HD frame flex?

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  • 12-10-2012
    lawman1991
    HD frame flex?
    Recently noticed a degree of flex coming from somewhere in the rear-end, I recently rebuild the rear with new lower bearings and a whole new upper linkage and something feels amiss, Tyres are at 30psi and the wheels are taught, so I know its neither of these. Could it be a problem with the maxle or the frame itself? :confused:
  • 12-10-2012
    Perpetrator
    Check the spoke tension on your wheels. The Ibis/Stan's wheels that came with my HD were tensioned pretty low and were pretty flexy (and I am a small 150 lb guy). They were flexing enough that they made a terrible creaking noise where the spokes contact each other when they cross. I tensioned them up and all was well with the world. Same deal on a friend's HD with the same wheels.
  • 12-10-2012
    lazarus2405
    Check torque on all your linkage bolts. Even if you're sure you wrenched it right the first time, it's never bad to check, and with a proper torque wrench,

    Is this flex something you can reproduce off the bike, or do you only feel it on the trails?
  • 12-10-2012
    lawman1991
    theres no noticable flex in the wheels, and putting pressure on the cranks all seems normal, but just going up and down the street something doesn't feel right.
  • 12-10-2012
    recleaver
    something is off, you should not be feeling any flex in that frame, it's stiff as hell.
  • 12-10-2012
    hanssc
    The other thing that feels like that is if you are running big tires on narrow rims or low pressure in the tires. At a certain point the sidewall folds over and it feels like the rear of the bike is flexy. With some wheel and tire combinations you either have to over pressurize the tire or run smaller tires (or ones with stiffer sidewalls) to solve it.

    I have had rides where I was certain something was terribly wrong with my bike (pulling over to inspect it etc.) only to figure out that the rear tire was folding over.

    H
  • 12-10-2012
    lawman1991
    Quote:

    Originally Posted by hanssc View Post
    The other thing that feels like that is if you are running big tires on narrow rims or low pressure in the tires. At a certain point the sidewall folds over and it feels like the rear of the bike is flexy. With some wheel and tire combinations you either have to over pressurize the tire or run smaller tires (or ones with stiffer sidewalls) to solve it.

    I have had rides where I was certain something was terribly wrong with my bike (pulling over to inspect it etc.) only to figure out that the rear tire was folding over.

    H

    It could be that, I run Stan's crest rims and Schwalbe Nobby Nic Gatestars with snakeskin sidewalls tubeless and this morning they were about 25psi, so not mega low. I know with my old non-snakeskin nics that they did fold over, but now with tougher tyres, I'm really stumped as to why its happening :confused:
  • 12-10-2012
    canuck_tacoma
    Are we starting to see the effects of all that Marijuana Legalization that's been going on down there?
  • 12-10-2012
    lazarus2405
    Quote:

    Originally Posted by lawman1991 View Post
    It could be that, I run Stan's crest rims...

    They have an inner width of, what, 21mm? That should be plenty wide for Nobby Nics.

    The better question is, what the hell are you doing with Crests on an HD? :p
  • 12-10-2012
    capthowdy
    Quote:

    Originally Posted by canuck_tacoma View Post
    Are we starting to see the effects of all that Marijuana Legalization that's been going on down there?

    Lol well played, sir.
  • 12-11-2012
    lawman1991
    Quote:

    Originally Posted by lazarus2405 View Post
    They have an inner width of, what, 21mm? That should be plenty wide for Nobby Nics.

    The better question is, what the hell are you doing with Crests on an HD? :p

    Its a HD140 and I weigh 160lbs and the crests have been great for over 18months, I will be switching them to some tune hubs and arch ex's in the future though.

    Also not sure where you think I'm from but pot aint legal in the UK :lol:
  • 12-11-2012
    Perpetrator
    Quote:

    Originally Posted by lazarus2405 View Post
    They have an inner width of, what, 21mm? That should be plenty wide for Nobby Nics.

