The Definitive Suspension Tuning Thread

S.

ex offender
not trying to grave dig, just thought i would do a search instead of starting a new thread

one for the mech engineers out there

ive been doing heaps of work lately involving excel calculation tables and spring constants and moments and all that fun stuff

has anyone ever thought about making up a table to relate suspension type to rider weight using calculations and moments about the swingarms within a frame?

is there mathematically perfect suspension set-up? can we create this for riders over and over through the use of calculations? i remeber seeing log computers on some of the orange/mojo suspension parts. how were they working out a more efficient system??

any idea's?
There is no such thing as a perfect suspension setup, because it's reactive. Some automotive researchers have experimented with active suspension, but it's unbelievably complex and expensive, and for that reason it was even dropped (and probably banned too) in F1.

Yes plenty of people have thought about optimising suspension setup theoretically. To my knowledge it's never been done very well for mountain bikes because the rider himself is the vast majority of the sprung mass (whereas on a motorbike he's still only 50% on a light bike, and in a car he's usually less than 10%), and the rider moves/deforms a LOT compard to a rigid body.

Check back with me in November or so and I might have some relevant information for you :)
 

cobba

Likes Dirt
Links for Manuals, Servicing & Info

Some of the Service Manuals listed here aren't available from the manufacturers website as they don't recommend that you service the forks/shocks yourself and some are so old they aren't on the manufacturers website any more.

Marzocchi:
*Currently no Service Manuals are available for Forks after 2006 but there is manuals for 2006 and earlier models listed below.
Fork Service Manuals: http://my-sport.spb.ru/manual_1/index-16.htm
Technical Info (includes exploded diagrams): http://www.windwave.co.uk/documents/techinfo/dealer_marzocchi_tech_info.html
Fork Service Manuals: http://www.wrower.pl/instrukcje/instrukcje-Marzocchi.php
Fork Service Manuals: http://www.birota.ru/manuals/marzocchi/index.php
Fork Service Manuals: http://enduroforkseals.com/id12.html
Fork Service Guide: http://enduroforkseals.com/id3.html
Fork Service Guide: http://enduroforkseals.com/id27.html
Rear Shock Guides & Manuals: http://www.windwave.co.uk/documents/techinfo/rearshocks.html
Marzocchi Owners Manuals: http://www.marzocchi.com/template/listManuals.asp?LN=UK&IDFolder=126
Oil Level Tables (they are sometimes different to the manuals): http://www.marzocchi.com/spa/mtb/products/oillevel
DH3 & XC700 Manuals: http://www.retrobike.co.uk/forum/gallery2.php?g2_itemId=25144
2009 Marzocchi Exploded Diagrams: http://www.marzocchi.ru/docs/forkmaps/forksmaps2009/
2010 Marzocchi Exploded Diagrams: http://www.marzocchi.ru/docs/forkmaps/forksmaps2010/
2011 Marzocchi Exploded Diagrams: http://www.marzocchi.ru/docs/forkmaps/forksmaps2011/

Magura:
Fork & Shock Manuals: http://www.magura.com/en/service/downloads.html
Fork & Brake Manuals: http://my-sport.spb.ru/manual_1/index-15.htm
Magura Support Forum: http://www.support-english.magura.com/

Fox:
Fork & Shock Manuals: http://my-sport.spb.ru/manual_1/index-9.htm
Fox Service Info & Help: http://service.foxracingshox.com/consumers/index.htm
Fork & Shock Manuals: http://www.birota.ru/manuals/foxflow/index.php
Fox Video Guides: http://www.foxracingshox.com/fox_tech_center/service_videos.htm
Fox Manuals: http://www.foxracingshox.com/fox_tech_center/index.htm
Fork & Shock Manuals: http://www.spoke-n-word-cycles.com/service.html

Manitou:
Fork & Shock Manuals: http://my-sport.spb.ru/manual_1/index-2.htm
Fork & Shock Manuals: http://www.birota.ru/manuals/manitou/index.php
Fork & Shock Manuals: http://www.manitoumtb.com/index.php?page=support
Fork Manuals: http://enduroforkseals.com/id12.html
Fork & Shock Manuals: http://www.spoke-n-word-cycles.com/service_docs.htm
Manitou Sport:http://www.mtb-kataloge.de/Bikekataloge/PDF/Manuals/Manituo_Sport.pdf
Manitou Three: http://www.mtb-kataloge.de/Bikekataloge/PDF/Manuals/Manituo3.pdf
Manitou Four: http://www.mtb-kataloge.de/Bikekataloge/PDF/Manuals/Manituo4.pdf
Manitou EFC: http://www.mtb-kataloge.de/Bikekataloge/PDF/Manuals/Manituo_EFC.pdf

