Have a Marin Quake here beside me, doing some fettling for a friend.
Looking at the suspension layout, etc - from what I can see, the wheel moves forward as the suspension compresses - surely that's exactly what you don't want?
Aside from that, it's all an impressively complex setup. If a battleship had suspension, I bet it would use a linkage like this.
Have you ridden it? It works very well.
the wheel moves forward as the suspension compresses
Isn't that exactly what happens with a single pivot? Up and forward?
I have the QUAD & QUAD II systems, both very good designs.
I thought it moved backward to start with?
Pik n Mix - MemberHave you ridden it? It works very well.
No, just sat here looking at it and trying to understand it.
woody2000 - MemberIsn't that exactly what happens with a single pivot? Up and forward?
Yes, sort of - the wheel moves in a fixed arc around the pivot. This (to my eye) looks to amplify that forward movement with the double linkage.
Better than the Whyte Prst1 front ends which moved backwards as it compressed. 😯
scruff - MemberBetter than the Whyte Prst1 front ends which moved backwards as it compressed.
I saw someone riding one of those once. Looked an absolute nightmare.
Actually, first 30% of travel has a rearward movement. After that it's all forward but viewed at the axle rather than on a graph it looks almost vertical due to the forward/rearward elements being pretty small. Check it out in Linkage software, it's well handy for sounding brainy on t'internet.
[i]I saw someone riding one of those once. Looked an absolute nightmare. [/i]
IIRC, they got rave reviews at the time.
They did. I dug up the copy of MTB Something where Guy K tested (and loved) it the other day.
I have a Quad II bike and it's flippin' brilliant. As has already been pointed out, the rear suspension extends slightly under pedalling (remember that sag setting is tres important with QUAD II bikes), which would point to a slight rearward movement in the initial part of travel. Both links are of unequal length, which compresses the shock without pulling the axle path too far forwards in the later portion of travel.
It's not uncommon, have a look at the shock placement on Specialized bikes and have a think about how the shock is actuated.
I demo'ed a whyte 120 last year and thought it was brilliant. I couldn't get round the awful looks, so it was excuded from my choices.