Page 1 of 2 1 2 LastLast
Results 1 to 25 of 45

Thread: Jumping a 29er

  1. #1
    mtbr member
    Reputation:
    Join Date
    Jan 2012
    Posts
    157

    Jumping a 29er

    Its been a few years since ive rode an actual jump park. Fortunately there are still quit a few "hits" on the trails i frequent. Ive been on a 29er that supplements my suspension 26er for about 4 years now, the most recent build being a smaller framed more aggressive 29er. I think ive concluded that the larger wheels really make timing landings difficult. Im so used to having that extra time between between landings that the bigger wheels just makes for much more unpredictable landings. A lot of it also depends on what the landing itself is like. Also the fact that i sit so much higher on my 29er than my 26er also makes jumping more awkward in general. For all the areas where 29ers excel i feel like this is a major downside to riding 29ers aggressively. It may just be that my brain is wired to landing a smaller wheel, after all ive been riding 26 inch mtbs for over 20 years, 29ers for about 4. Anyone else share these sentiments?

  2. #2
    transmitter~receiver
    Reputation: meltingfeather's Avatar
    Join Date
    May 2007
    Posts
    7,894
    why do you sit so much higher on your 29er?

    sounds like you may have a fit issue.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  3. #3
    mtbr member
    Reputation:
    Join Date
    Jan 2012
    Posts
    157
    So youre saying 29ers dont ride higher than 26ers? Maybe its just an illusion but i feel like im sitting way higher on my hardtail 29er than i do on my FS 26er.

  4. #4
    transmitter~receiver
    Reputation: meltingfeather's Avatar
    Join Date
    May 2007
    Posts
    7,894
    Quote Originally Posted by munstro View Post
    So youre saying 29ers dont ride higher than 26ers?
    that's right.
    Quote Originally Posted by munstro View Post
    Maybe its just an illusion but i feel like im sitting way higher on my hardtail 29er than i do on my FS 26er.
    compare bottom bracket heights.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  5. #5
    mtbr member
    Reputation:
    Join Date
    Jan 2012
    Posts
    157
    are you saying a 24 inch bmx bike doesnt sit higher than a 20 inch bmx bike? Or that an old kx 80 big wheel doesnt sit higher than a standard old kx80?

  6. #6
    Professional Crastinator
    Reputation: Fleas's Avatar
    Join Date
    Jan 2006
    Posts
    2,477
    Quote Originally Posted by meltingfeather View Post
    that's right.

    compare bottom bracket heights.
    Quote Originally Posted by munstro View Post
    are you saying a 24 inch bmx bike doesnt sit higher than a 20 inch bmx bike? Or that an old kx 80 big wheel doesnt sit higher than a standard old kx80?
    I believe all he is saying is "compare bottom bracket heights".

    26er to 29er, the only thing technically higher should be the axles. Sometimes the bars come out a little higher, but that may have more to do with fork length. That's not to say that there aren't some 26ers or 29ers that vary from that comparison. Most peoples' comments are usually that they feel more "in" a 29er, as opposed to on top of it.

    -F
    It's never easier - you just go faster.

  7. #7
    mtbr member
    Reputation: gsoroos's Avatar
    Join Date
    Jan 2012
    Posts
    125
    Wether you sit more upright on a bike or not has less to do with wheelsize, and more to do with setup and fit.

    Throwing BMX bikes into the mix is just more confusing. As I remember, if you have a 20 and a 24 wheeled BMX bike, you want the bar height from BB height, seat height, and seat to bar measurement pretty close. So if they are set up right, it doesn't matter which bike you're on, they 'feel' the same.

    Back to 26 vs 29 mountain bikes, it does sound like you need a proper bike fit. Possibly one or the other bike was fitting wrong and you need to adjust the bike, or get used to the fit.

    Not saying that wheelsize doesn't make a difference when doing jumps (bigger wheels have more weight etc). I think when jumping your center of gravity is "where" you are taking off and landing from. So like meltingfeather said check the BB height. if they are different, that could be what's throwing you off.

  8. #8
    mtbr member
    Reputation:
    Join Date
    Jan 2012
    Posts
    157
    comparing axle heights would make a lot more sense to me...bottom bracket height has very little to do with how tall a bike is when you look at things like seat tube lengths. Not to mention that the bottom bracket height changes on an fs bike the minute you sit on it depending on how much sag you are running. Anyhow im stuck at home playing daddy day care and thought i would seek some advice on jumping 29ers but rather it turned into the "op doesnt know how to buy a proper fitting bike...."

