Scary incident today, I had an interesting encounter with the limits of adhesion on the bike. I suppose this belongs to the list of uninteresting anecdotes most don't care to read about but I have serious safety issues to address.
I've been riding this bike for about 25K miles over the past 4 years on every type of pavement, including trashed Montreal roads and silky smooth track courses, yet this has never happened.
As I was braking fairly strongly from about 50mph after a careless driver moving much slower than me switched lanes 50ft ahead of me, the front wheel locked up with an accompanying ominous hissing sound. I backed off the brake lever for a fraction of a second to let the tire gain traction and applied brakes again, it locked up a second time. I was still traveling at about 30mph when it was all said and done. I parked the bike on the side to inspect the skid marks, the first one was about 8ft long. It happened too quickly to be frightening, I had never experienced front wheel lock up.
I looked around for debris or painted symbols/lines on the road that could have reduced traction, I couldn't find anything significant. Pavement was perfectly dry, on a sunny hot day. Tire has about 5K miles on it.
Why did this happen? Could it be that I pulled too hard too abruptly on the brake lever, given the emergency braking I had to do? Could it be that there's something not working properly in the braking system?
Personally, I would check tire pressure, road conditions (like you did), and tire wear. If you find the problem right there, fix it and go have a beer in the Old Montreal, you deserve it. If not, I'm sure someone much more mechanically-inclined will chime in.
ppm
It was locking up because you were grabbing the brake. You need to squeeze it progressively to allow weight to transfer to the front tire, which increases traction for more braking. It is difficult to brake well in an emergency situation unless you practice it constantly and becomes muscle memory.
I would ask...what was the air temperature and the Road temperature as well. Over the last week I driven in quite cool up here, 9C along route 327, 11C in Vaudreuil and I can say that is makes a difference in tire adhesion when the ashpalt is cold. The air warms up pretty quick in the morning, but the road (depending on amount of sunlight) may still be quite cold from overnight.
Either that or you have to get those muscle spasms on your right hand looked at... :blink:
After you have gone though the brake check as everyone has suggested, and if you found no problems with the equipment.... I would suggest a simple change in your brake control(you).... lets say you ride with 3 fingers on the brake lever..... start using 2, and practice quick stops... If it's still to much try 1 finger.... You'd be suprised how much difference it makes as far as not locking up the front.... Also how much pressure you can put on the brake when in a panic situation.. I only keep 1 finger on the brake and when the panic button was hit it had plenty of stopping power "without causing front wheel slide"....... Did I come up with this ingenious concept, no... Keith Code did.... "Track, or street use use what works best for you and the bike together"......
It does take a lot of practice to get that front brake down. My thought going into it was that the rear would lift up instead of the front locking up. So when the front locked up on me, I was a bit surprised, even with my sticky Rosso's. Really need to find that nice, progressive pull and the point at which to stop applying more break to get it all right.
even clean dry road can be slick, in Florida they use coral for some of the roads, and some places in the us that get too much limestone in the asphault they can be very slick, even when perfectly dry. These components dust badly, and just the lightest coating of this dust makes a huge difference(much worse if it has not rained in several days) and sticky tires actually are worse on this surface as they stay coated with a layer of dust and have very poor grip, roads like this are deadly when the rain first starts because they have effectively a layer of clay on them and are slick as a greased ball bearing.
The hardin valley exit off pellissippi parkway is like this, and you can do a full on four wheel drift in any car at that exit,when the rain fist starts as slow as 20mph.
my guess is that you over applied but there can be other factors, by the way were your tires cold? the sticky tires are actually lower in grip cold, than firmer ST tires. We see a ton of accidents around here from cold tires. 129 is famous for them people stop for a few minutes and the full power out back on the road and down they go, it doesn't help that a bunch of the rickey rocket types run race take offs, or track rubber that are slick as hell when cold.
Interesting replies. Thing is, I've been experimenting with the bike's traction ever since I got it, I never managed to lock up. I usually brake with 2 fingers but I can't remember whether I used the same technique this time around, I don't get to experiment with these emergency situations often.
Most likely, as it usually is, rider input is to blame. It is harder to judge how much force is required when things happen this fast, even harder to properly time the gradual buildup on the lever. I must say it came as a great shock to me that the bike would stay up in this situation, the steering only slightly jerked sideways. There goes modern chassis design!
Yeah, sounds like too fast and hard a grab on the front brake.
It can be tough to squeeze it slow when presented with a situation that needs emergency braking. :unsure:
A couple weeks ago I grabbed a handful on my other bike and got a good screech out of the front tire before I let off and tried again. Yikes! :blink:
[image: View Post]VFR4Lee, on Sep 7 2009, 11:45 PM, said:
Yeah, sounds like too fast and hard a grab on the front brake.
It can be tough to squeeze it slow when presented with a situation that needs emergency braking. :unsure:
A couple weeks ago I grabbed a handful on my other bike and got a good screech out of the front tire before I let off and tried again. Yikes! :blink:
Yep, What he ^^^^^ said.
End of thread · 11 posts recoveredWayback Machine snapshot 12 Apr 2010