8 replies to this topic

[Petorius]

Looking for a little guidance and this would seem the place to be, I have recently bought a rough Tiger cub with the notion of humiliating myself in some pre 65 trials. However the more I look into this the more difficult it seems to be to know what to options to take in setting it up. The first hurdle was actually easier than anticipated, I started it at the weekend and the engine and gearbox seem okay. I bought a 4.00 trials tyre to check if it would fit and seems okay in what I believe is the wider swinging arm except for the chain running very, very close to the tyre. I think I will try and mover the engine over a few mm and I also notice that there is a front sprocket available with an off set to bring the chain out, does anyone know how much this offset is?
Actually I have lots of questions so might as well just post them all together, the gearbox is standard road gearing I believe, what size sprockets would be best? Is it worthwhile fitting the low second gear option I have also noticed that it is available? The forks are 30mm Japanese, XL 125 or similar, are these viable? I do have the severely decomposed original forks and yolks. The wheelbase is around 50.5” at present, would it be worth extending the swinging arm a couple of inches? Is it worth bracing the frame at the top tube as I notice some people have done? I will have to make some foot peg mounts and fit a chain tensioner which I hope will be straightforward although I suspect there will be kickstart issues. I will have to invest in some rear shocks, I’m guessing 340mm would be most suitable, 40lb springs for an 80kg rider?
Any guidance is appreciated, there just seems to be so many options, I should perhaps mention the engine no is T20 75999, tiger cub tank and there seems to be bracing inside, well it looks like a channel section steel inside. Electrex electronic ignition seems a good idea so that at least is one decision made.

I’m sure there are lots of other things but hopefully things will become clearer.

Going to visit Telford show with a tape measure hopefully there will be some Cubs there.

Many thanks,

Mark

[wayne_weedon]

It should be "simple" alas it's a minefield a controversial one at that

[Old trials fanatic]

Good luck youve picked what is argueably out of the most complicated bikes to make into a competitive trials bike. Hope youve got deep pockets.

[brucey]

I think you need to ask yourself the following questions:

What sort of competitions do you want to do? i.e beginners and wobblers club trials to pre 65 championship rounds
What mechanical ability and facilities do you have?
What sort of budget do you have?

Then do some research by attending pre 65 trials like the Talmag (where most people are more than happy to talk about their bikes), look on ebay for parts and complete bike prices and go to Autojumbles (bigger the better) to pick up the bits you need.

Personally, I'd get the bike running reliably as it is and ride it to see if you like riding 'classic' bikes before spending too much money.

There are some photo's of my recently completed Cub on this forum which cost me in the region of £2K in parts alone! You can buy a really nice modern bike for that sort of money and require a fraction of the fettling and maintenance.

Even though I have just swapped my spare cub parts for a modern bike for modern club trials, I still wouldn't part with the Cub for the pre 65 stuff, but then I like playing in my shed!

Edited by brucey, 09 January 2012 - 10:37 PM.

[Petorius]

Thanks chaps,

Yes i think i might have a re-assessment, i rather like working on bikes and am fairly competent so that is part of the fun but the difficult part seems to be where to draw the line. My thoughts are that you just have to go your own way so i think that will be the plan.

[brucey]

Petorius, on 10 January 2012 - 10:44 AM, said:

Thanks chaps,

Yes i think i might have a re-assessment, i rather like working on bikes and am fairly competent so that is part of the fun but the difficult part seems to be where to draw the line. My thoughts are that you just have to go your own way so i think that will be the plan.

I would just like to add that you can build a really nice Trials Cub which would be more than competitive at pre 65 club level for very reasonable money. Believe me, I've seen them!

The trick is (and I may offend some purists here) to get the expensive bits like forks, ally wheels and tank (ty 175) from old twinshock bikes and adapt them to fit a Cub. I have used a set of 1970's Montesa forks on my bike and fitted Taper Headstock Bearings and the Montesa ally billet Yolks at the same time at a total cost of about £100. I've seen complete Montesa rolling chassis go on e bay for under £200 which is what you would pay for an alloy Cub back wheel.

Bruce.

[Old trials fanatic]

brucey, on 10 January 2012 - 12:55 PM, said:

I would just like to add that you can build a really nice Trials Cub which would be more than competitive at pre 65 club level for very reasonable money. Believe me, I've seen them!

The trick is (and I may offend some purists here) to get the expensive bits like forks, ally wheels and tank (ty 175) from old twinshock bikes and adapt them to fit a Cub. I have used a set of 1970's Montesa forks on my bike and fitted Taper Headstock Bearings and the Montesa ally billet Yolks at the same time at a total cost of about £100. I've seen complete Montesa rolling chassis go on e bay for under £200 which is what you would pay for an alloy Cub back wheel.

Bruce.

True but check first that the clubs whose events you wish to ride at will allow those sort of "mods" as there is an inconsistency stating "competitive at pre 65 club level" then using "1970's Montesa forks" etc. Good luck and enjoy your bike whatever you do.

[totalshell]

the basics for a competant cub that is eligble for 99% of pre 65 clubs are actually fairly simple.
you d want a later engine ( square for fashion not for function), a well sorted amal concentric carb, nicely set up heavyweight cub or c15 forks, new rear shocks ( any new trials shocks would be better than std..) miller footrests and brackets domino slow throttle wide rear swingarm , alloy rims and electronic ignition..

that should be good enough to ride through all clubs p65 sections and certainly even in an ultra competative club would be enough for a good rider to place well on.

i wrote an article for the club news letter describing the mods done to a std bike that was then used to win the welsh experts trial in the early sixties and the mods were very basic very..

[Hammertight]

totalshell, on 12 January 2012 - 08:43 PM, said:

the basics for a competant cub that is eligble for 99% of pre 65 clubs are actually fairly simple.
you d want a later engine ( square for fashion not for function), a well sorted amal concentric carb, nicely set up heavyweight cub or c15 forks, new rear shocks ( any new trials shocks would be better than std..) miller footrests and brackets domino slow throttle wide rear swingarm , alloy rims and electronic ignition..

that should be good enough to ride through all clubs p65 sections and certainly even in an ultra competative club would be enough for a good rider to place well on.

i wrote an article for the club news letter describing the mods done to a std bike that was then used to win the welsh experts trial in the early sixties and the mods were very basic very..

This letter should be compulsory reading for every Cub owner.....