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  1. #1
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    KM frame geometry questions

    I'm looking for an end all bike for myself. I currently ride a cheapo(Gravity) rigid 29er SS, which I love and an '04 FS Trek. I want a bike that can be SS or changed(long term) to 1x9 depending if my knee gets worse. If I go KM I'll buy built SS then upgrade over time.

    So my question is: Is the KM all it's cracked up to be? Is there a noticeable difference with the bent seat tube of the KM and a standard frame? Any other pros or cons that I should know about?

    Thanks in advance!
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  2. #2
    Ariolimax columbianus
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    i think the price/value of the km sells itself. i've had a few 29ers and i luv my km. got an ogre too. want another km just for a ss. the countless pages of km builds on this site should tell you something. it's be nice to test ride an el mar back to back, but for the price of the el mar and a fork you could almost buy two km's.

  3. #3
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    One thing to keep in mind if you buy the complete, it comes with a singlespeed specific hub. So if you were to convert to geared, you'd need a different rear wheel or wheelset.
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  4. #4
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    I agree with sasquatch. Also, the newer frames have more stand over height and a better rear disc brake mount. Search the forum for more details. The KM is a very utilitarian bike.

  5. #5
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    Quote Originally Posted by nativeson View Post
    i think the price/value of the km sells itself. i've had a few 29ers and i luv my km. got an ogre too. want another km just for a ss. the countless pages of km builds on this site should tell you something.
    IMO, it seems like the KM is a very popular whitebread option for a 29er. It doesnt specialize at any one thing but is a good all arounder.

    It was also one of the first mass available 29ers so you see a ton of them just because there werent the options back then. Have I considered a KM before, yes, would I now, no.

    Too many better options on the market now but not many provide the same value as the Surly.

  6. #6
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    Quote Originally Posted by sasquatch rides a SS View Post
    One thing to keep in mind if you buy the complete, it comes with a singlespeed specific hub. So if you were to convert to geared, you'd need a different rear wheel or wheelset.
    Thanks for the heads up. I didn't think of that.

    Quote Originally Posted by GTscoob View Post
    IMO, it seems like the KM is a very popular whitebread option for a 29er. It doesnt specialize at any one thing but is a good all arounder.

    It was also one of the first mass available 29ers so you see a ton of them just because there werent the options back then. Have I considered a KM before, yes, would I now, no.

    Too many better options on the market now but not many provide the same value as the Surly.
    I'm looking for a solid frame. Something that's going to last. I don't do big air or anything like that. I want to put some money into a build and not worry I'm going to out grow it. Could the KM be that bike?
    Just because you can't hear them scream doesn't mean they don't. Save a plant, eat meat.

  7. #7
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    Quote Originally Posted by Piratefly View Post
    ... Could the KM be that bike?
    Yes.
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  8. #8
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    So is there anything special to the bent seat tube? Do you notice a change in handling or anything? Or is it just a gimmick?
    Just because you can't hear them scream doesn't mean they don't. Save a plant, eat meat.

  9. #9
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    I thought it was so the rear wheel could be tucked under the frame to shorten the wheelbase and make the handling a little more responsive. I don't know if that's the reasoning behind it, but it makes sense. I think you'll enjoy one. I plan to build one up someday
    Mountain bikers who don't road ride have no legs...
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  10. #10
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    Quote Originally Posted by Piratefly View Post
    Could the KM be that bike?
    Probably, it's not a bad bike by any means. It's a great XC bike that is very versatile in how you want to build it up.

    I guess my original post was just that if you want something racy, there are racier frames, if you want something to shred the gnar, there are slacker frames.

  11. #11
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    I keep my rear wheel slammed all the way forward, and it does seem to handle tight corners better than other 29ers I've had. Though part of that may also be the shorter top tube = shorter wheelbase. Anyway, I like it quite a bit. And I've had a lot of bikes.

    Quote Originally Posted by Piratefly View Post
    So is there anything special to the bent seat tube? Do you notice a change in handling or anything? Or is it just a gimmick?

  12. #12
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    Quote Originally Posted by Piratefly View Post
    So is there anything special to the bent seat tube? Do you notice a change in handling or anything? Or is it just a gimmick?
    Gimmick?

