brakes bias front to rear - thoughts?

[denviola]

Was just reading in another thread about brake pad thicknesses and how the fronts last much longer than rears. I have thought about the braking system and wondering if there is a proportioning valve similar to a car/truck that modifies the amount of braking force due to load changes, such as riding 2 up instead of single. Seems to me that the rear does much more work than front. I've had to make only one panic stop and it was when riding 2 up, and the front didn't dive down and in my opinion (FWIW) did not put enough bias on the front brakes. That's not really a bad thing and keeps us on the Spyder, but it concerns me. Tried a couple of controlled panic stops riding single in an empty parking lot and again the front doesn't seem to do most of the braking. Maybe I'm not noticing correctly since there are 2 sets of brakes on the front sharing the braking force. Any experiences to share? Sometimes I miss dual brake levers......

 

[daveinva]

Hmmm, my experience is the opposite. My RS positively DIVES into braking when I practice emergency stops (riders should practice emergency stops, routinely, IMHO), those front brakes do most of the heavy lifting on my bike. It's a little less dive-y when a passenger is onboard given the weight distribution, but not by much.

That said, I wouldn't be surprised if there's more rear brake wear than fronts. When you load the front end of the bike, you're splitting the work between two sets of front brakes, but when you load the rear, you're working just one set.

 

[NancysToy]

Braking force on the Spyder is distributed by the VCM (Vehicle Control Module), in response to input from the wheel speed sensors, and the passenger seat sensor, among other things. The DBS (Distributed Braking System) is an advertised feature of the Spyder Vehicle Stability System.

 

[BajaRon]

I suspicion that the rear brake is applied first. I have never done any testing to see if this is true but since you can't change it I didn't think it worth the effort.

It is a certainty that the rear brake wears faster than the fronts. The 'Why' is what everyone want's to know. The front tires definitely have that traction advantage. Not only is there more surface area (combined) but they also have the advantage of weight transfer, while the rear wheel gives up weight in the transfer during stopping.

My theory is that stopping the rear wheel may give additional stability to the Spyder which may be a good reason to apply the rear brake first. So that in mild or average stopping scenarios the rear wheel is doing the lions share of braking. In harder or panic stops the front wheels are then applied with greater force. Since most of our stopping is in the former mode it would stand to reason that the rear pads would wear more quickly.

Sounds good to me and would explain the seemingly illogical pad wear pattern. But whether or not it true is anyone's guess.