Thanks everyone, reassuring that it's likely to be surface contamination rather than my own ineptitude, even if once it had started I perhaps didn't do the right thing to help the situation.
Sounds kinda shudderous. GWS.
BTW, I run GP4000s 25s at 7 bar for 70 kg of me. 6 sounds like the edge of I-want-snakebite territory, but I can't imagine it causing a skid.
In the summer I ran GP4000s ii 28mm's at ideally 6 bar, but down to 4 bar at times. No snake bite issues.
It does sound an awful lot like diesel, or a fine layer of chutney or black ice or something: You don't get any warning, the tyre-ground friction just stops working.
The main thing I'd have done differently would be not riding another 100km on a b0rked knee, but a good rule of thumb is that if the steering isn't working properly, grabbing the brakes is unlikely to improve the situation.
GWS!
I think there was a certain amount of adrenaline thing which meant that the level of pain didn't really register, which is probably why it started to hurt more towards the end.
Analysing the strava data of the ride, despite crashing in the middle, I took 4 minutes off the segment (24:48 down to 20:36). (I also took minutes off various other segments later in the ride (Holtenberg, Lameleberg)).
Sorry to read about your off. Bad luck and hope the knee recovers 100% and soon.
I took 400mg Ibu When I got home, took another 400mg the following day, No visible bruising, no visible swelling now, and it didn't hurt when I cycled to work this morning. I think I may have been lucky.
As others have mentioned, sounds like diesel or other oil.
Not much you could have done about the initial slide, but locking up on the brakes guaranteed a fall.
One drill I've been taught on a motorcycle skills day is to practice deliberately locking up wheels in controlled conditions, so that you know what it feels like and develop a muscle memory for what to do - which is to let the brakes off instantly. (Especially the front - you can get away with locking up the rear a bit longer). When you've practised hard enough, you can leave a row of black marks on a dry road, like a dotted line.
It may not have saved you - but locked up wheels are not going to regain grip in a helpful way. With the tyres no longer subject to braking forces, they may have regained enough grip to get around the corner.
Interesting. Might have to do some work on my bike handling skills.
As an aside, is there a cultural difference with PTWs in the Netherlands? Just about every biker I know in the UK, having seen you wipe out, would have stopped to find out if you were alright.
PTWs ? People on Two Wheels?
I don't know if it's a Dutch thing, but I've certainly noticed surprise from people in Sweden, Denmark, and Netherlands when I have stopped to help cyclists by the side of the road. On one ride I stopped to help a couple of guys who had a puncture in .nl, they were first surprised that I stopped, where then even more surprised by the size of the pump I pulled out my bag, and when they asked how far I was cycling that day... was worth it for the look on their face... A guy in Denmark was surprised someone stopped to help him with loan of a better pump when he had a flat. And after I offered help (and was declined) by a Swede, he caught me up a few km later to say thank you for asking.
But then in .nl I have a roughtly 30% success rate of non-muggle cyclists waving/nodding back when I see them on the road... Different cultures I guess...
Cat (the english daughter) rode her Brommie into a Wantage pothole a few years back and suffered what was at the time put down as soft tissue damage on her knee and leg. The only problem was that the real damage was not soft tissue bruising but something far worse and the doctor's advice to keep using the leg to help repair the tissue damage turned out to be the opposite of what was really required. It took 9 months with endless arguements with medical experts and repeated time off work (not to mention pain resisting all known painkillers) to resolve the issue. Moral of story, if the bruising doesn't clear up in a reasonable timescale and the pain doesn't go away scream for a decent specialist who understands knees. Don't let it go unattended!
I'm keeping an eye on it. I doesn't hurt now, there's no visible swelling, and no bruising. But if that changes, I'll see the Huisarts PDQ.
Last night I fixed the rotation of the handlebars that happened when I crashed. They were down at least 10°, it was an easy enough fix, loosen bolts, move, tighten. But I'm not 100% certain there isn't some bending of the handle bars on the X axis of the bike, and also wondering if I should have any concerns about metal fatigue in the handlbars.
The bars themselves are quite cheap BBB ones, but the bar tape was about €50[1], so I'm holding off from replacing them as precaution, but I think I'll keep an eye on it.
Thank you everyone for your help and advice!
J
[1] Bar tape has a scrape on one side from an incident with a NS train, it's fine in use, but I don't believe it will survive taking off and putting on new bars.