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Edited Date/Time
12/20/2021 1:34am
Will these bolt right up? I just happened upon an 8hr '06 yz450 and want to upgrade my 125 forks. I was curious if there is anything special I need to do?
I'm in the middle of putting 2008 yz250 forks on my 02 yz125 and the measurements for the steering stem are actually identical to the stock so I went ahead and had new bearings pressed on to the stem and will be using that set up when my frame gets back from the powder coater.
The Shop
From 2006 to 2005, it's pretty simple. You can use your existing brakes, spacers, etc...
You can use any triple clamps from 2006+ or you can actually keep your 2005. More below.
The Triple clamps from 2006+ mount the forks 2mm (.080in) further apart.
The wheel spacers (the left one is the one that matters) are the same part numbers for 2005 and 2006.
The lugs on the 2006 forks are each offset 1mm towards the center of the wheel so that you can use the same wheel and spacers as 2005. This matches the 2006+ triple clamps being wider.
If you keep your 2005 Triple clamps, and simply swap out the forks, your front wheel will be 1mm off center toward the right side. It's .040 in, and I didn't notice the wheel being slightly off centered on the track.
If you're keeping the 2005 clamps and want the wheel centered, you'll need to either grind or machine 1mm off of the left wheel spacer, or you can dish your rim instead (loosen all of the spokes on the right side of the wheel slightly, then tighten all of the spokes on the left by the same amount). Machining the spacer is a better solution. The right spacer does not need to be modified.
If you swap out the triple clamps, anything 2006+ will work. I believe they're all the exact same part number.
If you do, you'll need to replace your front number plate. 2006+ are mounted different and they aren't compatible with 2005. You may also need a new front fender. I don't know if the 2006 number plate is compatible with a 2005 fender.
The brakes and the fork guards are the same for 2006.
FYI: I bought 2010 triple clamps but haven't installed them yet (I still need to find some handlebar mounts).
I've been riding and racing with the wheel 1mm off centered, and for me, it is not even slightly noticeable. When I find a deal on bar mounts, I'll swap out the triple clamps. Until then, I'm riding with the 2005 triples.
Be careful with the articles on doing the conversion. There'a s lot of misinformation out there. One article says that you can use the 2006+ upper triple clamp with your 2005 lower triple clamp. This is completely wrong and I can't believe it actually worked. You can't have the upper clamp spaced 2 mm wider than the lower. Your forks won't be parallel and they'll bind as you ride.
The rest of the confusion is because all SSS forks are not interchangeable, and the 2 strokes and 4 strokes got some of the changes in different years. In 2008 or 2009, the lugs changed completely and you need a new axle, spacers, and fork guards (Your left 2005 spacer remains compatible but heavier than the new one). The brakes, brake mounts and cable routing changed in 2008 I believe. So, there are 3 or 4 different SSS forks. Some of the misinformation is just because of not knowing all of the changes.
For 2006, the information above is correct. I'll post my notes on doing the upgrade from any year forks in the next couple of weeks.
I believe the upgrade is worth it!
I hope this helps.
Enjoy!
Just like upgrading the 2005, you should be able to just keep your 2004 triple clamps, and mill 1mm off of your left wheel spacer to re-center the wheel.
I will say even for my 180# frame the 250's still going to need some more valve work to be called a success.
It sounds like you need to do a little article with your detailed research. Since I have the '06 bike, would it be best to just completely trade entire front ends(complete triple clamps/stems) to avoid any spacer issues? I am converting the 450 into another snowbike/timbersled so the SSS isn't that important in the snow, you just put super beefy springs in and away you go.
The brakes, spacers, cable routing are all the same between years, so swap out what you need to.
If you use the 2006 triples:
The fender off the 450 is the same part number as the 2006 125, so that works.
The only question is whether the triple clamp stems are the same length. If they aren't, you'll need to remove and press the stem from the 125 into the lower 450 triple clamp, and you'll need a new number plate. Part numbers are different for the number plate, but if the stem lengths are the same, the 450 number plate should be compatible.
What you will need to replace are the fork springs. The springs for the 450 are way stiffer than for the 125.
I picked up my pair from RaceTech. At 150lbs I went with the stock spring rate.
You probably already know this but just a reminder. If you use the '06 upper triple, you'll need to use an 06 lower.
I know that for the 2 strokes every single part except the springs are identical between the 125 and 250. This goes for every year from 2005 -2015. I don't believe I had info on the 2016.
So, if you're going to spend the money for re-valving that's cool, but stock, the valving is identical between the 125 and 250. I'm not positive about the 250f though, but I suspect it's identical as well. The 450's too.
example:
YZ250f offset
Up to 2011 - 25mm
2012-current - 22mm
YZ450f Offset
2006-2009 - 25mm
2010 - 2016 - 22mm
2016 - 2017 - 25mm
Also, The ID of the upper clamp is 2mm smaller (54mm down from 56mm) 201 and up 450f's and (I believe that the change happened in 2013) 2013 and up 250f's. So upper clamps from these years will not fit forks from earlier years. as the OD of the fork's upper is 2mm smaller (from 56 to 54mm) on 2010 and up 450f and 2013 and up 250f SSS forks. I just had an upper clamp machined to fit 2006 fork into it.
I short, in order to use 2006 through 2009 450f SSS forks or 2006 through 2012 250f SSS forks you will need to find the clamps that have the correct upper clamp ID and the correct offset that you want. If you want to make the change to 22mm offset and not machine anything, I"m pretty sure that the only clamp with 22mm offset and 56mm upper ID is the 2012 250f. Otherwise, it looks like you will have to machine the 2010 - 2016 YZ450f clamps. They will be 22mm with 54mm upper ID and 2013-2017 250f clamps will also be 22mm offset with 54mm upper ID. Also consider that the YZF upper clamps added the multiple positions for bar clamps in 2012 I believe.
Just to keep things interesting, there was also a difference in overall fork length between older model forks. The newer forks are a few mm shorter. The change was either from steel frame to aluminum frame or from '05 to the '06+ SSS stuff. There were also a couple changes in lower fork lug and hubs here and there that affect wheel centering and disk / caliper alignment. It's fun (or not) figuring all this out and making it work, but my goodness is it worth the difference to properly valved SSS stuff. It should be easier working from an '05 instead an '01 like mine.
Good luck.
YMMV. Please confirm dimensions of anything that you are going to purchase for this conversion.
Having said all that, I'm super happy with mine on my 2001 steel frame.
Edit: corrected the year upper clamp size went from 56 down 54mm on the 250f and 450. I'm pretty sure it was 2013 that it changed on 250f and 450f was 54mm upper from 2010 and up.
The left spacer is the same 2005 and 2006
But left and right Spacers 2002 to 2007 are the same ? As per parts -
YAMAHA YZ 125 250 2002-2007 YZF YZ-F 250 450 2002-2006 FRONT WHEEL SPACERS
So if you trim 1mm off the left spacer ( Would align the disk )
Then the Axle will sit 1mm proud on the right hand side of the fork when forks are parallel as the fork lug is free to move on the axle on the right ?
Is that a correct assumption ?
Pit Row
Not sure you can help but I bought a 2007 YZ 250 that had the forks swapped off either a newer YZ or maybe even YZF newer model. The stock spacers for the 2007 YZ 250 made the axle stick out of the lugs about a inch. I bought a newer axle and spacers and now the newer axle goes in about a half inch to far and does not set flush. Any suggestions on what might be the spacers to make the axle set flush in the lugs ?
Triple clamps, forks, lugs, spacers, brakes?
Thanks in advance .
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