trialsrfun

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.

Hopefully the above may help, good luck with your project.

Think this site is run as an hobby by a trials enthusiast.

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. As for yokes my preference would be 1.5 degree run out from these people https://villiersservices.co.uk/index.php?main_page=product_infoandcPath=83andproducts_id=295andzenid=mvt2bentf3hr71lhd9rqguvt24 when using straight leg forks. For leading axle then parallel might be best but for a British bike unless using Royal Enfield lower legs keep them straight with 1.5 yokes. ¥

So little to it it could not have cost much!

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.

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.

What is the current price for one US gallon of fuel

I think this one it is going to a Time Trial.

These are the settings I have on the VM26 fitted to my Bultaco, slide 2.0 needle 5DP7 main 125 pilot 27.5 needle jet 182 08

Surely if you bought the engine 'cheap' with the rolling chassis advertised above you would hve an inexpensive bike.

Spotted this on inmotion website recently it looks interesting, https://www.inmotiontrials.com/bikes/bultaco-pursang-mk11-370-rolling-chassis/

http://cemoto.tripod.com/bultaco.htm Think they are all on here.

Now that will buy a bottle or two!

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.

The seat is different for the plastic tank.

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.

There is a lot of Model 10 information and pictures on the retrotrials website. https://www.retrotrials.com/the-actual-bultaco-that-changed-the-sport-forever.html

These are the parts you will need, http://cottonvilliersspares.co.uk/clutch conversion.html

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.

Thanks for your valuable information, we got the bike running much better today well enough to ride in a forthcoming local trial.

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?

The initial damage was likely caused by someone removing the clutch basket without using the correct holding tool.