EC 300 Suspension setup for motocross.

[GasGasser]

Hi everyone!

To make a long story short we finally got a motocross track where I live, so now I wanted to know what to do to my suspension to make it work. The track is fairly fast, and as a rider I'm not that fast, but I get pretty much faster every time I'm on the track. Which makes it even more fun. I know that I at this point simply could swap the Gas Gas for a MX bike, but I still wan't the Gas Gas for everything else. Plus I really like the bike, it has never faulted or let me down. I guess I am emotionally attached to it

Soo...

Now I don't bottom out my forks or my shock, but they don't feel at home on a MX track. The bike feels like it doesn't really have any contact with the surface and it just jumps around.

I understand MX is not what these suspension units were made for, but I would like to get some tips and information on how to set up the suspension. With that I mean spring rates, clickers, oil level and viscosity etc. Not revalving because I don't want to spend that much money and honestly, I'm not that fast even though revalving probably would help boost the speed a little.

The bike is a 2003 EC 300 the "Euro" model since I live in Finland.

Marzocchi fork, standard springs, 110mm oil level and fresh Motorex 7,5w oil.
clickers with the compression turned in a fair bit and the rebound somewhere around the middle.

Öhlins rear, standard spring ~110mm race sag. Pretty much standard clicker settings, don't remember exactly.

Both the fork and the shock are serviced and in good shape.


I myself weigh about 66 kg's dry and with gear it would be somewhere around 72 kg maybe? Depending on the season of course


If you have any suggestions or tips it would be much appreciated / Jonatan

 

[skid jackson]

get ahold of some mc 250 forks!!
course I think you need new 3x clamps for that.
I've always been told you can set them up for woods or set them up for the track but you can't set them up for both. I'd look for an older Honda cr 250, or yz 125. Used yz 125's are cheap here in the states. You can always just trail ride the track ....
Good luck, hopefully someone chimes in with some usefull info.
let us know how you make out

 

[stay_upright]

If it's jumping around a lot try increasing F+R rebound damping.

MX suspension is a lot stiffer but I throught that was to be able to handle the big landings etc - if you're not having problems with that (yet) then perhaps your suspension is good for you...

Could you ride some-one's MX bike - maybe it will feel better/faster for you (it will be stiffer) but maybe it will feel worse - this would give you an idea what to do i.e of you want/need to stiffen things up.

If you think you want to move to mx stiffnesses as a cheap way to try maybe increase your fork oil viscosity say 7.5 (standard) to 10 or 12.5wt this would increase compression damping but also the rebound damping which may help with the 'jumping around' - also increase the preload and/or the compression and rebound on the rear - Your rear Ohlins should have high and low speed compression damping, have a play around with them both.

I suspect though if you're not bottoming your suspension out your will get a lot more speed by practicing more than fiddling with suspension unless the softness is causing specific problems.

 

[GasGasser]

Hi, I have now got the front end to feel almost good, but I can't get the rear end quite right.

As now, the clickers on my rear damper are at standard settings and the rear does not feel very planted.

I tried increasing the rebound damping (4 clicks), which gave me a lot more solid feel when braking and at low speed whoops but it got scary as hell when driving through whoops and bumps flat out in 4 th and 5th gear. I was getting tankslappers from hell all the time. So I turned the clicker back and now I don't get the tankslappers but the rear doesn't feel very planted. Also when driving through deep whoops in third gear the rear sometimes seem to kick real hard, lifting my feet of the footpegs, even if I drive through them the right way with the front wheel hitting the top of every whoop in standing position, as always.

I have the stock spring and about 108mm race sag. I weigh 165 lbs.

Also I guess when driving enduros, in about 50% the speed is usually pretty high. It's almost WFO all the time, with whoops and bumps. The rest is 2 or 3rd gear trailcarving in which the suspension works fine

 

[GasGasser]

Anyone have some ideas to get better high speed stability?

I did lower the forks in the clamps a bit and tweaked the suspension but I have yet to test ride it.

Any other ideas?

 

[skid jackson]

let me know how you make out ....
They are building an mx track close to me!!
gotta wonder if it will be ridable by an old fart like me with my woods suspension.

