Upgrading Suspension Help WR450 2007

[Snow Drift]

I posted earlier this year about my front forks and still need to sort them out. I am going to be re-greasing the head bearings so thought it would probably be a good time to sort the front forks.

 

I have read posts on here, watched videos on youtube and also looked at the manual, but I am still really new to understanding suspension and how the different components work and what to upgrade.

 

I would like to fit fork bleeders and then fit whatever else people recommend while I'm in there. I am only about 140 pounds (63.5kg) and just ride in fields and tracks etc. I don't know if the standard springs are acceptable with my weight.

 

Should I be changing the springs, the valves, or other bits? I saw a post about changing to Gold Valves, would I see any benefit in doing this and what other bits go hand in hand?

 

I am not quite sure how to learn more about suspension on these bikes in order to better understand it all. I would like to have the bike setup properly though as I'm working my way through it.

[FORMA MOTO]

Race tech will sell you a 'kit' for upgrading the forks for wear, and a separate set of springs and valve for upgrading performance

 

Call them

[Snow Drift]

I may try and give them a call direct, I'm in the UK and haven't seen many of their products over here. The problem is that I don't know exactly what I'm asking them, I'm really a bit out of my depth with suspension. However, there aren't many places that I know of that do this kind of work around where I am and the price for doing it would also probably be quite high, so want to learn and have a go myself.

 

I'm just struggling with the basics of the front and rear suspension and don't know where to find that info and explanation.

[GuyGraham]

Snowdrift - do it yourself

 

Any problems or queries, post on here and people will help you

 

 

You want a 'Fork Gold Valve Kit'

In it, will be instructions and a video to show you how to do it, plus extra shims so you can play around with the shim stacks

You will also get a code in the kit, to put in the RT website site - this will give you the shim stack recomendations based upon your riding terrain, weight, age etc

 

I can't describe the difference it will make to the shite that Yamaha put in the forks, but rest assured you will wonder why you didn't do it sooner

 

With regard to the shims, there is a simple formual to work out the stiffness for each thickness

It is nothing more than the material thickness cubed

 

shim thickness      stiffness value

0.1mm                   1

0.15mm                 3.3

0.2mm                   0.8

 

as you can see, a 0.2mm shim is 8 times stronger than a 0.1 shim

so if you replaced 8 0.1mm shims with 1 0.2mm shim, you would have exctly the same damping (if you replaced like for like on the diameter)

 

The only thing you may struggle with, is a tool to hold the cartridge when you undo the base valve in the bottom of the forks

I made my own out of some steel tube

If you get stuck, post up on here and I will supply the dimensions and a picture so you can copy it

 

 

Hope this helps

Edited January 2, 2015 by GuyGraham

[Snow Drift]

Thanks very much.

 

I don't fully understand the whole shim system yet but I'm sure I will understand it a little more once I get into it.

 

Is the rear shock not as much of a problem on these bikes or is it that it is not as economical to sort?

[GuyGraham]

Rear Shock seems OK to me, with the correct spring for my weight

Could possibly do with less compression damping, as I am on min on both the HS & LS adjusters, but its good enough for me not to mess at the moment

[bobpara]

There is a certain heirarchy you have to follow of you will be all over the map trying to dial things in

 

1) Everything needs to be working properly. No leaking seals, grease ALL of the rear suspension pivots, etc

    This also includes proper sag setting (see manual)

    Sounds simple but I think you'd be surprised how many jump to #2 before addressing this

2) Get front and rear spring rates right. Most Japanese bikes come from the dealer WAY under sprung for

    Like a 130 lb rider. My WR oddly enough (I bought it used) is a bit on the stiff side.

3) Only once the spring rates are right, only then should you focus on damping. It may involve pulling them

    apart a second time, but its hard to get it all right in 1 shot

 

The only way to get it right all in one shot is to call factory connection or one of the others and send the units to them for beaucoup $

[bobpara]

And then once you are done with that consider a Scotts steering stabilizer

I wiggled a crowbar into my wallet for one last summer (about $500)

 

All I can say is find somebody with one and try it

If you are not impressed within 10 minutes, dont bother

 

If you drop the forks in on a set of whoops it has a good chance of preventing an endo

In sand, it dampens out that 'wandering' feel

in the end you go 10% faster without almost even knowing it

[Snow Drift]

I have looked through the manual and can't see anywhere about how to adjust the sag etc. I thought that adjusting the compression and rebound effectively just adjusted how the suspension responds in and out when going over obstacles etc. I thought that the sag was to do with the weight on the springs and could only be adjusted by changing the springs.

 

One thing that I don't understand straight away is the rear spring has adjusters on the top to compress the spring. I have not altered this since I bought the bike second hand. How do I know where this should be set, before I start fiddling and working out how what springs I need. I presume you can't similarly adjust the front springs in this way anywhere?

 

I have changed all the bearings in the rear linkages and swingarm etc so it is all moving as it should. But when I sit on the bike the rear goes down but the front forks are rock solid. I have tried bleeding the air for the first time but nothing actually came out and the forks feel the same. I am roughly 136lb at the moment and the forks feel stiff.

