Front Tire Skid - Crash

[mtuduc]

I've been reading a lot about suspension tuning lately, and I may have come up with an explanation for dropping my bike last year. I used to break very hard (on the street). I would often squeeze the lever quite abruptly, but I never experienced any problems. Last spring, I resprung my forks with Race-tech Linear springs. I then tried stopping in my usual fashion, and the front wheel locked up and washed out immediately.

My question: Would the under-sprung, progressive-rate spring allow me to make the abrupt stops, while the linear, higher-rate spring would cause the skidding?

[Spidey]

I would often squeeze the lever quite abruptly

Here's the problem, not the springs.

Don't squeeze the lever abruptly for maximum braking.  You need to apply some force (actually, you can apply quite a bit) to get the initial bite and get the forks compressed.  That will allow you to being to weight the front the tire and to get it to bite.  Then increase the force on the lever until you're basically doing a stoppie.  If you apply full force or close to full force to the lever immediately, you overwhelm the tire's traction and just lock up the wheel.  You'll go down pretty much immediately, as you found out.  [Unless you're Lorenzo going into T11 at Laguna, which you're not]

That said, it makes some sense to me--with my limited knowledge of exactly how suspension works--that the softer, more progressive springs would give you a little more leeway when you abruptly grab the front brake by slowing down the force applies to the front tire at a different rate than your newer springs.  That isn't to say that your old suspension set-up was better, by any means.  It was just that it may have allowed you to get away with bad braking habits, while biting you in the ass in other ways.  

But honestly, it's hard to say it was the fault of the suspension characteristics.  It could just as easily have been tire pressure, tire temp, road surface, road temperature or a million other things.  Basically, your braking habits finally bit you.  (I've done the same thing -- more than once).  

[thought]

Here's the problem, not the springs.

Don't squeeze the lever abruptly for maximum braking.  You need to apply some force (actually, you can apply quite a bit) to get the initial bite and get the forks compressed.  That will allow you to being to weight the front the tire and to get it to bite.  Then increase the force on the lever until you're basically doing a stoppie.  If you apply full force or close to full force to the lever immediately, you overwhelm the tire's traction and just lock up the wheel.  You'll go down pretty much immediately, as you found out.  [Unless you're Lorenzo going into T11 at Laguna, which you're not]

That said, it makes some sense to me--with my limited knowledge of exactly how suspension works--that the softer, more progressive springs would give you a little more leeway when you abruptly grab the front brake by slowing down the force applies to the front tire at a different rate than your newer springs.  That isn't to say that your old suspension set-up was better, by any means.  It was just that it may have allowed you to get away with bad braking habits, while biting you in the ass in other ways.  

But honestly, it's hard to say it was the fault of the suspension characteristics.  It could just as easily have been tire pressure, tire temp, road surface, road temperature or a million other things.  Basically, your braking habits finally bit you.  (I've done the same thing -- more than once).  

from what i've seen of this man's posts... you should listen to him when it comes to crashing >.<  haha

but yeah... from what i read of the tense of your post... i'm guessing you've stopped braking as hard now?

[mtuduc]

Thanks for the input. And yes, I realize that the number 1 cause of the incident was my lack-luster lever control. I agree that by no means was the older suspension better. She handles like a dream compared to before. I was just curious to get another opinion on the affect of the spring without doing any basic dynamics/vibrations calcs.

Thought, Yes I stopped braking as hard. I switched to the gradual application that Spidey refers to.

It wasn't all bad. I finally got to paint the stripe on the tank and cowl that I've always wanted.

[bikepilot]

Yes, soft suspension will transfer the weight more quickly and soak up more ham-fisted brake operation than stiffer suspension.  With stiff suspension you need to be just a tad smoother (and should be anyway) to give the front tire a chance to load up and grip.

[mtuduc]

Thanks Bikepilot. I'm practicing much better habits now. And by 'now', I mean last week. Snow's back