02 ktm 125sx suspension for offroad

[yota]

I've logged about 100 miles on this bike now. no mx, all off road. Intend to do some hare scrambles and enduros once set up. The riding in central Florida is a lot of roots, logs and a lot of large high speed sand whoops. The roots are beating me to death. I put the shock high speed damping at 1 1/2 turns, lowspeed comp. all the way soft. Yesterday I put the stock straight spring from my 98 200 mxc on the shock. (Its 10mm shorter but as I weigh 160 lbs I was able to get the sag right) and it worked MUCH better (believe it is rated at 76 k/mm, but can't read the stamp anymore). When I put on the straight rate spring (progressive spring is rated 71 to 91 k/mm) I added 2 clicks low spd. comp damping. Also have comp. on forks turned almost all the way soft and they are still too stiff for roots. My question is am I going in the right direction with lighter springs for my type of riding? Is a straight rate shock spring the way to go? I will probably be sending my stuff to Jeremy for a revalve but would like to ride with softer springs first if this is the right guess.

I haven't messed with the oil level and weight yet as I don't have the spanner needed to remove the 48mm fork caps. any ideas? thx.

 

[Bud-Man]

Yota,
I just brought home my '02 125SX so I don't have any definite answers yet, but I will. Like you, I found the stock suspension to be brutally stiff. My '01 125SX had a lot of work done to it in order to make it good for HS type stuff. The straight rate spring will make the bike steer better but may sacrafice plushness compared to the progressive springs. I tried the PDS-6 spring on my '01 125 and didn't like it compared to the PDS-1. Both springs are rated similarly (7.0-9.0N/mm vs. 7.1-9.1N/mm) but they felt dramatically different. Have you tried backing off the shock's high speed adjuster? It should help the back a bit. I'd hold off buying springs for the bike until you decide who will do your suspension work. Go with their recommendations as the springs and valving have to work together. Unfortunately there isn't much you can do to the suspension that will make it soft enough for off-road use. It will need internal modifications to work the way you want it too. The good news is that the suspension has a lot of potential, it just needs set up for your weight and preference. Good luck!

 

[yota]

Bud-man, thx for the reply, I did soften the high spd 1/2 turn, maybe I'll try another 1/2 turn. I did a search and see a lot of people happy with MX-Tech for re-valves. Have you had any experience with them? I did see one post where a guy says the 700 bucks he spent with them seemed worthwhile. That seems like a lot of $ for suspension work, maybe it was a typo.

 

[Bud-Man]

Yota,
$700 sounds about right. ~$250/each end for revalve and piston kit + ~$170 for springs + Shipping and you're about there. Is it worth the money? I can't speak first hand but many people are happy with their work. I do know that this recent WP suspension is tricky to get right so a little extra money to have it done right is money well spent....at least in my opinion.

Oh, btw, for the fork caps, a simple but effective tool can be made by drilling thru an adjustable ("cresent") wrench and driving in pins of the appropriate size. That you way you can adjust the wrench opening to get the pins the correct distance apart and away you go. Cheap but effective!

 

[4banger]

A friend of mine has an 02 125sx and revalved the suspension himself to exc specs. He works for a dealer and a ktm rep sent him the shim stack specs for the exc model. It works great and cost him nothing. If you can get hold of the information, changing the shims around is a breeze. I rode it before and after and the sx is a brutal little beast in the woods. After the revalve, the bike soaked up roots and rocks and tracked great.

 

[Strick]

The cure: Lower fork oil to 150mm. Change the shim stack!
http://dirtrider.net/forums3/showthread.php?threadid=27569

Here is the thread where I got my info, and what I did. If you need more specifics let me know. Every rider who has ridden my bike since has commented on how well they like my suspension!

Good Luck!

 

[4banger]

It may be my junky old computer, but I couldn't get the link to work.

 

[yota]

I knew I'd come to the right place for good info. Strick, I'm very interested but can't bring up your url. has anyone put lighter springs in these forks?

also, I saw a post somewhere that a guy was using 2 1/2 wt fork oil in his 48's with a 160mm air gap. any thoughts on this? THX.

 

[Bud-Man]

Yota,
You can try the 2 1/2 wt oil but it may create problems on the rebound damping. I doubt it will cure the harshness though. I believe the link that Strick tried posting explained how to convert your single stage passive valve stack to a two stage stack. If I'm not mistaken, he added a .15x12mm "crossover" shim in the .10x24mm shims. This is easy enough to do and will yeild bigger benefits than the oil change. It still may be a bit stiff for a 125 and/or if you are light weight. Unfortunately, this will only help one end of the bike and the rear will still pound you to putty on the trail. The forks are easy enough to work on, but the shock is a totally different story :p !

 

[Strick]

O.K. I updated the link, sorry!

Bud-man has a very good point on the shock. I am in the process of getting that dialed, now that the forks are dialed. I am actually getting close! The key seems to be taking the rebound to the + side in combo with removing some of the low speed compression (if I remember correctly). I still may wind up sending my shock to Jeremy when he gets back. Like Bud-man said the forks are simple, but the shock is to go where few men have gone before!:eek:

 

[yota]

Using the 76 n/mm straight rate spring and backing way off on the low and high spd comp. damping helped the shock a lot. I'm talking twice as good as it was. I might try the 72 n/mm straight rate spring. at some point I'll probably give up and send it to Jeremy. I checked out the thread strick put up but I'm kinda slow on fork valving. I'll study it some more when I get home.

