Shock pressure for heavy rider

[matthieup]

So,

 

I have a trek Fuel Ex 8 2017 which is rated up to 136kg (https://www.trekbikes.com/za/en_ZA/bikes/mountain-bikes/trail-mountain-bikes/fuel-ex/fuel-ex-8-29/p/2140600-2017/?colorCode=black) 

 

To set the supervision they refer to the Trek website http://suspension.trekbikes.com/za/en/#calculator to calculate the pressure, rebound and sag settings. The problem is that they only calculate up to 113kg... (i'm at 123kg)

 

How should i go about calculating these? Can i just use the 113kg settings? Increase some? My main question on that is that the rear shock has the Trek aktiv technology, so i'm not sure how different it should be set

[Capricorn]

So,

 

I have a trek Fuel Ex 8 2017 which is rated up to 136kg (https://www.trekbikes.com/za/en_ZA/bikes/mountain-bikes/trail-mountain-bikes/fuel-ex/fuel-ex-8-29/p/2140600-2017/?colorCode=black) 

 

To set the supervision they refer to the Trek website http://suspension.trekbikes.com/za/en/#calculator to calculate the pressure, rebound and sag settings. The problem is that they only calculate up to 113kg... (i'm at 123kg)

 

How should i go about calculating these? Can i just use the 113kg settings? Increase some? My main question on that is that the rear shock has the Trek aktiv technology, so i'm not sure how different it should be set

did you do as the site advised you: to contact the shock manufacturer, which in this case, is Fox?

[matthieup]

I have been on their site and they also only give data up to 113kg

 

http://www.ridefox.com/fox17/help.php?m=bike&id=690

 

I've also read on other threads that people complain about the given values by trek as being too harsh. Maybe I'll use then the ones for the 10kg below and it should suit fine.

 

My main concern was also the rear shock having trek tech and not sure how this impact the standard Fox recommendation

[Hairy]

have you spoken to the bike shop you bought the bike from?

[matthieup]

that's the next step (well LBS as i bought 2nd hand)

[droo]

If you find yourself in Salt River, swing by Stoke and we'll do a setup for you. We've also got a Shockwiz for hire if you want to do some fine tuning on the trail.

[Capricorn]

If you find yourself in Salt River, swing by Stoke and we'll do a setup for you. We've also got a Shockwiz for hire if you want to do some fine tuning on the trail.

i'm curious: what's your general advice for riders that exceed the maximum weights as per the manufacturers guides?

[droo]

i'm curious: what's your general advice for riders that exceed the maximum weights as per the manufacturers guides?

 

 

TBH we've never had an issue we couldn't solve with a sag setup. 350PSI in a shock is a LOT of air.

 

When it's outside the parameters on the printed chart on the fork leg - I dunno. The best thing to do with those is peel them off and throw them in the bin. The pressures on those are generally at least 15% too high, probably to prevent damage by bottoming from underinflation plus a massive safety margin, cos America.

[Grease_Monkey]

i'm curious: what's your general advice for riders that exceed the maximum weights as per the manufacturers guides?

Nothing some bottomless tokens can't solve

 

I have also found suggestions are way too high. I'm on the heavy side - 105kg. I run 90psi in my fork and 200psi in my shock with lots of ramp up on both - have not yet bottomed out. To be honest though, I did struggle a hell of allot to get the settings right on my own - always ran high pressure to avoid bottom out, and then the small bump sensitivity was horrible.

 

Jacques from Cogent Industries helped me out to get volume spacers and tuning right.

 

OP, take droo up on his offer. It's amazing what a bit of experience amd knowledge can to do your suspension set-up, which ultimately transforms the way you ride!

[dasilvarsa]

http://www.ridefox.com/dl/bike/605-00-164-FLOAT-DPS-Tuning-Guide-white-revA.pdf

 

Ballpark 

 

Your body weight in PSI (fork)

Twice your body weight in PSI (Shock)

 

Body weight is in Kg 1Kg=1PSI

 

Add +- 5 psi that will escape when you remove the pump.

[Titleist]

The Trek site settings are way too high. I don’t really understand why they issue a bike with certain travel and then their pressures basically result in only using 40% of the available travel.

[Christofison]

TBH we've never had an issue we couldn't solve with a sag setup. 350PSI in a shock is a LOT of air.

 

When it's outside the parameters on the printed chart on the fork leg - I dunno. The best thing to do with those is peel them off and throw them in the bin. The pressures on those are generally at least 15% too high, probably to prevent damage by bottoming from underinflation plus a massive safety margin, cos America.

Should a heavier rider not get the fork and shock re-valved?

[Capricorn]

TBH we've never had an issue we couldn't solve with a sag setup. 350PSI in a shock is a LOT of air.

 

When it's outside the parameters on the printed chart on the fork leg - I dunno. The best thing to do with those is peel them off and throw them in the bin. The pressures on those are generally at least 15% too high, probably to prevent damage by bottoming from underinflation plus a massive safety margin, cos America.

 

 

Nothing some bottomless tokens can't solve

 

I have also found suggestions are way too high. I'm on the heavy side - 105kg. I run 90psi in my fork and 200psi in my shock with lots of ramp up on both - have not yet bottomed out. To be honest though, I did struggle a hell of allot to get the settings right on my own - always ran high pressure to avoid bottom out, and then the small bump sensitivity was horrible.

 

Jacques from Cogent Industries helped me out to get volume spacers and tuning right.

 

OP, take droo up on his offer. It's amazing what a bit of experience amd knowledge can to do your suspension set-up, which ultimately transforms the way you ride!

 

thanks guys. interesting stuff 

[droo]

http://www.ridefox.com/dl/bike/605-00-164-FLOAT-DPS-Tuning-Guide-white-revA.pdf

 

Ballpark 

 

Your body weight in PSI (fork)

Twice your body weight in PSI (Shock)

 

Body weight is in Kg 1Kg=1PSI

 

Add +- 5 psi that will escape when you remove the pump.

 

Nope. There is no formula, especially not for shocks. Too many variables - linkage curves, leverage ratios, weight distribution, etc etc.

 

Sag setup. The end.

[droo]

Should a heavier rider not get the fork and shock re-valved?

 

Never a bad idea, but this has more to do with bottom out and small bump sensitivity - nothing to do with sag. Sag has to do with air pressure / spring rate.

[splat]

So,

 

I have a trek Fuel Ex 8 2017 which is rated up to 136kg (https://www.trekbikes.com/za/en_ZA/bikes/mountain-bikes/trail-mountain-bikes/fuel-ex/fuel-ex-8-29/p/2140600-2017/?colorCode=black) 

 

To set the supervision they refer to the Trek website http://suspension.trekbikes.com/za/en/#calculator to calculate the pressure, rebound and sag settings. The problem is that they only calculate up to 113kg... (i'm at 123kg)

 

How should i go about calculating these? Can i just use the 113kg settings? Increase some? My main question on that is that the rear shock has the Trek aktiv technology, so i'm not sure how different it should be set

Take up Droo's offer and get them to help with shock pressure as well as your rebound settings.

I spent some time with Andrew² and they added some tokens and sorted me out - totally transformed my ride.

 

And yes, the recommended pressures are ridiculously high