revtothelimit - motorbike forum

Following a mate on his HD 1200 Sportster. He's been riding it for ages, used to be a CBT instructor years ago. Very wet day, lots of surface water etc, twisty but ordinary road. Following a lorry at very modest speed, halfway round a moderate LH bend he suddenly straightened up and went across the road through a gap in oncoming traffic, and stopped on the offside verge. Traffic steered calmly round him. He was SO lucky. Afterwards, his explanation was that his front tyre lost grip and washed out, so he couldn't steer any tighter and had to straighten out. I don't think he was as shaken as I was, watching it happen.

No obvious road surface issues, tyre is a 1/3 worn Bridgestone something, he swears he didn't touch the front brake, I didn't see a brake light and we'd been round lots of similar corners in the previous few miles.

I don't like unexplained incidents, so explain, please.

Perhaps the front wheel caught a bit of something slippy for a few feet, he panicked a bit and just stood the bike up?

Diesel, overbanding, tyre groove worn into tarmac full of standing water causing an aquaplane, small depression in the road with more standing water etc ...... thats a few possibles and i am sure many more can be thought of.

Maybe it was just the genetic Harley aversion for corners and it realised what it was doing and panicked **


**that bit is probably true but flippant

If he couldn't steer (no front tyre grip), how did he straighten up?

I can't explain it but have seen something similar. A friend and I were traveling back from Wales, he was in front and we were on a straight road that was broken by roundabouts around the Windsor area. The conditions were fine, not cold or damp and we were not riding in a spirited way - quite boring really. Going over a roundabout, both of my friends wheels washed out at the same time. He kept it upright and as I was behind him I had a good look around at the road surface and couldn't see anything that would have caused it - gravel, deasil - nothing. It's still a mystery that we bring up in conversation now and again.

Trinity765 wrote: Tue Nov 29, 2022 7:21 am He kept it upright

No slur intended, but 'he' probably didn't. More likely that he didn't react and do something to unsettle the bike so that, when he (the bike) reached a better surface, it regained grip and carried on.

From the 'foot position' thread:

Horse wrote: Fri Nov 25, 2022 11:24 pm In the late 79s / early 80s, Southern Television (covering the current Meridian area) did a couple of series of a programme called Talking Bikes.

One featured the Dunlop tyre testers, the same guys seen in Wobble and Weave (youtube if you've never seen it).

They were brain out mad feckers.

One section of curved test track has a radial ridge, abou 1.5-2 inches high across the track.

Voice-over:
"And this is to test how ... "
Honda Cb750F1, with mainstand sparking as its leant over, comes hurtling around.
"Tyres regain grip."
BANG
Bikes takes off when it hit the ridge, crashes back to ground, continued on, sparks from mainstand.

IIRC the i2i Academy get people to ride over sand mid-corner.

At 30mph you're doing 14 metres a second, so if your bike slips on a cover, you're further down the road before you can react.

Head and eyes up, looking where you want to go, keeping the power on, steady.

Reminds me of many years ago in the Scottish Highlands on my fully loaded and with pillion Norton Dominator 99. Streaming rain as usual up there, came round a bend to be confronted by a cattle grid while still cranked over. I had no time to do anything (being young and foolish) so just clung on. The front twitched sideways as it arrived at the grid, followed closely by the back - this was repeated on the far side of the grid and we carried on, suitably shaken but about a yard further across the road than my original line.

If I had tried to do anything I'm sure it would have ended in disaster. Saved by a featherbed frame and TT100s.

Oh, I'd love to see that clip of Talking Bikes mentioned by Malcolm.....

iansoady wrote: Tue Nov 29, 2022 9:51 am Oh, I'd love to see that clip of Talking Bikes

So would I!

It's probably in a dusty archive somewhere, along with the BBC's 'Sorry Mate'.

Coincidentally, in the context of this thread, another programme featured Manchester police. 3 bikes (also IRRC F1 Hondas) escorting an ambulance. Unsurprisingly, given the location, hissing rain. With the 'leapfrog' pass-stop/block-repeat method, it means the riders need to be going 2x the speed of the ambo. A lot of acceleration and braking.

TT

NB in the title sequence there's a guy spinning the rear of a traily bike, spraying gravel and dirt over people watching. He was a police instructor, they were his trainees!

Ooh ....