  9. #9
    mtbr member
    Reputation: gsoroos's Avatar
    Join Date
    Jan 2012
    Posts
    125
    Quote Originally Posted by munstro View Post
    "op doesnt know how to buy a proper fitting bike...."
    I'm sorry if I made you feel that way. That wasn't my intent or not my assumption, just a thought as to why you would be sitting more upright on a 29 vs 26. if everything else is equal, wheelsize shouldn't affect your position on a bike. Then again if the bikes are set up different, they are going to feel different. Again, sorry.

  10. #10
    Red Rock Roller
    Reputation:
    Join Date
    Apr 2012
    Posts
    348
    Munstro,

    I have the same feeling as you when the 29er lands. If you look at things from our perspective there is a 1 1/2" difference between the 26 and 29 from axle to ground and muscle memory will notice this and give you an unusual and wierd feeling when launching and landing. I have also noticed that when you launch and your ballence isn't right it is harder to correct while in the air due to the added rotational mass and increased force.

  11. #11
    mtbr member
    Reputation:
    Join Date
    May 2005
    Posts
    1,750
    I think bike geometry is more important than wheel size. You are also talking about comparing a full suspension bike to a hard tail. Maybe your 29er doesn't have the right geometry for you... Anyway, I took my SIR9 to Northstar once. There's a trail there that's like a motocross track tilted down the mountain - Livewire. I was able to clear the table tops and doubles on it fairly easily. Later on I built a downhill oriented Santa Cruz Bullit and it wasn't any better at jumping. In fact, the SIR9 was much better in the air because it was so much lighter. In my opinion, a 29ers are great for jumping as long as you aren't planning on doing fancy tricks like tailwhips or backflips.

  12. #12
    mtbr member
    Reputation:
    Join Date
    Jan 2012
    Posts
    157
    No need to apologize. Really I was hoping for some advice such as you need to pull up a little more to get some extra lift, try to overshoot your landings a hair, try to come down more with the front end, etc. Instead i got some jargon about bottom bracket heights, etc. Man i'm fortunate to be able to ride two different bikes fairly frequently! It really just feels like the tires land just a little sooner than expected, it probably is a muscle memory thing. Was curious as to whether this is an actual obstacle the mfgrs need to overcome or whether im the only one experiencing this phenom. FWIW i am riding a Kona Honzo which is a more aggressive geo 29er. I enjoy it just as much as my full squish it just seems like at times my timing on my landings and often the takeoffs is pretty off.

  13. #13
    mtbr member
    Reputation:
    Join Date
    Jan 2012
    Posts
    157
    Quote Originally Posted by Thor29 View Post
    I think bike geometry is more important than wheel size. You are also talking about comparing a full suspension bike to a hard tail. Maybe your 29er doesn't have the right geometry for you... Anyway, I took my SIR9 to Northstar once. There's a trail there that's like a motocross track tilted down the mountain - Livewire. I was able to clear the table tops and doubles on it fairly easily. Later on I built a downhill oriented Santa Cruz Bullit and it wasn't any better at jumping. In fact, the SIR9 was much better in the air because it was so much lighter. In my opinion, a 29ers are great for jumping as long as you aren't planning on doing fancy tricks like tailwhips or backflips.
    Thats pretty impressive. The bullit was always a killer jumping bike in my mind....

  14. #14
    transmitter~receiver
    Reputation: meltingfeather's Avatar
    Join Date
    May 2007
    Posts
    7,894
    Quote Originally Posted by munstro View Post
    are you saying a 24 inch bmx bike doesnt sit higher than a 20 inch bmx bike? Or that an old kx 80 big wheel doesnt sit higher than a standard old kx80?
    did i say that?
    no


    i said compare BB heights on your two mountain bikes and, assuming your fit is the same, that will give you your relative height off the ground on each bike.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  15. #15
    transmitter~receiver
    Reputation: meltingfeather's Avatar
    Join Date
    May 2007
    Posts
    7,894
    Quote Originally Posted by munstro View Post
    comparing axle heights would make a lot more sense to me...
    it might help reinforce your preconception, but that doesn't turn out to be reality.
    look at BB drop (the distance from the line connecting the axles downward to the BB).
    you will see that the number is significantly larger on a 29er, meaning that the 29er BB is lower relative to the axles than a 26" bike, which kind of blows a hole in comparing axle height to get an idea of how high the rider is off the ground.

    thinking about changing geo on a FS bike is going to send you spinning in circles. not only does BB height change, but just about every other geo number on the bike, depending on how much the suspension is activated and what the distribution is front-to-back.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  16. #16
    mtbr member
    Reputation: jncarpenter's Avatar
    Join Date
    Dec 2003
    Posts
    6,758
    I have always found the 29er to be more stable in the air...however, that also means it is a bit tougher to "whip" or "throw around" mid-flight.


  17. #17
    mtbr member
    Reputation:
    Join Date
    Aug 2010
    Posts
    122
    My 26 and 29 are both the same saddle height. My XTC's chainstays are even a couple mm shorter than my 26.

