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  1. #1
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    XC Race - 120mm travel

    Why all of the 120mm travel lately? I see Niner, Pivot and a few others have switched to Fox 34 120mm travel forks. What XC courses really need more than 100m travel and at a 1lbs weight penalty?

    Is this more of an appeal to the masses move or is there more to it? Is the extra travel really worth the weight?

  2. #2
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    There are plenty of places where I'm glad to have the 120mm fork and dropper seatpost on my bike. Plus, I like the 68 degree HTA.

    Compared to an older geometry, 70-71 degree HTA bike, I'm significantly faster downhill. I can take corners faster, hit lines I couldn't before, etc. It all adds up, and that 1lb difference is overcome by that additional downhill performance.

    There are plenty of places where I'd prefer a 120/100mm or 120/120mm bike over a 100mm FS. Pisgah, Moab Rocks, etc.
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  3. #3
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    Quote Originally Posted by Le Duke View Post
    There are plenty of places where I'd prefer a 120/100mm or 120/120mm bike over a 100mm FS. Pisgah, Moab Rocks, etc.
    True - I should have mentioned I'm racing here in the midwest where its not really rocky. More roots that anything.

  4. #4
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    I agree with Le Duke that it is really dependent on region (as are most of the equipment choices debated on the forum).

    I recently moved from Utah to Michigan, and there certainly is a difference in what equipment is advantageous. I'm still running a 120mm F34, but that's because my Norco Revolver does double duty as an XC and Enduro race bike, and the terrain I ride in the areas close to Lake Superior is a little rougher than the other areas in the midwest. I did go down to 100mm rear travel because of the move. Without sustained, rough, downhills, I just don't need the extra travel in the rear.

    If I was living and racing in Wisconsin, I certainly wouldn't need (or want for that matter) more than 100mm of travel. I also would forego the dropper seatpost.
    Last edited by brentos; 11-21-2017 at 06:43 PM.

  5. #5
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    Quote Originally Posted by brentos View Post
    I agree with Le Duke that it is really dependent on region (as are most of the equipment choices debated on the forum).

    I recently moved from Utah to Michigan, and there certainly is a difference in what equipment is advantageous. I'm still running a 120mm F34, but that's because my Norco Revolver does double duty as an XC and Enduro race bike, and the terrain I ride in the areas close to Lake Superior is a little rougher than the other areas in the midwest. I did go down to 100mm travel because of the move. Without sustained, rough, downhills, I just don't need the extra travel in the rear.

    If I was living and racing in Wisconsin, I certainly wouldn't need (or want for that matter) more than 100mm of travel. I also would forego the dropper seatpost.

    Kind of my thoughts as well. I'm typically racing in Southern Michigan, Indiana, Illinois and Wisconsin and just don't see the need for the travel - unless it has better handling characteristics and really is worth the weight. Even on these world cup courses I can't see them going to 120mm travel.

  6. #6
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    Quote Originally Posted by PMCB View Post
    Kind of my thoughts as well. I'm typically racing in Southern Michigan, Indiana, Illinois and Wisconsin and just don't see the need for the travel - unless it has better handling characteristics and really is worth the weight. Even on these world cup courses I can't see them going to 120mm travel.
    I don't see them going to 120mm in the front or rear for XCO WC races either.

    That said, despite the increased technical level of the WC courses, they don't really compare some parts of the country in terms of sheer abuse doled out by terrain and length of the descents.

    If I was racing WORS races I'd be on a 29er HT again. Instead, I live at 7,200ft and my daily ride includes more rocks than I could count.

    If I'm out in Moab or Western CO, that extra 20mm is pretty useful, as I'm sure Brentos would agree.
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  7. #7
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    Quote Originally Posted by PMCB View Post
    Is the extra travel really worth the weight?
    Ohhhh yeah!!!

  8. #8
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    Quote Originally Posted by Rolanddmc View Post
    Ohhhh yeah!!!
    what type of racing do you do and what part of the country?

  9. #9
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    It is just the way of things, like how the old compact SUV has grown to midsize or larger, or how the old Specialized FSR has grown to 150mm of travel, despite being the "XC race bike" years ago. They slowly balloon the travel, make it slacker, etc., until they have to come out with a new bike for you to get all hyped about.
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  10. #10
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    Quote Originally Posted by PMCB View Post
    what type of racing do you do and what part of the country?

    Europe and XC ...

  11. #11
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    You could move the other direction with the new Anthem 29er.