    Nah - it is 1" to 1" + shorter in wheelbase which makes a difference (some find it a positive difference, others who prefer a longer, stable wheel base may find it otherwise - but they have the option of running the wheel back in the dropouts if they so choose).

    It allows you to get the wheel nice and snug up there which shortens the wheelbase. Makes for a really quick handling 29"er, makes it a fun wheelie machine. Of course, with the horizontal dropouts - you have the option of running the wheel more rearward (I've done it all on mine) and yes, it does change the handling.

    As an example - comparing the wheelbase of my size XL Karate Monkey to my size XL Dos Niner:

    KM: 1093mm
    Dos: 1125.8mm

    32.8mm (1.29") difference between the two (and that's with ETT's that are nearly identical between the two size XL's of 632.2mm on the KM and 635mm on the Dos).

    You asked about longevity, durability, etc... . I bought the first generation KM in the summer of 2003 and just dismantled it on Friday following 9 years and 6 months of riding it. And there is nothing wrong with my original frame and fork, I just got a nice deal on a new KM frame to replace it. It's not the only 29"er I own and ride, but color me impressed with the geometry and handling of a KM. The frame is actually almost as forgiving as my rear 1" of travel on my Salsa Dos Niner thanks to the forgiveness of steel in the XL size. Adding the Racing Ralph 2.4 in the rear at a nice low tubeless pressure and the new KM is a fun ride for me.

    The newer frames is not as versatile as the older generations which allowed you to run V-Brakes, disc brakes, fixie, caliper brakes so you could build it out in a quite a few different set ups. The new frame has removed the brake bosses so it is disc only and Surly has added the Ogre which allows you to do all of that old "Monkey" business of building it out in various configurations. On the other hand, the new fork on the KM is designed to be more forgiving than before. I have yet to try mine on the new KM that I built on Friday as I am running a REBA Race up front. But I will be trying it out soon.

    The Karate Monkey is a well designed, durable, fun bike. Especially for the price. I wouldn't hesitate to recommend the frame/fork combo to you. I don't know anything about the complete bike they sell as I build all of my own to get the parts I want.

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    Last edited by BruceBrown; 12-16-2012 at 07:49 AM.

  13. #13
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    Thanks for the feed back guys! You've helped me solidify my decision. I'm going to start putting money away for one.
    Just because you can't hear them scream doesn't mean they don't. Save a plant, eat meat.

  14. #14
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    One thing people won't/don't tell you: Surlys paint/decals are awful.

    I own and love three different Surlys. I don't think even one of them (including my less than three month old Pugs) has a complete downtube logo. They just crackle and begin peeling after a very short time. Also, the paint scratches very quickly anywhere there is rubbing--e.g. where a frame bag is mounted or on the top-tube where your legs rub during mounting/dismounting. Vibrations from a water bottle in the down-tube cage have worn a round spot all the way through to the raw steel on my Karate Monkey after a single season of ownership.

    That said, I don't care. My Karate Monkey (full rigid/single speed) is my favorite bike.
    Last edited by Flat Again???; 12-24-2012 at 09:01 AM.

  15. #15
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    I always wondered about the KM, does the bent tube not offset the saddle back an inch more than a standard straight tube (relative to the bb)?

    Would you then need to push the saddle forward to match a normal setup (assuming you wanted to match it for whatever reason)

    And following from that does it not mean that you need to knock that inch back off the 'effective top tube' measurement (at least when comparing to normal shaped bikes).



    Im a big fan of Surly (have 3) but never fully understood the quirks of the KM sizing and quite fancy an Ogre, so it would be nice to get opinions. Thanks.
    I own a Surly, a Surly, a Surly and a Salsa. Probably some others in there too at the bottom of the pile.

  16. #16
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    Surly makes their decals removable for owners who want to go stealth.

    Strangely, my CC, after four years of ownership and regular use, still looks like new. I'm pretty impressed with Surly's powdercoating. Much, much better than (for instance) my old Gunnar, where the paint chipped off every time you looked at the bike. Very frustrating on a $1000 frame.

