Bicycle Mechanics - why elastomer springs?

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lxpatterson
11-02-12, 08:57 PM
I just finished setting up my winter bike, which has a late 90's JudyXC on it. I took the fork apart, because I actually had no idea what kind of fork it was....I remember lusting after that fork when I was a kid, because it was the best mid-range fork at the time.

Lucky for me I have a spring model not an elastomer model. But that got me thinking, why did they use elastomer springs in so many of those first generation forks? It's not like metal springs are some sort of space age technology.

garage sale GT
11-02-12, 09:13 PM
Metal springs would let the bike oscillate several times without a dampener. Elastomer springs are self dampening. They are mainly for lower end bikes so the design would not have to incorporate a dampener such as a hydraulic shock.
well biked
11-02-12, 09:20 PM
Elastomer forks are just about the cheapest way a functional suspension fork can be built. Some type of damping system is necessary if coil springs are used, and that costs more.

lxpatterson
11-02-12, 09:29 PM
Elastomer forks are just about the cheapest way a functional suspension fork can be built. Some type of damping system is necessary if coil springs are used, and that costs more.

I see. I thought all forks have damping, but i guess you're right, i don't remember seeing any damping cartridge in those old manitou forks.
well biked
11-02-12, 09:29 PM
Elastomer "springs" can also be fairly light weight, especially since the fork can have a very simple design and still be functional.

Don't get me wrong, I was a huge fan of early forks like the coil/oil Marzocchi's, they were much better forks.
FastJake
11-02-12, 09:40 PM
Elastomer "springs" can also be fairly light weight, especially since the fork can have a very simple design and still be functional.


+1

Elastomer forks can be very light and still decently useful. I have an old Rock Shox Quadra fork of this design. It only weighs 3.46 pounds, about 0.3lbs heavier than a new SID fork.

On the other hand I used to own a low end Rock Shox coil spring fork that was >5lbs of garbage with no damping whatsoever. IMO, the elastomer fork is a good design choice for low-mid range forks.
dsbrantjr
11-02-12, 10:42 PM
In addition to the above, elastomer won't rust, rattle or squeak like steel springs.