    Frankly, there are so many bikes out there now, it's crazy. And the bikes are so capable - most riders I see have no idea what the bikes they ride are actually capable of. I ride things on my Anthem 29er that guys ride around or walk on their 140mm travel 27.5 trail/enduro rigs with comments like "my dropper isn't working, so I can't hit that steep roll down" - which is why I just hit it without a dropper and my XC high seat post. My point is, these bikes keep getting better and better. Oh, the 120mm Fox 34 weighs an extra pound? Still pedals better than a 5 year old 100mm bike and...weighs the same as the 5 year old bike. So maybe it is an XC bike? Maybe trail bikes have just gotten faster? I have very specific requirements for my next bike, and I wouldn't spend money on a bike with 120mm of travel, but I wouldn't throw it away if someone gave it to me either.

  12. #12
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    More travel pedals better and better as time goes by so maybe people are going for more in some cases because why not? I know someone will say "because of a pound". Ok but some larger riders have to write off ever being a weight weenying climb machine anyway so they go for other things.

  13. #13
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    Quote Originally Posted by Len Baird View Post
    More travel pedals better and better as time goes by...
    My 6 year old 150mm bike seems to pedal the same as it always has. How long do I have to wait before it starts pedaling better?
    Do the math.

  14. #14
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    Until you buy a newer bike that pedals better.

  15. #15
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    My new Niner RKT came with the Fox 34 120 (and only 90 out back!). Agreed; its a lot of fork and adds 1 pound to my bike but man....that thing is great and I don't know if I would go back to a 100 (or less) unless I was racing XC exclusively and competitively. I also chucked another pound on there for a dropper and have been enjoying it...taking some time and I don't use it a ton but it's nice to have it when I want it. Again, unless XC racing is the only thing you do/you are super-competitive in the pro/ex cat, these newer school light-duty trail bikes seem to be where it's at. I came off a HT with an 80mm fork...the new bike is just as fast and way more comfy with 3 extra pounds.
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  16. #16
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    Quote Originally Posted by TiGeo View Post
    My new Niner RKT came with the Fox 34 120 (and only 90 out back!). Agreed; its a lot of fork and adds 1 pound to my bike but man....that thing is great and I don't know if I would go back to a 100 (or less) unless I was racing XC exclusively and competitively. I also chucked another pound on there for a dropper and have been enjoying it...taking some time and I don't use it a ton but it's nice to have it when I want it. Again, unless XC racing is the only thing you do/you are super-competitive in the pro/ex cat, these newer school light-duty trail bikes seem to be where it's at. I came off a HT with an 80mm fork...the new bike is just as fast and way more comfy with 3 extra pounds.
    How are you liking the RKT? I just ordered one myself.
    Curious if you've ever ridden this bike with 100mm travel fork to do a direct comparison. No doubt the bike rides well with 120mm travel on the front and I hear that a lot. I do wonder though when directly compared if the difference is so significant or if it tends to get overstated. Either way I ordered it with a 100mm travel since I do primarily race but love knowing that this bike was designed for 100 and 120 so it really makes it a versatile bike. I can't wait to get on it

  17. #17
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    So far the RKT is great. Again, my basis is a 6 year old 22 pound HT with an 80mm fork so anything will be mind-blowing to me...ahahahaha. I think it would be fine with 100, it changes the HA about 1 deg so 71 with the 100 and 70 with the 120. It's a fast handling bike with the 120...my HT was about 71 so I am used to steeper/older-school HAs and don't have any issues with it.
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  18. #18
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    Is it truly a 1# difference between a 32 120 and 34 120?

    One forum member posted up some numbers in another thread that say only 100g?
    Fox 32 to 34- weight penalty is about what?

    Can anyone confirm or refute the 100g vs 400+g diference?
    Last edited by Noclutch; 12-10-2017 at 06:38 PM.

  19. #19
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    ^^^My 120mm Fox 34 weighs ~3.9 pounds. The interwebs show a 100m Fox 32 in the 2.9 range for some models. 1 pound. I wasn't comparing a 120mm 32 but it won't be that much more than the 100.
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  20. #20
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    Quote Originally Posted by TiGeo View Post
    ^^^My 120mm Fox 34 weighs ~3.9 pounds. The interwebs show a 100m Fox 32 in the 2.9 range for some models. 1 pound. I wasn't comparing a 120mm 32 but it won't be that much more than the 100.
    Not true, because the 110mm and above F32 chassis is not the same as the 100mm and below F32 chassis. The 100mm and less StepCast chassis is lighter still.

    There is little difference in weight between a 120mm F32 and an F34. The chassis for the F32 is beefed up for those models that are set to 110mm or greater.

    Below are weights of forks I've owned, cut to the same steerer length, w/ starnut and axle, 100x15mm . My numbers show a 47 gram increase going to the F34 from the F32.


    2015 130mm F32 Factory w/ axle = 1786 grams
    2017 120mm F34 Factory w/ axle = 1833 grams
    2016 130mm Pike RCT3 w/ axle = 1923 grams
    Last edited by brentos; 12-10-2017 at 06:12 PM.

