Horizons Unlimited - The HUBB

Horizons Unlimited - The HUBB (http://www.horizonsunlimited.com/hubb/)
-   Yamaha Tech (http://www.horizonsunlimited.com/hubb/yamaha-tech/)
-   -   XT600 suspension..... (http://www.horizonsunlimited.com/hubb/yamaha-tech/xt600-suspension-33529)

mrluftkopf 4 Mar 2008 01:02

XT600 suspension.....
Hi All,

I just purchased a new to me '85 XT600 with only 7200km's on it. I like the price, and the bike genre seems to be well liked except for the soft suspension and the small tank. A Clarke tank can fix the later issue, but what about the suspension?

I want the bike to be capable off road, not mushy. I've had a DR350P with modified suspension before, and I liked it.

I know there are a lot of suspension options for this bike, but I have a few questions:

1) Will a similar year TT600 linkage help the rear suspension? Do i need the TT shock if I change the linkage?
2) Should i instead just rebuild the stock shock and use a new spring, if so what rate? I weigh 210lbs.
3) Works shock? Other?
4) Racetech emulator for the fork?
5) Substitute a fork from another newer bike? They are cheap on ebay...anyone done this on a XT or TT?
6) Just add new oil and seals for the fork? New stiffer springs? Again, what rates? Oil viscosity?

does anyone know the differences between the tt600 and xt600 suspension? The fiches say there are......is it worth it to change over?

I want the bike to handle in such a way that it instils confidence and is not twitchy or washing out, i.e. no big negative traits. This is not a racebike, but it should be fun.


ciao for now.....jimmy

RIDER 4 Mar 2008 10:20

Hi Jimmy

I can't help you with question 1,2 and 3 as I have not done any mods to the rear suspension.

For the forks I fitted Hagon springs (Start rate is 4kg/cm and end rate is 7kg/cm.) but I removed them as they where to stiff and I could feel every bump in the road. I then had some emulators made, the emulators have made a big difference when going over potholes and hitting rocks. The bike also tracks a lot better when riding on loose gravel and going through thick sand.

Hope this helps.

cyberzar 4 Mar 2008 13:22

Yamaha susp. tuning
1985 XT with 7200 km? are you sure? You mean engine rebuild, or the whole bike made in 1985 has only 7200 km? If correct probably shock should be fully working.


1) TT linkage swap will have no predictable positive result (and is probably not possible at all)

2) Consider that these bikes are build to be used also with two passengers, so 210 lbs is not too much. You could use a stiffer spring (for the rate, you will surely find good advice from sellers like KEDO - Performance Products) but consider the risk of having a bike not usable offroad.Anyway, you should check the rear sag on your bike to understand if you need to change spring.

3) The usual hint on these bikes is to get a used shock from Ohlins, model YA2201 (the one used on Yamaha TTs600 model) that can be adapted with small modifications. Find it used for 200\250 euros, then have it rebuild (if needed) for other 100\150. The problem is that they are very rare on ebay... The shock must have eyelet top and down. TTR models (eyelet up, fork link down) can be adapted only spending other 150 euros.

daclarkster31 10 Mar 2008 17:38

Hi mate, Myself and a mate did the west coast of africa on XT600E's and had to uprate the front and rear suspension as the standard was saggy as hell. I'm pretty sure we fitted hagon srings to the front which were fine, but we couldn't find anywhere that uprated the rear so in the end I took the rear spring out, sent it to a local spring maker (just a generic engineering spring maker rather than a bike guy), asked him to make one with another 30% added. A week and 40 quid later I had a 2 new springs that were absolutely spot on for the 10,000 miles of abuse that we gave them.
Its always worth thinking a laterally to some of these probs. Good luck regardless.

ekkemu 14 May 2009 08:28


Originally Posted by RIDER (Post 177907)
I then had some emulators made, the emulators have made a big difference when going over potholes and hitting rocks. The bike also tracks a lot better when riding on loose gravel and going through thick sand.

Hope this helps.