 

The steering damper is an interesting one. There are lots of bits and pieces that I would like to put on my WR like FMF exhaust and other bits but they are either not available over here or very expensive.

[FORMA MOTO]

You need to do a google search on 'how to adjust race sag'

 

You are out of the loop on all this

[foggy3061]

I have looked through the manual and can't see anywhere about how to adjust the sag etc. I thought that adjusting the compression and rebound effectively just adjusted how the suspension responds in and out when going over obstacles etc. I thought that the sag was to do with the weight on the springs and could only be adjusted by changing the springs.

 

One thing that I don't understand straight away is the rear spring has adjusters on the top to compress the spring. I have not altered this since I bought the bike second hand. How do I know where this should be set, before I start fiddling and working out how what springs I need. I presume you can't similarly adjust the front springs in this way anywhere?

 

I have changed all the bearings in the rear linkages and swingarm etc so it is all moving as it should. But when I sit on the bike the rear goes down but the front forks are rock solid. I have tried bleeding the air for the first time but nothing actually came out and the forks feel the same. I am roughly 136lb at the moment and the forks feel stiff.

 

The steering damper is an interesting one. There are lots of bits and pieces that I would like to put on my WR like FMF exhaust and other bits but they are either not available over here or very expensive.

 

You can only adjust the front fork sag by adding the preload washers; this is covered in the tuning section of the manual. If the forks are standard they won’t have any preload washers in.

 

You can adjust the sag on the rear of the bike by winding the two locking rings up or down to decrease or increase rear sag. It sounds like the springs on the bike (even if standard) may be a little firm for you. It would be worth researching spring rates for your weight and riding style and go from there. Fix the fork base (compression) valves too!!!!!

 

I wouldn't worry about a steering damper in the UK, I doubt you'll need one once the bike is sprung for your weight.

[bobpara]

From what I am hearing you have dicked with all the settings six ways to sunday.

Put all the dampening and rebound settings in the 'neutral' position until you have sag and spring rates right

By neutral I mean if it has 0 thru 14 adjustment position, put it at 7

Otherwise, like I said earlier, you will be all over the map

 

For example, you could have the dampening cranked way in and you may think your spring is too stiff

The spring could in fact be too SOFT but the dampening setting may trick you into thinking its too stiff

 

In fact, I'll go so far as to say that 80% of all riders out there have the wrong sag and/or the wrong springs for their weight and riding

Most riders are too cheap to wiggle a crowbar in their wallet for a proper set of springs (and the labor, frustration and time)

 

The damping settings are actually the third and least important settings on the bike.

Their biggest contribution being big jumps and big displacements of the shock.

[FORMA MOTO]

All the springs do is postion the bike and rider at a known height and provide a known resistance.

 

They have nothing to do with a 'soft' or 'hard' ride.  

 

That is all in the damping.

[Snow Drift]

Thanks for your replies it is all very helpful and is the basic information that I have been trying to get my head around.

 

When I replaced all the linkage bearings a few months ago I put the rear shock settings neutral and also the top clickers on the forks neutral. I have never touched the ones on the bottom of the forks but had a look now and they were pretty much neutral. I tried adjusting them each way and rocked the forks and put my weight into them but found very little difference. In fact the manual says that by screwing the adjusters in fully (clockwise) it should be stiffer but I seemed to find this a little softer than the other way.

 

Thanks for the recommendations on searching sag settings. I have had a quick look and will look at this in more detail and have a go at adjusting this soon. So it seems that you can work out if the rear spring is too stiff or soft by trying to adjust the sag and finding it isn't right there. However, is there a way to check the front springs in real terms without using an online calculator?

 

I will probably be ordering the gold valve kit soon from Race Tech, should I also order race tech springs or is there a preferred spring brand out there?

[GuyGraham]

Being in the UK Snowdrift, you can get RaceTech from PDQ, and K-Tech

Sometimes others come up on ebay etc

You can fit springs advertised for other bikes, as long as they are the same size

The rear shock spring is common across many of the Jap MX bikes - my spring came off a CRF MX bike

 

Have a look at the K-Tech website, - you can see the spring sizes and x-ref it withouther bikes which use the same springs

 

I am using YZF fork springs in mine, they are 5mm shorter on free length which I compensated for with 5mm spacers

[foggy3061]

I will probably be ordering the gold valve kit soon from Race Tech, should I also order race tech springs or is there a preferred spring brand out there?

 

I ordered KYB springs from a UK dealer. 

 

I found out the rates from the Race Tech calculator and double checked with Technical-Touch's tech department too. Then looked up the part numbers from the KYB catalogue and got a dealer to order them for me.

 

http://www.technical-touch.com/fileadmin/sitecontent/pdf-files/Cataloog_2015__1_.pdf

 

Fork springs page 32, Shock spring page 168.

 

I'm pretty sure Apico are the UK importer for Technical-Touch KYB.