s (hire) being driven by phone addicts and driving standards in general leaving an awful lot to be desired. I have owned a Francis Barnett Trials bike and then a Sprite 250 Trials. Around 1976 I became the owner of an ex-works 1972 Bultaco 325 Sherpa ‘T’ Kit Campeon, what a bike that was and I wish I had never sold it!? Just a bit about me and I look forward to being a member, cheers?