Front Wheel "Tucking Under"?

Quick one – I was making some progress on a descent today, first time out on a reasonable length ride in a few years. On a bend my front wheel felt like it was tucking under the bike and I was pretty close to coming off.

Any likely suspects to be looking at? It is a 7 year old bike, but I never had problems when I used to ride it regularly (3 years ago now). There is perhaps a slight buckling on the front rim, not much, but a bit of a wobble on – and that is all I can think of. Or should I be looking to the hubs (Hope Bulbs)?

How hard were you pushing/what tyres(eek!)

Most likely to do with the steering set up; either the stem is too long or too short for the head angle and fork length set up. Usual culprit is stem being too long, try summit a bit shorter.

According to the gps… 52km/h on Halo Coir Masters (tubeless) pumped to 40psi

And stem is 60mm I think.

Yeti 575 on Pikes

Is that faster then normal, have you been generally comfortable on the tyres?

I only get that sensation when I lay it in too hard, it’s normally followed by winding up in a heap in the nearest hedge!

Rebound set too slow?

To be fair I haven’t been on the bike in an age… well not one without a big motor and really chunky tires!

The tires were always fine in the old days, I moved to them after Nokian NBXs got too pricey!

Starting to think it may be the tires though… although the whole cockpit was replaced earlier in the year in preparation as I felt really unhappy with the old one on getting back in (bike too twitchy).

Rebound is possible but unlikely as it hasn’t been touched since I got it dialled in many years ago… unless it got messed with when the bike was serviced. Shall take a look at that too ta!

And I am fine on the hardtail Marin so it is just this bike rather than the rider 😉

If the Pike has only got 140mm, that won’t help…you would be better with a slightly longer fork on a 575.

Yeah, I keep thinking that myself. When I built the bike up the Pike was about as long as it got without remortgaging the house for a Fox 36 (I think that was just about released around then).

In two minds about doing any major upgrading as I think I will just get a new bouncy bike in the Spring. Perhaps it is time to retire the old Yeti…..

forks are diving.

Now that seems a very likely scenario – it was a steep ass hill, I am not that small, and the forks are old and perhaps the springs are a wee bit tired.

Unless I can find something used and cheap though I suspect that I will just have to ignore it for the moment, especially if I am thinking of something new next year (that new Cube Stereo is looking mighty fine!)

It won’t be tyres.

Given the other info, either the forks are diving, you’re too far over the front of the bike, or you are too nervous on the bars – understandable if you’ve been off the bike for a while.

Instead of turning into the corner, actively pull the “inside” handlebar down to lean the bike and use the edge of the tire to turn rather than (over)”turning” the bars.

Both my intense’s were the same, and the above solved the issue.

Oh and leave the front brake alone.

ryton57 – Member
Instead of turning into the corner, actively pull push the “inside” handlebar down to lean the bike and use the edge of the tire to turn rather than (over)”turning” the bars.

slainte 😉 rob

A fellow Jedi student saved me from correcting that myself! 😉

lol – I knows all about countersteering 😉

Got a few things to investigate now though! I don’t think it is anything I am doing – as I said, I am fine on the Marin it’s just the Yeti which is causing the issues. Most of it is from it’s original build so I suspect that it is generally getting pretty tired.

New toy in the Spring I think. Get myself fitter and lighter first! If needs be I can always move bits about from the Yeti to the Marin to make life easier on that one (it is slightly newer and has had a lot less use and abuse as it came along shortly before I started tailing off riding due to work and commuting)

CGG – just trying to spread the word.

slainte 😆 rob

chiefgrooveguru – Member

A fellow Jedi student saved me from correcting that myself!

I may have had a hard week, but that has got my head spinning about my own biomechanics re push/pull… Help…. 😯

P.S. If its the bike you obviously need a 29er/650b with dropper post and whatever else is being marketed right now, to save your skin.

😀

I made the correction as I think ‘pull’ suggests the wrong weight distribution and body position when cornering.

