fork stiffness comparisons- Mtbr.com
Results 1 to 14 of 14
  1. #1
    mtbr member
    Reputation:
    Join Date
    May 2014
    Posts
    1,367

    fork stiffness comparisons

    Is a good suspension fork with a 9 mm QR wheel just as stiff as a rigid fork with the same wheel?

  2. #2
    mtbr member
    Reputation: socal_jack's Avatar
    Join Date
    Dec 2008
    Posts
    1,373
    Not the one I had, that was a fairly long time ago some Rockshox model on a Spez FSR a real noodley POS. I imagine there are better now but I don't even think my Pike with a 15mm axle is as stiff as the rigid fork on my GT Peace.

  3. #3
    mtbr member
    Reputation:
    Join Date
    Jan 2013
    Posts
    162
    It really depends on the rigid fork. What kind of stiffness are you talking about? fore and aft flex or lateral wheel deflection? I have personally found my tapered carbon 9mm fork stiffer than my tapered Reba with a 15mm thru axle. Then again my old steel karate monkey fork was a noodle.

  4. #4
    mtbr member
    Reputation:
    Join Date
    May 2014
    Posts
    1,367
    My salsa cromoto. And I mean as far as steering response and flex on corners. I like how my rigid steers so much more precise and with do much more control than my old crappy spring fork did. Just wondered about higher end forks like Reba etc.

  5. #5
    mtbr member
    Reputation:
    Join Date
    Mar 2015
    Posts
    433
    Well there's a caveat that should be stated: assume the sus fork is set up properly.

    Being the hefty fellow I am, I tend to be riding around on forks that are too soft for me, and they are really squirrelly and feel like a coupla noodles. That's partially due to fork dive and partially due (probably) to not having the rebound settings just right, at least on one of my forks. Variable geometry on a bicycle is not exactly awesome.

    And as for the rigid forks, like the KM mentioned above, if they are flexy, they are probably doing what they are supposed to do. You can build them to handle like a tank but the thin, curved blades are supposed to be flexy.

    I gotta think if you want a crisp handling suspension fork, get a decent fork with the right adjustments, set it up right and I'll bet it'll do what you want it to do.

  6. #6
    SSOD
    Reputation: Crosstown Stew's Avatar
    Join Date
    Aug 2008
    Posts
    826
    There are tons of variables to this question but given everything equal, you should not notice flex in the forks unless your bushings start to wear and get play. Otherwise it's your wheel that flexes in the situation your describing.

    The reason your rigid fork has precise handling is because there is no suspension, locking out suspension will give you similar deflection side to side but you won't have fore and aft compliance because of the different materials between a steel fork and a suspension fork. However I've heard the RS-1 forks are a lot stiffer, but they are mostly carbon and have a robust crown unlike typical single crown forks.

  7. #7
    mtbr member
    Reputation:
    Join Date
    Jan 2013
    Posts
    162
    https://www.youtube.com/watch?v=1M2O-fTYVI4
    that should give you an idea of what to expect with fork fore and aft flex.

    RS1's aren't very stiff either
    https://www.youtube.com/watch?v=f0xAgGAejq8

    I think you'll find that a good set of wheels will make more of a difference in terms of steering response. My old Stans crest wheels would deflect and hit the crown of my 15mm fork while my new custom built set doesn't flex at all.

  8. #8
    .44
    Reputation: stremf's Avatar
    Join Date
    Dec 2012
    Posts
    1,230
    Uh, there is NO comparison on stiffness when comparing suspension to rigid forks. Doesn't matter if you build the flexist rigid vs high-end suspension fork pumped up to zillion psi. Flex is still there when comparing (even when locked out).

    I had some high end Fox and Reba forks. Wasn't thrilled with the suspension, so I've been on a rigid for a number of years. With the explosion of 29+ tires, I have no reason to look at another suspension fork.

  9. #9
    mtbr member
    Reputation:
    Join Date
    May 2014
    Posts
    1,367
    Quote Originally Posted by serious1
    I think you'll find that a good set of wheels will make more of a difference in terms of steering response. My old Stans crest wheels would deflect and hit the crown of my 15mm fork while my new custom built set doesn't flex at all.

    I got decent wheels on my rig. I am sure there is much much better available but they aren't cheap for sure. I am running Stans arch rims. I am not sure how they compare to the crest but I was told they were a good rugged rim.

    The second video was interesting but the first video I didn't see any difference in the 3 forks.

  10. #10
    Wanna ride bikes?
    Reputation: *OneSpeed*'s Avatar
    Join Date
    Oct 2013
    Posts
    5,843
    Quote Originally Posted by iowamtb View Post
    I got decent wheels on my rig. I am sure there is much much better available but they aren't cheap for sure. I am running Stans arch rims. I am not sure how they compare to the crest but I was told they were a good rugged rim.
    stans arch are good rims. they are the middle rim of the three. crest is light, single wall. arch is medium, double walled. flows are wider, stronger, and heavier double walled.

    what front hub are you running? is it convertible? and if so have you considered converting your front hub to run a 9mm QR thru axle?

    example: thru axle

    DT Swiss makes one too but it gets mixed reviews as being too easy to break.
    Rigid SS 29er
    SS 29+
    Fat Lefty
    SS cyclocross
    Full Sus 29er (Yuck)

    Stop asking how much it weighs and just go ride it.

