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Sensitive Steering

stevekozstevekoz Posts: 103
edited August 2013 in MTB workshop & tech
Hi all,

Originally my bike was running a 120mm RS fork with a 100mm stem, 6 degree rise and 640mm bars.

I felt like i was over reaching for the bars so swapped it out for a 60mm stem and felt a lot better. I then swapped out the bars to a a set of slightly longer 680mm carbon bars as that suited by grip. Then my forks felt short for what i was riding and how i was riding so and i've finally now swapped out the fork for a 140mm fox float 32 (+20mm). I know thats a lot of changes, but before i fitted the new fork my steering was responsive, not overly fast but confident feeling. The new forks have since made it feel very sensitive and quick.

I know the new forks will have changed the angle of my head tube etc, i can feel its slackened the angle and it feels much better if im honest on the downhills and even on the uphill it seems to have stayed the same so i've lost little in climbing ability. Which is great. But the steering is just too light and sensitive for me or at least thats how i feel at the moment.

Any ideas why that might be ? And how i could cure it ? Thinking going back up to a large stem and even wider bars?

Cheers guys

Posts

  • warpcowwarpcow Posts: 1,448
    Stevekoz wrote:
    The new forks have since made it feel very sensitive and quick.

    This shouldn't really be the case. It should feel less sensitive and slower to turn in with a slackened headangle (where nothing else is changed). Considering the a2c difference between the forks isn't much more than 10mm, it's unlikely to have made a massive difference to the feel. It's more likely that it's moved your weight further back off the front wheel. The quick fix for this is to move the saddle forward slightly, or an inline seatpost if necessary. Other alternatives are a longer stem or wider bar to bring the weight forward again, but those will have other effects on the steering.
  • stevekozstevekoz Posts: 103
    I was expecting it to make it slower and less sensitive myself so was shocked when it hadn't. I will adjust the saddle and i have a longer stem so i'll put that on and see how it rides then. Thanks
  • YeehaaMcgeeYeehaaMcgee Posts: 5,740
    warpcow wrote:
    Stevekoz wrote:
    The new forks have since made it feel very sensitive and quick.

    This shouldn't really be the case. It should feel less sensitive and slower to turn in with a slackened headangle (where nothing else is changed).
    Maybe what he's actually feeling is the rearward weight shift. Less weight over the front means the front wants to wander more.
  • nicklousenicklouse Posts: 50,675 Lives Here
    and the bike is a?

    too long a fork can make it feel like the front wheel just wants to fall over all the time.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • stevekozstevekoz Posts: 103
    Sorry, the bike is a Rockrider 9.1 size XL.

    I did seek the relevant recommendation from the manufacturer and they advised 140mm was within tolerances for the frame.

    Would steerer length have any effect? There is enough steerer for the frame to fit with only 1 spacer now where as before it had 4 spacers i think.
  • nicklousenicklouse Posts: 50,675 Lives Here
    Stevekoz wrote:
    Would steerer length have any effect?
    no. it will just change your position.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • stevekozstevekoz Posts: 103
    Didn't think so, but its just one of those things that popped into my head.

    Guess trying the longer stem and seat adjustments to change my position to suit the new fork is worth trying. I mean its not like i don't think i can get used to it just feels wierd right now compared to before and stuff like this always leaves me wanting to find out why - its the OCD in me.
  • OuijaOuija Posts: 1,386
    Shortening the stem will make the steering twitchier, much like the difference between the steering wheel on a lorry (rim further away from center) to that on a car (rim closer to center). Longer stems (and steering wheels) give you more leverage but you have to move the handle bars more to see the same amount of change in turning. Shorter stems require more effort but require less hand movement to see a larger directional change. However, by lengthening the bars you can overcome the latter problem as longer bars also give more leverage.

    The combination of a very short stem and very short bars, for instance, makes the bike very, very twitchy at low speeds but much more effort is required to combat the centrifugal force of the wheel at high speed (which is where a longer stem or a longer bar would help, giving you more leverage). Short bars on long stems and long bars on short stems tend to feel much the same IMO, cancelling each other out if you know what i mean. Kind of depend on how you take off one and how much you add to the other.
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