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  1. #1
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    BB Height on Guardian

    I've brought this topic up in other threads before, but I feel that I have enough evidence to start a full conversation on it now. First off, I'm not trying to "dog" on the Guardian. I love this damn bike, but I do have a few minor complaints and I'm hoping to give input to Airborne and receive some input on how to ride more efficiently.

    This is all about pedal strikes. I ride some very technical terrain. Everything from slanted hillsides, tight switchbacks, very hilly up and down terrain with roots and rocks. When I first transitioned to the Guardian from a 26er, I got pedal strikes all the time. Now, I maybe get a pedal strike about once ever 2-3 miles so my technique has improved as I've adapted to the Guardian. Problem is, I have to think about it quite a bit. I have to look down at the ground to anticipate how I'm going to roll over obstacles in the path when I should be looking ahead at the trail. I have to time my pedaling so the downstroke doesn't hit an object.

    Airborne has maintained that their BB height is right in line with other 29ers. I did my own comparison when I participated in a Trek demo day at my local trail. (the one I usually ride on) Riding 3 different Trek bikes over a 3 hour period, I got ZERO pedal strikes. I wasn't thinking about pedal strikes, I wasn't trying to avoid them. I just rode and didn't worry about it. Honestly, it didn't occur to me until after I was done riding. Then I just felt amazed that I didn't strike my pedals.

    Here are the 3 bikes I rode and their BB heights as taken from the Trek website:

    Rumblefish Elite: 33.8 cm
    Remedy (26er): 35.3 cm
    Superfly Carbon FS: 31.6 cm

    The BB height on the Guardian (as measured by me) is 29.8 cm.

    Now before you say that a low BB height makes for better handling, know that I've considered that but couldn't tell a difference in handling. I also know that BB height is a variable and depends on certain things such as the tread on the tire. Also, all 3 bikes I rode were FS and the Guardian is a HT, so that might be like comparing apples to oranges. Two other bikes I've ridden on the same trail is the Salsa Horsethief and the Motobecane FS (can't remember the exact name) and got no pedal strikes with them. However, I don't know their BB heights, either.

    I like to be solution oriented. Like I said before, I love this bike and I want to ride it well and have fun. So, I picked up a Reba and plan on trying it out at 100mm of travel which should raise the bike slightly. I'm also going to get some thinner flat pedals which should help. When I put some nobbier tires on it (thinking about Nobby Nics) that might help a little as well.

    Other thoughts and strategies?
    Nathan

  2. #2
    Airborne Product Dude
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    Those are all full suspension rigs.

    Like I've stated before, full suspension rigs have higher BB's to start with due to anticipation of sag, travel, and some other design/ride considerations.

    You can't compare an XC HT to a full suspension. 26, 29, or otherwise.

    To my point, BB heights from some other popular XC HARDTAILS:

    Trek Superfly Comp HT: 31.2
    Specialized Stumpjumper Comp: 30.4

    The 18" Guardian sitting in our showroom measures 30.3.

    Putting a 100mm travel fork on the bike will move the BB height up approximately 8mm from where it currently sits.

    Thank you.
    Airborne Dude.

  3. #3
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    Why is the BB higher on a FS than a HT?
    Nathan

  4. #4
    Airborne Product Dude
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    Quote Originally Posted by Barheet View Post
    Why is the BB higher on a FS than a HT?
    Did you read what I wrote above?

    Think about how a dual suspension bike moves and how the BB shell generally moves downward when soaking up travel. The height of the BB unsagged has to be higher to start with so that when the rider sits on the bike with his weight it sags down for the suspension to operate properly. Also by nature, many FS rigs are going to be ridden in rougher areas (hence the need for the full suspension) so frame designers/builders incorporate more height............at the expense of some other things. It's all a trade-off.

    I like this quote from a discussion a few months back regarding BB heights (no, it wasn't me) :

    Folks seem to be talking about pedal strikes like they are some kind of apocalyptic catastrophe. To jack up the BB in order to avoid all pedal strikes is a bit "the nail telling the hammer what to do."

    I'm in the low as practical BB crowd. Why compromise handling 99% of the time just to avoid that 1% where the hammer has remind the nail of it's place.
    Typical BB height for hardtails (26 and 29er sizes) tends to be in the range between 11" and 13" in terms of production bikes.

    I can hop on a bike and immediately notice a 1-1.5 inch difference in BB height. While handling isn't only influenced by BB height (there are a bunch of other design and biomechanical factors), it does make a big difference.

    It sounds to me like a FS rig with a higher BB may be the bike for you rather than an XC hardtail.
    Airborne Dude.

  5. #5
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    Thanks for the more detailed explanation.

    I read that thread too. I have to disagree with the quote because in my opinion, pedal strikes are pretty much an apocalyptic catastrophe. I've had some of the worst wrecks of my life due to pedal strikes including 2 broken helmets while riding in Montana and several near-wrecks in the last couple of months. A pedal strike can cause your bike to completely stop in an instant.

    Come to think of it, I don't see many other hardtails on the trails I ride. I must be one of the only black sheep still kicking it old school.

    So...what the BB height on the 18 inch Hobgoblin? :-)
    Nathan

  6. #6
    Airborne Product Dude
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    Quote Originally Posted by Barheet View Post

    Come to think of it, I don't see many other hardtails on the trails I ride. I must be one of the only black sheep still kicking it old school.
    I'm an old-school HT guy at heart. That's what you'll see me on most of the time. I like riding a dually but I tend to stick with my roots.


