Rule 9.2 states that "Brakes must be fitted to two wheels of the same axle. Either both front wheels or both rear wheels depending on vehicle construction." if the car had a front wheel collapse/ fall off (on a cycle car) or a back wheel collapse/fall off (in a tricycle) that could cause the other wheel that has a brake to life up because then the car would tip and ride on the frame and the single wheel, this would especially on the turn where the turn would the wheel would fail. So why do the brakes have to be on the same axle? The reason I ask this is because I lost a wheel during a race, the hub holding the wheel broke, and when this happened I was turning hard left and I lost my back left wheel (I have a 4 wheel car, brakes in the back) so my back left wheel lifted and I was unable to brake since the turns force was pulling the weight onto the frame and the front wheels, not my only remaining wheel with a brake.
-- Edited by Nitoragro on Monday 23rd of March 2015 12:06:25 AM
The brake rule is written in this way for safety... if not written "on the same axle" you would get someone with a three wheel car with brakes on only one wheel, or maybe brakes on two wheels on different axles, but then would have "asymmetrical braking forces" causing difficulty in maintaining directional stability under braking.
the rule was written thinking of three wheel cars...theoretically (obviously theory and "real life" aren't always the same) on a three wheel car even if you lose one wheel the other two should always still be touching the ground... and therefore one wheel would still be able to apply "braking forces" to the car... this is also the reason for rule 9.3 both brakes must have separate activation cables... this is so if one cable breaks you still have the other brake operational...
Now here is my "take" on this rule section (as a Tech inspector & safety marshal in the N.W. division)
The first statement of this section (rule 9.1) states tha "At LEAST two wheels must have brakes"....
now I have never had a 4 wheel car in a race I have worked at in the N.W. division (since 2004)
BUT:
If I had one come through tech I WOULD PASS a 4 wheel car with only 2 wheels with brakes I would STRONGLY suggest installing 4 wheel brakes for safety...
to avoid just the situation you experienced with your car... 3 wheel cars ALWAYS have at least 2 wheels on the ground (unless you ROLL them...HI MIKE!!!)
4 wheel cars might lift a wheel if one is lost...(as did yours) so it might be a "better safe than sorry" situation to have 4 wheel brakes on 4 wheel cars...
Do you think that maybe we need to insert a new rule? (something like "4 wheel cars must have brakes on all 4 wheels")
ask around your area about that... I'll ask around mine... I'm sure it wont be well received (who likes MORE rules?) but for safety... we might be surprised
just remember just because there is no rule MAKING you do something safer (like 4 wheel brakes on 4 wheel cars, or even 3 wheel brakes on trikes) it doesn't mean that it is not acceptable... possibly even PREFERABLE!!!
and in ANY race at which I am working (or driving) SAFETY is ALWAYS welcome....
That makes a lot of sense, working exclusively with a 4 wheel car I forget how the 3 wheel cars work, just since i've read that rule I never knew why it was like that.
The three wheel system with two brakes on the same "axle" makes sense. To Ron's point of a four wheel car having brakes on all four wheels can make sense too.
It might make thing a bit complicated if there were four brakes on a four wheel car. Same for a three wheel car to have three brakes.
I wouldn't be opposed to having a brake on the front wheel for a trike, mainly for stopping purposes. Due to weight shifting to the front wheels when braking is what I'm thinking of.
A normal wheel with a freewheel on one side could be adapted to host a rotor for a disc brake on the non-drive side to assist with braking. Some machining would be involved of course.
Or a drum brake, be it a moped wheel or a bicycle drum brake laced to a rim could be used.
I think Micheal Lewis from Portland, Maine has disc brakes on all three of his wheels in is Eracer car that has the current hour record at 62.05 miles.
Brakes are for emergency use only or for slowing down for a corner or after a car has crossed the finish line.
That's my two sense worth on brakes in regards to Nitoragro's question.
to avoid asymmetrical braking forces on a trike look into the old (late 1950's) Norton motorcycle "antilock" braking system.
your rear brakes could be left in the current configuration but the 3rd wheel uses a "hydraulic pump" to provide brake line pressure...
if the wheel stops turning the pressure in the brake line falls, therefore allowing the wheel to spin again... which on the motorcycle would
keep you from "washing out" the front tire and falling...
on a trike it would keep you from loosing directional control in an emergency application of the brakes and sliding out of a corner.
If I were to run a third brake, that's where this lever would come into play. I have one currently on 59 right now, never had a problem with it once everything was set up.
Plus the one I have doubles as a parking brake so my car won't go rolling off by itself. There is a pin that can be pushed when the lever is pulled to lock the brakes.
The dual brake would handle both wheels in the same "axle" line, while a separate lever would handle the third brake.
I'd steer clear of the other kind where there is a pivot between both cables. The lever I have on the car pulls both cables at the same time and won't bind one brake harder than the other.
Most likely these would be mechanical brakes, not hydraulic like you were talking about.
The photo with the barrel adjusters side by side is the kind I have. The other one where the barrels are inline is the kind I would avoid.
Hi all,
Again, I've not competed in Electrathon yet, but the greater stability offered when a brake failure occurs would likely make braking to a stop in a four-wheeler a much easier and safer proposition than a three-wheeler.
If you're keen to increase braking capacity for when one brake "circuit" fails (a cable on one axle, or hydraulic line to one caliper) then I'd suggest making front friction brakes mandatory for four-wheelers. Braking application adds forward weighting, which increases the brake capacity. Front-axle braking should mean roughly 50% reduced stopping distance compared to rear-axle braking. And I'd imagine all current four-wheelers are rear axle driven, so adding brakes to the undriven front axles should be relatively simple, and having one brake on the front of a four-wheeler still allows good braking capacity.
Friction braking means disk, drum, cantilever (if installed correctly) or even direct-to-tyre brakes, but KERS/regeneration on the front axle doesn't count.
There were a couple of cable-actuated devices similar to what Ron was speaking of too; the Positech and Calderazzo feedback brakes were developed for bicycles and could be accommodated, but both are cantilever-type brakes that are quite prehistoric now. Would probably be viewable through the International Human Powered Vehicle Association website if interested.
