suspension designs

[rocky j]

I have an old Trek Y3 frame sitting around at home (see below). After reading an article in Bike mag. on different suspension designs was wondering why the y3 style isn't still produced. Having the bottom bracket as part of the rear triangle I thought may have overcome the problem of chain tension topping out the suspension when pedalling.

Anyone who can enlighten me I would be thankful. The reason I ask is I'm thinking of rebuilding it for a friend who is getting into mtb, and wondering if it's worth it. If not I'll keep it to show the grandkids one day what we used to ride!

Cheers.

[roasted]

because if you stand up then the suspension is almost worthless.

[wooley_89]

whats standing up got to do with the suspension being useless? lol

[red_dog]

whats standing up got to do with the suspension being useless? lol

Maybe he's talking about the suspension 'Path'..... or the pivot point?
I dunno

[wooley_89]

maybe, lol. but that still doenst have much to dow ith standing up :-S

[Daver]

An URT like the Y3 (Unified rear triangle) is a pretty poor way of suspension designing. Firstly, mounting the entire drivetrain on a moving platform (eg independant of the seat) will mean that pedalling is going to be a chore, and as soon as you stand up you will get more bob than is useful- the bob is going to make the bike a lot harder to ride unless you sit in the seat, hence making the suspension worthless.

The other bikes from that era all used the URT esque suspension (Schwinn's etc) if that helps...

[.:Alan:.]

It would not petal well because the pivot is right near the bb so all your pedaling force would go into the suspension, but if you had the pivot further up the botom tube(dont know if thats what its called) your pedal power would go more to the ground because insted of going in to the suspension. So in other words if you were to pedal on the back wheel with that design instead of the bb you will get no bob although the suspesion wont work very well.