OSSA

Can anyone tell me what material the headstock / fuel tank on the Ossas are made of? For some reason I had it in my mind that it was magnesium but can't find anything to back this up. Still looking to powdercoat my frame so just need to know what it is made of before I get quotes. Anyone know what glues / chemicals they use during the bonding process?

Yesterday I had a strange incident while doing a rough track - rear brake got locked up. The disc and the saddle was overheated (it smoked), brake pedal was completely locked and unmovable. Needed some 5-10 minutes to cool down and then worked fine again, pedal started to move and brakes worked again. There were no leaks. Anyone else had this? Oil seems to be quite dark from the master cylinder inspection window. I wonder if I need to overhaul the master cylinder and the caliper hydraulics or just suffice with replacing the DOT4 oil for now?

Trying to decide if I should part out or fix my 12 280i. Broke the seat and can't find a replacement except 13+ which requires new fender and graphics as well. Also broke a pin in the shift shaft which can be fixed reasonably. Would probably have $600+ in fixing. Everything else is in great condition. what do you guys suggest? how much do you think I could recoup in parts?

Guys, what main bearings are you using in your OSSA Grippers. The ones i took out are SKF ( OTHER BRANDS ARE AVAILABLE ), 6205 2 RSH . I only ask as i read this in an OSSA manual, bearing in mind its not a manual for the 350 Gripper................. NOTE: The left main bearing (OSSA Part No. 991-141) is slightly different than the right main bearing (OSSA Part No. 991-140). They are essentially the same bearings, but the internal clearance between the balls and races of the left bearing are greater than in the right. This difference is noted by the letters "C3" either stamped or printed on some part of the left bearing (Fig. 76 and 77). It is not recommende…

At my first trial today which I thoroughly enjoyed,(Thanks Loughborough club) I lost a swing arm spindle bolt (Shame on me for poor preparation). But when we dug a little deeper it seems really strange that the position of the rear brake pedal is effected by the chain tensioner and by default chain tension. I'll blame this for my ineptitude to find the rear brake pedal for descents. Is this really correct. Thinking of removing original tensioner and fitting an aftermarket one to disassociate the 2, so the chain tensioner tensions and the brake pedal brakes, and I can fix its rest position in one place. Have I not got mine set up correctly, is it missing somethin…

hi. just bought a 2014 ossa 300i and i wonder what the top speed is? have not got it yet (transport) and there is ice on the road so i can`t try it now. I will drive it on trails and there will be some dirt roads also so it would be nice if it could run close to 70 km/h.. if not, where can i buy sprockets? best regards / new beginner swede

As above, what oil is it needed for the engine / box. ?

I have recently picked up a non running Tr280i that has been hand balled though a number of people of the last year or so. I was told it may have a clutch issue. After inspected it I found the clutch was completely missing. The only parts there was the hub and basket. I can buy the plates, fingers and a local shop is conforming the availability of the pressure plate and support plate. However I'm having an issue trying to find the clutch spring (number 12 in the part diagram #2420020212) does anyone happen to know where I maybe able to find one or does anyone have a bike they are parting out? I also believe my gear selector spring (number 20 in the parts di…

Could anyone give me any ideas where I can get spares for my bike. Currently nothing in particular, but seem to struggle to find bits.

Hi I have the rim and the hub and 36 x 90 degree spokes. I'm told they can't all be 90 degrees, half of them have to have a lesser angle. Anyone know what that angle is please? Its a front, 21 inch Akront from a 1974 MAR 250 Cheers Sid. Update.. The bike was a basket case and came with just the front hub and rim, no spokes. So.. In my ignorance I ordered 36 90 degree spokes from Poland because they were half the price of the Ossa kit. WRONG! I should have asked yous for advice first. There are two sets of eighteen, inner and outer with two different angles for each. I've just ordered the correct spokes from Trial World Thanks all fo…

You know whatits like, you are part way through a restoration when you get chance of another bike! I just got hold of one of these and need help in finding a manua and where to get parts from. Can anyone help. Thanks

Anyone have any tips on how to hold the nut on the rear brake pedal on the TR280 so I can remove it?

Who does Ohlins service in the States? Any recomendations? I have ave a bunch of hours on the rear damper and figured it is probably overdue. I don't have the tools to do it myself, although perhaps I should investigate that. mark

With reference to an earlier post on here about a broken threaded boss on the right side engine casing on a 250 Mar, I have the same problem on mine. Upon further inspection I noticed the hole for the thread was a further 10mm deeper from where it was broken off. Using an M6 machine tap I managed to tap the hole to the bottom giving more than enough length and strength for an M6 countersink bolt. The only problem I'll have now is sourcing a bolt long enough! Site won't let me send pic as over 2mb big. Can this be changed or is there something I need to do? I've sent pics before no bother.

does anyone have a wiring diagram for an ossa explorer or at least non battery bike with lights,have made a loom tested it with a battery,but dont know if I need a rectifier/regulator,nor sure of connections from stator.

Hello here again. This spring is there a specific way of getting these things to fit. I have been trying now for an hour and all i have managed to do is end up with two fingers with plasters on as this spring has managed to cut both. Every time i try to force the spring round to get the straight part of this spring into the slot of the swing arm it just will not go in because the spring is too big to move into the round machined recess. I thought that when i force the flat part of this spring round that the spring would become smaller allowing it to fit in but it actually gets bigger??? Now this spring is new and presume that there is only one type made but i recall tha…

just been washing my bike from Sunday and while I was checking it over with the engine running, the fan didn't come on. Is there any way of bypassing the thermostat before I spend money?

After putting a new top end on my 2011,i had it setup at my local dealer.It ran great and started with 3 kicks cold and one when warm.During the setup and for a while after i ran 140/1.Being a bit nervous about the expensive new topend,i changed to 100/1.After a while it got tougher to start when warm.When cold it would start 1st kick,but needed 3 or 4 when hot. Changed back to 130/1 and it's back to 3 when cold and 1 when hot.No idea that this technology was so sensitive. Just an fyi for others.

can only find lower ones for sale is top the same ,are they a special or can you get them of shelf

I recently added a trail tech in coolant temperature sensor to my 2014 Ossa TRi 250, I am seeing coolant temperatures of 220 to 230 degrees F during extended climbs of 1000 to 2000 feet at 5000 ft elevation. Can any Ossa owners confirm the coolant temperatures they see during high load operation. New cooling fan, radiator clean, fan relay good, fan turns on at about 160 and off at 155. No lifting of radiator cap relief, idle speed drops about 200 rpm at elevated temperature. See coolant temperatures of about 150 to 170 during normal trials riding activity.