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I am not intending going to watch although we have got a couple of brave souls from down here in Kent having a go ( good luck Gravesend club) I would have just liked a bit of back story I am sure there has always been a build up in the past. Perhaps I will get a look at a copy of TMX as I am not on any 'social media' type info sites

Have I missed it ? I thought the event was this weekend but nothing to preview the trial yet.

Go with the modern bike and just ride the easier routes, a twin shock will still typically be ridden on the easy route but significantly harder to ride as a novice.

If you are going to worry about the difference in unsprung weight between each end of a variable Spring rate Spring then I suggest you give up trials, as the first thing you add to your bike around here in the winter is a couple of Kilos of mud ! Yes I am aware that everything helps, in that case never eat a chip again.

There are valves, they are under the screwed in caps on the end (opposite the driven end)

I am not sure what you mean exactly, but if simply twisting the forks straight does not work my next step would be to slacken off all of the clamp points that's the 4 points on the yokes ( triple trees) the mudguard mounting and the wheel spindle then give it all a general shake and pull around, obviously I mean slight slacken and not loose or the forks will slide straight up through the yokes ! Then straighten the assembly and tighten, hopefully this will have it sorted of not then you may have a bent leg which would surprise me given the video evidence, hardly a big off !

I have just googled your style of oil pump and it is similar ( the same ) as used on an Ariel, the larger of the two pistons is the return pump. It is larger to ensure it is able to pump more out than is being put in, under the square headed screw is a spring and ball one way valve, I suggest a bit of muck has stopped this valve from seating properly and the return pump is then not doing its job. How old is the pump ? It could of course just be worn out as it is a simple close fitting plain piston in a smooth ( ! ) bore, I suggest you remove the pump and inspect. The ball and spring behind the pump is really a back-up you have got to get the pump right first.

If you drained 300ml from the crankcase that's your problem, I am not familiar with the cub engine but somehow you have 'wet sumped' so that's either the pump not returning the oil at a high enough rate ( if at all ) or the oil system is simply draining itself into your sump due to lack of non return valves ?? I would suggest you get yourself a schematic of the oiling system and find out how it is meant to work.

Hopefully he's just twisted the forks in the yokes rather than bent them, hold the front wheel between your legs and pull on the handlebars to straighten, I seem to do it most rides !

My Ariel used to leak from the rocker covers after a days hard use, I cured it completely by adding large vent pipes to both rocker cover caps. These run vertically up under the tank and have a small gauze filter on the ends to stop muck being pulled in. The engine was just not vented enough or it has a bit of blow-by, either way the venting cured the weeping problem.

Well done Vertigo, lovely looking bike to get the kids excited, only comments would be, how about some protection on that exhaust pipe ? Little people falling off in the mud and they don't have the self preservation instincts ( or burn experiance ) of adults to know not to touch it. Will it be entry level pricing or is it a rich mans toy.

Nearer 40 years ago down here in the South East (U.K.)

Go with a proper trials tire, IRC or Michelin (no experiance of the new Dunlop) You must remember it's the only thing touching the ground and giving you everything, grip, directional control, stability, power transfer, if you try a cheap imitation or knackered secondhand one you will not know if it's you or the bike that's failing the section ! Trials is still exceptional good value for money and the extra few quid on good tires cannot be underestimated. Lastly, put a cheaper tire on and when you come to sell the bike the potential buyer will probably knock you for the cost of the tire anyway as they will more than likely want a proper one.

Modern riding techniques mean that ground clearance is not as important as it once was, you are just going to learn how to unweight the bike over obstacles or double blip etc. You may find your slightly lower ground clearance has advantages in the stability department. At one time tight turning radius was all important, then moving the back round became possible so steering round was no longer the only way to position your bike. I bet my Ariel turns tighter than your modern bike, there again I can't for the life of me move the back round ! ,it also has very good ground clearance as unweighting that hefferlump does not happen !

Since some posts have now been removed this does not read as it did

Another possibility is to find a standard set of rings to match your bore and then get the piston modified to accept them You have to make sure whoever modifies the piston for you understands about side clearance, but its not rocket science.

I am pleased you agree with me, I was more concerned with the miss-interpretation of the product shown and how it was being used to wrongly argue a point. I agree that the system of clamping is not a good idea in this application.

The photograph of a bike rack on the floor is not a Dave Cooper rack and I think it's method of attachment is being miss interpreted. There is an assembly which consists of a tow hitch and a horizontal square tube attached to a clamp which then goes onto the swan neck tow bar. The two frames then slide into the horizontal tube and are held in place with pinch bolts, the bar that has been identified as going under the tow bar frame is in fact one of the bike supports, looks like the picture was taken at a garage sale. Before everyone gets carried away with redesigning this product take a closer look Or have I got it wrong ?

Two issues with the fibre glass tanks, firstly are they made with the correct resin ? Very difficult to prove as resin is resin, apart from the petrol resistant version is apparently very expensive and has to be purchased in quantities that only a mass producer would use hence the demise of your small producer ( Sammy Miller spares used to do HT5 tanks but were dropped a couple of years ago). Secondly, accident damage, my last fibre glass tank all beautifully painted up only lasted a couple of trials, a simple drop in a jumble of rocks ended its life, it's alloy replacement has had numerous clouts with hard things and although looks a little secondhand is still able to carry on.

Why don't you just give Dave a call I am sure he won't bite your head off.

Very enjoyable book, but I am also surprised at the lack of Vertigo history/detail and the over detail of the wheelie.

Looks like 2 bikes or did you change the forks between photos ?

Same applies to the paint, if it's rattle can then it may not be petrol resistant. Seek advice from a body shop or someone with modern paint experiance

I sprayed my alloy tank and then varnished with apparently the correct varnish only to find petrol softens it instantly ! Can't understand why rattle can varnish supplied from a car accessory shop is not resistant to fuel. Next time I will do my artwork then take it to be clear coated, the varnish brings the colour to life.

Are you sure you mean late 70's ? That looks more like early/mid 70's unless they carried on that style for the 125/172 model. Rear mudguard looks wrong, give it a good bounce and the tire might eat it ! Never seen a green Montesa, was it factory or did someone personalise it or sponsor it, or was it some sort of regional export model (Gasgas went all silver once to separate the U.K. bikes from the grey imports)