Suggesting ‘pulling’ on the inside bar indicates your weight should be low and ‘inside’ the bike’s line through the corner which would give no grip to either wheel.

Using ‘push’ instead suggests your weight should be ‘outside’ the line and using your inside arm (and upper body) to lean the bike into the corner – keeps your weight centralised and therefore pushing the tyre footrpint into the ground for maximum grip.

Hope that makes sense – hard to put into words in some ways.

EDIT – Not the clearest picture and I’m not claiming to be technically great, but in the photo you can hopefully see my inside arm is straighter than the outside and is pushing the inside grip down into the corner while my weight is still central.

slainte 💡 rob

I made the correction as I think ‘pull’ suggests the wrong weight distribution and body position when cornering.

Suggesting ‘pulling’ on the inside bar indicates your weight should be low and ‘inside’ the bike’s line through the corner which would give no grip to either wheel.

Using ‘push’ instead suggests your weight should be ‘outside’ the line and using your inside arm (and upper body) to lean the bike into the corner – keeps your weight centralised and therefore pushing the tyre footrpint into the ground for maximum grip.

Hope that makes sense – hard to put into words in some ways.

slainte rob

I absolutely agree, I’ve been Jedi’d as well. I just didn’t get the biomechanical description right – so yes, to have outside pedal down, you’d be “pushing” the bar down into the corner with your upper body.

EDIT: I have a picture similar to that (straight arm) 😀

If your fork settings are off (particularly if they’re air) then the bike will do all sorts of odd things. Have you checked your pressures lately? Someone mentioned dive, this could be unwanted difference in the chambers or simply inadequate pressure. Obviously not an issue if coil!

Similarly if the fork dives from braking before the corner and lacks the spring rate and/or rebound to recover it’ll feel squatted as you pull teh Gs.

I may have had a hard week, but that has got my head spinning about my own biomechanics re push/pull… Help….

Book a session with Jedi, it’ll all make sense after that 😆

You may be hitting the compression part of the turn a bit harder than you used to. This may result in pressure on the hands/fork and cause it to “dive”. Compression of the fork and the “tuck” can be a good thing as it sharpens the steering out of the corner, or a bad thing if not expecting it.

To some extent you can just increase either the fork spring-rate (more air) or increase compression damping a touch, to the detriment of sensitivity. But you can also adjust your body position low/back a little more through the compression part of the turn.

whenever I’ve had that feeling (twice – summer 97 and march 2000 😉 ) I’ve come to the conclusion that I’d not leant the bike enough for the entry speed and had overturned the bars instead – If I’m not concentrating but going q fast I tend towards this and sometimes have to wake up and force myself not to turn the bars and lean more instead

i’m crap on a bike, i’m a great example of ‘how not to do it’.

to my understanding, a bike feels stable because the front-wheel’s-contact-point is behind the steering axis.

this offset is called ‘trail’.

But as you lean a bike over and turn the bars, the contact point moves forward, the amount of trail is reduced.

try if for yourself; stand beside your bike, lean it over, and turn the bars into the ‘turn’ – look at what happens to the contact patch as you turn the bars.

i’m not sure how any of this helps, but there is a mechanical / geometry-related factor at work here.

A slacker head angle would help – to move the contact patch backwards, wider bars may help – to control the tuck, and stiffer forks – to hold the front end up – see head angle comment.

perhaps you just found the perfect amount of lean/turn to really do something weird to the contact patch…

If things are largely as they were before and you are riding as you were before I would suspect that the tyre compound may have gone hard over that number of years, particularly if the bike has been kept exposed to daylight. This will reduce the grip available.

Hmmm – few things to think on. Coil spring forks though, no no air pressure.

Just thinking – I may have had the seat post higher on this bike than t’other which would pitch me more forwards, could be something as simple as that.

And on the being sold into 650b/29″… there is a big difference between being sold into something and just plain fancying it 😉 Just been told that I should buy another bike by the better half anyway… but will hold off over winter!