YZ250 fork length info needed

dmm698
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8/1/2020 4:22pm
Can anyone with a YZ250 measure the overall fork length? I misplaced my measurements, and my 13 SSS forks have been sold. Trying to insure I get the showa forks I installed to the proper length. Thanks
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FGR01
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8/3/2020 2:29pm
On my 2006 YZ250.... 935mm from the top of the outer tube (highest point the top clamp could be clamped) to a point inline with the center of the axle. I measured this way instead of overall since the axle mounting distance is what will affect handling/geometry.
FGR01
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8/3/2020 2:32pm
Probably a measurement that matters more directly for handling, I am at 656mm from the bottom edge of the bottom clamp to a point in line with the center of the axle.
nch209
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10/2/2020 11:11pm
I am now going down the same road as the OP. On Thumpertalk there seems to be variances between 935mm and 945mm overall length for KYB's, and some say 125/250f's for the 935mm, and the 250/450f got the 945mm, but the above post and some of what I read seems to suggest different. I swapped AOSS KYB from my 05 250 that were 935mm to Showa PC Kit stuff that are 945mm. Hope to be able to get setup proper, but curious if any 250 smokers owners here have 945mm KYB's on their bikes. Was there some frame geometry change I am missing?

Thanks!
Factor E
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10/3/2020 1:30am
Call Enzo or Pro Circuit

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FGR01
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10/3/2020 8:08am
nch209 wrote:
I am now going down the same road as the OP. On Thumpertalk there seems to be variances between 935mm and 945mm overall length for KYB's...
I am now going down the same road as the OP. On Thumpertalk there seems to be variances between 935mm and 945mm overall length for KYB's, and some say 125/250f's for the 935mm, and the 250/450f got the 945mm, but the above post and some of what I read seems to suggest different. I swapped AOSS KYB from my 05 250 that were 935mm to Showa PC Kit stuff that are 945mm. Hope to be able to get setup proper, but curious if any 250 smokers owners here have 945mm KYB's on their bikes. Was there some frame geometry change I am missing?

Thanks!
I seem to recall the YZ250 (and possibly 125) fork length may have changed somewhere in the years between 2006 to present. I can say for sure these are the original forks on my 2006 YZ250.
10/3/2020 8:52am
For the 2015 to current YZ125 / 250 the measurement from the top of the outer tube to the axle is approx. 935mm. From the top of the cartridge cap to the axle is approx. 945mm.

When I do a fork swap I always measure from the top of the top edge of the frame steering head tube to the axle with the wheel and fender off, right down the center line. That's the more important measurement in getting a fork swap set up correctly. That throws out any variations in overall fork length, or bearing, seal and clamp thickness.

If I remember right I think mine measures approx. 895mm from the top of the frame head tube to the top of the axle tube. That's with the tubes set up in the clamps about 8mm from the top of the clamp to the top of the outer tube edge.

If you set that length to about 900mm it's going to have you in the ball park and then you can adjust as necessary to get the desired handling characteristics you're looking for.

Hope that helps.


10/3/2020 10:09am
Laying flat on a table or in the vice I got 938mm on a 2007 YZ250. And not that anyone asked but a 2007 YZ250F is 935mm, 2001 WR426 937mm. My accuracy is +/- 2mm since I haven't finished my morning coffee.
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nch209
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10/3/2020 11:44pm
Thanks for the help and the numbers. I think I am in the ballpark, and luckily have lots of space for adjustments. Now onto the shock. Another post for another time!
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