Fork dive while front braking.

aba2005

I've got a Tora 302 adjustable fork. I just want to know how much dive you should get when front braking or whether you shouldn't get any at all which would probably mean my forks need a service.

Thanks for your help.

supersonic

Forks dive due to weight shifts. This can be compenasted for by low speed compression damping, but its fixed on this fork. So there is nothing you can do apart from alter your weight or change the oil to something thicker.

aba2005

Ok, thanks. If I wanted to change the oil could my LBS do it or would I need to send it off somewhere like chainreactioncycles?

Can't get much lighter, i'm 6'2 72 kgs!!! So changing my weight isn't an option, lol.

supersonic

Given your weight, the oil sounds right. I'd just ride it! Forks are reactive to weight shifts.

aba2005

Ok, Thanks. I'm guessing the oil will need replacing every occasionally. How often should this be done?

supersonic

Every full service, usually once a year. these are quite easy to strip, and full service guides available from SRAM.

norco forever

what size front brake you running as that can have a huge difference unless your running V's.

nicklouse

norco forever wrote:

what size front brake you running as that can have a huge difference unless your running V's.

it makes no difference.

norco forever

i found fairly large difference between my 203mm disc and 160mm disc though would this be due to less modulation and more outright power?

supersonic

The size deosnt really make a difference, its the decceleration that does it. If you can lock the wheel with Vs or a disc, the decceleration is the same, and the fork will dive similarly.

Adding more compression damping lessens it, as does a stiffer spring: or a fork like the USE SUB, which uses a reactive link to use disc forces to counter the dive.

norco forever

my bad :roll:

nicklouse

dive is purely caused buy the transfer of weight to the fork. the braking force, disc size has nothing to do with it. But as sonic said you can use a link to transfer the reaction force fron the brake into the sus. system to help react against the compresion force applied by the weight transfer.

aba2005

Thanks for your help Supersonic