  18. #18
    mtbr member
    Reputation:
    Join Date
    Jan 2012
    Posts
    157
    Quote Originally Posted by meltingfeather View Post
    it might help reinforce your preconception, but that doesn't turn out to be reality.
    look at BB drop (the distance from the line connecting the axles downward to the BB).
    you will see that the number is significantly larger on a 29er, meaning that the 29er BB is lower relative to the axles than a 26" bike, which kind of blows a hole in comparing axle height to get an idea of how high the rider is off the ground.

    thinking about changing geo on a FS bike is going to send you spinning in circles. not only does BB height change, but just about every other geo number on the bike, depending on how much the suspension is activated and what the distribution is front-to-back.
    Ok so youre still going after me on the 29ers sit higher than 26ers point. I get it. You think they dont, i happen to generally think they do. When was the last time you jumped your 29er? Do you have any advice regarding the original question?

  19. #19
    Bnerd
    Reputation: RideEverything's Avatar
    Join Date
    Jul 2008
    Posts
    521

    Skill!

    This is going to be long and make me sound like a dick. So be it!
    Try to just take it as an opinion with some merit.

    What I notice about all of the "Jumping" threads is no one actually knows what the OP's riding skill level is. A video would make a world of difference when asking for advice.

    Trails are always named saying that they can 'jump' the hits on said trail. However, riding regularly in the Whistler Bike Park I see numerous people riding Crank It Up, Dirt Merchant, A-Line then claiming that they "rode" these trails jumps and all. When in actual reality they were popping a couple inches into the air and landing on the table of the jump.
    Then there are the people who do actually make it to the transition landing but with absolutely heinous bike handling and lack of skill. Those are the people that make me fear for my life when I'm riding those trails!

    Now onto what the OP of this thread is talking about.
    Wheel size may make the bike feel different when jumping but I think the biggest thing that people don't look at is their own skill set and confidence.
    I coach mountain biking to kids and when it comes to jumping the biggest excuse I hear is that my own bike has full suspension making it easier for me to jump compared to their smaller sized hardtail bike. I show them on the small practice jump we have at our camp that I can jump their bikes (Picture a 6'6" giant riding a 16" - 20" mtb!). Thus showing them that it is skill that helps them jump.

    What I'm saying is that I have the confidence and skill to jump any wheel size bike.
    To take your example munstro that would mean when I'm demonstrating jumping on a 20" wheeled bike I should have amazing hang time because of the smaller wheels! But no that is not the case! I have a feel for the size of the bike that is under me and I am very aware of when the wheels are going to touch down. So, regardless of wheel size, it is the skill that I possess that helps me jump and then land where I need to.

    ---------

    Here's my starting point tip:
    Learn how to level lift your bike on flat terrain. (A level lift is like a bunny hop/j-hop but both wheels leave the ground at the same time.) The level lift is the basis for most jumping. And learn how to level lift without using clipless pedals! I've seen some ridiculously bad jumping skills due to a dependence on clipless pedals! Learn without then go back to them.
    The timing of the preload is what needs to be worked on for making the pop happen at the lip of the jump. That pop comes from preloading the bike exactly like doing a level lift. Most of the preload goes into the pedals rather than the bars. And don't yank up on the bars when coming off the lip of the jump! Try to guide them up.

    Alright, I think my ranting is done.
    I'm sorry munstro that this was the jumping thread that I had to unload on!
    Oh, and I just bought a Kona Honzo as well. I have yet to hit a proper jump with it but I have been airing it off of little trail features. And I can't say that it feels like the wheels are meeting the ground any faster in the landings than my 26" bike!


    EDIT------
    The above technique is a very brief description on the starting point for jumping. There are many finer details that I have not posted just in relation to level lifting your bike on flat ground. Please use your brain when riding your bike!
    Last edited by RideEverything; 04-24-2012 at 10:54 AM. Reason: Saving people from themselves!

  20. #20
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    68
    Quote Originally Posted by RideEverything View Post

    Here's my starting point tip:
    Learn how to level lift your bike on flat terrain. (A level lift is like a bunny hop/j-hop but both wheels leave the ground at the same time.) The level lift is the basis for most jumping. And learn how to level lift without using clipless pedals! I've seen some ridiculously bad jumping skills due to a dependence on clipless pedals! Learn without then go back to them.
    The timing of the preload is what needs to be worked on for making the pop happen at the lip of the jump. That pop comes from preloading the bike exactly like doing a level lift. Most of the preload goes into the pedals rather than the bars. And don't yank up on the bars when coming off the lip of the jump! Try to guide them up.
    wow, learn something new everyday! thanks for the Tip!!