    The better question is, what the hell are you doing with Crests on an HD? :p

    Agreed, an HD should have Flows or better yet, WTB Frequency i23 TCS's.
    WTB Products Wheels Rims All Mountain Frequency i23 TCS

    ..and American Classic Valve Stems
    TUBELESS VALVES
  • 12-11-2012
    lawman1991
    flows are way over-built for my needs, I'm a light, smooth rider and have had zero issues with my crests. Yes they could be abit stiffer, but I'll be changing the wheelset once I finish uni and funds allow.
  • 12-11-2012
    canuck_tacoma
    Quote:

    Originally Posted by lawman1991 View Post
    Also not sure where you think I'm from but pot aint legal in the UK :lol:

    Ahh, guess the Hippies havn't gotten to your government yet.

    I have Arch's and run 2.35's, have had my links apart a few times and the bike is just as solid as the day I bought it. Mind you i rarely run below 30PSI.

    You sure your tire's bead is seated on the rim.?? If it isn't the tire will ride wobly.
  • 12-11-2012
    00sable
    I've run Arches with Trail King 2.2 and Mountain King 2.2 @ 30-35 psi for a while and they seem fine. No noticeable flex. I weigh 175
  • 12-12-2012
    slyfink
    I hate to suggest it... but...
    have you checked to make sure the rear triangle isn't cracked? I've seen an awful lot of cracked triangles in the shops I've been into that carry Ibis... and sometimes it's hard to tell.

    (I by no means mean this as a slight of Ibis. I have an HD and love it. I'm just stating what I've seen.)
  • 12-12-2012
    Trackho
    Could be loose linkage, mine loosened up on my SL. Flip the bike upside down, see if you can flex rear triangle relative to the front. If you can, tighten linkage as required. Prolly a good idea to check bearings as well
  • 12-12-2012
    fuenstock
    Yes, check your links and shock mounts,. I had a problem where the upper shock mounts and upper link would go loose ever couple rides and make the rear feel like it was flexing. I had to check for loose bolts every ride. I cleaned the threads of any grease and used a little lock tight, a good torque wrench and they have not came loose since.
  • 12-12-2012
    lazarus2405
    Did you check the maxle? I've seen a slightly-loose maxle cause play in the rear, almost as if your hub need to be tightened. That's a super-easy one to check.
  • 12-12-2012
    Betarad
    ^^^This was the cause of a slightly loose feeling on my HD early on. I mistakingly thought flipping the lever on the end of the maxle would have the same cinching effect an old-school QR has, but I learned it doesn't. So you have to have the maxle pretty tight in its threads to avoid this.
  • 01-11-2013
    Levi707
    I was able to get some flex out of my rear triangle on my hd. I had the early 135mm rear end though. It was mostly felt with out of the saddle sprints.
  • 01-13-2013
    Ethan F
    I've experienced the same effect and came to find the Maxlewas the culprit too. You cannot get enough tension on the lever by itself, if you try, you run the risk of breaking it. You need to use a 6mm Allen wrench on the opposite end to tighten it, this makes a huge difference, try it!
  • 01-13-2013
    Maverick005
    Not the cleanest 12x142 Ive used either, might check mine Ethan cheers, not had any flex issues, bike is stiff as hell, saying that ridden alot of carbon bikes and none compare to the feel of the HD cant explain it but its just bang on in all the right places on the trail.

    I find the maxle a pia, hard to tighten intially dosent seem to line up well hard to keep the handle in the groove for speedy wheel on wheel off miyagi speed style.

    Used the DT system on Santacruz, Specialised and it works great, can this be used on the HD/Ibis frames?

    DT RWS 12x142

    Cheers
  • 01-13-2013
    Rick Draper
    I agree on the maxle axle been crap, it was **** on RS forks and its **** as a 142x12 axle on the rear of a bike.
  • 01-13-2013
    Ethan F
    Unfortunately they are different thread pitches! The bike is very stiff, but if that Maxle is not tight, at least as tight as it is meant to be, you can generate wheel flex...like the frame feels like its not doing what it is supposed to be doing! The Syntace (SC, Spec...) system is much better!