Fork axel to crown lengths and offset comprehensive list

[andrello]

I cannot seem to find a good list of dimensions of popular integrated 700c forks. I remember seeing a post but cannot find it. I'll start to compile one here:

Alpha Q GS10
371mm length
41,44mm offset

Bontrager Race XXX Lite
??
40,45mm offset

Cannondale Supersix
??
45mm offset

Cervelo Wolf
??
??

Look HSC 5SL
368mm length
43mm offset

Oval Concepts JetStream R900
367.6mm length
44mm offset

Reynolds Ouzo Pro
372mm length
43mm offset

Scott Addict
??
??

Scott CR1
??
??

Specialized S-Works FACT
??
43,45mm offset

THM-Carbones Scapula
371mm
44mm offset

[BdaGhisallo]

The fork crown to axle length for Reynolds forks, both the Ouzo Pro and the new UL, is actually 372mm.

[andrello]

The fork crown to axle length for Reynolds forks, both the Ouzo Pro and the new UL, is actually 372mm.

Their website is incorrect?
http://www.reynoldscomposites.com/index ... ks_ouzopro

[BdaGhisallo]

Standard Crown Version
Weight: 380 grams
Steerer Tube
Diameter: 1” and 1 1/8”
Length: 1” = 285mm, 1 1/8” = 350mm


The 350mm distance is the length of the steerer tube, the tube that the stem attaches to. The fork crown to axle length is the length of the fork blades, which factors into the geometry of the bike and how it is designed, and that is 372mm.

[andrello]

Sorry, my vision is blurring. Thanks

[lancejohnson]

Don't forget the edge forks at 368. Available in 40, 43 and 50 right now, a 45 should be coming...

I also think Storck forks are something like 386mm and come in a 38mm rake (the THM made ones).

The CR-DO measure for TT/AlphaQ is consistent for the GS 10 & 30, and CS 10 & 20. The GS20 is 369, and the X2 is 374. TS forks are 372.

[teterider]

The Race XXX Lite (former AL steerer version at least) was 370mm

[cyclenutnz]

have a look here http://picasaweb.google.com/cyclenutnz/ ... 2368390242

any additions to the info on that sheet are welcomed.

[VT to CA]

Scott CR1 is 45mm rake and 380 crown to axle... I believe those measurements are the same for the Addict as well.

[KB]

have a look here http://picasaweb.google.com/cyclenutnz/ ... 2368390242

any additions to the info on that sheet are welcomed.

Well done mate. A list like this has been needed for some time.

[VT to CA]

have a look here http://picasaweb.google.com/cyclenutnz/ ... 2368390242

any additions to the info on that sheet are welcomed.

Well done mate. A list like this has been needed for some time.

Am I missing something? That list sucks... only a few companies and the weight data is so inaccurate you'd have to tear it down and start over for pretty much everything on there... a Look HSC-5 SL at 330g? Weird.

I think we should have a stickied list here, or even better, maybe a separate "fork specs" column in Listings... keep the weight column seperate, because weight can vary from individual fork to fork, and the beauty of multiple posts on the listings is that you get an idea for the "average" actual weight of something. "Fork Specs", since they are uniform, would just be one post per fork (if the fork comes in several rakes, then listings for each rake)... this would be an invaluable tool...

[cyclenutnz]

a Look HSC-5 SL at 330g? Weird.

that's for a current fork off a new 585 uncut. weighed an older one at 297 uncut.

In any case, I'm not concerned about weight, the dimensions are more important. The list is something I started collating recently and over time will be looking at improving it.

[JN2Wheels]

Resurrecting a very promising thread...

In the hunt for a new frameset, and frustrated by crap geometry information from the big name manufacturers, I've spent a lot of time pouring over stack vs. reach charts here, viewtopic.php?f=3&t=62975 , by djconnel. Some of the reach figures he has calculated are a little too imprecise for my needs, such as calculated reach assuming the frame size figure is where the virtual top tube is measured. Stack, however, can be more accurately calculated given BB drop, Headtube length, Headtube angle, and fork length/offset. All of these, except fork length, are given even in the crappiest of geometries, (Giant, Scott, Specialized). So, a more complete list of fork lengths could be incredibly helpful both in analyzing stock geometry and in calculating changes to that geometry when upgrading to an aftermarket fork.

So, can this thread be revived?? Specifically (for my needs), anyone have Specialized SL3/SL2, Giant TCR SL, BH G5, or Velocite Bora fork lengths, axle to top of fork crown where the fork crown race rests?

[djconnel]

Yes -- I agree that's a big problem (the dependence of reach on how the seat tube is defined). Life is easier with parallel top tubes....

[DaveS]

An even bigger problem is overlooking the fact that you can only compare reach values at ONE stack height. If the stack heights are different, then add 3mm to the reach difference for very 10mm of stack height difference. An example is the Cervelo R3 in the 51 and 54cm sizes. The reach difference is NOT 10mm. It should be 16mm and this is born out with a comprison of the TT lengths with the same STA. There's 1mm of roundoff eror somewhere.

Most forks fall in a range from 367 to 374mm, so the error in reach is not that large. Even if the difference was 10mm, a proper reach calculation would only be off by 3mm. That's not much.

Another problem is varying HTAs. Even the reach concept does not totally account for that. I've gone to using the free bike cad to better analyze reach. It really is accurate, once you learn how to use it.

http://www.bikeforest.com/CAD/bcad.html