Twinshock

Hi guys, bit of back ground first... now I'm actually doing some trials with my SWM TL320 I have been playing with suspension. But coming from enduro's I've come to the conclusion that I may be out of my water a little? She has Magicals springs up front and Sammy Miller gassers up the blunt end. When she came to me the front and rear were set up for a erm' heavier rider (well built Steve, all muscle!) with 50lbs/in rear springs and 135mm of preload in the front springs, I weigh 11 stone. I had very little front and rear sag. First trial I just rode her as was. She rode very high too, I could of rolled over a 45 gallon drum without scraping the bashplate! Since the firs…

I'm in the process of rebuild the engine on my 250 Armstrong so I have the rolling chassis sat empty and want to take the opportunity to move the footpegs a little. The frame was advertised as being Reynolds 531 and I always thought you could only braze 531. However it doesn't look like any of the frame is brazed by Armstrong. Does anyone know if all the frame is 531? In particular what material is the flat steel plates the footpeg brackets are mounted? I will also think about altering the steering head angle at a later date so any info / advice re welding or brazing in that are will be welcomed, thanks.

Hi , you all , a 1970 hodaka ace 100 , ,, custom mf to road toad , , with big sprocket , big Han bars ,, will just about crawl , it was a frame up ,,project . Just got the shifting working , working on orig tank , is next .. , the parts market is hot ,, right now , original parts are Exp$$$ , went on trail riding today , for hour , ,,,

Having some issues getting my cota 247 to run, got a spark but no joy yet. Will be putting a new sparkplug in as soon as I can get to a shop (B8HS i believe, though its currently fitted with a BR6HS resistor plug), but in the meantime checking other issues, timing looks about right so thought i'd check the coil Its got a red HT lead motoplat and with a bit of searching found this site, (http://www.yankeetwin.com/motoplat.html) that states the resistance across it should measure between 7000-9000 ohms. Mine measures 12,150 every time. does this indicate that its snafu and i'll need to locate another?

Can anyone tell me the theory/reasons why longer swingarms are said to give more grip?

As many of you may know the engine side covers are held on with an odd sized screw (at least odd to everyone I talk to). It's an M7x1.0 in both 55 and 38mm lengths. So far I have had no luck sourcing these. Are these even available from dealers in Spain? We're almost to the point of turning down M8 sized bolts or, God forbid, tapping the holes out to M8. Help!

Hello everyone and all. This is my first post and I'm sorry it's turned out to be a question. But I could do with a little help identifying what cc my ossa is. Now I have had a look throughout the forum for a few months now as well as the rest of the web but to no avail, so please forgive me if the info I require is on here somewhere already I've just failed to find it. It was sold as a 250 but after a quick web search I thought it to be a 310. But now after more searching and reading I'm left a little confused. This is what I know: it's a mk3 frame, with the layed down shocks. Both frame and engine have matching numbers starting with 57****, which the charts I've c…

I have led a sheltered life, in my sporadic trials carrer spaning close to 5 decades now i have only experience with a few engines. BSAs bantam cota 123 and ty250B s oh and a ty80 Now recently considering an engine swap then deciding against it, i got to thinking did the members of this forum have any particular engine type or capacity that they would chose for their ulltimate air cooled twin shock project. What engine what capacity and why exactly detailing what it is about its power delivery torque respone etc etc you like so much about this particular engine.

I own a 76 OSSA 250 MAR with the AMAL 627 Carb and have not been able to find any information on this Carb as most of the machines imported to Canada came with the IRZ unit. I am attempting to obtain the original stock configuration Jet sizes(Pilot, Needle Jet, Main Jet) and part numbers for various items(Needle Jet Holder, Float Needle, Float Needle Seat, Carb Gasket and O-Ring Kit)), along with the settings for the Pilot Air Screw, Throttle Stop Screw and the appropriate Clip setting on the Needle. I would if possible like to find any servicing/overhaul/parts information pertaining to this Carb in print(or digital) if available. Can anyone provide any assistance or dire…

Trawling around eBay and found this:- http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=290580270984&ssPageName=STRK:MEWAX:IT#ht_500wt_1152 Rather expensive? What do you think?

