Suspension set-up guides and info

[Gary]

@Rob Hancill
There are a lot of threads on the forum asking questions about suspension set-up.
I think it would be good to sticky a guide to suspension set-up for all users to easily find.

@steve_sordy just posted an excellent and fairly thorough PDF guide to suspension set up in the commencal forum.
Here:
https://bikerumor-wpengine.netdna-s.../2014/10/Bikerumor-Suspension-Setup-Guide.pdf
Everyone wanting to gain a decent understand of how to set-up their suspension should have a read through this honest and easy to understand guide on suspension set-up.

Seb Stott's video guide on basic set-up is very good too
Here:
and his slightly more advanced guide here:

For anyone looking to understand more advanced info on suspension technology and set-up here are a few more links:
Steve from https://vorsprungsuspension.com has done a series of indepth suspension videos and articles on pinkbike named "The Tuesday tune EPs" Here's episode #1
Inside Fox Float Fork Spring Systems - Video - Pinkbike
and a link to the full series videos
all Video Channel by videoThe Tuesday Tune Ep 24 - Pinkbike
The articles and Blogs by Steve can be found here
VorsprungSuspension's Blog - Pinkbike

Anyone looking to understand suspension frame design and kinematics characteristics could do worse than read what Andrextr has to say on the subject or watch his videos
Here's Andre's Youtube channel
andrextr
His playlists
andrextr
Rear suspension fundamentals playlist
MTB Rear Suspension - YouTube

Antonio Osuna's excellent blog where he compares and discusses various rear suspension linkage designs, the leverage curves, antirise, anti squat, pedal kickback and forces data associated with them and their characeristics in depth over many bikes and suspension designs.
Linkage Design

Software to use to determine the kinematics and characteristics of any frame for yourself.
Linkage Bike Simulation Software - Home


Little bit more indepth/advanced explanation of the first thing you should be setting up. Sag.
including how to and why descriptions of the process From Steve at vorsprung suspension:


And finally... a comparison between the current two biggest players in mtb suspension incl a little company/product history and differences in approach between the two

Fox Vs RockShox Mountain Bike Forks & Shocks

FOX and RockShox are the top two brands in the world of mountain bike suspension forks. So how do you choose the right suspension fork for your ride? We go deep on the details so you know what to look for when shopping for your next mountain bike or fork.

www.theproscloset.com

 

[All Mountain Coaching]

And for anyone interested, I have the shockwiz suspension tuning system for rental or available free on MTB courses.

 

[Krisj]

RockShox Setup Guide | SRAM
This is useful as a starting point for RockShox fork set up

 

[highpeakrider]

Can this be a sticky?
Lots of great info, thanks @Gary

 

[Gary]

Thanks @Rob Hancill
Taken the "sticky" request out of the title

 

[2unfit2ride]

Thanks for the links, very informative

 

[Topolino]

Attached is a link from MBR. I found it to be a very logical approach to suspension setup.

 

[steve_sordy]

I enjoyed that!

 

[Gary]

Updated the Original post to add a video on sag as it seems a massively misunderstood subject.

 

[Randles]

Extremely helpful many thanks guys!!

 

[steve_sordy]

Updated the Original post to add a video on sag as it seems a massively misunderstood subject.

I liked the vid you added, he had some interesting views and points to make. What appealed to me was his message that sag is a comparitor and a start position, not an end position. I agree with that of course, but I liked the way he put it across. His technique of getting a consistent body position by always ensuring all his weight goes through the BB also made sense to me, very much so. I will be interested to see what fork sag I get when using his technique after first setting it in the attack position. It also means that I should set the shock sag that way too, and not seated. And, like everyone else, he agreed that setting sag is only the start position.

 

[Gary]

I liked the way he put it across

There's always been link to Steve's full catalogue of vorsprung suspension videos in the original post.
Not that anyone seems to have bothered to click it

 

[OlaGB]

Sag and ramp, is where shockwiz really shines. Not always easy to find by feel..
And its pretty helpfull with rebound.

 

[Fivetones]

Great resources here. Thanks for posting @Gary. Pity the Linkage Design software is windows only.

Wanted to see what single pivot looks like on graphs like the LinkageDesign blog graphs ?

 

[Gary]

No worries @Fivetones
Check out Andre and Antonio's blog posts (they're all translatable) they've both plotted kinematics graphs for single pivots (not that all SP designs are the same). but it might be helpful for you.

 

[Fivetones]

No worries @Fivetones
Check out Andre and Antonio's blog posts (they're all translatable) they've both plotted kinematics graphs for single pivots (not that all SP designs are the same). but it might be helpful for you.

Working my way through Andre’s videos. Fantastic resource.

 

[HORSPWR]

Updated the Original post to add a video on sag as it seems a massively misunderstood subject.

Sag exists for one reason only. Without it your wheel cannot drop down into an undulation or hole if your fork is already at the top of your stroke. In order to have constant grip with the ground your wheel needs to be able to track the ground and without sag it can’t do that.

 

[Gary]

it actually doesn't exist for one reason only


but...
alas...

that was not the point of my update.

 

[RickBullotta]

Use a ShockWiz. You can now rent them online. It *will* help you get your suspension dialed. The key is to go ride a variety of terrain, and I recommend two setup sessions for each end (two for the fork and two for the shock).