  21. #21
    transmitter~receiver
    Reputation: meltingfeather's Avatar
    Join Date
    May 2007
    Posts
    7,894
    Quote Originally Posted by munstro View Post
    Ok so youre still going after me on the 29ers sit higher than 26ers point. I get it. You think they dont, i happen to generally think they do. When was the last time you jumped your 29er? Do you have any advice regarding the original question?
    I'm not "going after you." I responded to what you said. Lighten up, dood. It sounded from what you said like you might have a fit problem.
    If you think 29er axle heights mean they ride higher, you're just ignoring reality. Same as if you think your bike is what is messing up your jumping technique.
    I jumped my 29er this past weekend... like I do almost every weekend... at the pump track at a local park with miles of MTB trails.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  22. #22
    Ambi-Turner
    Reputation:
    Join Date
    May 2010
    Posts
    117
    This is a great topic. It seems I need more speed on my 29er and a bigger hit to get the same air. It could be because of the wheels natural tendency to roll over the terrain. The bike also seems more sluggish in the air. I'd really like to try some real bike park features to see what my 9er can do, but it seems that's the realm of 26er bikes. Not many jumps on my trails.

  23. #23
    mtbr member
    Reputation:
    Join Date
    Jan 2012
    Posts
    157
    Quote Originally Posted by meltingfeather View Post
    it might help reinforce your preconception, but that doesn't turn out to be reality.
    look at BB drop (the distance from the line connecting the axles downward to the BB).
    you will see that the number is significantly larger on a 29er, meaning that the 29er BB is lower relative to the axles than a 26" bike, which kind of blows a hole in comparing axle height to get an idea of how high the rider is off the ground.

    thinking about changing geo on a FS bike is going to send you spinning in circles. not only does BB height change, but just about every other geo number on the bike, depending on how much the suspension is activated and what the distribution is front-to-back.
    Sounds to me like what your saying is that 29ers have lower bottom brackets than 26ers, which really has nothing to do with the question of applying different jumping techniques to the two different wheel sizes. I can land on a dime on my 26er and feel like i dont have much control of where i land while on the 29er. Maybe im applying too much body english and manipulating the bike in the air like i do my smaller bike, when really i should be focusing on landing a fraction of a second sooner than im used to on virtually every other two wheeler ive ever lofted into the air. Heres an older pic demonstrating my jumping skills....
    Attached Thumbnails Attached Thumbnails Jumping a 29er-aspen-jump-copy.jpg  


  24. #24
    mtbr member
    Reputation:
    Join Date
    Apr 2005
    Posts
    1,871
    munstro, MF is being patient with you here. you keep saying the 29er 'sits' higher from the ground. I think what you are trying to say is that 'despite the fact that the pedals, BB, handlebars, and seat on a properly set up 29er are the same distance from the ground as on my 26er, the 29er feels different when jumping'.

    Yes, others have noticed that same difference in the jumping feel, even though the bike 'sits' the same distance from the ground.

    Bottom bracket drop relative to the axles is not a complicated topic -- it feels as if you are assuming bottom bracket drop is somehow complicated as a concept, but if you want to understand the answer to your original question, you will have to spend a few seconds trying to understand what BB drop means.

    I like to jump my HT's, and as a general rule of thumb, i find that a 29er needs a shorter chainstay length in order to 'feel' somewhat similar to a 26er HT. This is consistent with what the industry learned long ago in the urban/bmx world. For a given size wheel, different bmx frames have different amounts of BB 'Drop' (I use quotes here, since for small wheels there is no drop -- instead the BB is higher than the axles, which makes j-hops even easier).

    hope this helps.
    Originally posted by bucksaw87
    I still fail to see how mustaches, fixies, and PBR are ironic.

  25. #25
    Professional Crastinator
    Reputation: Fleas's Avatar
    Join Date
    Jan 2006
    Posts
    2,477
    One more thing from me...

    I am equally bad jumping on any bike, but what I noticed on my old MCR9 was the extra chainstay length. That was probably the biggest factor in jumping that bike. The wheelbase was just a little longer, plus the rear wheel seemed to hang just a little longer when doing drops. The fix was more speed or more weight transfer, but I am famous for my dead-sailoring so I try to moderate both of those.

    My new Nimble9 with chainstays that are very close to my old 26er StumpJumper pops off those jumps and leaps off those drops in a more controlled manner, with less body English from me. The fact that I have my bars ~10mm higher than the old MCR gives me more leverage in the fore/aft direction as well.

    If you have a 29er with low bars and/or long chainstays, the front will feel harder to loft. This might be messing with your usual warm fuzzy jumping feeling.

    Thanks for the jumping pointers R.E.! I'm going to practice. There's a heavy teeter-totter around here that doesn't tip if you're going fast. That should get me up there.

    -F
    It's never easier - you just go faster.

Page 1 of 2 1 2 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •