KT250 forks on TY

[njtrials]

Has anyone used KT250 forks on a TY? If so, pros and cons? Did you use a KT or TY wheel? If using a TY wheel, how did you mount the brake arm? Possible scenario is KT250 forks used on a TY175 to have larger/stiffer 34mm front end to get rid of the flex with the small 28mm(?) 175 fork. I haven't been able to source a TY250 set and came across a set from a KT.   I was also wondering how the leading axle from the KT would work. Hoping someone has tried this over the last 50 years.

Edited yesterday at 01:36 AM by njtrials
Clarification

[feetupfun]

I've done it the other way around, fitting TY250 forks to a KT (wanting to increase the trail). I used a TY wheel. An axle spacer was needed for this. It was just an experiment and I went back to using KT forks on my KT. There were two problems with the TY forks on the KT. The amount of trail was too much which upset the steering and the front mudguard hit the exhaust header on full compression of the forks. I then modified some KT triple clamps to provide only about 5mm extra trail over standard and was very happy with the result.

If you fit KT forks to a TY250, the KT wheel assembly will be a bit too wide because with KT triple clamps, the fork tubes are slightly (2-3mm) further apart than with TY250 triple clamps.

I've not tried to fit a TY wheel to KT forks.

KT forks are longer overall and have more travel than TY250 forks and would reduce the trail by about 20-25 mm due to the leading axle design. They are functionally very similar inside with the main difference being that the KT forks do not have anti-topping springs. They are so similar inside that you can use TY internals in KT fork tubes and vice versa.

It sounds like a fun, interesting project.

[njtrials]

feetupfun, 

To be clear I would want to use the KT triples as well, so if using the 175 wheel a spacer would be needed? Still not sure how to anchor the TY brake arm. I think the KT uses a lug cast into the backing plate and lower. 

 

 

 

[feetupfun]

19 hours ago, njtrials said:

feetupfun, 

To be clear I would want to use the KT triples as well, so if using the 175 wheel a spacer would be needed? Still not sure how to anchor the TY brake arm. I think the KT uses a lug cast into the backing plate and lower. 

 

 

 

I'm glad you mentioned using the KT triple clamps as well as the forks. Did you realise that KT triple clamps are a lot further apart than TY triple clamps, so there will probably be some work involved with fitting the KT triple clamps into a TY frame. I haven't tried this to know what's required but at least the angular offsets of the KT fork tube holes will be incorrect if the KT triple clamps are moved closer together. The other stumbling block there is that the TY steering stem may not fit the stem holes in the KT triple clamps. 

As for attaching the TY brake link, it would be pretty easy to make a clamp that fits around the left side KT fork bottom for the TY brake link to attach to.

No idea what spacers might be needed for TY wheel in KT forks with KT triple clamps. If you have a TY wheel or TY forks in their triple clamps and some KT forks in their triple clamps, you can measure them up and compare.

Also have a think about where the KT fork tubes will end up at full lock relative to the TY fuel tank. Unless you limit the steering angle, I suspect they might hit the TY tank. This is because the KT triple clamps are designed for leading axle forks which usually positions the fork tubes more rearwards when straight ahead and closer to the midline of the bike at full lock, compared with (in-line axle forks) TY triple clamps.

For what it's worth, the standard angular offset for both sets of triple clamps is the same (1.5 degrees). I modified my KT triple clamps to reduce the angular offset to achieve the same trail dimension as a TY (to make my KT steer better). You could do something similar to a set of TY triple clamps to achieve the same trail as a KT250 with a lot less trouble than doing a front end swap. However, I'm only guessing that this is what you are trying to achieve. What are you trying to achieve?