  11. #11
    mtbr member
    Reputation:
    Join Date
    May 2014
    Posts
    1,367
    Quote Originally Posted by BENKD29 View Post
    stans arch are good rims. they are the middle rim of the three. crest is light, single wall. arch is medium, double walled. flows are wider, stronger, and heavier double walled.

    what front hub are you running? is it convertible? and if so have you considered converting your front hub to run a 9mm QR thru axle?

    example: thru axle

    DT Swiss makes one too but it gets mixed reviews as being too easy to break.
    Hope hubs front and rear. I could buy the adapters if needed and go 15 mm axle/maxle if needed. I love rigid! Just on occasional really rutted trails at times I have been known to wish I had front suspension lol. Not all the time just on occasion.

  12. #12
    Wanna ride bikes?
    Reputation: *OneSpeed*'s Avatar
    Join Date
    Oct 2013
    Posts
    5,843
    right, if your currently running a QR in a drop out fork, you can't switch to a 15mm TA without buying a new fork.

    that's where the 9mm QR TA comes in. much better than a standard 5mm QR. you can convert your hubs to accept it (with end caps) and it will fit in any standard drop out fork. in my opinion that's how they should all come, but unfortunately few hubs are designed to accommodate it.
    Rigid SS 29er
    SS 29+
    Fat Lefty
    SS cyclocross
    Full Sus 29er (Yuck)

    Stop asking how much it weighs and just go ride it.

  13. #13
    mtbr member
    Reputation:
    Join Date
    May 2014
    Posts
    1,367
    Quote Originally Posted by BENKD29 View Post
    right, if your currently running a QR in a drop out fork, you can't switch to a 15mm TA without buying a new fork.

    that's where the 9mm QR TA comes in. much better than a standard 5mm QR. you can convert your hubs to accept it (with end caps) and it will fit in any standard drop out fork. in my opinion that's how they should all come, but unfortunately few hubs are designed to accommodate it.
    I have heard of those 9 mm axles. Is it something a person would notice with a steel fork? It feels pretty good and responsive now.

  14. #14
    Wanna ride bikes?
    Reputation: *OneSpeed*'s Avatar
    Join Date
    Oct 2013
    Posts
    5,843
    Quote Originally Posted by iowamtb View Post
    I have heard of those 9 mm axles. Is it something a person would notice with a steel fork? It feels pretty good and responsive now.
    oh, well if it ain't broke... i was just thinking you were having issues. i realize now i got a little off topic. but still, there's no down side, it's not going to hurt you. i guess if you had a suspension fork with dropouts it would be useful to help eliminate the flex, but as you said, you could just buy a 15mm fork. since you bought one of those bikes with a goofy wheel size it's unlikely you have a suspension fork laying around in the parts bin. :P

    Quote Originally Posted by stremf View Post
    Uh, there is NO comparison on stiffness when comparing suspension to rigid forks. Doesn't matter if you build the flexist rigid vs high-end suspension fork pumped up to zillion psi. Flex is still there when comparing (even when locked out).

    I had some high end Fox and Reba forks. Wasn't thrilled with the suspension, so I've been on a rigid for a number of years. With the explosion of 29+ tires, I have no reason to look at another suspension fork.
    ^ i agree with this. i have two Reba's and they are a great fork for the money! but still not as rigid/stiff as a rigid fork. I wouldn't want to go any lower than a RS Reba.

    i heard there is a significant improvement in stiffness if you jump to a Fox 34mm fork, but have no first hand experience. though i am curious because I'm 205 lbs and can feel a good amount of flex in forks/axles/wheels. I'm slowly upgrading my bikes and components to eliminate as much of it as possible.
    Rigid SS 29er
    SS 29+
    Fat Lefty
    SS cyclocross
    Full Sus 29er (Yuck)

    Stop asking how much it weighs and just go ride it.

Similar Threads

  1. Fork stiffness
    By grok22 in forum Shocks and Suspension
    Replies: 0
    Last Post: 04-15-2014, 08:24 PM
  2. Replies: 3
    Last Post: 04-10-2014, 05:17 AM
  3. fork stiffness...
    By cunningstunts in forum Shocks and Suspension
    Replies: 4
    Last Post: 04-25-2013, 09:54 AM
  4. Upgrade for stiffness, fork or wheels?
    By Finksta in forum 29er Bikes
    Replies: 13
    Last Post: 04-15-2013, 04:39 PM
  5. Objective measurements of fork stiffness?
    By outlierrn in forum Shocks and Suspension
    Replies: 1
    Last Post: 07-31-2012, 10:39 PM

Members who have read this thread: 1

Posting Permissions

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

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.