Suspension Setup recommendations.

That is a good video there are several others on the internet that are good an deal with things a little different. All the videos and write ups have small errors if you watch them all and read them all you will be able to pick them out.

(He missed putting on the retaining clip and you need to use a fork seal bullet, plastic bag or tape when sliding the oil seals on and the first part of his inner cartridge bleeding method is not ideal.) He uses a plastic "H" and says someone before him messed it up with a metal one. Then he proceeds to use a file on the forks

The article you linked, I have read before, there are to many errors in it regarding the forks that I would not take any of their advise on oil levels/ bleeding though the vent holes. The oil levels they list are way off and you can not remove oil though the bleed holes in an easy or reliable manner. (Stock is listed at 360ml for outer cartridge)

Inner cartridge fill and bleeding as well as the free piston mod is covered well in this page. http://www.smartperformanceinc.com/YZMODASSEM.htm

The service manual for the TC 250 covers the forks very well.

My recommendation is min 320ml - max 360ml in the outer cartridge. Use the smart performance method to fill and bleed the inner cartridge. (let them drain and wipe them off before installing the inner cartilage into the fork so it does not add any unmeasured oil.

I ended up with 345ml in my fork for a final oil amount. You have to take the forks off to add and remove oil into the outer chamber to reliably do it.

Thanks and how about spring weights big n small, also im going to use 5w oil, removing the 20ml was from the inner via air bleed screw but correct bleeding of oil should set correct level yes?

IMHO, RaceTech spring rate chart front #s are not even close. Way too stiff.

Just a quick one i thought the cap size was 50mm but is it 49mm?????? Thanks anyone

CAP SIZE IS 49MM I WAS TOLD WRONG

http://www.madison.co.uk/products/m...twin-chamber-forks-cap-compression-cartridge/

just ordered one of these for £30

UPDATE..New 5w oil fitted and used the above method, ended up with 325ml in the outer as spring weight still 4.6 and decided its easier to add than remove at the moment. test ride in the morning on Derbyshire lanes on rocky trails mainly so needed softer i.e. less oil!!


RESULT...Bike rode good a little firm on front but ended up with 2 clicks off compression from standard job done, does seem to ride high up front so will try the 4.4 spring when i can find

Just looking for some shock spring rate advice please...

I've known for a while that I need a heavier shock spring so time to change it...
Heres the deal now:
Racetech 6.0kg spring
Rear rider sag: 109.5mm
Rear static sag: 20.5mm
15mm preload
107kg no gear
122kg with gear (robocop with a 3L camelback
Front rider sag: 76mm
Front static sag: 46mm

I'll have to buy a spring and won't have the luxury of checking and exchanging, so I want to get it close.

Racetech calculator suggests a 6.4kg

Do you* think a 6.4kg will get my sags closer to "the formula"???

Should I go heavier?


* you = any suspension guru that wants to chime in

You want about 30-35mm static and 100-105mm rider, or a delta of about 65-75mm. You have 21mm and 110mm, or a delta of about 89mm. If your measurements are accurate, you want to be quite a bit stiffer than 6.4. I think 6.8 is going to be closer.

I just looked at RaceTech, and it recommends 6.8 for your weight (not 6.4?), but it looks like they only make up to a 6.4. I'd contact someone else and see if you can get something stiffer...

Thanks Kyle.
I put in 107kgs as it says "without gear"
Racetech calc result below.
Should I be inputting my weight with gear?

Modifiers:
Riding Type: Desert / Enduro / Trail
Age: Standard Age - Up to 44
Skill Level: Dirt Local Intermediate / B Class
Height: Tall (6'3" or 190cm plus)
Gas Tank: Standard Gas Tank

REAR SHOCK SPRINGS
Recommended Shock Spring Rate: 6.387 kg/mm (use closest available)
Stock Shock Spring Rate: Not Avilable


FYI. I measured sitting with my hip centered above pegs which was about the same as standing with no weight on the bars.

Ah, I see the difference! Since you wear a lot of gear (I do too!), I put your weight with gear into the calculator. I don't know how their magical formula works, so you could be doing the right thing.

In any case, based on your sag numbers, I don't think that 6.4 is going to be stiff enough. I'd try a 6.8. Maybe call a local shop and see if they have (or can get) that rate?

