Fork bleeding...

B

buffmaster

Mi. Trail Riders

Member

Apr 11, 2001

558

0

• May 9, 2004

• #1

When should you bleed the air from your forks? I've got the Motion Pro bleed valves installed so I can bleed 'em whenever I want, but a friend of mine told me that it's almost worthless to bleed them except for when you're putting the bike away. Anyone got any opinions?

 

rickyd

Hot Sauce

Oct 28, 2001

3,447

0

• May 9, 2004

• #2

I was advised too blled mine after every moto.. Its easy too do..
Rick

 

Jeff Gilbert

N. Texas SP

LIFETIME SPONSOR

Oct 20, 2000

2,963

2

• May 9, 2004

• #3

I bleed mine after every moto after it has cooled down a bit, hope I'm doing it right.

 

C

canyncarvr

~SPONSOR~

Oct 14, 1999

4,005

0

• May 10, 2004

• #4

Bleed them every time you stop.

Pressure build up will depend on the type of fluid used and the amount of hydraulic action taking place. Any build up of 'air shock' pressure will negatively effect fork action.... given that it was set to suit in the first place.

Almost worthless to do until you're done riding? What is the thinking behind that? Does that thinking include only checking/filling your tires to proper pressure is worthless until you're done riding?

If you hear air escape when you hit your bleeders and can't tell the difference in handling immediately afterward I'd be surprised. If you hit 'em and you don't hear anything then guess there wasn't much of a buildup....but now you know that.

 

S

skipro3

Mod Ban

Dec 14, 2002

902

0

• May 12, 2004

• #5

I agree with CC. I hit my bleeder button every time I stop and take a break in my riding. I unweight the front forks and extend them to their full length, then touch the button. I've had them build up pressure just sitting in the garage from a cool morning to a warm afternoon without the bike even leaving it's stand.
One reason maybe to bleed them after a ride would be to relieve the pressure on the fork seals?

 

Jaybird

Apprentice Goon

LIFETIME SPONSOR

Mar 16, 2001

6,449

0

Charlestown, IN

• May 16, 2004

• #6

This build-up of pressure is not air. It is the gases released from the oxidation of your fork fluids.
I can't imagine it effecting the action of the fork to a noticible degree no matter what.
If you had pressure build up from just sitting in a garage from morning to afternoon, then I suggest your fork oil is as rancid as it can get and need to be changed out immediately.

Take a whiff of the bleeder next time you release your pressure (which at the end of the day is more than sufficient) and see if you smell anything. If it smells like burnt motor oil, your fluid is oxidized and should be changed out.

 

S

skipro3

Mod Ban

Dec 14, 2002

902

0

• May 19, 2004

• #7

Jaybird said:

This build-up of pressure is not air. It is the gases released from the oxidation of your fork fluids.
I can't imagine it effecting the action of the fork to a noticible degree no matter what.
If you had pressure build up from just sitting in a garage from morning to afternoon, then I suggest your fork oil is as rancid as it can get and need to be changed out immediately.

Take a whiff of the bleeder next time you release your pressure (which at the end of the day is more than sufficient) and see if you smell anything. If it smells like burnt motor oil, your fluid is oxidized and should be changed out.

Click to expand...

Fresh oil and replaced every 6 months. Eric at Nor Cal, a Race Tech franchise, does my shock and fork mainenance on a trade deal with me. I think I'll stick with his expert opinion and recommendation to bleed the pressure off the forks. It is most definately noticable.

 

bclapham

LIFETIME SPONSOR

Nov 5, 2001

4,340

0

• May 19, 2004

• #8

what has any of this got to do with MX tech services?

 

M

muddy226

Sponsoring Member

Sep 14, 2003

271

0

• May 19, 2004

• #9

I bleed the forks after every moto, assuming that the space in the forks not filled with oil is filled with air, which expands when heated by the fork action, thus creating pressure build up. I have often wondered what happens when the fork has cooled again, does the resulting vacuum draw more air in past the seals etc? And if air is going to get in anyway, why do we spend so much time when rebuilding forks to ensure that all the air has been expelled from the oil? If the bleeders work why can't we just do a rough job of getting out most of the big air bubbles, then ride it and use the bleeders? Anyhow, sorry about the more questions than answers, but I always bleed the forks, and nearly always get a satisfying hiss.