Suspension set-up guides and info

Zimmerframe

MUPPET
Subscriber
Jun 12, 2019
13,770
20,451
Brittany, France
WTAF bro? ?
I think what Gary's saying is - that's very interesting and ingenious - BUT ..... probably doesn't really yield the results you want.

For starters, don't worry about sag of the bike on it's own. Suspension sag's on it's own, some more, some less.

Secondly, sag is kind of a guideline and then how you position yourself on the bike when measuring it for instance - and how you weight yourself, will hugely influence the results you will get.

From what you've written, it kind of sounds like you've decided what pressure you should have and then have manipulated the way of testing your sag to make the sag fit that ???
 

Gary

Old Tartan Bollocks
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Mar 29, 2018
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the internet
From reading what he wrote....


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Bones

E*POWAH Master
Subscriber
Apr 3, 2020
745
984
Harrogate
Obviously amused the resident troll. But these forks are fitted to standard bikes and the recommendations don't include a Fucking 3.5 kg battery. As also stated I am still making adjustments but I know the sag is not miles out and screwing up the settings.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,361
8,586
Lincolnshire, UK
.............................When you parking lot test your bike while in the neutral position (hips over the BB or back an inch or 2) and hopping like a bunny the suspension should compress and rebound as close to perfectly even as possible.
Going for even? That is the first time I have seen someone actually supporting what I have been doing for years. I thought it was just me.
Or maybe they were saying the same, but I just didn't understand? :unsure:
 

emtbPhil

Well-known member
Jun 20, 2021
372
417
UK
Obviously amused the resident troll. But these forks are fitted to standard bikes and the recommendations don't include a Fucking 3.5 kg battery. As also stated I am still making adjustments but I know the sag is not miles out and screwing up the settings.

Errrrrrrrr how is a 3.5kg battery any different to someone who weighs 3.5kg more than you? or a 3.5kg backpack.... whut?
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,361
8,586
Lincolnshire, UK
I had problems setting up the sag on my bike. The fox factory 38s with 170mm travel need around 100 psi to keep them at full extension and stop them decreasing under the bikes own weight. This was causing the sag measurement to decrease when decreasing air pressure to suit my kitted out 87kg.
So 95psi gave about 30mm,90 gave 28mm 85 gave 25mm and so on.
I ended up taking the battery out and setting the sag with the battery in my backpack and taking my weight up to around 92kg
Still working on other settings using the bracketing method but the sag is spot on doing it that way round with the battery fitted back in the bike.
A few questions:
Why do you need to inflate the fork "to stop them decreasing under their own weight"? Even at 100psi, they will still "decrease under their own weight", but it is so small you can't see it. But it is irrelevant anyway. What matters is what happens when you are sat on the bike, or more precisely when you ride the bike.

You report that lower fork air pressure gives you less sag? You must be measuring something incorrectly, or the new fork is suffering from internal friction, static friction, or something like that to give varying and contradictory readings. Did you set the compression damping to minimum before sag setting? I never accept the initial sag setting on a new fork, it is only a benchmark to get started. I always adjust the pressure later to get the feel I'm looking for.

How on earth can removing the battery and putting it in your backpack be the right way to set sag? You have not altered the total weight of man+bike, but you have altered the weight balance of the bike. Whatever careful sag settings you make, as soon as you return the battery to its rightful place, they will be different!

Something is wrong. It could be faulty forks, but I suspect a misunderstanding of what is involved in setting up suspension.
 

David0208

Member
Mar 30, 2019
103
64
United Kingdom
FFS! I went out for a bike ride and came back to this! :ROFLMAO:

I think that we can take from this that suspension setup and suspension jargon could be made simpler (Now, don't! Yes you!), this conversation happens a lot. I blame the double negatives . . .

Anyway, if everyone would like to gather round and take your tops off (I prefer skin in skin) and lets all hug it out.

P.S. I'm buying a rigid bike. :giggle:
 

emtbPhil

Well-known member
Jun 20, 2021
372
417
UK
FFS! I went out for a bike ride and came back to this! :ROFLMAO:

I think that we can take from this that suspension setup and suspension jargon could be made simpler (Now, don't! Yes you!), this conversation happens a lot. I blame the double negatives . . .

Anyway, if everyone would like to gather round and take your tops off (I prefer skin in skin) and lets all hug it out.

P.S. I'm buying a rigid bike. :giggle:

Funny you should say that - I was out tonight on my gravel bike, loads easier to setup :D
 

Zaskar20

Active member
Aug 17, 2021
140
133
UK
I had problems setting up the sag on my bike. The fox factory 38s with 170mm travel need around 100 psi to keep them at full extension and stop them decreasing under the bikes own weight.
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.
 

Gary

Old Tartan Bollocks
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Mar 29, 2018
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A few mm of sag under the bike's own weight isn't an issue. So don't worry about it. The fork will still extend fully when the bike is unweighted while it's being ridden.
An air spring is progressive by nature so much softer in its initial stroke than the end stroke. the softer initial spring force is also what gives the fork its suppleness and good small bump performance.

By all means overspring a fork if you're going to be using it solely for dirt jumping but otherwise you ideally want to set your fork up based on a sag point that gives you good small bump performance, a supportive midstroke and decent end stroke bottom out resistance. (using all the travel when needed but never bottoming harshly)

Read through the first post in the thread if you're struggling.
 

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