Bonneville America Forums Forums Rider Safety Forums Riding Technique Crunch day

Well it happened to me the other day. still trying to figure out what happened. I knew my front tire was cupping cause when decellorating at 50 or so the handlebars shake back and forth. One time last summer riding in town,,30 mph I hit the front brake moderately and the handlebars nearly pulled out of my hands. well I forgot about that until thursday. I was following a garbage truck which I thought was going to pull into the same driveway I was heading into at about 35 mph and he stopped 100 yards early and it surprised me a bit and I stabbed the front brake. The next thing I new the handle bars cranked and I saw and heard the bike hit the pavement on its side and I knew I was next. I'm glad I was wearing gear, my helmet is junk along with my textile tourmaster jacket and boots. the footpeg broke off and the memphis fats and the cheap vinyl saddlebags held the bike up for the 10 ft. slide on the road. The left ankle hurts a lot but the doc says it will be alright. Would the alternate side cupping on the front tire cause it to pull one way or the other when braking hard? or is it my mistake for improper braking technique. I don't believe there was any sand or gravel on that part of the road but my thought was with the uneven tire surface area due to the cupping.

mike

Sorry to hear about your spill, Mike.

Mike,
Sorry to hear about your spill at least you came out alright, everything else can be fixed.

Sorry you crashed but at least you aren't hurt too badly. Sounds like improper braking to me but I wasn't there so I could be wrong.

Yeah, it's really hard to say from the write up exactly what went wrong except that you tried to guess where the trash truck was going, then it didn't do what you thought.

Very hard to say what happened. I saw a vid where one rider filmed his buddy in front of him as they were riding. All of a sudden the front bike started to wiggle out of control and wham... the rider went flying (he was okay in the end). Even after reviewing the tape the crashie can't figure out what happened to cause the accident.

Question: Do you have a spirit bell hanging on your bike? If not, someone needs to give you one. They are important. Sometimes there are unexplainable forces at work.

I ain't superstitious, but I discount nothing when it comes to riding.

Just my uneducated opinion, (sorry about your crash, btw...) but I doubt if tire "cupping" had anything to do with it. More likely than not, you've got a brake problem or a front wheel alignment problem that would cause a braking problem.
Warped rotor, stuck piston in one of the calipers, something along that line.
I've cupped 3 front Avon Venoms pretty badly before I changed them out and never had the experience you describe. They would cause a low speed front end wobble only if I took my hands off the bars.

I'd check things over rather carefully before riding again.

Sounds like a brake problem to me, either mechanical or operator. There are other possibilities for that tire cupping even though I don’t think it added to the crash. Among wheel bearings being a major culprit, I had a shimmy in the front end and it turned out to be rear wheel alignment. Once I got the rear true to the front it went away. It was wiggling since the first day I took my hands off the bars and noticed it. I meant to have the Steeler take a look at it, but I forgot to tell them when I took it in for service. Just recently put a nineteen tooth sprocket on the primary drive and I got screwed up counting turns on the adjustment screws for the rear axel. The notches weren’t close enough to anything to use as references so I used a very large caliper to measure from the swingarm pivot axel to the rear wheel axel centers. The front end shake, wobble, shimmy, is gone.
Now about that mishap you had, I’m very glad for you that it wasn’t worse, but sad that it happened. Hope all you injuries are minor and you mend fast. I also hope that it doesn’t cost the other arm and leg to get,er fixed up again. And when she’s up and running, go to a safe place and practice those panic stops so you’ll know just how much front brake it’ll take before the front wheel starts to slide. That’s something we all need to do after taking most of the winter off! Thanks for the wake up call.

I feel responsible due to not using any rear brake at the time but it seemed like I used just as much force on the front other times but just got front fork dip then. It happened so fast, like the mentioned video, I had no time to notice any other action of the bike, just crunch. It could of been a piece of gravel or winter sand but I doubt it. It was probably just me being a dumba$$. The adjuster came over today and took pictures and said he was going to get Triumph prices and let me know. He mentioned totalled, but said anything was possible even though it was all just scratches. I think the gear would add up to more than bike damage. anyway I am going to go and have the dealer check out the front end when the tire gets replaced to kill 2 birds or else I would change the tire myself.
thanks for the comments.

mike

the sand or gravel is a good thought and very possible. That would cause the tire to slide sooner then normal.

Could have been some dribble from the trash truck as well. At any rate, it sounds like the front brake locked up. When that happens, there is no way to predict what happens next except that it is seldom anything good.

EWWW, dumpster juice.
you wouldn't believe what drips out of those trucks...

mike

I love it when I get behind one of those municipal waste trucks and feel the spray.Refreshing on a hot day on the highway.

And, it leaves behind such a brisk, manly aroma that drives the chicks wild...

Sorry about your crash.
Now the pleasantries are out of the way, I won't worry about hurting your feelings .

First of all; you were too close to the garbage truck. You were following it so there is no excuse for a panic stop. You should have left yourself plenty of reaction room for the unexpected, that's rule #1 of riding.

Second, you state that this (grabbing and yanking) happened before, but you forgot about it.

Bad Mike, no cookie.

Your brakes are part of what keeps you alive on these things. You should have fixed it before riding again.

OK, that's enough chastisement, consider it (the crash) cheap education. By cheap I mean that you have no long term injuries and can talk about it.

Now for the brake grabbing problem:
Some good suggestions here, but I doubt that it was anything on the road since it did happen before. There's only one front wheel so the pulling part could indeed be due to the cupping if it's bad enough and more pronounced on one side, especially if the brake locked while a particularly bad cup was in contact with the road. In which case, you need a new tire.

The grabbing/locking could be caused by a warped rotor, that's been an issue with these bikes.

Bill, complacency sux. I probably was too close even though I didn't come near it ,why else would I have panic'd when I realized it stopped. Man a cookie sounds good right now too. At the time it grabbed the first time I was talked out of the tire theory by others. I am under the notion that anytime you break hard and have the handlebars tweeked a little or have a little lean going these bikes with dual disk front brakes are going to dump you. Looking at the scuff marks on the front tire, I can see the initial scuff on the middle of the tread and it moved to the side to where the tread quits meaning it skidded and kept skidding after the handle bars turned. As far as a warped rotor I have not noticed any pulsating during normal braking. I did notice shaking of the bars during decel though,,,cupping. Tire's been changed, attitude renewed, definetly going to change my habits too.
Thanks all for the input.

mike

I dunno about the dual disk dumping theory. I have a Speedmaster too and have never had any issues with the brakes, and I've had to apply them in less than ideal positions, leaned and/or turned.
And, thinking about it, the rotor warping was an issue with the B.A.s and the single disk front.

Maybe you just have really strong hands.

Can't speak to your accident, glad you are okay though!

You might check your fork tubes. Are the tops flush with the upper triple tree? Dangit. 33,000 miles since August 2007 and Friday I noticed that Cinnamon Girl's right fork is almost a quarter inch above the triple tree. Funny the things one notices seemingly out of the blue. That would explain cinnamon girl's tendency to steer right when the hands are off the bars... oh well time to change out the fork oil and upgrade the springs. yup and correct the fork tube position!

Thanks Moe, I think I'll check them out in the morning.

mike