 

[Porkyford]

And for anyone interested, I have the shockwiz suspension tuning system for rental or available free on MTB courses. View attachment 7532 View attachment 7533 View attachment 7534

What compression ratio are you getting on the Fox dps?

 

[All Mountain Coaching]

And for anyone interested, I have the shockwiz suspension tuning system for rental or available free on MTB courses. View attachment 7532 View attachment 7533 View attachment 7534

What compression ratio are you getting on the Fox dps?

How do you mean?

 

[Eckythump]

What compression ratio are you getting on the Fox dps?

If you are asking about the Shockwiz compression ratio you need to do the setup wizard on your bike to obtain it. You will need to do it again if you change the number of volume reducers too.

 

[Porkyford]

If you are asking about the Shockwiz compression ratio you need to do the setup wizard on your bike to obtain it. You will need to do it again if you change the number of volume reducers too.

Thanks for your help, I have done the set up wizz and it said 2.9. My mates levo shows 2.6.... same bike but smaller size... I thought they both read the same!! I’m on a L and he’s on a M... ?‍

 

[Eckythump]

It can be different for the same size bike with the same shock. Someone being heavy handed with the grease on rebuild can make a difference

 

[33red]

Here is my question about my 2017 120 mm HT bought recently(it was unsold).
What are the advantages if i increase it to 130 mm in 2 months when the maintenance is due.
I bought the bike with 3.0x27.5, now i use a Rekon 2.8(rear) and love it. I would replace my front with a 2.8 Rekon(not available in 3.0).
I figure the longer fork would replace the BB about where it was with 2x3.0
Now i use 60PSI in the fork would that change?
The fork is SR Suntour Raidon XC-RL-R 27.5 Air 15QLC2 Remote Lockout, air/oil, Travel: 120mm, aluminium steerer tube 1 1/8" - 1 1/2" tapered, thru-axle Boost
I mesured the stanchion and they are long enough.
I hate bangning my bike so i do not want a lower BB.
I ride relaxed no big jumps/drops.
Thanks

 

[RickBullotta]

Here is my question about my 2017 120 mm HT bought recently(it was unsold).
What are the advantages if i increase it to 130 mm in 2 months when the maintenance is due.
I bought the bike with 3.0x27.5, now i use a Rekon 2.8(rear) and love it. I would replace my front with a 2.8 Rekon(not available in 3.0).
I figure the longer fork would replace the BB about where it was with 2x3.0
Now i use 60PSI in the fork would that change?
The fork is SR Suntour Raidon XC-RL-R 27.5 Air 15QLC2 Remote Lockout, air/oil, Travel: 120mm, aluminium steerer tube 1 1/8" - 1 1/2" tapered, thru-axle Boost
I mesured the stanchion and they are long enough.
I hate bangning my bike so i do not want a lower BB.
I ride relaxed no big jumps/drops.
Thanks

You have two options: shorter cranks or a taller fork. To achieve the latter, you don't need to get a new fork. You can put a taller crown race on it. It looks a little unusual but it does the job quite well. You can have any height you want made by MTBTools:

Extended Crown Race for Fat Bike Suspension Fork Clearance - Custom Mountain Bike Parts | Custom Mountain Bike Parts for MTB Riders, by MTB Riders

It will slacken the head angle a bit (I prefer it that way) and will lift the BB height approximately 1/2 of the height of the spacer.

My friend just did both on his older KTM eMTB (went with 160mm cranks and a 17mm spacer) and he's very happy with the results.

 

[Gary]

it'll raise the BB aprox 3mm (yes. 3mm.. look at that on a tape measure. it's fuck all)
Pedal strikes are entirely the fault of the rider. Not the BB height or crank length. (especially on Emtbs). Learn to look ahead properly and time pedal strokes and ride with correct foot position. this will sometimes mean raising/dropping a crank arm to pass an obsticle/dip/rise/rut/rock etc. other times it will mean riding cranks level. through practice/time on the bike you'll learn when each approach is appropriate.

the extra 10mm travel will allow you to run very slightly more sag (mm not %), so the fork should be very slightly more supple on small hits and (if set up correctly) will swallow slightly larger bumps. (due to 10mm more big hit capability)
the change in H/A is negligable (less than a half a degree).
you may want to drop your bar height 5-7mm to compensate for the increase in axle to crown height. not everyone is sensitive to this. (I am)
Riding a hardtail well is more about learning to be dynamic and using your body to compress/pump than suspension travel. Stand up as much as possible. Emtb HT even more so as the rear ends are harsh AF with all that extra weight

hope some of this helps.

 

[MitchF]

“it'll raise the BB aprox 3mm (yes. 3mm.. look at that on a tape measure. it's fuck all)”

???one of the best responses I’ve read

 

[Flatslide]

I'd like to add this link from one of our local suspension wizards too. Dougal tuned the Lyrik on my Remedy 9 rsl with his - Unharsh my ride - tune. The fork is awesome now as from new it behaved like it was running 100% high speed compression.
Suspension Setup | Shockcraft

 

[Eddy Current]

This is a helpful thread but unfortunately you can change the natural behavior of a suspension by adding or removing tokens or tuning the rebound settings. If it’s designed to be progressive you can turn it less progressive but ain’t going to perform like a suspension developed to be linear. This is a equation that involves the architecture of the rear triangle, your own weight, the kinematics of the bike, the geometry as well, and the shocks