Put some 0,4kg/mm springs in (still not totally happy with the sag numbers) and had a look at my compression stack (base valve).
Here's what I found, please tell me what you think
12x ,1
22x ,1
22x ,1
12x ,1
21x ,15
20x ,15
18x ,1
16x ,1
14x ,1
12x ,15
11x ,2

That setup is on the enduro/woods/soft side of things, in my opinion. The first shim (12 x 0.1) is a "bleed shim," which makes it so that there is always a leak path and makes the fork soft/plush. There is also a fairly small number of face shims, 0.1 on the taper (sometimes you'll see 0.15), and a fairly small clamp (11 mm).

How does the bike feel to you right now? That's the biggest question. What are you trying to improve?

It would be good to know what the midvalve setup is also.

If you ride mostly MX, I would consider removing the bleed shim. There are some other changes you could make too, like moving the crossover and/or changing the taper thickness and/or changing the clamp, but we'd need some more feedback on what the bike does now that you want to improve.

I've tested it and with the lighter springs it's an improvement.
The damping (mainly compression) is what I don't like, especially on the square potholes and rocks.
It blows through the stroke and then hits hard.

I'm a pretty slow rider, so I'm not after hardcore mx valving, and would like more comfort (plush) but don't want to give up to much on bottoming Resistance (in case of a jump).

"Blows through the stroke" is good feedback. I could be wrong, but I suspect it feels harsh because it's too soft, resulting in it riding low in the stroke where the air cushion is harsher and where it can bottom. Could be wrong though!

Try this:

22.1 (2X)
21.15
12.1
20.15
18.1
16.1
14.1
12.15
11.2

No new shims required, just remove the bleed shim and move the crossover.

This might not be the final solution, but I think it will be a step in the right direction.

If it's too harsh on small chop after that, you can try moving the crossover back up.

I'm going to try that!
By moving the crossover up higher it will make the low speed lighter and more high speed damping right?

Rode my friends TM MX250 with the same fork but mx valving, way better!
Will try what you suggest, thank you for your input! Will report back with my findings.

Yeah, see how you like that. I would still not call that a full-on MX valving setup, more like an enduro or XC race setup. I doubt it will be super stiff, but it should have more control than the current setup, and your feedback will give us a direction to work.

As far as the crossover: crossover position doesn't really effect highspeed; the best way to think about that is highspeed damping all happens after the crossover closes, and once the crossover closes the stack is effectively the same regardless of where the crossover is. What the crossover effects is how soft the initial lowspeed is, and how long that "lasts" until you get into the high speed (crossover closed).

With the way your bike is right now, only having two 0.10 thick shims before the crossover, the first stage will open very easily (it is very soft), and it will close the crossover gap very quickly. For your use, I think you'll be better served having the first stage be a bit stiffer (for some control) and having the crossover open a bit longer. For what it's worth, there are lots of MX-style setups that don't use a crossover at all, and some guys like that feel better. For now, I'd keep it (helps with plushness) but make some tweaks to firm the lot up.

Did some testing with the new shimstack, played around with the clickers (both compression and rebound) it's way better but there's still room for improvement.
Tested it on a hardpack enduro/crosscountry style track (whoops, rocks, small jumps).
It soaks up the smaller hit much better, and doesn't blow through the stroke as much as it did. It hasn't bottom out once, I have about 4cm before it bottoms.

Will test it on a mx track later this week. Going to fiddle around with the clicker some more.
I'm quite sure I still need more compression dampening especially for the bigger jumps.

Took it to a mx track yesterday, a bit more compression dampening on the fork all I can say is WOW!
So much better, track was perfect though (hard pack), minimal braking bumps and ruts but suspension acted predictable and actually absorbed the hits (didn't bottom out once and jumped high).
Thank you so much Kyle! Should've done this a long time ago but was kinda scared to make drastic changes to suspension (live and learn). I'm very pleased. Had a blast yesterday!

Did some more mx riding, both sand and hard pack. Still need more bottoming resistance, should I try moving the crossover even up farther?

Post up the stack that you are currently running.

Are your fork springs right for your weight? How does the sag check out? What oil level are you running in the forks? How harsh is the bottoming, and how frequent? How do the forks feel on smaller bumps, braking bumps, and trail trash?

22.1 (2X)
21.15
12.1
20.15
18.1
16.1
14.1
12.15
11.2

Fork springs could be one step lighter I think.
I'm running 270ml of 5w oil in the outer chamber, 5w in the inner chamber (pre expanded and free from air).
It isn't bottoming hard, and only on jumps, and medium sized whoops. I'd like it plusher on the braking and small bumps but I don't think that's going to happen (more bottoming resistance and plush).

I'm kinda hesitant to pull the midvalve out, have done this on a few open chamber forks though.
As of lately I'm riding more mx then trail, and this is were I think the forks suffers the most.