 

[Skidad]

I would try adjusting your rear race sag to 100mm or even 95mm from your 110 and see what happens. What have you got to lose and it's typical MX sag. Personally I'm not a fan of huge sag #'s and would rather see the suspension ride higher in the stroke. You may also have to lower the forks in the clamps if you have them raised now. Short of revalving how agout springs. You could try going up 1 # on the back to a 5.3 and get either a set of .44's for the front and use just 1 to get a .43 rate (stock is .42 I believe) or a true set of .43 springs. With the .44's you have more options really. Going up just 1 rate may even help you in the off raod stuff without being overly stiff. Obviously when you added rebound to the rear is started to pack down every hit. For kicks try going the other way on the rebound but stiffen the compression a click or 3. 1 adjustment at a time though and don't be afraid to go to extremes to see what happens.

 

[GasGasser]

Thanks skidad

I'll try some new settings tomorrow when I hit the MX track. The race sag setting sounds interesting, I've always wanted the suspension to work higher in the stroke than it does now, specially the front end which seems to work pretty low in the stroke. It seems that it just blasts through the upper stroke to just work in the middle. It doesn't bottom out riding the enduros, leaves about an inch of travel unused. Don't know yet about the MX track.
I did lower the fork legs in the clamps for more stability which helped a bit in the high speed whoops.

Right now I'm using the basic setup suggested by Les, though it seems to apply only on the 04-06 models it works pretty well in the tight enduro stuff for my 2003 EC 300.

It's just that at higher speed it feels unsecure, and I can't get to the speed I know I would be able to ride with a good setup. Also I tend to lean pretty much forward? when riding standing, so I guess the .44 springs would help me out. Notice that this does only occur when riding in 4, 5 or 6 gear wide open. Otherwise it works fine!

Gotta record some movies where the suspension action and rider stance can bee seen, it would be to much help.

I'll try to get this sorted tomorrow on the track, and thanks again for the input! Keep up the nice work!

 

[skid jackson]

If you crank up the rear preload to get your 100 to 95mm race sag ...
keep in mind that the ohlins guy told me they like to see preload at about 7mm no more than 9mm. Which is pretty much spot on with gmps' 8 to 10mm suggestion. For the hell of it I cranked up the preload on my 06 300 to get near 100mm and did not like the results. Thats not to say 100 mm is bad ... just make sure you have the right spring for it.

 

[Skidad]

If you crank up the rear preload to get your 100 to 95mm race sag ...
keep in mind that the ohlins guy told me they like to see preload at about 7mm no more than 9mm. Which is pretty much spot on with gmps' 8 to 10mm suggestion. For the hell of it I cranked up the preload on my 06 300 to get near 100mm and did not like the results. Thats not to say 100 mm is bad ... just make sure you have the right spring for it.

Oh I agree with 10mm preload or less, that's why I suggested to go up 1 step on the spring. You won't need the preload cranked to get the 100mm. The front also for balance. Mix 1 .42 spring with 1 .44 and you get .43.

If you're not ever bottoming the forks you have too much oil in them and their hydro locking. Remove the bleeder screw and suck out 10cc at a time. The Zokes can use 150mm gap for off road and be fine. You do want to bottom them a few times a ride.

 

[GasGasser]

Well I set the race sag to 105 mm before we went to the track. At first the bike was truly horrible it just bounced around the whole time. After an our of experimenting I got a setup that was rideable.

Don't remember the clicker settings exactly but they would be somewhere around this range:

Fork: Compression: 24 clicks from full soft. (the right leg adjuster was jammed with mud so I could not adjust this any harder nor count the clicks the normal way)
Rebound: 14 clicks out.
Damper: Compression 18 clicks out.
Rebound: 21 clicks out.

This way the bike felt pretty good, only the forks bottomed out frequently. They did use all the stroke. Hard to tell if the rear end was bottoming out. Gotta try some stiffer springs, maybe a set of .44's. Do I need to buy a stiffer rear spring aswell if I get stiffer fork springs?

This was on a MX track, haven't trailridden these settings yet.