trialsrfun

We were sitting further back behind that rock on the web picture so could not see any fuel leaks but the carb mod is 100% effective on my bike, was his bike at some crazy angle when the fuel leaked out Bob.

Thank you Andy for the excellent picture of Antonio Bou riding off the rock that I now have as a desktop image, overall I thought his bike looks very std but is it me or are the footrests much lower mounted than normal and the front fork yokes (triple clamps for you guys in the US) appear different also. The top one is not the 06 type as it does not seem to have the slots milled in where the legs go through and the fork legs appear to slope back as though the steering stem and legs are not parallel so making the bike wheeelbase shorter, what do you all think then again it may just be the camera angle ?

We too run our Betas at 70-1 (50-1 while running in) on Silkolene semi-synthetic pre-mix, I know loads of you run with fully synthetic oils but my understanding of it is that a trials bike does not run at a high enough rpm to maintain a sufficiently stable engine temperature to enable a fully synthetic oil to do its job properly.

Stay with the gallons Charlie they switched us to litres and now we pay about the same per litre as you do for a gallon.

Bobs suggestion is exactly what I did with my sons bike moving them out as and when he felt cramped on the bike, there is definitely a noticeable loss of leverage though when the grips are moved inwards. But to try costs nothing remove the left hand grip move in the levers and twistgrip and have a go. We used a pair of expanding plug type bar end stops until the grips were back out to the bar ends, these work well but you can get debris down the twistgrip barrel so maybe a need to remove and clean after a mucky trial if the bike has been dropped. The Tomasselli bars that Beta fit as standard are a little narrower than Renthal anyway. Have you tried tipping the bars forward or moving them backwards to see if it makes all the difference.

I am following this with interest as I am building a Cub at the moment, OTF mentions the air filter flow rate can make a difference so which air filter is the best. Some people fit the gauze cone type others the alloy Miller one with the paper element filter (I think this is a car filter cut in half) but surely unless there is a decent splashguard around it the paper type will get wet and give trouble so what filter do we fit to a trials cub. Steve+Cub sorry I am unable to help good luck with the bike.

Subira the Mont looks the real deal superb, I always fancied a 315r but never did get one. Right now I have a 250 Rev 3 which is a brilliant bike.

I fitted a tubeless IRC with tube to the back wheel of my 325 Sherpa it has 2 security bolts in the Akront TC rim positioned opposite each other. There is a little bit of tyre creep (rotates around the rim slightly) but overall it works very well. Woody do you by any chance have the security bolts at 90 degrees to each other so leaving a lot of rim unsupported. The main reason for me buying a tubeless tyre was non availibility of tube type when I needed one.

Very nice job Marky, was the colour scheme Scorpa inspired ?

Does anyone know what might have happened to any/all of the Works 315Rs, did any (or the trick parts) escape into the hands of joe public ?

Superglue or Liquid Nail ?

I too am having difficulty obtaining a Cub splined kickstart assembly but lots of people seem to have fitted a Gas Gas kickstart to their Cubs, how do they get them to fit, does it need, the Cub kickstart shaft splines (assuming you have one in the first place) altering to suit the GG lever the GG lever altering to suit the Cub splines is there another way ? Why not just stay with the cotter pin type all the bits are readily available and this system is used on many other bikes & has been used to propel thousands of bicycles along for years. Does anyone know how to fit the GG lever to a Cub.

Friend of mine rides a Cub and he too runs with a small Japanese carb about 18mm choke he picked it up from a Stafford Autojumble for little or nothing. The bike runs really well on it but we do not know what it came from and have not seen another like it so it looks like a Del-Orto is one way to go assuming that you can ride at most events with one. Judging by the number of Cubs with a Del-Orto fitted they must be accepted by most clubs.

I had thought of riding in some Midland Classic trials once the Cub is completed but what is ok and what is not, or do they have a class for non original bikes ? Are the Yorks Classic events similar in severity then to the MC ones.

It seems that the 29t sleeve gear is for trials, 29t trials 28t road 27t close ratio 25t extra close reatio Also both gears throughout the gearbox always add up to 45 teeth per pair, have to add I am not the anorak that worked this one out.

Sounds an interesting project, take lots of photos including close ups of everything before you start work and throw nothing away save everything it can always go back on again later. If you want to ride it it needs to run well so the ignition needs to be just so as well as the carb. Do not have any experience of the BSAs but I think many people run the PVL ign. system. Good luck.

The Imperial equivalant of 428 chain is I think 1/2 x 5/16 for good advice try Sprockets Unlimited their email is astrosprox@btinternet.com Cannot help with the plug as usually they are a direct replacement check the thread it can be Helicoiled to repair it. What is the bike ?

The sleeve gear is 29t which I believe is for trials, got the idea of 13/60-62 from the Sammy Miller catologue these ratios would seem to be very much lower than the ones you have Subira. Is the WR gearset the trials one with the 29t sleeve gear. Know what you mean Totalshell about the Villiers gearing I too have tried every combination low 1st, high 1st, different 2nds & 3rds you name it. Best set up for me is 20t engine with heavy duty endless chain from Simon Bateman/Nametab Eng. trials cluster with a 2 cog 2nd again fron Simon, 13t on gearbox & I think 62 on rear wheel. 2nd is useful and no big jump between 3 & 4 also the primary chain which compared to a Cub is minimal lasts ok without stretching.

Thank you all for your help, work has kept me away from the garage recently but I will check all the items suggested.

Not too good along a narrow rut with those fork legs & rear sprocket, seat height a bit elevated as well. Same problem I imagine as all scrambles/moto x engines have difficult fitting a weighted flywheel on the ignition side to give bottom end power.

What is the performance difference between a std cam & an R cam when fitted to a 199cc Cub. If the R cam is used do you need to fit stronger valve springs. Also engine, gearbox & rear wheel sprockets, I thought of going with 17t engine, 13t gearbox & 60 or 62 rear wheel on 420 chain, does a wider size chain catch or rub around the gearbox sprocket area. Which is the best Carb to use I am told the Del-Orto 22mm is very good is this correct.

Dabill & Morris excellent, does this mean 8 riders in total ? Last time we were sitting right at the front by the 2 sections where Dougie lost his time penalties before getting 5s, Fujinami then rode up to them touched his wheel on the start of each to take a 5 & rode on thereby saving overall points, I think we were among several hundred people in that part of the arena that immediately realised just what this meant for Dougie, things went deadly quite & you could feel the tension. I imagine Fuji said to a mate (if he could find one) go out the back and start the car A while later though he did get some applause. When Dougie rode around the outside edge of the arena after he was eliminated the look on his face said it all he was gutted. Good luck this time Dougie we all will be cheering for you.

We have got the tickets but who will we see there & what might they be riding. Is Doug on the Montesa or what, last time he changed marques he rode out of a packing case with fireworks and music might we get a repeat. Anyone out there know.

Chainsaws also have carbs or injection systems enabling them to run normally in any position.

Wonder where some of these modified bikes disappear to sitting in a shed somewhere I imagine.