I had a early 70's T bucket for a while that had really really skinny tires and huge rears and frankly the front tires did not have enough traction in a hard stop to really matter and I honestly felt when they would lock up so easily I had less control as far as steering because one tire would lock up more like when slowing down to make a left turn onto a road . then flat spotting the tires were a thing to . Many of the old T buckets had little single position calipers about the size of a motor cycle caliper and did not do a whole lot in a hard panic stop but were plenty for basically a motor cycle tire. Great brakes do not mean **** if the tires do not have enough traction . I saw a car last year that had some high dollar 6 piston stuff that were like 13" rotors and he had 4" wide front runners . A 8" disk and a single piston would have been as good . so no brakes is unsafe but so is lots of braking and a tire to small to do what it needs to do because lock up can be worse . On My 28 A PU I actually went a size wider on the tire so I can have more braking at the front I was always locking up one front coming off the highway fast on a side street. I then played with the valve so I had as much rear as I could get with out lock up . I had a lot of time in getting the best I could . To be blunt the type of cars that guys would consider running no front brakes are the type of cars your at running 80 MPH in heavy freeway traffic . I cant even imagine drivng that 7o Fad type T on the free way this morning going to work on damp roads . I was running 85 and getting p***ed in WI LOL I have set of 12 spoke spindle mounts and they may see some street use but it will be back roads putting around or a Sunday cars and coffee type thing .
How much steering do you have with locked up skinny front runners ? I'm all for front brakes but better have the tires to make them work . The ideal solution would be a anti lock set up with skinny tires but that not going to happen on a HAMB car.
When I first built my Willys, I had '56 Olds drum brakes on the rear and in front, I had adapted junk yard slave cylinders to the old mechanical front brakes. Basically, dumb high school engineering yielding no front brakes, ok rear ones. It only took one event on rainy roads to convince me to get the front brakes working. I was coming to a stop light at modest speed when I applied the brakes. The rears locked up on the damp road with wide rear tires and the car instantly started going endo. It got perpendicular to the road when I was able to steer it straight just in time to save 2 or 3 surrounding cars. I'll NEVER ride in a rear-brakes-only car again. A disaster waiting to happen.
I was taught dry road one vehicle length for every 10 mph from bumper of vehicle in front of you unless racing
No. The law (federal and most states) allows cars built with only rear brakes to operate on public roads with only rear brakes, it doesn’t say anything about modifications. In the same way, cars built with only one taillight are allowed to operate with only one taillight. Doesn’t mean that it’s a good idea. Don’t give the bureaucrats any ideas.
To be able to go with the modern traffic it is a real good idea to be able to stop with the modern traffic.
You mentioned most the excuses drivers had for not running front brakes or backing the slack adjusters so they were ineffective. Another was the inability to steer if you locked up the front brakes. However, the truth is that the front brakes do a really large share of the work in sudden stops. I did a good bit of work with brake balancing on large trucks with air brakes. Even spent some time on the IH test track in Fort Wayne. I believe an IH engineer told me the front brakes contribute around 40% of the total stopping power. There is a whole lot of weight transfer to the front axle on a hard stop.
I hope you realize brakes on a race car is not for the purpose of slowing the car down. [A racer doesn't want to go slower] The purpose of brakes on a race car is to transfer weight onto the front [where cornering forces, weight transfer, slip angle meet at a point of equilibrium] @Olboy you haven't lived until you've jumped onto a purpose built racing machine that goes down a straight and turns in deep with no brakes I had one of these 52 years ago
It took a second. Front brakes on the 2 front tires of an 18 wheeler are 40%. For cars with reasonably close sized wheels and tires, the common figure is 60% or more. https://engineerfix.com/what-percent-of-braking-is-done-by-the-front-brakes/ EDIT: @Kerrynzl and only one foot peg! I don't think anyone here is saying it's the best, safest way to go. The examples are lightweight, vastly smaller front wheels and tires and edge cases, not anything common. If safety is a major concern, nothing built pre-65 (You know, what this site is about) meets standards of even 30 years ago. Strap into your multi airbag and ABS equipped, tire pressure monitored, stability controlled, crumple zoned, blind spot monitoring and collapsible interior designed modern car. Have fun with these folks. https://www.consumerreports.org/car-safety/what-makes-a-safe-car-a6584555585/
18 wheelers have trailer brakes too.... bobtail of a cl*** 8 tractor is a totally different story with weight bias in braking because of the lack of weight on the rear axles... I have an 18 percent grade in a section of my gravel driveway....I've had run-a-way events over the years where you just slide away with small tire contact area and rear brakes only ...plus I drive in the rain and rear brakes only on a wet surface....rear end may want to p*** the front end silly me, I am an all axle have brakes guy....and I trailer my T with Nash Metropolitan rear wheel brakes only, down my driveway
Anti lock brakes is not going to happen on a HAMB car. But what could and should happen is adding an adjustable proportioning valve to the front brakes. You can dial down the front brake pressure as needed, to an appropriate level. Ideally, the rear tires should lock up slightly before the fronts.
I started performance vehicle brake testing in the early '70s that included some tractor trailers, and learned that erratic steering control during hard braking is why some drivers/companies dis-connected/removed front tractor brakes, giving up the small percentage of braking they provided. The main issues were no power steering, and drum front brakes. Trucks in this era were pretty basic by today's standards, but as driver comfort and strict mid-'70s FMVSS braking standards became law that required front wheels to have brakes, power steering and eventually front air discs became standard, drastically reduced any steering control issues during hard braking.
The Jalopy Journal
