06 YZ450 front end on 98 YZ250

[scoobydoo]

Can anyone help me out here? Have chance of a nice 2006 YZ450 front end to go on my 98 YZ250 2 stroke. Questions are will it bolt up? brake caliper? Will the rake, trail be messed up? 

Dont mind a bit of messing around and am handy with the spanners so no problems there, just want to know if it will work before I drop my money on them

[CaptainKnobby]

Rake is determined at the steering head .....the angle of it. I dont know the angle differences between the two.
You will more than likely have to get the Triple clamps(Top and Bottom) put them on the 98 and see if they work. That would be the main thing.
If the Bottom clamp with the steering stem fits at the bottom of the steering head and this is with the bottom bearing fitting all the way up into the bearing race.
Also you would have to make sure the stem wasnt to long so as it would be sticking to far up outa the top clamp.
This would be your only hold up and that would be the clamps.
You also asked if the Beake caliper would work on your 98?

If you are getting the whole front from the 06, and what I am calling the whole front is .......Top/Bottom clamps, Forks, wheel with the rotor.

I believe the rotor on the 06 is 270mm as for the 98 I'm not really sure but would be guessing it is 270mm also. What makes the caliper not fit is where it bolts onto the fork.
As far as the caliper working in general then yes it would work.
Main thing is to look at the caliper on your 98 the way its bolted on the fork leg and see if it bolts at the same location on the fork leg of the 06.
I pretty sure the brake caliper will fit on the 06 fork leg as far as bolting on.

[Clutch44]

They both are 260mm. But I would see if you could get the caliper with it too. Or find one on ebay.

[CaptDan]

You will need 2004 triple clamps to match the '06 (46mm) forks your '98's steel frame, because the fork stops are different between the steel & AL frames. People have modified the AL frame triple clamps and/or steel frame stops to get things to work together, but the '04 clamps would be the easiest.

However you do the triples, the '98 front wheel should bolt-up, but check the caliper-to-rotor spacing. May require different or modified spacers.

I believe the caliper mounting points didn't change until 2008, so running your '98 caliper should be a non-issue.

Offset & rake will be unchanged. (2 & 4-strokes all ran a 25mm offset until '10(?). Just take care when doing the suspension setup. Re-valving & springing may be mandatory.

Cool project!

Keep us updated with what you do.

[scoobydoo]

Thanks guys for all your help, think I know enough now to make the decision to go for it. I just need to speak to a few suspension tuners on our side of the pond to see if I can get them revalved to work in the woods.

the bike they’re going on is a 98 Euro WR250Z, chassis wise identical to that years YZ250. The original forks are grim compared to a 16 YZ250X, didn’t realise how bad til I rode the 16!

Edited December 2, 2018 by scoobydoo

[scoobydoo]

11 hours ago, CaptDan said:

You will need 2004 triple clamps to match the '06 (46mm) forks your '98's steel frame, because the fork stops are different between the steel & AL frames. People have modified the AL frame triple clamps and/or steel frame stops to get things to work together, but the '04 clamps would be the easiest.

However you do the triples, the '98 front wheel should bolt-up, but check the caliper-to-rotor spacing. May require different or modified spacers.

I believe the caliper mounting points didn't change until 2008, so running your '98 caliper should be a non-issue.

Offset & rake will be unchanged. (2 & 4-strokes all ran a 25mm offset until '10(?). Just take care when doing the suspension setup. Re-valving & springing may be mandatory.

Cool project!

Keep us updated with what you do.

Is the spacing different on the clamps from 04 to 06? Do I need top and bottom triple clamps, or will the bottom one do it? Have found a nice procircuit lower triple for a good price from 04 YZ

[EmpireofDerp]

Thanks guys for all your help, think I know enough now to make the decision to go for it. I just need to speak to a few suspension tuners on our side of the pond to see if I can get them revalved to work in the woods.
the bike they’re going on is a 98 Euro WR250Z, chassis wise identical to that years YZ250. The original forks are grim compared to a 16 YZ250X, didn’t realise how bad til I rode the 16!

Did you have your 98 forks sprung and valved for your weight and use? Cheaper and faster to just set up what you've got. Since you're using the bike for woods, the OC forks you've got can be made to work great.

[scoobydoo]

19 minutes ago, HevyRotashunz said:

11 hours ago, scoobydoo said:

Thanks guys for all your help, think I know enough now to make the decision to go for it. I just need to speak to a few suspension tuners on our side of the pond to see if I can get them revalved to work in the woods.
the bike they’re going on is a 98 Euro WR250Z, chassis wise identical to that years YZ250. The original forks are grim compared to a 16 YZ250X, didn’t realise how bad til I rode the 16!

Read more  

Did you have your 98 forks sprung and valved for your weight and use? Cheaper and faster to just set up what you've got. Since you're using the bike for woods, the OC forks you've got can be made to work great.

I haven’t, we don’t have a load of options this side of the pond for revalving etc, just thought the later forks were that much better to be honest, can the early ones really work that well?

[EmpireofDerp]

 

 

I haven’t, we don’t have a load of options this side of the pond for revalving etc, just thought the later forks were that much better to be honest, can the early ones really work that well?

