Hi. i bought a set of TY250 forks to fit to my TY175. The problem is they don't have the lug on the fork that retains the arm that holds the brake drum in place. I thought the forks were inter-changeable but obviously certain TY250's had different forks.Can any one advise how to get these to fit. If I need a new wheel or drum to match does anyone know what specific TY variation these forks are from. My TY175 is a 1976 american market edition. bought as a non runner and now working fine. these forks are apparently from a 1977 TY 250. I am a complete novice, I'm just getting back into bikes after a very long lay off and hopefully into some trials once bike is sorted and i've got some practice in. I attach some photos and would be very grateful for any help. 

Hi there,

I imagine a small local machine shop or enthusiast could fabricate a bracket to solve the problem - no need to weld on anything - just two "omega" shaped bent steel strips with a bolt either side should clamp onto the fork and hold the brake arm. At least, that's what I'd try first!

Mark

The forks you bought are from a TY250 mono which is a completely different bike to a TY250 twinshock.

The brake plate on a TY250 mono engages with the lug on the LH fork slider on the forks you bought.

Those triple clamps will not match well with your TY175. They will have very limited steering angle side-to-side unless you get a different fuel tank and modify the bottom triple to suit the TY175 frame.

TY250 twinshock models forks and triples can be interchanged with TY175 forks and triples without modification. TY250 twinshock forks look a lot like TY175 forks but have bigger diameter tubes and sliders. TY250 twinshock forks are also slightly shorter (about 20mm shorter overall)

Your new forks have tubes that are too big in diameter to fit TY250 twinshock triples without modification, and your forks are leading axle, so the steering geometry will be wrong unless you also use the TY250 mono triples.

I have mounted them to my TY 125 / 175 and with a bit of research you find matching bearings.  I believe I used a pair from a Suzuki DR that fitted spot on.

I made a braket in CAD then the piece was laser cut out of T 6 alloy, bent and then mounted (looks very contemporary). 

So it doesn't matter so much that you have to fork of the mono TY.

Edited September 23, 20178 yr by pschrauber

There may be a possibility that the larger diameter forks will not be eligible for some twin shock events?

lf you keep the rebuild and swap contemporary in appearance I would be very curious if there would be an issue as especially in Britain there are so many twinshock bikes with tubless rims and even forks from bikes of the nineties around. As long as they are fitted in contemporary way I think it is OK. Would state so even for Euro and Nordic Inter Cup.

 

See here, (found photos of it):

Edited September 23, 20178 yr by pschrauber

5 hours ago, pschrauber said:

I have mounted them to my TY 125 / 175 and with a bit of research you find matching bearings.  I believe I used a pair from a Suzuki DR that fitted spot on.

I made a braket in CAD then the piece was laser cut out of T 6 alloy, bent and then mounted (looks very contemporary). 

So it doesn't matter so much that you have to fork of the mono TY.

Is see that the photo shows a Majesty frame. What did you do to the steering stops to restore the steering angle?

Do whatever you want, you can just grind them off or live with them they will hit the gap between frame and fork center tube. I think it is up to owner and which tank he uses if:
- original,

- Majesty or

- the plastic tank seat base combo,

so I strongly believe everyone should find the best solution for his need, the aluminium stops are beefy you can modify them a bit too!  

OK thanks. The TY175 I rode that had a TY250 mono front end also had a standard TY175 tank and it had a huge turning circle. If the owner had modified the stops to get a better steering angle then the fork tubes would have hit the fuel tank. I can see that if you use the right type of Majesty style tank then there might be clearance for the fork tubes and have a decent turning circle.

Thank you very much guys. That's all been very helpful. I assumed the forks would have been off a twin shock as I was told it was a 1977 reg and I didn't think monos were around then so I assumed would be a straight swap.

So as you say markParrish and Pschrauber I can fabricate or get a bracket made. That looks relatively easy and as an ex engineer I can get that done one way or another. I will probably heath robinson something up temporarily with jubilee clips so I can see what sort of a problem the turning circle is as you say feetupfun. And then make a decision on a permanent solution. I dont really want to change the tank for nostalgic reasons.

Or I could sell this front end on and look for a twinshock 250 front end.

Hmmm does anyone need a ty250 monoshock front end (year unknown) ? 

Thanks again for your help.

 I would be interested. I will pm you.

Later YZ & TT brakes & hubs should fit, these are the conical type hubs. I have heard of the 80/81 250/465 twin leading shoe brake plates being used but they are hard to find & cost a mint if you can find them

I've got a set of the same forks which I may end up having to use as my C model forks have play & keep blowing seals

Thanks tony27. Does that mean i could fit one of those hubs to my existing TY175 twinshock front wheel?

No, they use the cast lug on the fork leg to locate the brake

Keep the forks and try to find the matching hub, wheel and brake. TY mono forks are a VERY good mod for both 175 and 250 TY's - I have been on the lookout for a while without success. A friend, who rides much better than I do, swears by them. I don't know what changes he had to make for enough lock (he had the SM style seat tank) but he is a big fan of the extra trail that comes from the leading axle.