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  1. #1
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    29er fork on a 26er

    Can I put a 29er fork on a 26 inch bike? Thanks

  2. #2
    local trails rider
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    Yes, BUT.

    Many (most?) 29er forks have more rake/off-set than most 26er forks, to make steering more sensitive.

    Also, if you want rim brakes, they'll be located all wrong.

    Why do you want to do this?
    Do you mean suspension forks or rigid?

    "it IS possible that you are faster or slower than anybody else who is having at least as much if not more or less fun"

  3. #3
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    The axle to crown length of a 29er fork will probably be longer than that of a 26er fork. I tried this once and it turned my bike into an poor handling, pedal, powered chopper.
    What are you trying to do?

  4. #4
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    It is a reba sl sus. fork. I will use it with disc. I have it already and I have a 26 inch allu frame. so I am thinking to use it on it.

  5. #5
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    Make a 69'er
    The most important thing is what God thinks about it. He will have the final say. Joshua Stinebrink

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  6. #6
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    It works better with a 650 fork and wheel. The front is not so chopped and the 27 front rides like a 29er. I do it on my old Ti 26 Fatchance.

  7. #7
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    Quote Originally Posted by Markleo
    Can I put a 29er fork on a 26 inch bike? Thanks
    Sure. But as JudgeMorris notes, you would want to pay close attention to axle-to-crown distances.

    I did once run a Karate Monkey fork on a 26er hardtail. That worked out fine. Axle-to-crown was only a three millimeters different (468mm versus 465mm) from that of the Instigator fork. The v-brake mounts were in the wrong location, but that didn't matter because I was running disk brakes.

    You should also be able to run an 80mm 29er fork in place of a 100mm 650b fork. I did the math on that once, and the axle-to-crown distances work out to be close enough.

  8. #8
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    Quote Originally Posted by JonathanGennick
    You should also be able to run an 80mm 29er fork in place of a 100mm 650b fork. I did the math on that once, and the axle-to-crown distances work out to be close enough.
    On a 26 bike, I was talking about nothing taller than a 650b fork set at 80mm. Anything else is way to tall.

  9. #9
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    Back in the seventies, my ultimate Boonie Bike design was a stripped down Schwinn Varsity with a 26" rear wheel. I liked the stability and flotation on the rear. What I want now is to get a 29er and put a fat 26" on the rear, I think the geometry will be better that way. (I did try putting a 27" fork and wheel on a Speedster once, but it didn't have the advantageous geometry, so I think that might be similar to putting 29er forks and a 700c wheel on a 26" frame.) It sort of leans back the angles, I always thought it felt better for going down steep gravel roads, not quite fast enough handling for single track or whatever daredevil **** most of you kids are doing nowadays. YMMV.

  10. #10
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    I've been reading alot about 650b conversions and want to try it on my Santa Cruz Blur LT2. The problem is that I have a 2010 RockShox Revelation QR fork which is a no go for 650b.
    I also recently built up a 29er hardtail with a 100mm 29er Reba. For my testing purposes, can I just use the Reba 29er fork on the Blur to see how 650b(front and back) would feel?
    What would be some cons of using a 29er fork for a 650b wheel(other than changes to the axle to crown measurement)?

  11. #11
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    If you can get a lower head set spacer you may get your Ac close.
    http://www.enduroforkseals.com/id183.html

    Otherwise the extra offset on the fork and lower AC is going to mean you are not going to notice much off the extra stability the 650B wheel provides. May still notice the extra cornering grip and roll over?

  12. #12
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    Quote Originally Posted by gvs_nz View Post
    If you can get a lower head set spacer you may get your Ac close.
    http://www.enduroforkseals.com/id183.html

    Otherwise the extra offset on the fork and lower AC is going to mean you are not going to notice much off the extra stability the 650B wheel provides. May still notice the extra cornering grip and roll over?
    hm I'm kind of confused. Let me see if I'm understanding this correctly.
    The 26er revelation fork is 150mm and the 29er Reba is 100mm. I took a rough measure of the AC for both and for the revelation it is roughly 20.75 inches and for the reba it is roughly 20.3.
    So what you are saying is that with the shorter AC measurement of the Reba, I'm going to end up with a steeper head angle which is going to negate the extra stability offered by the 650B wheel(because the bigger diameter 650b wheel effectively slackens the head angle, all else being equal).
    Is that right?

