GSB's Whyte PRST-4 build

[Duxuk]

It's obviously not a PRST 1 swinging arm. What is that one from? Love the whole bike. I dream of a 150mm at each end PRST, possibly a 29er? If such a thing existed I'd sell my wife.

 

[GSB]

Swing arm is from a 2002-ish Marin with the TALA system. Should be a direct fit to a JW2 or PRST-1. 29” in a PRST frame would take some engineering though, 27.5” barely fits!

Definitely confused by that front end, Whyte plus fours with telescoping legs? The mechanical origami that defines the kinematics on that set-up give me a headache.

Also, unless materials tech has moved on, I didn’t think it was possible to weld carbon fibre to 6061 aluminium, how on earth did you get that front fork to work?

 

[Lacuna]

Re:

I don't the telescoping fork legs are actually functional; just slid over the standard forks legs and bolted up to give extra tyre clearance and a 15mm bolt through axle

 

[Stevo666]

Re:

First class deduction sir....spot on!
But the one I'm currently building will have both functional systems, firstly see if I can. And more important...any benefits.
Soft leg suspension with remote lockout and prst-1 link suspension for the big hits..

 

[Duxuk]

Please God. Make someone design a linkage front suspension bike with a system like the Whytes but with a longer cockpit and 150mm of travel at each end. If my prayer is answered it's proof that God exists. If not he's moving in a mysterious way. again.

 

[dyna-ti]

Please God. Make someone design a linkage front suspension bike with a system like the Whytes but with a longer cockpit and 150mm of travel at each end. If my prayer is answered it's proof that God exists. If not he's moving in a mysterious way. again.

£120 for a 3D printer

 

[Lacuna]

Please God. Make someone design a linkage front suspension bike with a system like the Whytes but with a longer cockpit and 150mm of travel at each end. If my prayer is answered it's proof that God exists. If not he's moving in a mysterious way. again.

Here you go: https://structure.bike/

 

[Duxuk]

Yes, I've seen the SCW 1 and it would be interesting to ride but....it lacks the downward sloping top link. This is what gives the Whytes the "J shaped" axle movement. The wheel axle has to move backwards before it compresses the shock. If you hit a bump this happens but if you push down on the bars your weight tries to squeeze the wheel forward, counteracting compression and bobbing and conserving energy to propel you forwards, rather than ending as heat in the shock. This only works if you have sufficient pressure in an air shock or preload on a coil. If you set up with any sag your Whyte will bob horribly. Set up correctly and it's a dream!

 

[Lacuna]

Re:

Yes, but allowing the axle to move backwards first steepens the head angle and destabilises the bike. The Structure frame and also the Trust linkage fork are designed to slacken the head angle under compression to build in additional stability under compression, which is when you are most likely to need it

 

[Duxuk]

Re: Re:

Yes, but allowing the axle to move backwards first steepens the head angle and destabilises the bike. The Structure frame and also the Trust linkage fork are designed to slacken the head angle under compression to build in additional stability under compression, which is when you are most likely to need it

I can see that but what I mean is that the purposes of the 2 designs are different. I like the anti bob feature of the Whyte and think it contributes to faster lap times on my local red graded circuit. It's no downhiller, it's more of a cross country and trail full suspension. I would just like the same but with more travel as my ideal all rounder.