[canadmos]

I have a Fox 36 Float (2015 model?) which over the last week or two, I've noticed that I can feel it "top out" if I lift on the bars. It doesn't top out very hard, nor can I hear it clang or anything, but I can definitely feel it in the parking lot and while reefing on the bars going slow over roots.

If I compress the fork a little, I can then pull up on the bike and make it happen every time. Its not rebounding all the way? When I make it top out like that, the fork raises probably less than a millimeter.

Anything in particular that might cause this? Other than this, the fork seems to operate pretty damn good. It has about 2000km on it....which I'll be honest I haven't really done any maintenance on it. Though I do keep is clean and make sure to wipe the dust wipers after every ride.

 

[Muddy]

I put effort into purging all the air in my Solo Air Totem every few rides. If 60psi is being used, 15-20psi gets pumped at a time then the fork gets cycled a dozen times. Once up to riding pressure a couple psi can need to equalize still. I just do it out of habit.

 

[Westy]

Check your shimz, probably needs moar.

 

[Adventurous]

Is it just on extension that you feel it? Or do you have a "dead zone" where there's no damping during compression as well? Ever noticed it leaking any oil?

 

[Nick]

is there a negative spring you're pulling up against??? HMMM?????

 

[Westy]

Should have gotten a Rux

 

[canadmos]

Is it just on extension that you feel it? Or do you have a "dead zone" where there's no damping during compression as well? Ever noticed it leaking any oil?

No dead zone, fork feels normal other than when pull up. It's never leaked any oil.

 

[Westy]

What happens when you max out the rebound?

 

[canadmos]

@Westy I can't feel it and it seems to rebound fully, with the rebound turned in all the way.

I'm running the rebound about 9 clicks in, right in the middle.

I tried sticking a zip tie down the dust seals but didn't hear any air come out. Might try changing the oil in the lowers later, but not sure that that would actually have any effect on it?

 

[Westy]

@Westy I can't feel it and it seems to rebound fully, with the rebound turned in all the way.

I'm running the rebound about 9 clicks in, right in the middle.

I tried sticking a zip tie down the dust seals but didn't hear any air come out. Might try changing the oil in the lowers later, but not sure that that would actually have any effect on it?

Old floats used to have a coil negative spring. Sounds like 2015 brought forth a new air negative spring, This design will top out a little harder as the pressure equilibrium point is at full top out (I think). There may be a top-out bumper in there but it isn't going to be as plush as the coil. The old coil design actually had a bit of positive travel past the top out point.

 

[Westy]

In theory, if all is working well. If you let the air out of the fork while it is compressed, the negative spring should cause the fork to collapse with resistance to extension. If you let the air out with it at full extension, with the bypass port open, it shouldn't move.

You could increase the negative chamber pressure by pumping the fork to a higher pressure, compressing so the bypass port is closed, then bleeding down to the desired final pressure. This should soften the top out and will shorten travel. This probably wouldn't stay this way for long during riding.

 

[canadmos]

Old floats used to have a coil negative spring. Sounds like 2015 brought forth a new air negative spring, This design will top out a little harder as the pressure equilibrium point is at full top out (I think). There may be a top-out bumper in there but it isn't going to be as plush as the coil. The old coil design actually had a bit of positive travel past the top out point.

Thanks for the info and video.

So question is, why would it change in feel now, after so many miles are on it. Perhaps the air spring just needs a new set of seals?

Per your latest post, I'll experiment with that. I'll let the air out and refill to see if it has any affect. I'll also get on ordering a float service bag.

 

[Westy]

Thanks for the info and video.

So question is, why would it change in feel now, after so many miles are on it. Perhaps the air spring just needs a new set of seals?

Per your latest post, I'll experiment with that. I'll let the air out and refill to see if it has any affect. I'll also get on ordering a float service bag.

Not sure why it would change. Actually if the main piston seal was bad I would think it would get stuck down or setting into the travel.

Perhaps too much lube oil filled the negative chamber? Not bypassing?

