IDC

Are you sure that the frame and engine numbers start with 70**** and not 72****? If the numbers start with 72 it is a 1980 TR77 250, mine is a 1977 TR77 engine and frame number starts with 63**** so it could be that later bikes had longer forks or the forks are from another machine altogether?

If it is a TR77 then the stanchion length is 585mm ( I have just measured the old ones off my bike to check) In-motion and Feked do replacements https://www.inmotiontrials.com/product/fork-stanchions-pair-ossa-tr77-tr80-gripper-betor/ https://www.feked.com/ossa-mar-fork-tubes-stanchions-250-350cc-tr77-tr80-models-585mm-x-35mm.html refer.

Are the spokes new or are they the original ones from the stripped down wheel? In general the inner spokes will be slightly less than 90 degrees and the outer ones will be slightly more than 90 degrees. If you are going to rebuild the wheel you need to know the offset between the hub and the rim and then adjust each spoke angle to accommodate. Fit the inner spokes first maintaining the offset and then fit the outer ones again maintaining the offset, then tighten and true the wheel. Regards.

Hi Sid, attached pictures as requested, the thing to note is that the outer cable gets pushed to operate the brake instead of the inner cable being pulled. Regards, Ian.

Hi Woody, thanks for your thoughts. I have removed the mudguard brackets but it has not made any difference to the spacing between the fork leg bosses which is 106mm.The spindle assembly including the spacer and speedo drive is 110mm, so there is 4mm too much somewhere? I am at a loss to know what has happened as the wheel was on the bike when I got it, I should have paid more attention when I removed it! I can only think I have mixed up something in the months the wheel has been off or the fork legs were forced apart, I think it will just be one of those mysteries. Regards, IDC

I am in the process of rebuilding my TR77 and have come across a problem whilst trying to re-fit the front wheel. The hub/spindle assembly is too long to go between the fork legs, please see attached photos. The only thing I can think is that the spacer between the speedo drive and the ns bearing is too long? The spacer I have is 17.5mm long 20mm od and 12.5mm id, Ossa part no 106604 which I think is common to MAR versions as well. Has anybody got their front wheel out at the moment and if so can you please confirm the dimensions of the spacer on your bike. Thanks.

Ratios are on attached photos plus some other info you might be interested in. Regards, IDC

In motion do a set of pushrods if you are interested https://www.inmotiontrials.com/product/clutch-push-rod-and-ball-set/ refers. Regards.

Thanks for the comments guys. I have now managed to remove the spindle by cutting off the flange on the bushes and carefully drilling down between the swinging arm and the spindle in multiple places to relieve the grip the bushes had on the spindle, I was then able to recover the o-rings and drift the spindle out. I cannot believe how tightly the plastic/nylon? bushes had gripped the spindle, it would not move. Whether it was due to some chemical reaction between the bushes and the grease that had caused them to swell I am not sure, they spindle has probably not rotated/moved in excess of 25 years! The hole on the top of the swinging arm is a plain hole and originally there was some dense foam type material that plugged it, on the underneath there is an oil/grease nipple with a spring loaded ball bearing in the center. I think I will tap the top hole and fit a grease nipple where it will be more accessible.

Not sure if these are the same but the attached photos show spokes of my TR77. Regards.

Hi ColinPybus, thanks for your comments. I have still not managed to extract the spindle from the swinging arm bushes, it is seized solid will not budge even with a big hammer and a drift. I am now thinking of carefully drilling the bushes between the spindle and the swinging arm to weaken the grip the bushes have on the spindle. Hopefully I can do this without damaging the spindle or the swinging arm but if the worst comes to the worst I note that replacement spindles and bushes are available. Regards.

Thanks for the advice Woody, I will order some replacement bushes and get the big hammer out!

Thanks for the reply feetupfun. I was not clear in my original post, the swinging arm has already been removed from the frame and I was expecting the spindle to rotate in the nylon bushes easily but it seems seized. I am not sure how much force to use to extract it just wondered if anyone else has found this on an MAR or TR77 and how they got around it.

I am considering have the swinging arm off my TR77 powder coated and if so I thought it would be a good idea to remove the bushes and spindle. The spindle seems a really tight fit in the bushes, can anyone advise me of the best way of removing the spindle and the bushes. Thanks.

Thanks fourex, some interesting parts on that site.