  21. #21
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    Not completely related, but the two best upgrades I made to my Specialized Epic when I had it was to add a dropper post and throwing a 120mm Pike up front. Not XC at all, but it made it a better, all around bike for me. I didn't lose anything going up or on level trails, but definitely made an upgrade on the downs.

  22. #22
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    Quote Originally Posted by brentos View Post
    Not true, because the 110mm and above F32 chassis is not the same as the 100mm and below F32 chassis. The 100mm and less StepCast chassis is lighter still.

    There is little difference in weight between a 120mm F32 and an F34. The chassis for the F32 is beefed up for those models that are set to 110mm or greater.

    Below are weights of forks I've owned, cut to the same steerer length, w/ starnut and axle, 100x15mm . My numbers show a 47 gram increase going to the F34 from the F32.


    2015 130mm F32 Factory w/ axle = 1786 grams
    2017 120mm F34 Factory w/ axle = 1833 grams
    2016 130mm Pike RCT3 w/ axle = 1923 grams
    But you're not factoring in the changes in the chassis they make every year to get the weight down. Comparing 2 different forks from 2 years apart really doesn't help.

    This post shows there is a little over a 1/4 lb going from a 2017 Factory 34 to a 2017 Rhythm 34 Fork.
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  23. #23
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    Still don't know the difference between '17 or 18 Factory 32 x 120 and a 34 x 120.

    Seems The Fox site will give you every bit of information ( right down to the part number) except for the weight.
    For example a 910-20-385 weight with axle is X #. And a 910-20-415 weight with axle is Y # !!

    Their 32's fork builder and 34s builder is fun but still doesn't answer the question.
    Last edited by Noclutch; 12-13-2017 at 04:54 AM.

  24. #24
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    So an XC bike will descend great with a 120mm fork, versus a 100mm fork, I get that. But besides weight, what is the trade-off for climbing ability? The slacker head angle created by the 120mm fork seems like it would put your weight back on the bike and be a significant penalty on the climbs. Is there really a free lunch here? With the new geometry bikes, I can descend better on my 120mm fork AND climb the same or with nominal difference as compared to a 100mm fork?

  25. #25
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    100 - 120mm ... climbing ability unchanged....

  26. #26
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    My two cents, particularly of someone who regularly rides in MN, WI, and MI... 120mm is absolutely better than 100mm.

    I seriously doubt there is a 1 pound difference between the F32 100 and F34 120. Even if there was, the point of a race is to win, not have the lightest bike possible. If that were true everyone would be on rigid single speed bikes with rim brakes and small tires with the least amount of casing and tread.

    The compromise of having a slightly heavier suspension is off-set of by the increased performance. Improved stiffness leading to better predictability, tracking, traction will lead to faster times. AKA winning. There is really no downside, except maybe a hundred grams of weight.

    I love bench racing though.

  27. #27
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    I think the real weight difference is between the Fox 32 SC 100mm and the other Fox forks. The Sid World Cup, like the Fox 32 SC, is only 100mm. Both are nearly a pound lighter than their 120mm brethren. Iím really surprised Fox and Rockshox havenít developed their high end XC forks in 120mm.

    I would really like to demo a 120mm fork on my local trails in Utah, which are very steep and loose. Too slack of a setup and you are lifting the front wheel on those steep climbs, if you lean forward to compensate, your rear wheel spins out losing traction. Now youíre walking your bike. Going 120mm for most people might be a no-brainer, where the climbs arenít steep but still packed with rocks and roots, the extra travel would be welcome and you wouldnít really feel a difference on the moderate climbs. But on the steep stuff Iím skeptical that there are no trade offs. There has to be.

    Some people say that larger framed bikes should have more travel suspension in the fork, that an XL frame should have 120mm travel minimum, just to scale the frame proportions to a larger size. Intuitively this makes sense, if a frame has larger dimensions it seems that a fork should also. This is similar to the argument that smaller frame sizes should have smaller wheels, and vice versa. But itís probably complicated, as some frame parts grow in larger sizes but others like the rear triangle donít. What say ye, smart fellows?

  28. #28
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    Quote Originally Posted by The Boz View Post
    I think the real weight difference is between the Fox 32 SC 100mm and the other Fox forks. The Sid World Cup, like the Fox 32 SC, is only 100mm. Both are nearly a pound lighter than their 120mm brethren. Iím really surprised Fox and Rockshox havenít developed their high end XC forks in 120mm.

    I would really like to demo a 120mm fork on my local trails in Utah, which are very steep and loose. Too slack of a setup and you are lifting the front wheel on those steep climbs, if you lean forward to compensate, your rear wheel spins out losing traction. Now youíre walking your bike. Going 120mm for most people might be a no-brainer, where the climbs arenít steep but still packed with rocks and roots, the extra travel would be welcome and you wouldnít really feel a difference on the moderate climbs. But on the steep stuff Iím skeptical that there are no trade offs. There has to be.

