Suspension set-up guides and info

[FábioPereira]

hi! some help for a noob here.
I wrongly put 150 psi on a fox 34 fork with 120 psi max.
When I notice, I correct it without run the bike.
Can this cause any issue?

 

[thebarber]

hi! some help for a noob here.
I wrongly put 150 psi on a fox 34 fork with 120 psi max.
When I notice, I correct it without run the bike.
Can this cause any issue?

It should be OK,
Let the air out to get the correct sag and start from there

 

[FábioPereira]

It should be OK,
Let the air out to get the correct sag and start from there

I did that just after realize the mistake.
Thanks!

 

[thebarber]

I did that just after realize the mistake.
Thanks!

Just keep an eye on the pressure and remember when you attach the pump, air from the fork will fill the hose so the pressure will be down a fraction of what it was set at.

 

[FábioPereira]

Just keep an eye on the pressure and remember when you attach the pump, air from the fork will fill the hose so the pressure will be down a fraction of what it was set at.

Understood! Many thanks

 

[urastus]

Understood! Many thanks

Did you pump the fork at all while you were pumping it up? If not, then it probably wasn't @ 150psi in reality. If you are a noob, do you understand to pump the fork to equalise the pressure in the fork? If you did not do this while pumping, you may now need to add a bit more.

 

[FábioPereira]

Did you pump the fork at all while you were pumping it up? If not, then it probably wasn't @ 150psi in reality. If you are a noob, do you understand to pump the fork to equalise the pressure in the fork? If you did not do this while pumping, you may now need to add a bit more.

At first I didn't. But after noticing the error (putting 150 psi), I took all the air out and started pumping again and every 20 psi pumped the fork until it reached 105 psi as the fox recommends.

 

[1oldfart]

I am in Quebec. Since i rent a room my control is limited. I park my Ebike in the garage and it is heated at about 22 celcius. Tomorow that Ebike will be riding and outside it will be about minus 16 celcius. Is there a chart i can look at? I would like to know how much PSI the now 180(inside) will turn into(outside). Over the last 2 months i got used to my new Ebike so i am pushing it more. Oops, i am talking about my rear shock.

 

[steve_sordy]

I would take your shock pump with you and see how the bike rides. Be prepared to add some air.

I reckon that temperature change would drop your pressure from 180 to 156, so it might feel a bit soggy. But of course, the action of the shock will warm it up, (as it does normally). Difficult for me to predict what will happen. If you have an air fork that same principles are at play.

Because the mass of air inside the shock is a constant as is the volume (uncompressed), then the formula for outside pressure is:
inside pressure x (273 + outside temp) / (273+inside temp)

180 x (257/295) = 156

 

[urastus]

riding and outside it will be about minus 16 celcius

If I lived there I would never have discovered mtb! I'd be like the michelin man on skis or snowshoes - you'd be lucky to see my beady little eyes

 

[Mike Malanowicz]

I can confirm this.
I fitted a pair of Fox 38 180mm yesterday to my approx 55lbs eBike. Unless I put more than 100 psi in I didn’t get the forks fully extended!
This was ok for me as I weigh about 17 st with all my gear, so I needed at least that much air in, but for lighter riders there would be trouble getting the full extent of travel.
I don’t know about sag readings under 100 psi, but they are bound to be affected if full travel is not achieved.

I do have the same sort of issue with my FOX 36 Rythm :/ and this is unfortunately "normal" in FOX forks. Sometimes, when this becomes a big problem (for example travel is shorter by 2cm) , the damper unit has to be replaced, which can help for a while.

 

[PeterP]

Hi Gents,

I have to admint , I didn't go through all of info's at the start; But this doens't seem like a 'Suspension setup" question.

I have a 160mm Manitou Mattoc Dorado air front fork. So it should have 160mm travel right?
Mine has 110/120 in standard position. It sucks the entire fork down. This makes setting it up hard and 'weird'. (This is with air out or in)
With some force and air is out, I can force the Front suspension to 160mm.

I've did some googling and for instance I saw some here:

Can anyone help me out? What should I do?

 

[urastus]

I think you have a vacuum.

 

[PeterP]

I think you have a vacuum.

After some search i found out its probably something like this indeed. I've also noticed my suspension pump isnt working correctly..(new one) that also didn't work.

After some fiddling, air in, air out, removing the top cap en pulling en pressing hard, i got my 160 travel back.

I didn't want to try and dissasemble the entire fork. Going to italy in 3 days

 

[urastus]

After some search i found out its probably something like this indeed. I've also noticed my suspension pump isnt working correctly..(new one) that also didn't work.

After some fiddling, air in, air out, removing the top cap en pulling en pressing hard, i got my 160 travel back.