I found myself in this situation too, I want better suspension on my XT. I read about RaceTech emulators, but I couldn't find a model for the XT 600. Where did you get your emulators from? And did you also change the springs with the Hagon progressive ones? What about oil viscosity with the emulators installed? 10W or 15W?

Did any of you use the Hagon rear shock? Does it improve performance significantly? Any info if it's worth buying it (275pounds) would help:

Hagon Monoshock

Thanks a bunch!

ekkemu 14 May 2009 08:31

Jimmy, what mods did you do so far and what was the result?

To all: Do you know if a front fork from a different bike can be easily adapted? I am thinking of an upside down fork from an enduro bike (WR, EXC, XT, etc).

ekkemu 14 May 2009 08:37

One more question for you guys. I found a TT rear shock. Do you think that it will fit a 2001 XT 600 E? What's your thoughts on how it looks?

1983 1984 TT600 REAR SHOCK TT XT 600 XT600 83 84:eBay Motors (item 220411870255 end time Jun-08-09 18:15:58 PDT)


wolfzero 14 May 2009 13:38

thats a very early tt shock and probably needs a full rebuild $$$?, plus you will need to make provision for the remote resevoir on that one.

Pawlie 14 May 2009 21:11

About the fork swap.......

I have been keeping quiet on this project as it's not 100% completed yet. I had to work this out on my own as I made the same inquiries as you and came up mostly blank.

The following might be of value to you. might not. But you paid nothing for it so take it FWIW.

Do I have pictures? yes. Do I have the computer savy to post them here? Not a chance! I would gladly e-mail some if someone wanted/had the skills to make them show up here.

I love riding my old xt but modern dirty bikes are in my stable as well and being spoiled by modern suspension was the inspiration for upgrading the old girl.

I chose conventional right side up forks. Astetically(sp?) I feel they suit the bike better. The maintence periods/costs are less than associated with an upsidedown design. If you need the very latest tech forks on an xt, you are throwing a big $$$$ solution at a turd. A very likeable turd, but a turd none the less.
Most Importantly! In the case of the DRZ conventional fork I used. It has a lengthy surface area on the upper fork leg to which you can clamp the tripple trees. If you look at a lot of fork swap projects on the internet they often appear like choppers in photos. Basically the forks on the modern bikes are all longer than what is required on the XT. This badly affects handling in many ways. Let's not get into this subject or possiable solutions here. The lengthly clamping surface mentioned above allows you to slide the forks up in the tripple trees returning the bike to it's proper ride height and hopefully wheel base. Vastly improving it's handling traits.
The problem with many upsidedown forks is the upper tubes are tapered and the useable clamping surface is small, not allowing enough adjustment as required by the xt's shorter stature. This problem and many other are solvable but typically will cost serious dollars to fix.

Rather than adapt a bunch of stuff from different bikes I basically used all DRZ hardware. Brake, wheel, fork, tripple tree, stem. The forks I have, contain racetech one step up from stock springs which I had on hand. They perform well with the added weight of a heavier bike but I have not ridden the machine enough to know if they are required or not.

Many things need dooing but are basically simple jobs.
Welding new steering stops
New bearings Stock on bottom(nice tapered roller), modified(less than perfect but durable enough on top.)
Spacers to mount up headlight frame to new tripple tree
Figure out what you are going to do for ign switch mounting
front brake line routing
Steering lock (I have none)
Speedo solution(I have an aftermarket digital)
A couple of spacers here and there for the steering neck.

Please note I also have Dr Big's up and foreward bar risers on my bike. Without this modification I would not be able to move the fork tubes up enough to return the bike to the correct (stock ride height) The tubes would bump into the bottom of the handlebars otherwise. If you go to thumpertalk and search DR Big risers you will get a million hits on them. If riding a DRZ with this modification you will never consider going back to stock. They are awesome. If you have the skills to make your own. Do it.