    Some people say that larger framed bikes should have more travel suspension in the fork, that an XL frame should have 120mm travel minimum, just to scale the frame proportions to a larger size. Intuitively this makes sense, if a frame has larger dimensions it seems that a fork should also. This is similar to the argument that smaller frame sizes should have smaller wheels, and vice versa. But itís probably complicated, as some frame parts grow in larger sizes but others like the rear triangle donít. What say ye, smart fellows?
    Are larger riders hitting larger rocks or roots?

    If not, you should use the same amount of travel as a smaller rider when hitting the same rock, provided properly set up and tuned suspension.

    If the extra 20mm of stack height is a problem, get a new stem. A Syntace FlatForce will solve most of your problems.

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  29. #29
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    Quote Originally Posted by Le Duke View Post
    Are larger riders hitting larger rocks or roots?

    If not, you should use the same percentage of travel as a smaller rider when hitting the same rock, provided properly set up and tuned suspension.

    If the extra 20mm of stack height is a problem, get a new stem. A Syntace FlatForce will solve most of your problems.

    Sent from my XT1585 using Tapatalk
    Fixed it for you, as you're only right if the larger and smaller riders had the same amount of total travel.

    The difference in ride experience between 100 and 120mm travel is the amount of feedback transmitted to the rider. The 120mm fork uses 20% more travel for any given impact than a 100mm fork, all else equal. If you use 25mm of travel on a 2" tall root, compressing a 100mm fork through half of its travel, the 120mm fork will use 30mm of travel, also compressing through half its travel (assuming you were sagged 25%). That's if you tune both to use full travel on the biggest obstacle you encounter, or set sag to the same % and happen to have the same progressivity in the spring.

    The downsides: there's 20% more change to the bike's dynamic geo, there's 20% more squishiness to bob and dive, and there's more fork flex. All for taking a bit more edge off of the bumps. If you're converting a 100mm fork to 120mm (leaving the rear the same), you have a slacker STA, taller BB, shorter reach, longer horizontal CS length, increased rearward weight bias, less standover, taller stack, etc. to deal with too.

    There exists size specific tubesets, which tunes stiffness for larger/heavier riders. Rather than increase travel, you should seek to increase fork chassis stiffness. The Fox 32 SC is a flexy fork; think RockShox Quadra vs RockShox Judy back in the 90s level of difference. It has less torsional rigidity than a RS1 and FAR FAR less fore/aft rigidity. Early 29er adopters were begging for stiffer forks than the heavier non-SC 32, for the kind of riding that modern XC racers now ride. They were happy for the 34 then, despite it weighing over 4 lbs. I guess in XC racing, people can get over whatever they're giving up, as long as it shaves grams and doesn't break (and trust that the stiffness-to-weight ratio is no worse). Flexiness probably is seen as compliance... xD
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  30. #30
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    Thought I would jump in on this thread. I also have a RKT 9 RDO and mine came with a Fox Factory 32 with FIT4 damper (not the Step-Cast which was released after). Riding here in the Mid-West (Ohio mainly) it has performed really well and made the RKT 9 RDO a super-snappy, but comfortable XC bike. On longer rides, like Mohican, I do notice a bit more arm fatigued as compared to when I was riding an older Jet 9 RDO with a 120mm RS-1. However the Fox Factory 32 is much, much better than the prior gen 100mm SID I have on my HT Air 9 RDO.

    That all being said, I'm now very interested in the new Fox 34 SC 120 mm. It looks to be about .5 - .6 pounds heavier than my current fork, but I'll take the minimal weight increase for the added capability. I do plan to take the RKT out to Colorado in July for some XC riding in Snowmass/Aspen and Vail/Minturn/Avon regions. In past years, I took an older RIP 9 RDO with a 140 Pike, which was really nice on descent but a little sluggish on all the climbs.

    It looks like the Fox 34 SC 120mm is going to ship around the end of May. I'll try and post a follow up once I get the new fork installed and do a comparison on the same trails that I rode the 100mm on. Assuming I'm happy, I'll likely move the Fox 32 100mm over to my Air 9 RDO to replace the SID. The only issue there is that the front wheel on the Air 9 is currently not Boost.

  31. #31
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    My 100mm 32 SC is great for XC races and I loved it in the Whiskey Off-Road last weekend (just like the year before).

    At Sedona though, you can get in over your head. It was ok, but it really sketched out some of the descents down Highline and the Hogs. There was one or two that I walked rather than risk and I would have liked to have a 120mm 34. On the other hand, a buddy (with a 34) put on beefier tires after the race for Sedona, which seemed like a great idea considering my skinny race tires. I would have much rather ridden my bigger AM bike (which was at home) in Sedona.
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