 

[HAB]

• The new Floats with the air negative spring do indeed have a (small) rubber topout bumper.
• If your damper cartridge was leaking, you likely wouldn't notice any oil on the outside of the fork. The seals that would be more likely to fail are on the damper shaft, and the base of the damper bladder. In either case the oil would leak into the lowers, not out of the fork. If there's air in the damper cartridge, you'd almost certainly feel some inconsistency in the damper, and hear noise from the foamy oil moving through the damper.
• The most likely culprit is that your negative spring isn't auto-equalizing correctly, and the negative spring pressure is low. An air spring service would fix this.

 

[canadmos]

Well I dumped all the air out and it seems to be a little better, after a little bouncing around. I'll just ride it as-is until I get the service kit for the air spring in hand.

One thing that I have also noticed is that I do hear the fork making a "sucking" noise on bigger hits (like roots and stuff). I am pretty sure it didn't make that noise when I first got it.

 

[canadmos]

Went for a beer run to a buddies house tonight on the bike. Reduced the PSI in the air chamber from just under 100 to about 85-90psi. Not sure exactly, as this awesome (but HORRIBLE) Shimano PRO shock pump only displays increments of 25psi (WTF???).

Felt much better....Though it does sink into the travel much more. Perhaps its time to raise this puppy to 160mm.

 

[Westy]

Went for a beer run to a buddies house tonight on the bike. Reduced the PSI in the air chamber from just under 100 to about 85-90psi. Not sure exactly, as this awesome (but HORRIBLE) Shimano PRO shock pump only displays increments of 25psi (WTF???).

Felt much better....Though it does sink into the travel much more. Perhaps its time to raise this puppy to 160mm.

Unless you are morbidly obese, I think your problem is waaay too much pressure.


Rider Weight

Air Pressure

< 125 lbs.45 psi

125 - 135 lbs.48 psi

135 - 145 lbs.50 psi

145 - 155 lbs. 53 psi

155 - 170 lbs. 55 psi

170 - 185 lbs. 62 psi

185 - 200 lbs. 69 psi

200 - 215 lbs. 76 psi

215 - 230 lbs 83 psi

230 - 250 lbs. 90 psi

 

[canadmos]

Unless you are morbidly obese, I think your problem is waaay too much pressure.


Rider Weight

Air Pressure

< 125 lbs.45 psi

125 - 135 lbs.48 psi

135 - 145 lbs.50 psi

145 - 155 lbs. 53 psi

155 - 170 lbs. 55 psi

170 - 185 lbs. 62 psi

185 - 200 lbs. 69 psi

200 - 215 lbs. 76 psi

215 - 230 lbs 83 psi

230 - 250 lbs. 90 psi

It does feel good at that high pressure, though. And I'm using all the travel... I'm also somewhere between 210-220 lbs.

 

[Westy]

It does feel good at that high pressure, though. And I'm using all the travel... I'm also somewhere between 210-220 lbs.

Lay off the Tim Horton's and back bacon eh!

 

[HAB]

Unless you are morbidly obese, I think your problem is waaay too much pressure.


Rider Weight

Air Pressure

< 125 lbs.45 psi

125 - 135 lbs.48 psi

135 - 145 lbs.50 psi

145 - 155 lbs. 53 psi

155 - 170 lbs. 55 psi

170 - 185 lbs. 62 psi

185 - 200 lbs. 69 psi

200 - 215 lbs. 76 psi

215 - 230 lbs 83 psi

230 - 250 lbs. 90 psi

Those pressure recommendations are low. I'm running 66psi, at 160lbs.

 

[canadmos]

Those pressure recommendations are low. I'm running 66psi, at 160lbs.

See @Westy, its not the bacon's fault!


Went for a ride today and it sure is still doing it. It's definitely not rebounding to full extension. I'm pretty sure that is what I'm feeling when I skip over roots or pull up on the bars.

On another note, it felt pretty good as well at the lower pressure. Though, it does sink into the travel a bit more, even with the low speed compression dialed in a bit more. Would this be helped with another air spring volume spacer thingy?

