Braking Question

[marc-f]

Hello,

 

Having done Levels 1 & 2 earlier this year in Calafat with my friend Kreacher, we have been trying to practice all this and namely at the French track "Ledenon" (left turning track with very blind and steep parts).

 

On turn 6, I was experiencing some instability from the back wheel when braking hard and was wondering if a touch of back brake could help (I did not try this as i had a lot to think about getting into that left hand off camber hairpin).

 

You can see in the attached video (camera is fixed on my rear subframe - pointing at Kreacher - the white CBR) that when I start braking the back moves.

 

Thanks for your comments and suggestions.

Cheers

Marc

 

Actually, I have Race ABS which does link the back brake to the front to some extent so I guess the use of the back brake is already there. Anything else I can try to further stabilize the bike ?

 

 

[phillyjoey]

To my not so trained eye that doesn't look too bad. When i watch pros under heavy breaking all their back wheels do that but worse from being so light. But I am sure some one with more knowledge will be along shortly.

[Hotfoot]

I agree, that doesn't look bad to me either. If you brake really hard, you shift a lot of weight to the front wheel, so it is VERY common for the back to get very light and want to wag a bit like that. Some things to look at: are you bracing your arms on the bars while braking hard? Tension in your arms can tranmit back to the rear and cause the back to wag or wander sideways. Example, if you come in "too hot" to a turn, panic brake, and feel the back end start to come around, you want to immediately relax your arms (and ease up a little on the brakes) so it can straighten out.

 

Also you can look at suspension settings, there are some suspension issues that can worsen this problem - I think if the rear rebound is too soft, and there is something in the front that can cause it, too - possibly front end too low? Anyway the problem you are trying to fix is the back tire getting unloaded too much, or too quickly.

 

I do not think back brake will help - you are taking a tire that is already so unweighted that it is sliding around, I think the rear brake would be more likely to break it loose than straighten it out.

 

Personally, I haven't touched my rear brake in years, I don't even know if it works. (But I use it on the dirt bike all the time, and on the street on my cruiser sometimes, too.)

[Kevin Kane]

Personally, I haven't touched my rear brake in years, I don't even know if it works. (But I use it on the dirt bike all the time, and on the street on my cruiser sometimes, too.)

Hottie;

I made the same comment to the tech inspectors at a CCS Event at Loudon one race weekend and they refused to allow me to race until I came back with a rear brake that worked. They said "what if your front brake lever broke off in a crash and a Corner Worker had to retrieve my bike. How would they stop it if it didn't have a brake?" He then added 'what would you use to slow your bike if you ran off onto the grass without a rear brake?"

 

Needless to say I learned quickly how to bleed a brake and I never ride if my rear brake doesn't work.

 

...and then there's Will. When I am refueling the bikes with him at a School he is constantly reminding me that at slow paddock speeds you control the speed with the rear brake.

 

YRMV

 

Rain

[Hotfoot]

Personally, I haven't touched my rear brake in years, I don't even know if it works. (But I use it on the dirt bike all the time, and on the street on my cruiser sometimes, too.)

Hottie;

I made the same comment to the tech inspectors at a CCS Event at Loudon one race weekend and they refused to allow me to race until I came back with a rear brake that worked. They said "what if your front brake lever broke off in a crash and a Corner Worker had to retrieve my bike. How would they stop it if it didn't have a brake?" He then added 'what would you use to slow your bike if you ran off onto the grass without a rear brake?"

 

Needless to say I learned quickly how to bleed a brake and I never ride if my rear brake doesn't work.

 

...and then there's Will. When I am refueling the bikes with him at a School he is constantly reminding me that at slow paddock speeds you control the speed with the rear brake.

 

YRMV

 

Rain

 

Good point, the rear brake should definitely work, and a conscientious tech inspection should check to make sure it does. I guess I better check mine! In my defense, though, on my little bike, if my front brake lever wasn't working, I could probably just put my feet down and stop it like Fred Flintstone.

 

(Disclaimer... that is a JOKE, I would not try to stop even a little bike with my feet, I really will be checking my rear brake to make sure it works. Thanks for the reminder, Rainman!)

[Kevin Kane]

on my little bike, if my front brake lever wasn't working, I could probably just put my feet down and stop it like Fred Flintstone.

 

(Disclaimer... that is a JOKE)

Hottie;

This one is priceless; I was wondering if we should now call you Wilma or Pebbles?

[Hotfoot]

on my little bike, if my front brake lever wasn't working, I could probably just put my feet down and stop it like Fred Flintstone.

 

(Disclaimer... that is a JOKE)

Hottie;

This one is priceless; I was wondering if we should now call you Wilma or Pebbles?

 

Yeah, well, I got some good practice yesterday... my little bike quit on me at CA Speedway, on the far side of the track, and I had to do the "Wilma" thing for what felt like half a mile to get it through the grass and back to the paddock area. The crash truck was busy picking up someone else but I could see them grinning at me as I 'paddled' by. It did make me appreciate having a bike so small and light that I could actually DO that, instead of just standing there and waiting for a truck.

 

Now if I can just get this annoying electrical gremlin sorted out.. just the phrase "intermittent electrical problem" is enough to make my mechanic run the other direction.

[Kevin Kane]

Now if I can just get this annoying electrical gremlin sorted out.. just the phrase "intermittent electrical problem" is enough to make my mechanic run the other direction.

Hottie;

My track Duc's motor cut out on the main straight at NJMP when my Cam Timing Sensor failed. Electrical gremlins are the most frustrating because you can't see (well, I can't) most broken electrical parts. Fuses yes but most things not so much.

 

Good luck with finding the gremlin and a new mechanic. BTW, I had to rule out the "Fred Flintstone" as I needed to get off the line to avoid getting Scott Russelled but didn't have boot soles thick enought to try it.

 

Rain