Mountain Biking - Different riding style forks = different characteristics?

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S.D.XC
12-19-08, 04:56 AM
I was just thinking, what if i put a DJ fork and went to ride XC, would there be any difference? (and also the other way around)

Is there any difference between forks for different styles of riding?


ed
12-19-08, 06:12 AM
Well, a DJ fork will be heavier and is usually sprung a little heavier.(that can be fixed) If you buy a coil sprung fork with different springs, you can adj that. An air fork is even easier.

If you truly go "Dirt Jumping" with an XC fork, expect something to eventually break.

Food for thought:
I had tossed around the idea of getting an '08 Marz 4x WC when I had the red Komodo. It's a pretty light fork and still pretty stout. It's not a "DJ" specific fork and could break under severe abuse, but I have read reviews from people who have taken the thing DJ and Urban and it's held up nicely. It's still light enough to be XC'able w/o too much effort. The 20mm TA would be a nice addition. Last summer they were like $625 everywhere, but you can find them readily now for $390'ish.

S.D.XC
12-19-08, 07:47 AM
sprung heavier??


mtnbiker66
12-19-08, 07:59 AM
There would be no difference, all forks are the same. The fork makers just want you to spend more money.

ed
12-19-08, 08:13 AM
sprung heavier??

Stiffer.
Example:

Gold Label Jump series 2


Category: High End 32mm Street and Dirt Jumping
Travel: 80mm or 100mm
Wt. Lbs: 4.6
Wt. Grams: 2086.1
Spring: X-Firm Coil Spring
Steerer: 1 1/8th High-strength steel
Damping: FFD with rebound adjust
Adjustments: Rebound
Stanchions: 32mm Gold Al
Casting: One piece Reverse Arch (RA) Magnesium
Axle: 20mm Hex Lock Thru Axle
Crown: Hollow Aluminum
Lubrication: Semi Bath with Evil Genius Seals
Wheel Size: 26
Disc Mounts: Post
Disc Size Size: 210 Max
No Boss Option: Only
Ride Height (mm) : 460, 480
Color: Disco Gold
Notes: Grind bolt on spring leg



Basically enough to take the initial shock out of a biffed landing. It's all relative to rider weight of course. As I said above...preload is always adjustable...especially if you buy air. Rockshox coil forks are kinda pissin me off. The last I was aware, they don't have adjustable spring preload. "Change Spring".

S.D.XC
12-19-08, 08:29 AM
so it's mostly about the stiffness of the spring and the strength of the fork...rite?

but wouldn't air forks' valve blow?

kenhill3
12-19-08, 08:39 AM
Rockshox coil forks are kinda pissin me off. The last I was aware, they don't have adjustable spring preload. "Change Spring".

Hey Ed-

Wasn't the deal with spring forks, that if you adjusted for rider weight by preloading or compressing the spring, that you also effectively reduce available travel? Change the spring itself and you keep the travel? I'm not that smart about forks, but that is what I've always understood.

ed
12-19-08, 09:45 AM
No. The end of spring travel doesn't cause the bottom-out in the fork. There's something else in there that ends travel. I don't know if it's the push-rods or some bumper or what. I got 130mm of travel with my Fox 32 Vanilla whether the preload was maxed out or all the way off. It just made the spring firmer and more difficult to reach the end of travel with the same rider weight.

born2bahick
12-19-08, 10:23 AM
so it's mostly about the stiffness of the spring and the strength of the fork...rite?

but wouldn't air forks' valve blow?
Not If it's an air fork built for the application.

ca7erham
12-19-08, 03:34 PM
Rockshox coil forks are kinda pissin me off. The last I was aware, they don't have adjustable spring preload. "Change Spring".

Not true. My dart had a little knob that said Preload. It didnt do anything, but it was there.

ca7erham
12-19-08, 03:35 PM
but wouldn't air forks' valve blow?

Only if its a headshock. I've bottomed my fork before, and it hasnt blown.

dminor
12-19-08, 04:12 PM
so it's mostly about the stiffness of the spring and the strength of the fork...rite?A dirt jumping fork is a beefier fork all the way around. The crown might have a bit more material in it; most will have a beefier dropout area for supporting a 20mm thru-axle; the stanchions, although outwardly the same diameter as lighter models, may be of heavier-walled tubing; and it might have a chromoly or heavier-walled-aluminum steerer.


Hey Ed-

Wasn't the deal with spring forks, that if you adjusted for rider weight by preloading or compressing the spring, that you also effectively reduce available travel? Change the spring itself and you keep the travel? I'm not that smart about forks, but that is what I've always understood.


No. The end of spring travel doesn't cause the bottom-out in the fork. There's something else in there that ends travel.It's usually the bottom bushing slamming into the bottom-out bumper. To answer ken's question: it's called coil-bind; but I don't think there is enough preload adjustment on a fork to shorten one up to the point of coil-bind. I think it may be possible on some rear shocks to do that but I've never encountered that happening on a fork. And, yaeh, the best way to accomodate for weights is to change the spring - - there's not enough range in the preload to overcome too heavy a rider on too light a spring.

S.D.XC
12-24-08, 04:44 AM
thanks everyone for all the information...

:)