  17. #17
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    Quote Originally Posted by dickyelsdon View Post
    I always wondered about the KM, does the bent tube not offset the saddle back an inch more than a standard straight tube (relative to the bb)
    Nope. The seat tube angle is not affected, it's just the bottom part that's bent to allow clearance for the rear tire.

  18. #18
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    Quote Originally Posted by Saul Lumikko View Post
    Nope. The seat tube angle is not affected, it's just the bottom part that's bent to allow clearance for the rear tire.
    Ah yes, just look in detail at the geo chart. The bottom part looks offset at first glance but it actually curves round the wheel and back to the BB, so the upper part is actually in line with the BB, therefore no geo oddities.



    Thanks.
    I own a Surly, a Surly, a Surly and a Salsa. Probably some others in there too at the bottom of the pile.

  19. #19
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    Quote Originally Posted by Piratefly View Post
    I'm looking for an end all bike for myself. I currently ride a cheapo(Gravity) rigid 29er SS, which I love and an '04 FS Trek. I want a bike that can be SS or changed(long term) to 1x9 depending if my knee gets worse. If I go KM I'll buy built SS then upgrade over time.
    It's all possible. I had my Monkey with 3x9, 1x10 and SSP - all worked well! Ask your local dealer to build up your custom monkey. Use a standard rear hub for gearing and take a Surly SSP kit for singlespeeding at first. If you want to use gears in the future, you don't need a new rear wheel

  20. #20
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    Quote Originally Posted by seat_boy View Post
    Surly makes their decals removable for owners who want to go stealth.

    Strangely, my CC, after four years of ownership and regular use, still looks like new. I'm pretty impressed with Surly's powdercoating. Much, much better than (for instance) my old Gunnar, where the paint chipped off every time you looked at the bike. Very frustrating on a $1000 frame.
    "removeable" implies you have a choice!

    Anyhow, my 4 or 5 year old Cross Check is my oldest Surly, and it too has the best paint. However, I've had it set up as comfy road bike during this time. It's rarely see dirt or mud. Offroad use has taken a much quicker toll on my Karate Monkey and Pugs!

  21. #21
    Always Learning
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    Quote Originally Posted by Flat Again??? View Post
    One thing people won't/don't tell you: Surlys paint/decals are awful.
    Hmmmm.....9 1/2 years on my first Karate Monkey and only the Fatties Fit Fine decals on the chainstays were looking ragged thanks to my big feet and heels. The rest of the decals were fine and the bike went through numerous washes, rains, mud fests, snow, etc... .

    All sizes | KM5mmSpacer | Flickr - Photo Sharing!

    Paint held up pretty well for a bike nearly 10 years old, but usual knicks and chips from off road riding.

    All sizes | KMbox | Flickr - Photo Sharing!

  22. #22
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    I kinda did what your considering. GT Peace 29er SS......good bike. Then built a sweet 1X9 Karate monkey. Now that being said The GT SS climbs sand better and super steep hills with the longer wheel base and the monkey is a bit more nimble doing stupid stuff. Now the monkey has so many possibilities its ridiculous.

    KM is solid bike with a great paint job. Decals are kinda candy ass but who cares. Plus its steel . I'm puzzled why Aluminum is the flavor of choice by so many builders. Weight?? Maybe certainly not because they ride so much better.

    Buy a Monkey don't look back. Its rare people regret Surly bikes.

    Chris

  23. #23
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    KM frame geometry questions

    I have spare 100mm travel 510mm AC fork. Need to built a 2nd bike.

    KM with 468mm fork length has 68mm BB drop.

    Cotic Solaris with 80mm travel 470mm has 60mm BB drop.

    With rough maths KM with 100mm fork will have 60-62mm BB drop.
    I need good tire clearance with FD.

    KM with 100mm will not have high BB comparing to Solaris but this is one piece of puzzle, as the bike is designed as 80mm ~470mm AC corrected.

    What do you say? Which is most "trail" frame taking into consideration that will be with 100mm. Like the tire clearances of KM.

    Maybe to look something else ?
    Last edited by ocean_29; 02-01-2013 at 06:13 AM.

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