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tire slip???(11 posts)

tire slip???kushogun
Nov 15, 2001 11:37 AM
Hey all. I am riding on a set of 700 x 23 Axial Pros. They have around 500 or so miles on them, so not too used. Anyways, when I climb out of the saddles on very steep, short (150 yard) climbs, the rear tire slips. Like a drag racer, the tire slips and spins out. I still move forward, but the slipping causes not only a disruption of climbing tempo, but wasted energy input, and loss of much needed forward momentum. Is it a tire problem or technique problem? I weigh around 140 so my light weight doesn't exactly keep the bike planted to the asphault. Still am surprised that this happens. Any suggestions would be great! Stay out of the headwinds across Kansas and happy riding everyone!
??Dog
Nov 15, 2001 12:01 PM
Probably not the tire. I've ridden those for well over 10k miles, and maybe had a slip once or twice, and then only on 20% grade type hills.

While your lower weight reduces the pressure of the tire on the road, it also reduces the resistance to forward travel (inertia). So, getting heavier would not help.

Weight balance might be the issue, though. Keep your weight further rearward in situations in which the tire might slip. You ever mountain bike? If so, this would be instinctive by now. Also, keep the power pulses smoother. Lower gears, or rounder strokes.

Can't think of what else.

Doug
re: tire slip???grzy
Nov 15, 2001 12:06 PM
You need to get smoother on the bike. Ultimately any thing will slip if you're far enough forward, the hill is steep enough, and you're jerky on the pedals. Skilled MTB riders are very familiar with this phenomenon. You can try shifting into a larger gear such that you don't put as much torque into the rear wheel (trick used in the snow on a car w/std. transmission).
get a larger innertube (nm)Rusty McNasty
Nov 15, 2001 12:44 PM
Let go of the front brakefirstrax
Nov 15, 2001 12:45 PM
(posted this response already... seems to have vanished)Jofa
Nov 15, 2001 12:53 PM
I'm surprised too as I've only ever known this happen on wet roads. I've ridden a great deal in Cornwall (UK) which specialises in very short, extremely steep climbs, and there are one or two which are infamous for inducing wheelspin in the wet, which is frequent as many Cornish roads also route freshwater springs.

It isn't the tyres. In this respect, tyres are simply tyres: if you spin one you'll spin another- the spread of grip characteristics across different brands isn't enough to have an effect here. I hesitate to use the word 'technique' with regard to cycling, and add to the big pit of mythology in which every excuse for being a bit unfit is buried, but I'd say this is something you can stop by changing your approach. Look at the way mountain bikers tackle very steep, slippery inclines. They keep their weight well over the back wheel (though off the saddle), turn a low gear, and keep their upper-body movement down.

There is a flamboyant school of climbing which light riders often adopt, which involves a lot of animated body motion respective to the bike. Pantani is good at this- as are many others who benefit from an extremely high power/ weight ratio, and as a result climb hills very well. Because they do so well, it's sometimes thought that this grutuitous hurling about of their bodies is the secret to their success. It isn't, but it may result in their wheels slipping on steep climbs. If this sounds like you... stop it. Relax and climb naturally.

Jofa
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center of gravitygtx
Nov 15, 2001 1:02 PM
there's a very steep, short hill that I have to hit out of the saddle and it's often wet and slick. When I hit it on my regular road bike, I have to do as grz says and adjust my weigth a bit, like I was riding a mtb in the mud. I was surprised, though, when I recently did this on my Merckx, which has very laid back geometry--I couldn't get the tires to slip, even if I wanted to. In fact the Merckx feels perfectly balenced whenever I'm out the saddle--it's the most stable sprinting bike I've ever had. It's a center of gravity thing, not the tires. And yeah, like grz said, smooth spin and bigger gears will make it go away.
Not slip and normalLI Biker
Nov 15, 2001 1:44 PM
When you stand, your rear wheel and tyre will go backward about three inches. I don't understand it, but read it and since then observed it.
Not slip and normalbrider
Nov 15, 2001 1:48 PM
Unrelated to the thread, but true nonetheless. This is an effect of moving the center of gravity forward -- the rear wheel travels backwards relative to the constant speed of the rider. This is something to especially watch out for in a pack going up hill -- leave enough gap so that the rider in front can stand and not make wheel contact with you.
Traction Bars and Bleach (nm)Chen2
Nov 15, 2001 3:45 PM
Practice in the SnowB2
Nov 15, 2001 6:18 PM
Traction is more of an issue mountain biking. In mtn biking, you want to keep your weight forward when climbing to keep your front wheel on the ground. The problem is that when your weight goes too far forward, you loose traction in the rear wheel.

Just recently I did a mtn bike ride in the snow. Great practice - if I pedaled too jerky, the rear wheel slipped. If let the CG move to far forward, the rear wheel slipped.

Like some of the previous posts said - pedal smoothly and don't shift your weight forward on the bike so far.