Suzuki SV650 Riders Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
50 Posts
Discussion Starter #1
I've got a 2003 SV650S. Only got 2300 miles on it. The rear brakes are utterly useless. I've bled them 3 times now. No change. I've got about 1 maybe 1 1/2 inch of pedal play that just won't adjust out. They will lock the rear wheel, but but don't do much of anything until it locks up. Are all 2nd gen SV's this bad? I used to have a 2002 SV and it had pretty good rear brakes.......
 

·
Registered
Joined
·
4,657 Posts
I've got a 2003 SV650S. Only got 2300 miles on it. The rear brakes are utterly useless. I've bled them 3 times now. No change. I've got about 1 maybe 1 1/2 inch of pedal play that just won't adjust out. They will lock the rear wheel, but but don't do much of anything until it locks up. Are all 2nd gen SV's this bad? I used to have a 2002 SV and it had pretty good rear brakes.......
normal. use the front.
 

·
Registered
Joined
·
6,503 Posts
Definitely not normal. Rear brakes are hard to bleed. Note that there may be two bleed nipples on the caliper, one inner and one outer. First gens have two, not sure about second gens. The best way to bleed rears is backwards, with a large syringe. Pump the fluid into the caliper backwards to the reservoir. Pack an old towel around the reservoir in case it runs over.

The rear brake should have about 1/2" free play and then firm up and work.

Note that stock SVs on stock tires can stop very quickly. Tony Foale did testing with professional riders on almost 80 motorcycles, including the best from Aprilia, Ducati, Yamaha, Honda, Triumph, etc. The lowly SV placed 4th shortest distance. To do that you've got to use both brakes properly.
 

·
Registered
Joined
·
4,657 Posts
I don't know Andy, his "problem" sounds like every description of the second gen rear brake that I've ever heard.
 

·
Registered
Joined
·
799 Posts
Note that stock SVs on stock tires can stop very quickly. Tony Foale did testing with professional riders on almost 80 motorcycles, including the best from Aprilia, Ducati, Yamaha, Honda, Triumph, etc. The lowly SV placed 4th shortest distance. To do that you've got to use both brakes properly.
interesting, you missed something.
it does because it transfers weight to front. which means you can use front brake much more aggressive and where all stopping power comes from, front.
weight is transferred to the front of bike, rear is unloaded and it locks up easy. in anything but very low speeds rear is worthless on sportbikes.
cruisers on other hand benefit from rear brake due to longer wheelbase and less transfer to front.
yep, great book :)
 

·
Registered
Joined
·
4,657 Posts
BTW, the 1.5" of pedal "play" is strange.... are you missing the return spring by any chance? There should be two springs- one for return and one that goes to the brake light switch. The big return spring means it should always feel pretty stiff.
 

·
Registered
Joined
·
6,503 Posts
The bikes that stop the best do so because they are able to generate the highest (normal force X coefficient of friction / total mass). There are other factors, but generally this is the biggest part.

The problem with transferring 100% of the weight to the front end is that the rear end then looses traction. It's easier for human beings (even expert riders) to drag the rear brake a bit while transferring most weight to the front end. This gives more control than trying to put 100% of the braking on the front tire. You want some weight on the rear also.

The trick is to modulate the front and rear brakes so that as the weight transfers the rear brake is putting less and less force on the rear tire. It's not an easy technique to learn, but over time every rider should learn to do this.

Another good technique to learn (although one that should be tried very cautiously) is keeping the bike going straight with the rear tire locked up. This is not a safe maneuver to practice so you should start at quite low speeds, and maybe even on a bicycle first.
 

·
Registered
Joined
·
799 Posts
are you saying there is less force if rear wheel is unloaded or even of the ground?
most expert riders don't use rear at all on sportbike. when they do they use it for different reason, not to stop.
 

·
Registered
Joined
·
799 Posts
BTW, the 1.5" of pedal "play" is strange.... are you missing the return spring by any chance? There should be two springs- one for return and one that goes to the brake light switch. The big return spring means it should always feel pretty stiff.
sometime pedal travel can be more or less due to pad or rotor wear and seals on piston. as well as air in line.
 

·
Registered
Joined
·
6,503 Posts
Yeah, Veee, if the rear tire is unloaded there's less force on it. That's what unloaded means.

I should add that brakes are used more to slow down for corners on motorcycles, even in daily riding (exceptions exist, like stop and go traffic). MotoGP bikes, for example, all have rear brakes on them. Those fellows are pretty expert. They are often braking very hard indeed without stopping. The rate of deceleration can win races just like the rate of acceleration.
 

·
Registered
Joined
·
799 Posts
I should add that brakes are used more to slow down for corners on motorcycles, even in daily riding (exceptions exist, like stop and go traffic). MotoGP bikes, for example, all have rear brakes on them. Those fellows are pretty expert. They are often braking very hard indeed without stopping. The rate of deceleration can win races just like the rate of acceleration.
and your point is??
I am pretty sure everybody here knows what brakes are for. :rolleyes:
 

·
Registered
Joined
·
6,503 Posts
Yes, that's true. But if you put 100% of the weight on the front tire under heavy braking and then try to do any maneuvering you are SOL. And the best riders use both brakes to set the chassis and initiate weight transfer. Track testing with telemetry shows that the most effective braking is when the front/rear braking bias is in the neighborhood of 80%/20%. Riders don't actually perceive this, but the best ones know how to scrub off speed controlably.
 

·
Registered
Joined
·
799 Posts
have you ever been on sportbike going faster than speed limit and brake hard?
if you did you would know that rear brake is worthless and will lock up soonest you pull front hard.
next time you watch races pay attention to rear brake when they braking for corner.
we are not talking about run to supermarket.
 

·
Registered
Joined
·
50 Posts
Discussion Starter #15
Thanks for all the input, guys. Only one bleed nipple on the caliper, Andy. I guess the **** things just aren't worth a ****. About the only time I use the rear brake is at reallly slow speeds anyway. I guess I'll just learn to live without 'em. Just downshift. SV's have got so much compression braking that's practically a rear brake by itself.
 

·
Registered
Joined
·
799 Posts
Thanks for all the input, guys. Only one bleed nipple on the caliper, Andy. I guess the **** things just aren't worth a ****. About the only time I use the rear brake is at reallly slow speeds anyway. I guess I'll just learn to live without 'em. Just downshift. SV's have got so much compression braking that's practically a rear brake by itself.
you have floating caliper with one piston, there is no 2nd nipple.
another reason for lever travel, caliper moves around and aligns itself.
same way as front one works.
if you do have air in line do quick bleed on banjo bolt at master. just treat bolt as nipple, quickly loosen it and tighten it.
 
1 - 18 of 18 Posts
Top