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MTB Suspension fork dimensions


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#1 supavan

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Posted 18 August 2012 - 09:15

Hi everyone.

I'm trying to find out if there is any difference in the length between the Fox F32 RL 100 and 120. I'm talking crown to dropouts.

The reason I ask is that I've had to replace my bike's frame which came with a Fox F32 RL 100mm suspension fork. The new frame is a GT Sensor 1.0 which would normally be fitted with a the 120mm variant of that fork.

I'm pretty sure the fork would be 20mm longer to allow for the extra travel but I can't confirm this since I can't find any dimensions on these forks.

As much as don't want to mess up the frame's design angles by fitting the wrong length of fork I don't want to go spend thousands to get a 120mm if the actual external dimensions are similar.

Measured from where the crown meets the frame to where the centre of my 9mm QR skewer is, I get approximately 48cm.
If only my body was as fit as my mind seems to think it is.

#2 LourensD

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Posted 19 August 2012 - 11:11

Think these might help:

http://forums.mtbr.c...ary-470024.html
http://www.pinkbike....?threadid=78006

20 mm decrease from 120 to 100 in Axle to Crown length will only increase your bike's head angle by one degree. 0 degrees being completely parallel with the ground and 90 degrees bieng completely vertical. See: http://en.wikipedia....dimensions.svg.

I think the GT Sensor has a head angle of about 69.5 degrees, so putting a 100 mm fork on will increase it to about 70 degrees more or less. This is still normal XC-bike geometry

#3 supavan

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Posted 19 August 2012 - 11:29

+1 Lourens. That is exactly what I've been looking for. Thank you.
If only my body was as fit as my mind seems to think it is.

#4 droo

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Posted 20 August 2012 - 02:35

1 degree difference in head angle is a lot... do a bit of homework, you may find that you can extend the travel on your existing fork to 120mm by shifting some spacers around.