Ricfrog

I'm thinking about changing my 120mm forks to 160mm forks on my specialized camber. This is due to the 120 forks bottoming out and not being able to take the harsher trails (as I grow more confident). Will this put to much strain on my head set and will it improve my ride? Thanks for your help Rich

corrado33

Bottoming out the forks has less to do with how large they are and more to do with the resistance they provide. Are you a heavy rider? Is the 120mm fork a coil spring fork? Is it an air fork? If it is an air fork, is it to the correct pressure for you?

When you sit on the bike VERY gently, how much does the front fork compress? 10%? 20%? 30%? 40%?

70sSanO

Not to send you in another direction, but you may want to check our MTBR and see what they may say.

John

dabac

+1


If you are bottoming out on a correctly set up fork, you are riding harder than the bike was intended for.


Changing one part will only move the limiting factor somewhere else.
As in something quite important breaking on a landing.


Check the set up.
If it's good, and you still bottom out, get a bike intended for harder riding.


Or expect breakages. and pain.
Going from 120 to 160 is 1/3 as much travel.
It'll change the steering geometry considerably. Even if the bike holds up, you may not be happy with the results.

RubeRad

+1, there's a pretty big hole in BF usership/expertise where MTB are concerned, and that hole lives at mtbr.com. I go there for MTB-specific questions.

cpach

Swapping in a longer fork will decrease your head tube angle which will make the bike slacker--it will steer slower, which will make it more stable at speed, at the expense of requiring more input to keep on a line at low speeds, such as when climbing.

It will also raise your bottom bracket and your center of gravity which has the effect of making the bike less stable steering, but will increase pedal clearance.

Also effected is your seat tube angle--it will also become slacker, which means you will need to move your saddle forward on its rails to maintain the same position, if there is room on the rails.

Generally, it's reasonable to increase travel 10-20mm, but I'd bet your bike would ride worse than it does now with a 160. If that is what you want, you have the wrong bike. Besides the geometry changes, it would unbalance the suspension on your bike.

Also, if you're bottoming out now there's a lot of suspension setup you can do to help. First of all, the air pressure/sag needs to be appropriate. Also, you may be running too slow of a rebound, so your fork is packing up with successive hits. Lastly, if you add volume spacers to your suspension it will make the spring rate more progressive, which will make the suspension resist compression more later in it's travel, reducing bottom out.