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Discussion Starter · #1 ·
I found a nice handy chart for axle to crown measurement for 2000+ Rock Shox forks. I can't find anything for Fox shocks. In particular, I was looking for axle to crown measurements for all of Fox's 100 mm travel forks (26" wheels).

Anybody?
 

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Discussion Starter · #3 · (Edited)
You are correct sir! :)

Thank-you. Thank-you very much.... hey, where'd you get that handy dandy document ;)

Now if only I knew whether or not Rock Shox axle to crown measurements were to the top of the stanction at the top of the crown, or to the race. Interestingly, Fox show both. That's handy. In fact, they even show the compressed height in parentheses...how nice. Of course, if you just take the original measurement and subtract the travel, well, it's the same number. Still, I'd rather have more info than less :)

I wonder about the different features of forks, and if they change anything. It looks like the info is as is.

Now I just need specs regarding weights and features.

The reason I'm asking is because I am a frame geometry geek and I'm comparing bike geometry between manufactures. It's not clear whether manufacturers are re-quoting the same frame geometry specs with different forks, even though some forks differ from others in their axle-to-crown by nearly 1 cm in some cases. Anyhow.... now I see that the Fox F100 is equal to the Rock Shox Recon XC....which is about all I needed to know for now :cool:

Got those Fox axle to crown specs for the 2007 and 2009 forks too?
 

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The other thing to keep in mind is that most bike manufacturers are quoting whole numbers for geometry, and sometimes to 0.5 degree accuracy, but for production bikes they're still quoting a rounded number as everything affects that dimension like running different size tires front and back, the variables in negative travel on the fork, fork brand A2C, fork A2C tolerance (+/- 5.0 mm on most brands), whether the marketing department is paying attention to the design/fabrication department, etc..

There's no substitute for a test ride to know if the bike's geometry feels right.
 

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Discussion Starter · #6 ·
rockyuphill said:
The other thing to keep in mind is that most bike manufacturers are quoting whole numbers for geometry, and sometimes to 0.5 degree accuracy, but for production bikes they're still quoting a rounded number as everything affects that dimension like running different size tires front and back, the variables in negative travel on the fork, fork brand A2C, fork A2C tolerance (+/- 5.0 mm on most brands), whether the marketing department is paying attention to the design/fabrication department, etc..

There's no substitute for a test ride to know if the bike's geometry feels right.
Exactly. Some guys are pretty good with the specs. Alex at Brodie told me exactly how they derive there specs, even giving the stack heights for the headset's and giving me specific insight into the models I'm looking at. The Rocky Mountain are a safe bet that they are fairly steep because they quote 71 almost across the board, and show some differences too.

thanks for the links crisillo, I think I have the right Rock Shox axle-to-crown pdf, but I'll check your links again.
 

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Discussion Starter · #7 · (Edited)
A few more questions about bike geometry and fork axle-to-crown heights.

1) Does anybody know where the Rock Shox axle-to-crown measurement are from at the axle? Are they from the centre of the axle or from the top of the axle? The Fox diagram is explicit in showing that it is from the axle centre. It's a difference of only a few mm, but I'm curious anyhow... :p

2) Fox states that the measurements are +/- 5.0 mm. Any idea if Rock Shox specs are using the same tolerances?

3) Fox shows an F90 "fork" on their axle-to-crown spec sheet. Can you make an F100 into an F90? I think you can lower the fork to 80 mm, but can you go to 90 mm?

thanks,

:)
 

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Discussion Starter · #9 ·
Cool. Which Rock Shox is that a pic of? Where'd you get that? In the Rock Shox chart I can't even find a fork with 473 mm for 100 mm travel and 453 mm for 80 mm travel. The Reba is the closest with 473 for 100 and 458 for 85.

Actually, I was hoping RS went to the top of the axle, which would mean they are actually another 2 mm or so higher than they state, compared to the fox forks specs. I am buying a bike and swapping the Rock Shox Recon XC for a 2009 Fox 32 F100 RLC. Was hoping I was scoring even more drop in the axle-to-crown height. The 0.1 mm difference is less than nothing, especially considering the +/- 5.0 mm thing. I see RS states +/- 5 mm in that pic too, just you said a few posts back (doh!).

Yes, it's me, the geometry techno-weenie. On a search for steeper head angles. And yes, I know I'm insane :p ....but I've had too many slack head angle experiences in my life. First when I stuck a Mag 21 on a cycletech wildthing in the early 90's and then again when I put a longer fork on my Brodie Libido, and now when I bought a new bike. Never imagined a xc fs bike would have a slack head angle. Oh well. I'm sure many like it. I like steeper (70 to 72). To each their own :cool:
 

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morkys said:
Cool. Which Rock Shox is that a pic of? Where'd you get that? In the Rock Shox chart I can't even find a fork with 473 mm for 100 mm travel and 453 mm for 80 mm travel. The Reba is the closest with 473 for 100 and 458 for 85.
those are the 08 SID specs...just look for the fork specs
 
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