    Quote Originally Posted by Barheet View Post
    So...what the BB height on the 18 inch Hobgoblin? :-)
    The BB height on the HobGoblin is 33.0 cm (approx 13").
    Airborne Dude.

  7. #7
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    I'm pretty green at this, but I like the idea of a low BB for handling purposes. If your having that much trouble I would recommend looking at thinner pedals. If that doesn't work you could always look at a shorter crank. Going from a 175mm to 170mm would help with the strikes. It may be worth other tradeoffs if the strikes are that big of an issue for you. But like I said, I'm a newbie so maybe thats a bad solution.

  8. #8
    Airborne Product Dude
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    Quote Originally Posted by Fargo1 View Post
    I'm pretty green at this, but I like the idea of a low BB for handling purposes. If your having that much trouble I would recommend looking at thinner pedals. If that doesn't work you could always look at a shorter crank. Going from a 175mm to 170mm would help with the strikes. It may be worth other tradeoffs if the strikes are that big of an issue for you. But like I said, I'm a newbie so maybe thats a bad solution.
    The statements below are coming from me, Jeremy, as a rider and are my personal opinion:

    I certainly am not trying to offend anyone by saying this............but.................thinner pedals aren't really the answer IMHO. Pedal strikes are a matter of technique. You simply can't pedal over everything on the trail.

    In the many years that I've been riding and racing mountain bikes, I've had the opportunity to ride with lots of people with varying degrees of experience of varying types of terrain. For the most part, the folks who have rampant problems with pedal strikes tend to be new riders, or riders who only ride on flat/smooth trails that get thrown into technical/rocky/rooty trails. Experienced riders who ride on such trails know when they can pedal and when they can't; its a skill that is one of many that comes with time in the saddle.

    Certainly you can chase after the problem by putting thinner pedals on the bike, or switching to a FS rig with a super-high BB, but in the end all you are doing is addressing the symptom and not the cause.

    Again, I mean no harm and don't mean to offend.

    Jeremy
    Airborne Dude.

  9. #9
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    Ok for starters, I brought this on myself for daring to compare a HT with some FS bikes. Learned something new about that, so problem solved there. But I've already spent the money on the Guardian and won't be in the market for a FS for a year or so, so why not try some things to get the height up a bit? I use every bit of the 80mm of travel anyway on these crazy trails I ride. Might as well go to 100mm. As far as pedals go, I lost 6 pins in my pedals in the first 3 months of riding my new bike, but haven't lost any since then. My technique improved with the low BB height.

    This is not a matter of a noob on a bike who simply can't seem to grasp the concept of pedaling over technical terrain. This is a matter of an experience mtber who is used to a high BB height suddenly on a bike with a low BB height. I also have ridden with many different people on the trail and I've seen a lot of pedals that were marred, scraped, bent and pins missing due to pedal strikes. I know I'm not the only one. Yes, it's technique, as evidenced by the decrease in pedal strikes over the past few months.

    This is not a "rampant" problem I'm having. Just wanted to compare bikes is all.
    Nathan

  10. #10
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    Jeremy - I fully understand what you are saying about technique. And I like that the Goblins have a lower BB. Its one of the reasons I am really considering them.

    So I was just wondering is their a problem with thinner pedals? Are they weak or tend to bend? I realize its not a real solution to pedal strikes. And honestly I don't see where another mm or two would really matter. It would seem to me that if you are striking the pedal hard enough to cause concern you need much more space than a couple of mm.

    How about shorter cranks? Would that be an option? Again, I like a lower BB. I'm just trying to learn some stuff here and maybe help another rider.

  11. #11
    Airborne Product Dude
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    Quote Originally Posted by Fargo1 View Post
    Jeremy - I fully understand what you are saying about technique. And I like that the Goblins have a lower BB. Its one of the reasons I am really considering them.

    So I was just wondering is their a problem with thinner pedals? Are they weak or tend to bend? I realize its not a real solution to pedal strikes. And honestly I don't see where another mm or two would really matter. It would seem to me that if you are striking the pedal hard enough to cause concern you need much more space than a couple of mm.

    How about shorter cranks? Would that be an option? Again, I like a lower BB. I'm just trying to learn some stuff here and maybe help another rider.
    There's nothing inherently wrong with thinner pedals, although "thinnner" is only an option in flats/platforms. Clipless-style pedals like SPD's, EggBeaters, Time's, etc really can't be very thin due to the mechanisms involved and being at least 2-sided. So for clipless riders like me "thinnner" isn't an option.

    Shorter cranks isn't much of an option in my opinion, as then you would suffer everywhere else on the trail where you want the extra leverage of the longer arms and, more importantly, it may not be the best biomechanically for all sizes of riders. For example, at nearly 6'1" I'm not going anywhere near 170mm cranks; I prefer 175 on mtb and road, 177.5 on my TT bikes, and 180mm on my BMX bikes.

    I'm certainly not bagging on anyone for having pedal strike issues, just trying to help. I've run beginner MTB clinics in the past and enjoy teaching the "hows and whys and techniques" rather than just telling someone to throw money at an issue.

    Thanks!

    Jeremy
    Airborne Dude.

  12. #12
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    Thank you, thats kind of what I thought, but wanted someone more knowledgable to address it.

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