 

[yota]

So I read the thread from Greg from Oz on shim changes in my 48mm forks. I call Performance Engineering which is in nearby Winter Garden to get the 2 crossover shims and the parts guy tells me that they don't have any shims. I say aren't you guys in the suspension revalve biz? He says yes. So I say then how can you not have shims. He says they have shims but they are not for sale. I say but I bet if I asked for springs you would sell those. Sure, he says. In other words, I say, if I want to do the work myself you won't sell me the parts . He says he just does what he is told.

 

[marcusgunby]

loads of companies will sell you the shims-try www.race-tech.com or www.ccycle.com

 

[4banger]

http://www.werproducts.com/


They have a page that shows what shims they sell and they are all between a buck and a buck fifty.

 

[Jeremy Wilkey]

this is from jon @ mx-tech
we now make 90% of the shims, so if you need any-feel free to give us a call

 

[yota]

hey guys, thanks. I guess I was just a little dissapointed. I thought I could just pick them up at PE and do the work fri. night and test sat. guess I'll just have to order and wait. One thing I am testing tomorrow is the weighted flywheel from my 200 is going on my sx 125 tonight.(same part # as flywheel they put on 125exc. I'll let you know how this works offroad. by the way, I put the v-force reeds from my 200 on the 125 2 weeks ago and along with the doma pipe it rips. (already dented the doma). went leaner on pilot and one needle clip position (50% cam 2/50%prem pump).

 

[svi]

Marcus,
Can you recommend anybody over in England to get shims off?

 

[marcusgunby]

Try Chris Taylor Racing (CTR) on england code?44? 1530 810625 tell him i sent you and he may give you a bit of discount but dont bank on it;)

 

[mxbundy]

Hey Yota,

This is off topic, but do you do any FTR races. I was just wondering, because I have a bike that i leave in FLA. to race during bike week and selected hare scrambles.I was thinking of selling the wr that I have down there and getting a 400sx, so i`m very intrested to see how your bike turns out.
I know a lot of people in FTR, do you know Randy Faul, Scott Sears or Big Man?

later mxbundy

 

[yota]

mxbundy, I just started doing some FTR stuff ( 1enduro, 1 harescramble) but I have been riding with FTR guys for a few years at Croom, Ocala and Titusville. I have met some of the guys you mentioned but don't know them well. A buddy of mine, Josh, knows all those guys. The FTR and CFTR people I have met are a great bunch of people, a real family affair. I'm going to ride a select few rounds like Richloam but I don't plan to get too serious. Did my stuff in the 70's. It's nice to ride some new areas though.

 

[livtoryde125]

I noticed you said you were going to put a 125 exc's flywheel weight on your sx. My question is, can you take the flywheel weight off of the 125 exc to make it more like the sx or is it not removeable?
Thanx

 

[yota]

no, I took the flywheel off my 200 mxc (same part number as 125 exc flywheel) and put it on my 02 125sx and it works great for off road (also my 200 revs like crazy with the unweighted sx flywheel), No, you can't remove the weight from the flywheel on the exc without cutting out all the rivets. You could install an sx flywheel.

 

[livtoryde125]

Any idea how much that would set me back?

 

[yota]

I don't know, you would have to have your ktm dealer look it up, for best prices on ktm parts try Mike at cycle zone 866 843 7433.

 

[yota]

ok, for those who care, I got my suspension back from Jeremy and Jon at MX
Tech a few weeks ago and have done 4 rides, approx 130 miles total, 2 different riding areas, one with tight woods and lots of roots and the other more wide open with a lot of high speed sand whoops. The first ride was in Rootisville and for the first 3 hours or so I left the clickers where MX Tech set them and thought, well its better but not magic or anything. Then I started turning compression on both ends softer a click at a time. Things started working much better.

You are probably expecting me to rave about the suspension and I'm gonna, but what I couldn't believe was the difference the revalve made to the handling. I've ridden KTM's for years and the 02 125, although better turning than my 200, still required that I sit practically on the gas cap and muscle it through turns to get good results, but not any more. My riding position in corners is about like my Yamaha now and the KTM corners better!
I know some of you guys are going to say its from the straight rate spring but I had put that on way before I sent the suspension to Jeremy. It must be how the bike sits now as I enter a turn. Its awesome.

My last 3 rides were at Croom and what a blast. I've had a lot of bikes in the woods over the years (I'm in my 40's, which is why I did 4 rides before I decided to comment, I don't rush to judgement anymore) and although most were MX bikes converted to the woods (I like the close ratio gearbox) this bike's suspension is head and shoulders above the rest. When I did my first ride at Croom with the revalve on Thursday, I went even softer on compression on both ends until I found the sweet spot. This thing soaks up roots, small logs and sharp hits like magic and I'm still able to blitz the whoops faster than I ever have. I rode Croom again Sunday (what a zoo with all the xmas gift riders) and again today and it just gets better and better as I get more confidence in what the suspension can handle. I can't tell you how bad the stock 125SX suspension was in the woods but ask anyone you know who has one. The best money I have ever spent on a bike.

I know this must sound like spam but its just that I'm excited to actually have something exceed my expectations for once. I have no connection with MX Tech and I paid the same as anyone else for the work. Thanks Jeremy and Jon, you made my xmas.