  13. #13
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    Quote Originally Posted by pwu_1 View Post
    hm I'm kind of confused. Let me see if I'm understanding this correctly.
    The 26er revelation fork is 150mm and the 29er Reba is 100mm. I took a rough measure of the AC for both and for the revelation it is roughly 20.75 inches and for the reba it is roughly 20.3.
    So what you are saying is that with the shorter AC measurement of the Reba, I'm going to end up with a steeper head angle which is going to negate the extra stability offered by the 650B wheel(because the bigger diameter 650b wheel effectively slackens the head angle, all else being equal).
    Is that right?
    with a 29'er wheel on the REBA Yes. with a 650b on the REBA no. I dont have the exact measurements but it should equal the same as the 150mm Rev with the 26" tire.
    The most important thing is what God thinks about it. He will have the final say. Joshua Stinebrink

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  14. #14
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    Quote Originally Posted by pwu_1 View Post
    hm I'm kind of confused. Let me see if I'm understanding this correctly.
    The 26er revelation fork is 150mm and the 29er Reba is 100mm. I took a rough measure of the AC for both and for the revelation it is roughly 20.75 inches and for the reba it is roughly 20.3.
    So what you are saying is that with the shorter AC measurement of the Reba, I'm going to end up with a steeper head angle which is going to negate the extra stability offered by the 650B wheel(because the bigger diameter 650b wheel effectively slackens the head angle, all else being equal).
    Is that right?
    You will be fine.

  15. #15
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    Quote Originally Posted by pwu_1 View Post
    hm I'm kind of confused. Let me see if I'm understanding this correctly.
    The 26er revelation fork is 150mm and the 29er Reba is 100mm. I took a rough measure of the AC for both and for the revelation it is roughly 20.75 inches and for the reba it is roughly 20.3.
    So what you are saying is that with the shorter AC measurement of the Reba, I'm going to end up with a steeper head angle which is going to negate the extra stability offered by the 650B wheel(because the bigger diameter 650b wheel effectively slackens the head angle, all else being equal).
    Is that right?
    Here's the numbers. All with relatively same height tires.
    Floor to crown of a Fox F29 100 and 29er wheel is approx 820mm add 10mm for a Reba so 830mm. Revelation 150 with 26" tire approx 820mm floor to crown. Difference in 26" tire to 650b tire is approx 15mm diam.

  16. #16
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    so a 29er fork on a 26er is called a 69er?

    Why 69?

    I can't afford an FS 29er and am planning to add, preferably, a rock shox recon series 29er fork/wheel with a better front brake to my m4 Stumpjumper...
    but I'd like to hear more about builds and results.
    I often start riding and cannot stop.

  17. #17
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    I have an old steel Fisher Tassajarra that has been collecting dust since I got my new Orbea and I want to try to convert it into a cross bike.

    I'd love to be able to throw a 29er wheel and fork on the front but I'm not sure I understand the effects on the frame and geometry. Surely the front end would rake out a bit creating a slacker headtube angle, but will this also raise my bottom bracket and cause undue stress on parts of the frame that weren't designed for it? Also, not sure I understand the concern with axel to crown measurements.

    Could I use an actual cyclocross fork and wheel? The headset is 1 1/8 on the Fisher now. I have rim brakes on the bike and don't want to spend the $$ to upgrade to discs.

    Any help you all could provide would be great!
    Life is like riding a bicycle. To keep your balance you must keep moving. ~ Albert Einstein

  18. #18
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    This might do the trick: Salsa Cycles | Components
    I've got one of these forks on my 29/650B frankenbike. Running a 29er wheel with 2.4" Ardent tire in it with room to spare. Should be able to fit a 700c wheel in there. I'll test it with a wheel off my road bike when I get home.

  19. #19
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    thought about it

    I'm building a Blur XC and was thinking about 29 front and 650 rear. To get the geometry I'd want though, I'd have to reduce the travel in my f29 100 to 70mm. I'm not sure that's really possible, and also wonder if having the larger wheel is worth losing all of that travel. Seems my ride would be out of balance suspension-wise, as the rear would still have 100mm.

    I decided to buy a 120 26er fork and run straight 650b. I won't know for some months how I feel about my decision. I will still have some ways to experiment with a B9er format, but the more I read and ponder, the more I think I'll probably keep the 29 wheels on my 29er hardtail and run my full suss with 650's.

  20. #20
    Nouveau Retrogrouch SuperModerator
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    Quote Originally Posted by CBRsteve View Post
    I have an old steel Fisher Tassajarra that has been collecting dust since I got my new Orbea and I want to try to convert it into a cross bike.

    I'd love to be able to throw a 29er wheel and fork on the front but I'm not sure I understand the effects on the frame and geometry. Surely the front end would rake out a bit creating a slacker headtube angle, but will this also raise my bottom bracket and cause undue stress on parts of the frame that weren't designed for it? Also, not sure I understand the concern with axel to crown measurements.

    Could I use an actual cyclocross fork and wheel? The headset is 1 1/8 on the Fisher now. I have rim brakes on the bike and don't want to spend the $$ to upgrade to discs.

    Any help you all could provide would be great!
    You need to keep the fork length (axle to crown race seat) the same with a new fork.

    A 29" fork would slacken the frame angles by a couple of degrees.
    A 'cross fork would steepen the frame angles by a few degrees.

    Either would change the handling drastically.
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  21. #21
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    Lots of variables due to frame geometries, fork A to C measurement and travel.
    If you've got a 26" frame, a 29er fork (would reduce its travel to its lowest if possible) and a 650b wheelset and are prepared to take the "risk", I'd say go for it - give it a try and see for your self how the bike feels.

  22. #22
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    Old thread...but I'd like to know how this story turned out...

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