Suntour:
Fork Manuals: http://my-sport.spb.ru/manual_1/index-26.htm
Fork Manuals: http://www.srsuntour-cycling.com/index.php

White Brothers:
Fork Manuals: http://my-sport.spb.ru/manual_1/index-30.htm
Fork Manuals & Info: http://www.mountainracingproducts.com/white-brothers/white-brothers-technical-and-setup-info/

RST:
Fork Manuals: http://www.rst.com.tw/ct/techsupport/techsupport.jsp
2008 Manuals: http://www.birota.ru/manuals/rst/index.php
RST Manuals 1998 to 2001: http://www.rst-europe.com/manuals/main.htm
RST Manuals 2000: http://www.wrower.pl/instrukcje/instrukcje-RST.php
RST 2000-2010: http://www.paul-lange.de/service/support/rst-explosionszeichnungen.html
& http://www.paul-lange.de/service/support/rst-anleitungen.html


Rock Shox:
Fork & Shock Manuals: http://my-sport.spb.ru/manual_1/index-21.htm
Fork & Shock Manuals: http://www.birota.ru/manuals/rockshox/index.php
Fork & Shock Manuals: http://www.sram.com/en/service/
Fork Manuals: http://enduroforkseals.com/id12.html
Rock Shox Manuals 98 to 06: http://www.wrower.pl/instrukcje/instrukcje-RockShox.php
93 to 96 Mag 21 & Mag 10: http://www.mtb-kataloge.de/Bikekataloge/PDF/Manuals/mag21.pdf
96 Judy XC, SL, DH & SFX: http://www.mtb-kataloge.de/Bikekataloge/PDF/Manuals/judyxc.pdf
96 Quadra 21R: http://www.judethomas.com/quadra96.pdf
Old Rock Shox Service Manuals: http://www.retrobike.co.uk/forum/gallery2.php?g2_itemId=67375

Old Rock Shox, Manitou, Pace, Grivin, Halson & Mountain Cycle Manuals: http://www.suspensionforkparts.net/other_manuals.php
 
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stpFREEEK

Likes Dirt
Hey there, been out of the loop for a while(school is shitty...) but i managed to get my hands on a set of Fox 40 RC2s (for free...). they came off a Glory 07, but im only 60kgs and i find em fairly solid. ive set compression(both high and low speed) to lowest setting, and set preload to lowest. does anyone know what spring is in them, where you pump em up on the leg, etc...I got the forks without a manual or anything, ill get that off my mate later

cheers
jack
 

Sov

Likes Dirt
Some automotive researchers have experimented with active suspension, but it's unbelievably complex and expensive, and for that reason it was even dropped (and probably banned too) in F1.
Complex, expensive and FAST. Banned from F1 in 1994. There's a great article here about the various systems that Lotus and Williams used in the late 80s / early 90s.
http://www.f1fanatic.co.uk/2007/05/17/banned-active-suspension/

Similar thing happened in the WRC in 2003 I think. Kinetic (an Aussie company) developed an active sway bar system for Citroen that helped win the title for them, and was banned the following year.

Remember the K2/ProFlex semi-active shocks from the late 90s? I can't remember exactly how they worked, but I seem to recall an electrically controlled valve that metered oil flow between the shock body and the reservoir. i think it was controlled by a couple of AAA batteries.

But yeah, totally agree with S. about the sprung vs unsprung mass relationship on mtbs.

Data logging is an interesting one too. It's all well and good getting data off a bike but I imagine it's not easy working out how it translates to what the rider feels!
 
