Softer Fork detrimentally effecting braking power?
P-Jay
Posts: 1,478
I recently had my forks serviced (2006 Fox 36 Talas R) whilst I was chatting to the guy who did them (in Mojo) he asked what sort of sag I was running because, even taking into consideraton my ‘generously apportioned’ body they were running a high PSI.
When I got home I set them at my usual pressure (110ish PSI) and checked it, about 6% sag, OK waaay too hard. Felt a bit daft but because of a bit of a process of evolution, weight loss, cack-handed set-up and other things I’d taken to running a very hard fork and compensating the for the lack of high speed compression by running a very low pressure front tyre.
I set them at around 30% sag and the change was amazing, I upped the tyre pressure and I’ve got tonnes off front end grip, less rolling resistance and generally going faster and harder than ever. Happy days..
Until it comes to slowing down again, it feels like the front brake is completely devoid of power. At first it made for a few hairy moments on tight sections, but Saturday I grabbed a handful of stopper to make a turn, nothing really happend and I went straight off the trail in head on into a tree.
Brakes has good feel and lever pressure is the same. After the tree incident I changed the pads at the trail side incase they’d be contaminated some how, (probably when I refitted them after the fork went on) it improved them a little, but no major change.
So does the softer fork kill the braking performance? I tested the new pads on a tarmac section and a full ‘emergency’ stop makes the fork go down to 90% sag (probably to where the bottom out damping starts) or is it just I’m going faster and they have to work harder.
Brakes are 2006 Juicy 7’s and to be fair, worn to hell. The pistons never move the same distance and the levers have more play than is healthy but they’ve always worked up to now, but I’m trying to say my beer tokens for a new bike so I’d rather not replace them now if it’s just the fork is too soft.
Bike is a 2006 Enduro Expert, 203 rotors front, 180 rear and I’m about 16st now so they work hard.
When I got home I set them at my usual pressure (110ish PSI) and checked it, about 6% sag, OK waaay too hard. Felt a bit daft but because of a bit of a process of evolution, weight loss, cack-handed set-up and other things I’d taken to running a very hard fork and compensating the for the lack of high speed compression by running a very low pressure front tyre.
I set them at around 30% sag and the change was amazing, I upped the tyre pressure and I’ve got tonnes off front end grip, less rolling resistance and generally going faster and harder than ever. Happy days..
Until it comes to slowing down again, it feels like the front brake is completely devoid of power. At first it made for a few hairy moments on tight sections, but Saturday I grabbed a handful of stopper to make a turn, nothing really happend and I went straight off the trail in head on into a tree.
Brakes has good feel and lever pressure is the same. After the tree incident I changed the pads at the trail side incase they’d be contaminated some how, (probably when I refitted them after the fork went on) it improved them a little, but no major change.
So does the softer fork kill the braking performance? I tested the new pads on a tarmac section and a full ‘emergency’ stop makes the fork go down to 90% sag (probably to where the bottom out damping starts) or is it just I’m going faster and they have to work harder.
Brakes are 2006 Juicy 7’s and to be fair, worn to hell. The pistons never move the same distance and the levers have more play than is healthy but they’ve always worked up to now, but I’m trying to say my beer tokens for a new bike so I’d rather not replace them now if it’s just the fork is too soft.
Bike is a 2006 Enduro Expert, 203 rotors front, 180 rear and I’m about 16st now so they work hard.
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Comments
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well, sometimes fork dive can make the brake feel a little less sharp, but usually actually power is still as good if not better due to more grip... sounds like the brake got contaminated when servicing... clean the rotor and get new pads...I like bikes and stuff0
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sounds like you need to check the brake out.
a softer fork will allow the wheel to track the ground better so should give better braking."Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
Parktools :?:SheldonBrown0 -
you probably contaminated the rotor at the same time as the brake.
give it a quick wipe with 99.9% isopropyl alcohol (must be 99.9+% or you will contaminate them more).
Also sand the pads slightly (I use a knife sharpening block).
Rebed them in, and try again.
If still kaput bit more work.
If your rotor is a one piece rotor, just stick it in the over at gas mark 3 for 20 mins.
If the rotor has an aluminium carrier, bit more work.
Pencil torch (blue flame shooty thing). Slowly go around the disk burning all the oil off. Look VERY closely as you do this, if there is oil you will see it thin as the flame heats it. If oil, keep fire on that bit until stops smoking. Do not confuse it with the condensation (gas+o2 = water + heat and stuff).
This should fix the issue.
Fork oil is designed to be extremely resilient, so hard to burn or clean off.
A sign of good quality oil is how fking hard it is too get rid off when you spill it on the wrong place.Why would I care about 150g of bike weight, I just ate 400g of cookies while reading this?0 -
Thank for the tips.
It's not likely I got fork oil on the rotors, Mojo did the service and they come back spotless. It's ether grease from the headset barings or front hub barings (changed them at the same time) or general being a div and not being more carefull cleaning my hands when I stuck it all together but I'll go through the above just in case.
Thanks!0