When was the head bearings last changed? Get front end up and feel for notches when turning slowly.

Seems strange for a diesel/slippery road bit.

Last one I saw was on my Balkans trip, following a bloke on a GS. Pissing with rain, getting dark, and we were not pushing it because the road was slippery. He lost it on a bend, low sided and he slid across the road, the bike pirouetted several times and ended up on our own side and I managed to stop before hitting it. That was almost certainly diesel, and it happened so fast he didn't have a clue what happened. He thought the bike went down on the high side, it didn't.

wheelnut wrote: Mon Nov 28, 2022 11:17 pm Perhaps the front wheel caught a bit of something slippy for a few feet, he panicked a bit and just stood the bike up?

I ran over a number plate with the front wheel laying in the road one morning. I was on an H2. It went knee down (unintentionally), followed by arse, elbow, ambulance. Didn't occur to me to get the plate & track the fucker down.

Horse wrote: Tue Nov 29, 2022 7:36 am

Trinity765 wrote: Tue Nov 29, 2022 7:21 am He kept it upright

No slur intended, but 'he' probably didn't. More likely that he didn't react and do something to unsettle the bike so that, when he (the bike) reached a better surface, it regained grip and carried on.

Yes, I agree as he is an experienced rider on road and off road.

Trinity765 wrote: Wed Nov 30, 2022 7:18 am

Horse wrote: Tue Nov 29, 2022 7:36 am

Trinity765 wrote: Tue Nov 29, 2022 7:21 am He kept it upright

No slur intended, but 'he' probably didn't. More likely that he didn't react and do something to unsettle the bike so that, when he (the bike) reached a better surface, it regained grip and carried on.

Yes, I agree as he is an experienced rider on road and off road.

It's easy to say "Oh yes, all you need to do is keep a relaxed grip, look where you want to go, and maintain steady throttle" that's a tad difficult for most riders. First hint of a slide or twitch and it's tense up - look down at road - chop the throttle. His off-road experience may have made the difference.

Sorry I haven't been back sooner - busy. Some interesting ideas and war stories there. I don't really like rding with him much - he is too erratic re speeds, positioning, decision making in general, in spite of his experience (CBT trainer, lots of years riding etc). I think he may have had a "funny feeling" - real or not - from the front, and reacted, wrongly. The road had no apparent significant irregularities. The last time we rode that road, he discovered afterwards that his back tyre was about 10psi too low, which messed up the HD's "normal" handling (!), and I suspect that experience may have been in his head this time. He's never done anything like that before, tho!

I also think that what bothered me more than anything was that I seemed to be more concerned about it afterwards than he was.

Malcolm's suggestion may be close to the mark:

Quote: "First hint of a [imagined?] slide or twitch and it's tense up - look down at road - chop the throttle".
[/quote]

Possibly a petrol spillage. It's just as slippery as diesel but almost invisible, and it evaporates really quickly so the evidence is gone.

Years ago, I was just turning right towards c London from my flat in Rotherhithe at the roundabout when another rider came flying across in front of me turning left from Lower Road and ended up sliding across the road. He went down pretty hard and it was an ambulance job. I noticed that he'd crossed a wet-looking streak and I dabbed a finger in it - it was petrol. The police were on the scene in five or six minutes and asked me if I had any idea why he came off. I mentioned the petrol, but by that time it had evaporated.

Just recently there was a fatal on a motorway slip road when a rider highsided and was hit by his own bike. The accident investigation couldn't come up with a cause - I wondered if it were petrol too.

There's a fair chance that when drivers find a petrol station that's cheap, they are over-filling.

5pm driving home from work in the dark. I'm behind a car on an unlit road with no rear facing lights on, including number plate, nothing. It's a newish car with those full width rear lights. However, his front lights are on as I can see the hedge light up with his lights.

When the car gets to next village he wakes up and puts lights on. Question is, are these front only DRL lights improving safety or making things worse, presuming they were DRL's ???

Dodgy69 wrote: Wed Dec 21, 2022 7:14 am When the car gets to next village he wakes up and puts lights on. Question is, are these front only DRL lights improving safety or making things worse, presuming they were DRL's ???

Similar with the 'auto' headlamp setting in fog, which can be bright enough (unlike some drivers) and not switch the headlamps on -leaving just the daytime fairy lights.