The results from this project have been teriffic. Vastly improved suspension action. Stiffer front under braking loads. And improved braking force. I have put in about 750 Km of off pavement riding and have experienced no evil suspension traits to date. There is no where to hide bad susp. traits in off pavement riding, they will show their ugly head! But not enough testing has been done yet for me to give it the full thumbs up.

The problem created is the 25yr old rear end on the xt seems that much worse. Please spill if you have good solutions to this problem.:thumbup1:

I'm no expert mechanic or suspension tech but pulled off this mod sucessfully. So can you.

A final note of caution:
I have learned that suspension geometry is both an art and a science. Changing stuff, wheel base, ride height, trail, rake, fork offset, axel location, can go horribly wrong and will be very expensive to make right.
If straying far from what the OEM's have figured out for the machine. You are proabably going the wrong way. They have done the math!
Each bike and fork combo must be carefully considered to end up with a workable solution.

The experts will laugh but basically I eyeballed most of the variables discussed above (in side by side comparisons of parts)and applied my very crude understanding of suspension. To this I threw a bunch of cheap parts sourced from fleabay. I rolled the dice on this project and think I won.

An underlying principal was, always be able return the bike to stock if I messed up. No permanent changes were made before I could road test the machine. If it didn't work out I would just flog the parts for little to no loss.

The bike is a 1986 xt 600 NAm. model, 43F for the euros (note: early xt=longer travel susp. than later bikes). The front end parts came from a 2003 Suzuki DRZ 400s.

Have Fun,

cyberzar 14 May 2009 23:49

rear shock
ekkemu: no, can't use an early TT shock, it's too long (43 against 39). The ideal is get a Ohlins from a Yamaha TT600s (see herehttp://www.rallye-tenere.net/Stamb_tt_600_s-e.htm), it's a plug and play (almost) work. An ohlins from a TTR600 will need a lower joint change to fit in your bike. Probably you will need an harder spring too..

wolfzero 15 May 2009 12:50

Pawlie yes it is posible to screw up the handling of the bike by going far away from the oem set up but it is also possible to improve it a hell of a lot too, the basic designs of these bikes are over 20yrs old and the tech has come a long way since.

i'm running an usd front end and a custom rear set up which has made the bike handle the bumps and corner far better than the oem setup.

Pawlie 15 May 2009 17:01

Please tell us about the mods you have done.

Preferably with practical information we can apply to our own projects. I'm particularly interested in the rear of the bike, as I have the front working quite well.


wolfzero 15 May 2009 17:56

i dont know if my mods would work so well on an off road bike as i've supermoto'd mine.

the front is WP forks off an early ktm with the yokes off a late model ktm650 to allow the fitting of a lighter alloy wheel off a yam yzf600 fitted with a R1 brake disk the caliper is a tokico 4 piston caiper off a 1999 gsxr750.
the bars are magura fat bars and the oe clocks and headlight have been replaced with a digi dash and accerbis headlight.

the rear is a heavily modified R6 swing arm which is slightly longer than the original, the rear shock is off a ttr unfortunatly not the ohlins model but it is far better than the oe xt600 one.
the rear wheel is also of a yzf600 and the caliper is the other tokico 4 piston caiper off a 1999 gsxr750 a bit of overkill but it was easier to use the pair of calipers as i only need to keep one set of pads in stock :thumbup1:

ekkemu 16 May 2009 21:50


Originally Posted by Pawlie (Post 241826)
The problem created is the 25yr old rear end on the xt seems that much worse. Please spill if you have good solutions to this problem.:thumbup1:

kedo.de sells Wilbers shocks and you have a 320 EUR option for the one which is stepless adjustable in spring preload but no rebound adjustment and a 420 EUR option for the one which is stepless adjustable in spring preload and rebound in 22 step. They will also fit a spring according to your "ready-to-ride" weight. From what I understand, they are made for the XT, so it's plug-and-play.

RIDER 17 May 2009 19:14

Hi Ekkemu

I had the emulators made at a local machine shop. They are cheap and easy to make. If you give me an e-mail address I will send you a drawing so you can have them made anywhere that has got a lathe.


All times are GMT +1. The time now is 17:57.