Hi I don’t see any form for Rickman , I have a couple project bikes a Rickman 250 vr 73 montesa , Rickman hodaka 100 hodaka I purchased from motorcycle salvage yard in Michigan ,,,frame , mainly , had it shipped , just got lucky was looking at frame tag stamped H Most small Rickman are Zundapp stamped z ,purchased most mislanious on ebay , wheels forks . We’re off a super rat 1972 , , it runs with hodaka 100 Purchased on ebay , runs and shifts , its early year 6/ 71 . Small tag left side intact with model number , the whole project cost 1500. Usd so far , might find a better performance engine , it’s stock engine 100 hodaka with supe…

Well i have finally for my sins aquired an Ossa MAR Mk 2 Needs a bit of work, dont they all?, so i'm asking for a bit of help and info. Parts needed. Barrel and piston as mine has a couple of broken fins and i am a bit particular about things Chrome fork tubes. Mine are pitted. See above Silencer. Does anybody make an aftermarket one? Does anything else fit? Advice. It's fitted with a dished sprocket. Need a new one. Are these available anywhere? What gearing is the best compromise? Will only be used off road as not registered. My carb Amal Mk1 is showing signs of wear so will need a new one. Should i get a Mk1 ? or a Mk2 or what. If i stay with the Mk1 car…

Hi all Looking at picking up an old 348, which is apparently 1980 vintage. Question is, what parts are still available. For example, say the crank is knackered, can you get the bearings? And pistons? Gaskets? Its from a good friend so have the opportunity to at least take the cylinder off to see whats what. The bike runs, so thats a start, but has not been used for 10 years. I want to come to a mutual agreement on price depending on what needs fixing...... Thanks Steve (Hants)

Hi All Hope I can pick some brains on here. I've just finished rebuilding an '83 MH349 and am now in the process of "shaking it down" in preparation for my glittering career in twinshock trials (maybe). I come from a motocross / enduro background and have no experience of trials bikes, but one thing I've noticed is the bike is really noisy. I don't have access to a DB meter, but I'd reckon it's as noisy as a loud 2 stroke motocrosser. It's got a brand new WES tail pipe from InMotion on it, mated to the original front pipe. It's not leaking anywhere and the WES silencer has got packing in it. Bizarrely, the noise seems to be coming from the front "expa…

Hi I have just got a SM Products Ossa tank to replace the tank on my 74 MAR. The new tank differs from the old one in several ways. It is angular on the top whereas the old tank is rounded as seen on most MAR pictures, the tank is slimmer and is vented from the filler cap instead of the seperate pipe just forward of the cap. Anyone know if the new tank is based on a different year/model ? As my bike has a Cheney frame I am not so worried about originality, but don't want to use a totally wrong tank. Incidentally my painter deemed the old tank too difficult to re do as he said he could not get the multi layers of paint off - anyone know of a tank person who would be happ…

I did a search and some reading. There were some posts discussing using modern tubeless tires on vintage bikes / rims and how some owners have had issues with the tire dropping off the bead at the low pressures normal run. My 73 OSSA has an Akront rear rim. Unfortunately, probably on account of the slight ding in the rim from the previous owner, my Dunlop D803GP tire is dropping off the rims bead area. The oem Akront rear is a 1.85 width. Dunlop is suggesting a 2.15 width. I purchased a used OSSA wheel assembly from a different model than the MAR and unknowingly, it had the 2.15 wide rim. So, looking for opinions. Stay with the 1.85 wide rim and in…

hello there i was just wondering if anybody had any thoughts on wether petrol has changed over the years ( apart from the cost!! ) , a lot of people seem to have problems with carburation on older machines a mechanic told me that petrol has changed , so that settings on carbs ect maybe different. it could be worth bearing in mind when setting up carbs as i am right now. thanks .

Thought this was a great thread over on another forum. For those that find neat twinshocks on craigslist but don't have plans to buy them, maybe someone here will find the info useful. I apologise if my US location offends anyone. I don't know the equivalent of Craigslist in the UK. I'll start. A bunch of Hodaka parts bikes in Pennsylvania. https://harrisburg.craigslist.org/mcy/d/hazleton-hodaka-dirt-bike-lot/6775910399.html

Hi folks, Thought some of you might enjoy seeing my winters project. Not sure how many of these you see over your way, but not too many in these parts.

I have just finishing rebuilding an Armstrong 320 which I would like to register for road use. I've registered new bikes with certificate of newness but this can't work like that can it? It has been registered at some time in it's life but the documents are long since lost, anyone got any advice how to go about it? Will I have to go to have it inspected by DVLA? Any advice appreciated.