my project currently has some 36mm jap forks in that are not really suitable for trials, I am planning to change to bultaco 35mm leading axle forks as I have access to some, my question is what type of yokes? cubs are non parallel with 1.5 degrees in the yokes as standard, but given that I am changing to leading axle forks should I be looking of parallel yokes to compensate for this change or would non parallel ones work without causing issues to trail/rake?
1 hour ago, trialsrfun said:
Hi Erem,
The 35mm Montesa fork legs from the 1970s Cota bikes are very suitable for your Triumph Cub but ideally need to be fitted into lower fork legs from Triumph, Norton or AS/Matchless these two brands use the same forks.
The lower fork leg from th Montsa is slimmd down to fit into the type of fork you choose then usually a joining piece to make up the gap between the two turned to suit.
Best to find someone to do the machining work who has done this conversion before. If you can make it to the Telford off road show next month there will be people there who do this sot of work.
The Triumph lower legs seem much harder to find than either of the other types they weigh more and are slimmer internally so the donor legs have to be turned to a smaller diameter than needed for the other makes. Both Norton and AJS Matchless lower legs are I think being remanufactured.
I think lots of the alloy lower legs were removed and replaced with new due to wear developing causing mot failure, this wear is unimportant though when another leg is fitted inside the worn one.
I have sent 2 emails and received a standard generic reply saying your enquiry has been successfully submitted and will be processed as soon as possible.
Is it that they are just so busy or cant be a***d?
Think this site is run as an hobby by a trials enthusiast.
I recently got a 1961 tiger cub. Unfortunately the front fork comes from a Montesa. I would like to go to scottish pre 65 2 days trial. Which front fork can I get suitable for this trial ? I read something about marzocchi hydraulic fitted into an original forks ?...
Thanks in advanced
Hi Erem,
The 35mm Montesa fork legs from the 1970s Cota bikes are very suitable for your Triumph Cub but ideally need to be fitted into lower fork legs from Triumph, Norton or AS/Matchless these two brands use the same forks.
The lower fork leg from the Montsa is slimmed down to fit into the type of fork you choose either Triumph lower legs which are steel or alloy AJS type then usually a joining piece to make up the gap between the two turned to suit.
Best to find someone to do the machining work who has done this conversion before. If you can make it to the Telford off road show next month there will be people there who do this.
The Triumph lower legs seem much harder to find than either of the other types, they weigh more and are slimmer internally so the donor legs have to be turned to a smaller diameter than needed for the other makes. Both Norton and AJS Matchless lower legs are I think being remanufactured.
I think lots of the alloy lower legs about on autojumble stands were removed and replaced with new due to wear developing causing MOT test failure, this wear is unimportant though when another leg is fitted inside the worn one.
Hi I’m thinking about building a trials project, I’ve various bits including a tiger cub engine and a c15 frame that looks like it’s been modified for trials. My first question is has anyone put a cub engine with a c15 frame and was it successful ? Or should I just source a tiger cub frame ?
Speaking as a Cub owner I think a better option might be to put a C15 engine into a Cub frame but back to your question the C15 frame is sturdy and handles well I once put a Villiers engine in one which was removed from a Francis Barnett that broke in half to make a trials bike but why not try to get a Cub frame to keep it easier.
Cannot argue with the bike though, place that engine and gearbox into the next generation swing arm frame which had the Roadholder teleforks possibly a few minor course alterations could by then have been implemented and you have a bike that would average a 100 mph lap. Bet that would put a breeze down his trousers.
I think best sounding bike ever is a cammy Norton single followed by Triumph twin and triple these only equalled by the MV Agusta three with Ago on board.
Where I live it's maybe $1.85 a gallon (3.8 liters) but I think it can be double that in California cities.
In this part of the UK petrol is £1.20p per litre diesel £1.30p. £/$ exchange rate is I believe around $1.26 for £1 so £4.56p for your 3.8 litres of fuel here in the UK. UK fuel prices have reduced previously being up to about 20p per litre more.
Looks like your shed is on a slope so why does it flood ? Is it just a leaking roof ,if so sort that out as you have the basis of a solid looking workshop.
Get rid of all the crxp, spend a few quid (bucks) on the roof and possibly lining the walls and you have a man cave, next get the outlaws to lay on some power and you are good to go, the added benefit of somewhere to tinker when you need your own space.
good luck
As above add rainwater gutters to the shed roof, put a perimeter land drain around the building and feed that and the roof water to a soak away a few yards away from the building on the lower side.
Hello all need a bit of advice. The aluminium tank on my 350 sherpa is making a rattle/banging Noise likes something in there. I've had a look down in there and it seems when the fuel sloshed front to back islts like a flap is banging. Has anyone had this problem and is there a fix or is it a new tank. Thanks
There is a stiffener or baffle plate located somewhere around the centre of the tank which was fitted when the tank was made, it is held ??? by spot welds but can become detached it will be this which has come adrift. The tank will need gassing out on a vehicle exhaust then opening up to weld back in place.
The shock bolts are normal M6 on the earlier bikes, MK1 2 and 3, they went to M7 on the green bikes
Strangely, the fork yoke bolts are M7 on the earlier bikes and changed to M6 on the later bikes...
Fitting the engine, I've never been able to fit one with the barrel in place, or remove it. I take the barrel off before removing and fit it after the engine is back in the frame - I could never do a rubik cube either...
Nor me with the Rubik cube. When I fitted the engine into my TR77 the motor with top end on was placed on a workmate bench then the frame somehow lowered over it and sort of rolled in position I do know when it was finally built the downtubes were covered with bubble wrap to protect the finish. Never having owned an earlier model I was unaware that the shock bolt size was changed.
Best to do a dry build prior to painting to see if any brackets need attention, fitting the motor is a bit like doing a Rubik Cube but once you find which way not too bad. I would lower the footrests in the way Woody has done on his bike, the originals are far to high. Shock mount bolts are M7 fine a size not always easy to find, I got them for my bike from Barfast Engineering Newcastle under Lyme (find them on google) also check everything around the rear wheel spindle to see if it is bent. A better made replacement in high tensile stainless is available as well as a carrier for modern Beta type spockets which has a third bearing and completely cures the problem. If you can make Telford show in Feb Steve Sell is usually there he is definitely the best person to speak to for everything OSSA.
Am assisting with the restoration of a pretty standard Yamaha TY 175 into a bike that will be ridden in trials, is the air cleaner/airbox perfectly ok as is or are there performance improvements to be gained by changes or even replacing with a different set up?
tiger cub forks
in Pre-65 Bikes
Posted
OTF I think the Royal Enfield fork bottoms are accepted in Scotland at the two day I have seen them fitted to several bikes there.