Aircooled Monoshocks

Some purists might be outraged by such a project. Normally I too find engine swaps to be a distasteful subject, but... after several years trying to keep from doing this, I just came home from work one day and started in on it. I guess the winter weather has effected my judgement. The front subframe has been welded together out of alloy strap material from the hardware store, and short chunks of renthall handlebar. It's very satisfying to be able to make something like that, finally having a tig welder to play with. The project has a long way to go, but should prove to be a fun ride and a great conversation starter. Also perhaps a handy excuse for lackluster finishes i…

Well, since the A/C Mono forum has gone a little silent, I thought I'd throw something in for us to chew on. This 85' TY350 has been in the family since we bought it new and I like to ride it at our Vintage events in Non-Comp, just-for-fun class. It has become a test mule for my wild-hair, "hmmm, what if we did that?" brainfart projects and has been modified so many times it starts to whimper when I walk in the shop door. Photos are of a couple of the latest changes: I revalved a Works Performance shock, added a steel-braided line and a adjustable remote reservoir. The intake is a one-piece reedcage/manifold I made several decades ago and uses early CR125 dual-stage r…

I know some people frown upon it, but I'd like to convert my TY350 Mono to a twin shock. Has anyone done it and can pass their wisdom on to me?

Hi what is the best castor based 2t oil and the easiest to get hold of? and what ratio to run it at on my tlm200 (aircooled) p.s i want to get the the castrol r smell but i have read that its not got for trials bikes cause it clogges up the piston or something like that? thanks sam

hi any info on chapman bsa as just got mine out of shed after 9 yrs looking at v5 and frame no /engine no all match no 0618 not sure if it is no 6 or 18 the first keepers f lewis of worcester as reading forum they say only 20 were made

Hi Guys, I was wondering if anyone has any answers for stopping the pinging or minimising it on my TY250. The motor is fresh and unmodified but it pings it head off. I beleive the original pistons had dishes in the crown ( I could be wrong) but my piston is flat. I'm using 95 octane fuel mixed at 50:1. I have tried raising the needle which improved it a little but its still doing it. I know some peoples answer will be to run it on Avgas but this is really not an option I want to do, as it is road registered and I fill it up at the servo sometimes. I have heard that removing the head gasket to reduce the amount of squish greatly reduces the pinging has anyone who has…

Does anyone remember seeing a picture of a monoshock Ossa in the motorcycle news back in the mid '80's. I think is was a prototype that never made it into production. I'm sure it was designated a '303'. I'd like to see the picture again if anyone has it.

Here's some rare Mecatecno trials bike photos from the late 80's and early 90's. Melcior Estorch - Early 90's - The only picture of a Mecatecno Skywalker being ridden on the internet Rare 1988 Mecatecno 326cc ridden by Ronald Garcia - very few made Marcelino Corchs riding the rare 1988 Mecatecno 326cc Marcelino Corchs losing control - poor bike Loius Gallach riding the rare Mecatecno Dragonfly 326cc Rare Mecatecno 326cc - none in UK- Loius Gallach riding the Mecatecno Dragonfly 326cc - 1 in UK only

can anyone cast there minds back to when the ty250r / pinky ruled the roost! what were the best mods at the time? ive got a drilled out alloy sprocket guard and a alloy mick andrews tailpipe plus a pad (bultaco type) chain tensioner! /HEBO pegs! thats it? what have you done to yours to make it work/look better?

A few pics of my pinky, non std tank and non std colour rear guard and seat unit (never did like the 'pink' colour scheme!!)

In February 2016 i spotted an ad on the net, about a day's drive away for a set of 4 (four) Japan market 1984 ty250 monos plus spares. Had to borrow a pick up and drive there and bring them back. Paid about £820 for the lot. 3 S models and 1 R model, one even a decent runner, and useful spares inc a 5th motor. 3 steel tanks, 1 plastic tank and a majority of the plastics turned to dust. Amazing what UV does...

Hello It's wonderful to join you all I have a tx 240 but the disc valve came loose and jammed, I would say it's a catastrophic engine failure as the flywheel slipped, crank gears slipped, disc valve broke in 2. Flywheel previously welded on and crank taper is in bad shape. Cylinder and piston are fine and bearings all ok Where would I start looking to get a rotax 240 engine to replace my old one or part to fix her. I bought a rotax 122 engine but it would require some fabrication to work- drive sprocket won't fit its too low for the chain. We're worried about the strength of the frame if we start cutting. What alternative engines are the…

Probably the only red 88 one in the country. Yes , parts are a little bit of a problem!

Does any body have any information on the 175 Chapman-BSA which was produced in a small batch, and used the Yamaha DT175mx engine.?Any help would be very much apricaiated, i know there where only around 25 made in total. jh

I've been thinking about getting myself an aircooled mono to go with my garelli 323, and was wondering what is considered the best allround aircooled mono??? I might do a few mods to whatever i buy like changing the footpeg position if needed.. i bought a 91' TY250r pinky(with a modified cylinder) on the weekend but am wondering should i buy something else instead? heres a pic of the TY

I have searched the forum but all posts relating to parts are years old, I have found Joel's site but it's in French. Before I embarass myself with emailing them, does anyone know if they reply in English. I'm mainly trying to track down a rear mudguard and perhaps a set of rings. I only have half of the Mudguard as it has been trimmed short but I could re build the missing part then prep it and take a mould so I can replicate some in grp but I would rather have a good plastic one also. I have googled till my fingeres are sore, I did find them on a french site but they are no longer in stock but they do have usefull other Jcm parts. Here's the link if it helps anyone e…

As the a/c mon shock forum has gone a bit shall i say boring am hoping this will spark off some fun.. what was the first mono shock trials bike, not a ridgid, was it the legendary ty 250 mono or the JCM 323 or was there other pre production bikes. What year did the ty mono did development I know pre 1984 as one N Berkett was a develepment rider but in 1983 was on a jcm so was the ty all done and off to the next challenge??? we are talking months days not to sure what do you lot think.pretty sure 1984 was the year....I have 323 that was made on the 17th aug 1983 that i think is the first production bike...as th ssdt was the challeng for a bike what was there???

Hello, Trying to learn about TY Yamaha's prepped by John Shirt in the mid 80's. I have one that I know has been in the US since 1985, I've noticed a few items that seem to be different than a stocker, Mine has John Shirt stamped in which appears to be a different style silencer than stock. Can any one tell me what John did to these bikes. Thanks, SB

Merlin Mecatecno, JCM and Garelli.... it may have been linked to before, but an excellent youtube clip

I know theres been a lot of praise for the above bike inc pinky! but what are your veiws on this model heading for future classic status , and will they ever really be worth everything? bearing in mind there is still lots of them about?