 

[HAB]

Volume spacers mostly impact end stroke, so no, they won't do much for how far you'll sag into it. Nor will increasing compression damping, that's more speed sensitive than position.

 

[canadmos]

Volume spacers mostly impact end stroke, so no, they won't do much for how far you'll sag into it. Nor will increasing compression damping, that's more speed sensitive than position.

I mean it blows through the travel now, like on braking it dives quite a bit. If I'm just sitting there on the bike its fine.

 

[HAB]

I mean it blows through the travel now, like on braking it dives quite a bit. If I'm just sitting there on the bike its fine.

What are you running for damper settings?

 

[Jm_]

Did you try it meow?

 

[canadmos]

What are you running for damper settings?

After reducing the pressure last night I fiddled with low speed throughout today's ride, so....

Low speed - 3 clicks from full closed. Probably a little too much, but much less and it collapses.
High speed - 14 from full closed.

Didn't touch the high speed side today. Todays ride was mostly swooping turns and soft ground. Very little roots and crap.

PSI in the fork is probably around 85-90ish. Seriously, the gauge on this pump sucks, but the rest of it is great.

Look at the gauge on this thing...

 

[Westy]

See @Westy, its not the bacon's fault!

It's like your 'Merican or something.

 

[Jm_]

After reducing the pressure last night I fiddled with low speed throughout today's ride, so....

Low speed - 3 clicks from full closed. Probably a little too much, but much less and it collapses.
High speed - 14 from full closed.

Didn't touch the high speed side today. Todays ride was mostly swooping turns and soft ground. Very little roots and crap.

PSI in the fork is probably around 85-90ish. Seriously, the gauge on this pump sucks, but the rest of it is great.

Look at the gauge on this thing...

I wish someone would design a decent shock pump. They want to shove Boost and Metric Shocks and god knows what else down our throats, but these damn shock pumps blow chunks. Fix the goddamn shock pumps first, then start figuring out what new standards to market.

 

[Westy]

I wish someone would design a decent shock pump. They want to shove Boost and Metric Shocks and god knows what else down our throats, but these damn shock pumps blow chunks. Fix the goddamn shock pumps first, then start figuring out what new standards to market.

I have a Topeak Shuttle gauge. Don't know how accurate, but nice and consistent. Can slap it on any POS pump and get good results.

 

[HAB]

I bought some decent quality gauges from McMaster (supposedly accurate to +/- 1%) from McMaster and slapped them on some shitty pumps. I've got a 100psi one for forks, and a 300 for shocks.

 

[Jm_]

I don't mean the gauge specifically, although that's part of it, the whole design is just dumb, nothing to brace the pump on, especially at higher PSIs above 150 or so, stupid release valve is right where you put your hand to brace against (idots). They are just stupid overall. Of course, Lizards never worry about any of the details, they just want to get the next fork and shock out on the market. You can buy a new one when it comes time to re-pressurize it.

 

[Nick]

I have a DT Swiss shock pump that is better than any others I've used.
JM's ergonomic complaints aside, it's accurate and consistent and has a zero loss chuck so you don't lose pressure when removing from the shock.

 

[canadmos]

Pending shock pump improvement, everything inside the fork on the spring side looks normal. Nicely lubed anyways...

Hardly any oil came out the spring side, though. Not that there is much in there anyways. Cleaned it all up, regreased and reassembled according to this. Carefully paid attention to making sure the air shaft was extended and pumped to 50psi before putting the lowers on. Then slowly as I could compressed the fork a few mm until I felt the air equalize inside.

I didn't replace anything, just cleaned, regreased, new oil etc, but from initial floor test I am pretty sure it is still going to top out. Need to put it back on the bike before I say anything though.

Also note to self, do not stick finger in the Fox Gold oil. That stuff is like honey.

 

[canadmos]

Have had a few rides on it since pulling it apart and changing the oil. I don't think it is very noticeable now.

I am back up to somewhere between 90-100psi and dialed out the compression damping bit. It was just too softy mcsoft with the lower pressure. It was using up the travel on every little bump.