Ty 175--ty250

[charliechitlins]

Besides 75cc, of course.

Are the frames /geometries different?

How do they compare when ridden?

[toofasttim]

Completely different frame Charlie.

[feetupfun]

Dear Charlie

These are two of my favourite bikes and I often have trouble deciding which to ride.

First the differences in geometry and weight:

The TY175 has a 48.5 inch wheelbase. The TY250 is 50.5 inches.

The TY175 has a more raked steering head angle (less steep) but with the same triple clamp offset so it has slower steering than the TY250.

Both wheels, brakes and the front ends are interchangable (except for the dished sprocket on the TY250). The TY175 forks have skinnier tubes and have lighter springs than the TY250.

The TY175 (83kg) is 10 kg (22.4 pounds) lighter than the TY250 (93kg). About 8kg of this difference in weight is in the engine.

Riding them:

Chalk and cheese. In sections, the TY175 feels much lighter than the TY250 and because of this can be ridden much longer without taxing the rider's endurance. However the TY175 has a unique feel to the front end that I've never come across on other trials bikes of the same era. The front end never feels totally confidence inspiring on obstacles. There are a few possible reasons for this:

The forks flex noticably in rocks with an adult size rider.

The steering rake is more like an MX bike of the era.

The handlebars always seem too far back even when they are rotated well forward in the clamps. I am only 1740mm (5 foot 10 inches) tall.

On my competition TY175, I've moved the pegs down and back to give more room and have fitted the front end from a TY250. This improves things a lot but the front end is still not as good as say a Cota or OSSA or the TY250 of the same era.

The TY250 front end is more refined than the TY175 but one is always conscious of the TY250's weight when in sections. Both bikes are capable of turning as tightly or even more tightly than most of the other bikes probably due to their relatively short wheelbases. If there was a forte for both of them, I'd say it was in tight turns.

The first TY250 had a motor that was not as forgiving at low revs as later model 250 motors but they are all are very competent and run very evenly and smoothly with standard settings. The first model TY250 flywheel was lighter than the later models and the porting was different too. The B and later TY250 motors all lug and rev out with magnificent gusto.

The TY175 motor has noticably less grunt than the TY250 as you would expect but has the widest usable rev range I have ever witnessed on an old trials bike. It runs strongly right down to the point wher you could count the strokes yet will rev out far higher than other similar era bikes. This proves to be very important in competiton because you can run gearing that provides great clutch-out control at low ground speed yet the bike can also get to a usefully high speed in the same gear.

The TY175 would usually be the bike to choose if you wanted to score the least points at a trial but because of the front end and cramped riding position does not feel as satisfying to ride for me as the TY250.

In case you are a bit of a hoon, both are fantastic for pulling extended wheelies on.

The TY175 makes the better trailbike ie the handling is quite good at higher speeds and when sitting down. I don't know why but suspect it is because of the slower steering.

David Lahey

Self confessed twinshock trials nut

Gladstone

Australia

[endo kid]

LOOKS LIKE THIS JUST ABOUT ANSWERS THE QUESTION

[charliechitlins]

That's for sure!

Thanks.

And, yeah...more rake will give you more stability at speed.

I remember my 175 fondly.

I wish I had a decent photo.