Off! Rear Wheel Slide: how, why?

[alp1950]

Ironic really. Thinking how nice to be on completely dry roads for the first time for several days but going home this evening came a cropper. (Road bike Kinesis Racelight; Continental Gatorskin Hardshell 700x25).

Right hand turn around fairly tight radius roundabout. Relatively slow speed and not particularly aggressive lean when suddenly rear wheel slides away and I'm down. Rather unpleasant moment, presumably just as slide started, when I saw that rear wheel was at an impossible angle & knew this was irretrievable and I'm going down!

Obviously rear tire lost traction but not sure why. Road was dry, no debris, road markings or drain covers. No obvious diesel spill. Not a roundabout I've ever felt felt really comfortable with: it is very tight, and would probably suit a criterium course. Often find myself going just a bit too fast into it and having to compensate by drifting to the outside slightly. On this occasion though I'm sure my speed was sensible and I was holding my line (admittedly rather tight) on the inside without trouble. Pedals well clear of road & unless I'm mistaken I wasn't leaning too far over and no recollection of touching the brake.

Previous offs have been infrequent, and there has always been an obvious explanation usually involving a combination of speed and poor road surface. A bit perplexed particularly as this occurred in reasonable road conditions and at slowish speed. Makes you worry a little about the implications- if you can go down so easily in apparently optimum conditions. My best guess (and hope) is that I hit a patch of diesel even though there was no obvious road staining- but how easy is diesel to spot in streetlights anyhow?

 

[Andrew_P]

Sounds a bit strange and is bound to be a confidence knocker, could have been diesel/oil further back maybe only on your outer tyre edges? Newish Tyres?

I had a few skits lately that have knocked my previous bullet proof confidence.

 

[deptfordmarmoset]

Sounds a bit strange and is bound to be a confidence knocker, could have been diesel/oil further back maybe only on your outer tyre edges? Newish Tyres?

I had a few skits lately that have knocked my previous bullet proof confidence.

I can't say what the cause was, but LOCO, your point about diesel or oil on the outer tyre edges is a good one that I'd never thought about before. I've recently been using a spray lube for my drive chain and I've noticed traces of oil on the floor but never stopped to think that this oil could be lingering off centre on the tyre walls, unaffected by straight-line cycling, until you need the grip in a corner.

 

[Falwheeler]

Happened to me once, cycling along one minute next I'm lying on the road, I wasn't even on a bend. No idea what happened, I assumed it was diesel on the road

 

[alp1950]

Sounds a bit strange and is bound to be a confidence knocker, could have been diesel/oil further back maybe only on your outer tyre edges? Newish Tyres?

I had a few skits lately that have knocked my previous bullet proof confidence.

Thanks for that.

There has been a lot of construction traffic on that road & tonight although the roundabout was clear of debris it was wet (which was odd as it has been dry all day). Also the the construction traffic has resulted in large amounts of dirt and debris along the 1km stretch before the roundabout. Diesel spill further back, debris picked up on the outside of the tire or some unseen crud on the roundabout could be any number of reasons possibly related to the ongoing building works.

 

[martint235]

I can't say what the cause was, but LOCO, your point about diesel or oil on the outer tyre edges is a good one that I'd never thought about before. I've recently been using a spray lube for my drive chain and I've noticed traces of oil on the floor but never stopped to think that this oil could be lingering off centre on the tyre walls, unaffected by straight-line cycling, until you need the grip in a corner.

Apart from the slippy qualities I read somewhere that lube will accelerate the perishing of tyres so I always make sure any drips are wiped off the tyre and the floor

 

[gaz]

Gatorskin hardshells are known for having a mind of their own.

 

[alp1950]

Gatorskin hardshells are known for having a mind of their own.

Interesting.

Tell me more

 

[gaz]

Interesting.

Tell me more

They have pretty low grip, anything that might make your wheel slip, probably will.

 

[Andrew_P]

Must admit I had heard that too about Gatorskins, I went for the GP 4 Seasons 28mm for the winter rides. But I reckon 25mm if that is in contact with the road in a straight line

I always wipe down my tyres after lubing. The reason I mentioned the outer is that I often muse looking at the front wheel noticing that the side contact points remain dry until I corner (when the road is moist as opposed to wet)

As a side note what is the most effective Tyre degreaser? I could smell the diesel this morning and was looking for it, nay waiting for it but couldn't see it, I just hate that feeling!

 

[Matthew_T]

Was it a cold day? I have noticed that when I go out on a dry evening, I can see a glittery effect on the road caused but the cold air causing a little bit of freezing in the cracks of the tarmac.
Another thing is that your tire might have caught a liitle lump or change in surface from the roundabout.
Plus do you have a google link to the place where it happened so we can have a look ourselves?

 

[fossyant]

Sh1t happens sometimes, don't over analyse it. You've mentioned you are pushing it in the corner. Diesel spills are also dangerous in the dry, but you can't see them as well as in the wet. Could have easily been debris.

 

[Jezston]

I have Conti 4 Seasons on my 3-speed wheel and Gators on my fixed. Additional grip on the 4 Seasons is MASSIVE. Confident going through wet leaves, rainbow tarmac, puddles, whatever on these. They are SO grippy, much more so even than my fat hybrid tyres.

 

[Jezston]

Also, is it actually Diesel then that leaves the greasy rainbow patches on the road? I always thought it was leaking oil. Why Diesel in particular?

 

[fossyant]

Also, is it actually Diesel then that leaves the greasy rainbow patches on the road? I always thought it was leaking oil. Why Diesel in particular?

It's diesel. Diesel contains oil. It's mainly overfilled trucks/busses - just spills out. Just think how much oil would be needed to create some of those slicks.