MTB Handling- Understeer

[RexFuzzle]

So I have a problem whilst going downhill- The front wheel tends to not stay under the bike much, i.e. it is very keen to slide sideways. I don't enjoy the feeling and don't think it should be. Question is, other than the tyre choice, what influenced this? It is purely the head angle? Shock setting?

I am guessing it is a combination of things, but which one would be the easiest to change?

[Smolly]

Rider weight?

[Iron]

Tires

Tire pressure , get this right

Shock setup, and this right will be the easiest and best place to start.

 

Rider skill

Edited June 27, 2012 by Iron

[Smolly]

Using front brakes?

[covie]

Tires

Tire pressure

Shock setup

 

Rider skill

 

could also be flex or a wheel not being true. but more than likely you need to check your rebound and dampning settings with your tyre pressures. What shock are you running?

[Grebel]

What is your body position like? You might try moving further back (Not too far) if your weight is too far forward

[mikeMT]

could actually be something as simple as tyre been under inflated for your weight, had a similar issue, took the tyre up to 2bar and no more issue.

[RexFuzzle]

75kg

Position: Back, but not over the saddle

Tyres: Crossmark- around 2bar or more.

Wheels: Mavic Crosstrail. True as far as I can tell.

Shock: Axon Air.

Don't see how it can be the shock as it happens on smooth roads too, ie where the shock isn't moving (What I can see). As far as I can tell it is simply the wheel not having grip and sliding- maybe I am expecting too much?

[mikeMT]

well if its happening on smooth roads i would definitely look at changing tyres, perhaps a dud set?

[BLACKvoodoo]

I had the same issue, Wrong tyre for what I ride, Shock settings,tyre pressure

But it was mostly tyre pressure

[droo]

Crossmarks in winter aren't the grippiest, but what you're describing sounds more like you've got your weight too far back. The more weight you have on your front wheel, the more grip it's got through a corner. Also, if you're braking in the corner it'll cause the bike to sit upright instead of leaning into the corner, which makes the bike "push" through the corner instead of rolling. Do all your braking (or at least as much as possible) before the corner, even if it feels like you're going in too slowly, and just allow yourself to coast through. If you must, drag the back brake lightly to maintain speed, but don't touch the front brake in the turn.

 

If it's bike-related and not technique, check wheel bearings and headset bearings for tightness, and make sure there's no play in your fork bushings.

[Mojoman]

I run those crossmarks at almost 3 bar with no issues on dirt roads (dry) and paths. But I am 100kg.

[covie]

I am not a fan of crossmarks well def not as a front anyway, but going sideways on flat ground? That makes no sense, do you have any play in your shock/headset assembly? At 75k you can run them probably 1.8 front 1.9 rear.

[BLACKvoodoo]

I think your strokes to short and you're getting premature extension.

[dracs]

What is your body position like? You might try moving further back (Not too far) if your weight is too far forward

Crossmarks in winter aren't the grippiest, but what you're describing sounds more like you've got your weight too far back. The more weight you have on your front wheel, the more grip it's got through a corner. Also, if you're braking in the corner it'll cause the bike to sit upright instead of leaning into the corner, which makes the bike "push" through the corner instead of rolling. Do all your braking (or at least as much as possible) before the corner, even if it feels like you're going in too slowly, and just allow yourself to coast through. If you must, drag the back brake lightly to maintain speed, but don't touch the front brake in the turn.

 

If it's bike-related and not technique, check wheel bearings and headset bearings for tightness, and make sure there's no play in your fork bushings.

hmmm?? So which one is it then - weight forward or weight back? currently also have crossmark on the front and in tight stuff find I tend to understeer Edited June 27, 2012 by dracs

[RockCoach]

Once you have got tyres and pressures sorted...

 

Is the tyre scrabbling for grip? Your weight may be too far back so lean forward briefly to get the front to bite.

Do you touch your front brake on the entry to a turn? Even slightly? That will cause the wheel to want to stand upright which will throw your whole cornering balance out.

Is your body in a low standing attack position on corner entry? Outside pedal down?

Are you leaning the bike over far enough keeping your body a bit more upright?

Do you turn your head and upper body mid corner to 'aim' for the exit.

Do you keep arms and legs relaxed to soak up undulations?