MTB rear suspension system

Skiziridis

Right boys and maybe girls,

I hope this is the right place to post this.
As I am doing a project on designing a rear suspension system for a MTB , I would like to ask you if it is possible , to send me your views and your needs from a rear suspension system . I would really appreciate it! It doesnt matter if you ride downhill XC etc.. many thanks!!

VWsurfbum

multi link system incorporating a remote lock out system.
scott use a system that locks the shock but its a pull shock, so designing something that remotely mechanically locks the rear end so you can have a choice of rear shocks would be good?

Skiziridis

you just gave me a good idea mate i might include that..i am looking for various needs , eg lightweight, allows sensitivity adjustment etc. whatever you like to have on a rear suspension actually!

VWsurfbum

well remember me when your rich

ride_whenever

single sided swingarm 100mm travel frame. To go with the lefty...

thel33ter

Simple, protects the shock from crud like Marin's quad link II. Big bearings so its reliable, doesn't put too much force on the shock so it doesn't need loads of compression damping.

Some kind of mechanical lockout would be nice too, but I can't think of an easy way to implement it.

supersonic

I would like a rear suspension platform with 100-150mm adjustable rear travel and geometry, moderately rear axle path, no pedal feedback, no bob at minimal extra weight and a slight net tendancy to extend under braking.

Anonymous

I want a rear suspension system that has a rearward axle path, but zero chaingrowth, meaning no pedal kickback. I also want no pedal induced bobbing.
And 247mm of rear travel, progressively sprung.

Anonymous

oops, my bad, I meant 240.7mm of rear travel, not 247mm, obviously :oops:

supersonic

Also prefer an instant centre migration curve to start out just above the front axle and end up near the BB.

VWsurfbum

supersonic wrote:

I would like a rear suspension platform with 100-150mm adjustable rear travel and geometry, moderately rear axle path, no pedal feedback, no bob at minimal extra weight and a slight net tendancy to extend under braking.

close?

Anonymous

supersonic wrote:

Also prefer an instant centre migration curve to start out just above the front axle and end up near the BB.

Funny that. I'd prefer it to start off near the handlebar clamp of the stem, then arc down through the bb, then to within a few mms from the rear axle. That should give good consistency.

bluechair84

yeehaamcgee wrote:

I want a rear suspension system that has a rearward axle path, but zero chaingrowth, meaning no pedal kickback. I also want no pedal induced bobbing.
And 247mm of rear travel, progressively sprung.

there was a motorised AM bike in the news section of BR a month ago or so... Seemed a bit cr@p apart from a cog on the frame that took the chain to the virtual pivot location first. Seen a few of these chain guides on old GTs, Brooklyns I think... maybe a Nicolai too?

I'm sure there is an old tank of a DH bike fulfilling this

Shaggy_Dog

Personally, I just want it to feel fast. I want to be able to pedal hard across roots and rocks and keep the rear wheel connected to the ground for maximum power transfer, without sending too much feedback into the pedals.

I have ridden nearly every suspension system out there and only a handful come anywhere near their claims. The only two that come to mind are the Trek ABP/full floater/DRCV system and the Giant Maestro.

Anonymous

bluechair84 wrote:

yeehaamcgee wrote:

I want a rear suspension system that has a rearward axle path, but zero chaingrowth, meaning no pedal kickback. I also want no pedal induced bobbing.
And 247mm of rear travel, progressively sprung.

there was a motorised AM bike in the news section of BR a month ago or so... Seemed a bit cr@p apart from a cog on the frame that took the chain to the virtual pivot location first. Seen a few of these chain guides on old GTs, Brooklyns I think... maybe a Nicolai too?

I'm sure there is an old tank of a DH bike fulfilling this

Putting the drive at the pivot point, virtual or not, achieves nothing though.
It adds insane complexity and gains nothing that cannot be done through simpler means.

bluechair84

yeehaamcgee wrote:

Putting the drive at the pivot point, virtual or not, achieves nothing though.
It adds insane complexity and gains nothing that cannot be done through simpler means.

Why not? Surely you get no extension in chain length so the shock can do its thing?

supersonic

True, but it completetly changes the levels of anti squat.

Anonymous

bluechair84 wrote:

yeehaamcgee wrote:

Putting the drive at the pivot point, virtual or not, achieves nothing though.
It adds insane complexity and gains nothing that cannot be done through simpler means.

because the drive sprocket will be offset from the pivot axis, causing a moment in one direction.
Even when the chain actually passes through the pivot point, there will be a moment induced.

Shaggy_Dog

I'm a rider, not an engineer, but I understand a little about chain growth and axle paths. One thing that bothers me, if you have a rearward axle path, how do you avoid chain growth? Surely the two are part and parcel?

supersonic

Indeed ;-)

Assuming the general sort of geometries we see.

Anonymous

supersonic wrote:

Assuming the general sort of geometries we see.

hbrashaw

a frame that weighs 500g, has 50-300mm travel, is strong enough to huck off the empire state building and live, no chaingrowth or pedal bob, and costs £50.

lawman

im gonna be slightly realistic and ask for a 150mm twin link design, like vpp, dw etc, with a rearward axle path,no chain growth, very minimal pedal bob, and a rising rate thats supple but firm pedaling beggining of the stroke, nice and tight in the middle and bottomless feeling at the end, all built around a frame with a 66ish degree headangle, low bb and preferably carbon and weighing under 6lbs

hbrashaw

if you actually have to make this, what he said ^

Anonymous

jairaj

:? bloody hell rear suspension is complicated!

I think you guys have scared the original poster off with your crazy talk!