Fork Travel Dilemma

I'm currently building a 2012 "warrantee replacement" Niner EMD with a Fox 32 F29 RL Fork. But before I put it together this week I've been asking myself whether I really need 100mm of travel or should I have the fork adjusted to 80mm to better suit my build. What's driving this is I have been riding my Scalpel 29 since last Aug with 80mm of travel up front and have yet to have an issue. I know the shorter travel will help on the climbs (usually where I need the most help) and the longer travel will benefit on the downs. Once this bike is together I don't really wanna go back and change it...thought's???

Mark, I would consider the head tube angle and the change in trail (ht axis vs axle location) as a primary concern. Shorter fork = steeper head angle and reduced trail, which makes the bike more twitchy and easier to flip over the bars. If you were an out-of-the-saddle human gazelle, that could be a good thing. With your style, I'd stay long- both on the Scalpel and on the Niner. Body size and body weight have nothing to do with it, it is about how the bike handles. Adding 20mm to my Mach 4 gave me a -1 degree change in head tube angle (from the increase in height up front and the fulcrum at the rear axle), and the bike tracks much better. It also soaks up square edged bumps without pitching me over the bars now.

All you mtbr.com'ers will love this response: RIGID
Mark, what happened to the EMD? ate too much dust?

BigWheels wrote:All you mtbr.com'ers will love this response: RIGID
Mark, what happened to the EMD? ate too much dust?

Frame cracked behind BB on the drive side. I'm sure it had to do with Trainer duty last winter. I sent it in and they replaced it with a 2012, no questions asked. The only problem, which I don't feel is a problem is the tapered headtube...so I bought another fork and head set...

@ John- I checked and there is 1 degree difference in the headtube angle:

Headtube Angle
80mm= 72
100mm= 71

Wheelbase
80mm= 1107mm
100mm= 1114mm

I will forego advice invole the eighteen inches of travel i get out of my fork...
Go with 100.
You should be locking out on the climbs anyway ( especially with a fox which usually have super-solid and very adjustable lockouts).
Since you sit and spin anyway, just work on shifting your weight if you start to get front wheel lift ob climbs.

72 degrees is steep, brah! Def-o go for the 100. 80mm forks are for smooth race courses and Spooky's bikes. Hey Matt, you hear that? The 1990's called, and they want their forks back!

Both of my bikes have 100mm. In the 90s we rode 72mm travel forks.

That's right, you were talking about selling your pushed 80mm fork- I take it back!

Some guy in Stuttgart bought it. If you go to the European Military races, you will probably see it.

The OTB factor is something that didn't come to mind when pondering this and going OTB is one of my least favorite things to do on a MTB even though it is a 29er. So, y'all have convinced me that making changes to this fork is not a good idea...thx for the input!!! Now, if I could only get the 1.5" headset race in my PO box I'd be happy...

OTB on a 29er is three inches farther to fall. Yet another reason Steve, John, and I are doing it right.

spookyload wrote:OTB on a 29er is three inches farther to fall. Yet another reason Steve, John, and I are doing it right.

Actually it's only 1.5 inches... your fall is based on the fork height which would reflect only half of the three inch size increase

Besides, 29er riders don't fall... we suddenly disomount... someitmes upside-down

Actually, Matt is right. It is 3 inches, 1.5 below the axle and 1.5 to the fork crown. Low center of gravity, and a shorter fall. If Spooks had been rolling on a 29er, they probably would have had to reattach his jaw before they wired it shut. I'd say that riding 6undzwanzig saved him from really getting messed up!

eurotrash wrote:Actually, Matt is right. It is 3 inches, 1.5 below the axle and 1.5 to the fork crown. Low center of gravity, and a shorter fall. If Spooks had been rolling on a 29er, they probably would have had to reattach his jaw before they wired it shut. I'd say that riding 6undzwanzig saved him from really getting messed up!

Actually, properly designed 29er frames are not just bigger 26er frames. Well designed 29er frames are made to accomodate the wheel size, while still keeping the center of gravity, seat height etc. all the same as would be on a 26er... So if it matt had been on a well-made 29er, the fall would have been the same.

eurotrash wrote:Actually, Matt is right. It is 3 inches, 1.5 below the axle and 1.5 to the fork crown. Low center of gravity, and a shorter fall. If Spooks had been rolling on a 29er, they probably would have had to reattach his jaw before they wired it shut. I'd say that riding 6undzwanzig saved him from really getting messed up!

Never really went OTB on a 29er because the rear wheel can never crest the arch. I usually just get to the split second pause and fall to the side. If Matt was riding a 29er the root wouldn't have been an issue. It would've just been another bump in the Trail with the better traction and all...