I didn't want to try and dissasemble the entire fork. Going to italy in 3 days

It sounds as though the hole / dimple that allows pressure equalization between air chambers was blocked; you've unblocked it. Supposedly it gets blocked with excess grease used during assembly. See in the video from 9'50" in. I'm surprised that what you did isn't a recommended quick fix - basically force fork up sharply to increase pressure on opposite side, or pump up, and force fork down sharply. One or the other has a good chance of blowing the obstruction out of the pressure equalising dimple thing. The only catch is that whatever caused the blockage may do so again - hence the recommended cleaning out. I imagine you'll be right though

 

[Pokitren]

It sounds as though the hole / dimple that allows pressure equalization between air chambers was blocked; you've unblocked it. Supposedly it gets blocked with excess grease used during assembly. See in the video from 9'50" in. I'm surprised that what you did isn't a recommended quick fix - basically force fork up sharply to increase pressure on opposite side, or pump up, and force fork down sharply. One or the other has a good chance of blowing the obstruction out of the pressure equalising dimple thing. The only catch is that whatever caused the blockage may do so again - hence the recommended cleaning out. I imagine you'll be right though

This is roughly what my bike shop did. I tried to fix it myself for a long time, and then I gave it to the man for repair. I love to ride, and things don't always go smoothly with repairs. I hope to find answers to my questions on your forum.

 

[Sander23]

I've got a rockshox pike ultimate with 140 mm travel. I've set it up at 120 psi (at 99 kg with riding gear and a seccond 3.5 kg battery)
That gives me about 30% sag.
Mainly do xc-trail and sometime some enduro riding.
On the bigger hits I'm have some travel over, can't even bottom it out it seems.

The fork has 1 token installed. Will I be using more travel if I remove that token?
Or should I just keep it this way?

 

[salko]

Yes.

 

[Bones]

I've got a rockshox pike ultimate with 140 mm travel. I've set it up at 120 psi (at 99 kg with riding gear and a seccond 3.5 kg battery)
That gives me about 30% sag.
Mainly do xc-trail and sometime some enduro riding.
On the bigger hits I'm have some travel over, can't even bottom it out it seems.
View attachment 92655
The fork has 1 token installed. Will I be using more travel if I remove that token?
Or should I just keep it this way?

Remove the token. Most riders don't ride hard enough to need them fitted. If it bottoms when correctly set up then fit them back in.

 

[1oldfart]

I've got a rockshox pike ultimate with 140 mm travel. I've set it up at 120 psi (at 99 kg with riding gear and a seccond 3.5 kg battery)
That gives me about 30% sag.
Mainly do xc-trail and sometime some enduro riding.
On the bigger hits I'm have some travel over, can't even bottom it out it seems.
View attachment 92655
The fork has 1 token installed. Will I be using more travel if I remove that token?
Or should I just keep it this way?

Are you satisfied with this NN?

 

[Sander23]

I like the fork , it feels great. The difference with the old fork(suntour raidon 34) on my previous e-hardtail is massive.

This is also my first higher end fork so setting this up is new to me and am trying different setups . Never had any low/high speed compression and tokens.

 

[skinipenem]

I've got a rockshox pike ultimate with 140 mm travel. I've set it up at 120 psi (at 99 kg with riding gear and a seccond 3.5 kg battery)
That gives me about 30% sag.
Mainly do xc-trail and sometime some enduro riding.
On the bigger hits I'm have some travel over, can't even bottom it out it seems.
View attachment 92655
The fork has 1 token installed. Will I be using more travel if I remove that token?
Or should I just keep it this way?

Are you hitting any larger drops, flat landings, or big hits? If not then maybe leave the spacer in for when you do.

Does the fork feel harsh? If so. Try it without the spacer.

There is nothing wrong with not using all the forks travel as long as it feels good. If you take out a spacer you will use more travel which could be good or bad. Kind of depends on how much travel you are using in the rear as well so you keep balanced fore and aft. I don't think most upper level riders care much about fork sag as long as front to rear geo isn't out of whack.

Easy enough to take a token out of the fork and try it. Only takes a minute with the fork. Then report back here for us all to learn.


Totally armchair quarterbacking here BTW. and off the cuff advice without knowing how much compression you have on your fork which will slow the fork down and decrease your travel.

 

[irie]

I've got a rockshox pike ultimate with 140 mm travel. I've set it up at 120 psi (at 99 kg with riding gear and a seccond 3.5 kg battery)
That gives me about 30% sag.
Mainly do xc-trail and sometime some enduro riding.
On the bigger hits I'm have some travel over, can't even bottom it out it seems.
The fork has 1 token installed. Will I be using more travel if I remove that token?
Or should I just keep it this way?

I'm ~83kg ready to ride. Have a Pike Ultimate Charger 2.1 RC2 150mm (no tokens) which used to "suck down" ~15mm. After installing the C1 160mm air spring upgrade which has a smaller negative air chamber there's virtually no suck down. On my (heavily modified) 2022 Rail 5 I only need ~60psi to get 30% sag.

Have a Rockshox Deluxe Select+ shock with the Megneg upgrade, no tokens and two negative rings, which works very nicely with the Pike. Have ~220psi for 30% sag.