Yes they can and if you're riding woods you'll need to have the new ones done as well. The sss you're wanting to install are a Motocross specific fork and will work less well than a revalved and sprung OC fork for woods riding. If your weight is within the spring range of the sss forks, you may be able to live with them in stock form for woods but they'll always be valved too stiff.

 

[CaptDan]

9 hours ago, scoobydoo said:

Is the spacing different on the clamps from 04 to 06? Do I need top and bottom triple clamps, or will the bottom one do it? Have found a nice procircuit lower triple for a good price from 04 YZ

In 2006 the spacing between the fork legs was increased by 2mm, so the triple clamps will need to match top & bottom. (That's why I mentioned keeping an eye on the spacers if you run the '98 front wheel.) 

That ProCircuit lower clamp is a great deal. A few guys here jumped on it. It would be ideal if you could get an aftermarket '04-'05 top clamp (with movable bar mounts) while you're in there.

If it were up to me, I'd run an OEM '06 lower triple with an OEM '07+ top clamp (for the adjustable bar mounts.)

TT member kenpowell did something similar...

The O.C. forks can be made to work very well, but I've heard that the '98-'01 forks were especially tricky to get right.

All I know is that all I did to my '06 forks was change the oil -- nothing else -- and they were just short of magical. (I'm 180 lbs. woods rider)

That is a super sweet WR. I'd do the fork swap simply because that bike is a keeper!   ?

[asian195]

Things you will need to fit SSS forks onto your bike.
06 triple clamps
Brake caliper bracket
Front axle
Front wheel spacers
Front brake line.

Things you need to do.
Use your 98 steering stem in the 06 triple clamps.
You can use your brake caliper, but gotta use the 06+caliper bracket. This is the time to upgrade to an oversize rotor kit, just be sure to order it for the forks not the bike. 06+....

[scoobydoo]

7 hours ago, CaptDan said:

In 2006 the spacing between the fork legs was increased by 2mm, so the triple clamps will need to match top & bottom. (That's why I mentioned keeping an eye on the spacers if you run the '98 front wheel.) 

That ProCircuit lower clamp is a great deal. A few guys here jumped on it. It would be ideal if you could get an aftermarket '04-'05 top clamp (with movable bar mounts) while you're in there.

If it were up to me, I'd run an OEM '06 lower triple with an OEM '07+ top clamp (for the adjustable bar mounts.)

TT member kenpowell did something similar...

The O.C. forks can be made to work very well, but I've heard that the '98-'01 forks were especially tricky to get right.

All I know is that all I did to my '06 forks was change the oil -- nothing else -- and they were just short of magical. (I'm 180 lbs. woods rider)

That is a super sweet WR. I'd do the fork swap simply because that bike is a keeper!   ?

Thanks for your kind words about my bike, has been a labour of love to get it to how it is today, although it was a low hour bike when I started the restore. Raced one back in the day and loved it......you're right it is a keeper for sure.

So, what bike did your SSS forks come off to work so well? Do you know the spring rate? And what oil and how much? Am keen to do the swap as the forks on that 16 were so sweet and I dont feel like dropping a ton of cash on the original front end to keep on chasing my tail.....

[CaptDan]

I picked up a used, all-stock 2006 YZ250 a few years back. Like I said, I had fresh oil put in the forks and just ran them like that. No change in oil weight or amount. No valving. I didn't even mess with the clickers. I have no idea what the spring rate was -- whatever came stock, I guess. MXA says 0.43 kg.

https://motocrossactionmag.com/tw0-stroke-tuesday-we-test-the-2006-yamaha-yz250/

My friend with a 2007 CR250 was surprised that the YZ was more refined than his custom-tuned forks.

Asian195 is pretty spot-on, but you shouldn't need to swap stems; the '06 450 stem should be the same length as the 250 2-strokes.

[scoobydoo]

so just an update for those searching this thread later, it appears that the forks and triples fitted to an 06 YZ450 are identical to those fitted to the 06 YZ250 in all but spring rates.

Have bought the forks and will report back on lock stops and brake caliper mounting......

[CaptDan]

   ?

[scoobydoo]

So, another update, 06 YZ450 forks have turned up and I’ve just had a trial fit onto my 98 WR250Z, brake caliper bolts straight up, stock 98 wheel, spacers and axle with 06 wheel spindle nut and it all lines up ?

brake line needs changing due to shorter route, need some 1 1/8” bars and lock stops to modify and I’m good to go. The stops are ok but only touch on 1/4” or so of the frame tab, have heard this can cause problems, any one know for sure?

[Kinger317]

lock stops to modify and I’m good to go. The stops are ok but only touch on 1/4” or so of the frame tab, have heard this can cause problems, any one know for sure?

I believe too small a contact area caused this on a bike I bought and immediately tore down. Also make sure you get the full rotation.

[Kinger317]

That is a pro taper set of triples taken off an aluminum frame bike. The bottom bearing did not look correct making the frame stem higher… Anyway there was only about a quarter inch of contact

 

Edit: just don't crash the bike! Nice project