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Justin Fox

Likes Bikes and Dirt
Just set up my Reign to the suggested settings for my weight and dang the ride's so ridiculously soft now I can't even balance lol. Not sure if I like it, but I'll have to test it out on a trail soon.
 

jda

Likes Bikes and Dirt
Hey there, been out of the loop for a while(school is shitty...) but i managed to get my hands on a set of Fox 40 RC2s (for free...). they came off a Glory 07, but im only 60kgs and i find em fairly solid. ive set compression(both high and low speed) to lowest setting, and set preload to lowest. does anyone know what spring is in them, where you pump em up on the leg, etc...I got the forks without a manual or anything, ill get that off my mate later

cheers
jack
Mate I recommend you learn what each of those adjustments does for a start so you can start using them and set up your fork properly. You have a high end fork there with lots of adjustment, turning all the damping off is a waste of the adjustment you have available.

Generaly you should run as much LSC as you can without making the fork feel harsh to stop it diving as you come into corners and apply brakes, I'm not sure how to set HSC on the fox as I run boxxers with the floodgate. Measure your sag if your worried about the spring rate in them, should be around 20% on a DH fork.
 

F1234K

Likes Dirt
I just added this to the wiki, but being unable to add images I decided to post it here too with the images so I can link to this from the wiki:

Notes on the Marzocchi 2004/5 RC compression mod:

I thought I would add some of my own ideas into this as I recently did this modification to my 2005 RCs.

My first note is that you most likely won't find this size piping at a plumbing depot, but if you go to a store that sells electrical conduit you should be able to find small enough diameter PVC piping to do the job.

Instead of making the holes as shown above I decided to do things a little differently. It turns out it is also much easier.

I got hold of some PVC with an internal diameter of 15mm which is obviously too small so will not slide over the internals of the fork. Instead of making the holes as described above I cut a slit down the lenght of the cutoff. This allowed me to pry it open and slide it over the compression rod for a VERY tight fit. As you slide it on you will notice the gap where the slit is opens up just enough to allow a column of holes to be left open. This way you can have 3 settings: Light (3 holes open), medium (2 holes open) and heavy (all holes closed off) simply by turning the piping so the slit opens over the holes you wish to expose.

There are 2 reasons why I did it this way:
1 - I don't have to drill out the inside of the pipe which could be imperfect afterwards. This way gives me a solid clean fit.
2 - As the forks goes through it's travel it will bypass the holes from top to bottom. If you close off say the 2 big holes then the fork behaves as if you have already moved past them by compression and you loose out on the easy flow of oil the larger holes give you. They are larger at the top to allow more oil to flow so it is more squish. This didn't make much sense to me so I decided to close the holes off in columns instead so you still have holes for the entire first part of travel, you just have less of them. This in my mind should be more progressive than covering holes in rows.

Here are some images to explain what I am on about:
IMG_1314.jpg

IMG_1315.jpg

IMG_1316.jpg

IMG_1317.jpg


I am running at with the 2 holes open and the 3 holes closed off (Medium setting). So far so good. I have noticed a considerable improvement in how it compresses into jumps and hard cornering. I will ride it some more and see if its all good, but so far it feels fantastic.
 

Flow-Rider

Burner
Reviving an old thread.

Marzocchi Z1 is making a come back/ Fox racing.

Looks like fox will be manufacturing under the banner of Marz using an Evol air spring and fox damper. It looks to be a middle budget type of fork but those sort of forks have always been a winner for the home mechanic to service.

new-bomber-z1





mars.jpg
 

SummitFever

Eats Squid
It's not the same fork as a Fox 36.
I'm just wondering why Fox would do this. Will it be a budget line so as not to affect the "high-end" Fox brand? It's probably aimed at tapping into the goodwill associated with the Marzocchi name but even so, over the last 10 years there hasn't been a lot of that.
 

Mr Crudley

Glock in your sock
Always interesting when competitors now have to be friends after a buyout. Might not be more than a sticker kit.

Sent from my F5121 using Tapatalk
 

Flow-Rider

Burner
I'm just wondering why Fox would do this. Will it be a budget line so as not to affect the "high-end" Fox brand? It's probably aimed at tapping into the goodwill associated with the Marzocchi name but even so, over the last 10 years there hasn't been a lot of that.
They've kept with the same theme as Marz as in having a stiffer fork and using fairly basic internals, the stanchion tubes are thicker and the bottom leg has a different design. I suppose to a point they are riding the name brand but they do employ engineers that worked under the Marz banner. I can't tell anyone why they haven't branded it in a FOX but if they offer a good product at a reasonable price point, I'm not going to complain.
 
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