are disc brake conversions bad ?

[johnneilson]

Jim was following a Chevy

John

[johnneilson]

In all honesty, it is your decision what parts you put on your car

All I can offer is try to pick a setup that you will be able to get parts for in the future

There is nothing worse than having a setup that parts are not readily available

John

[jeepguy1948]

I personally will go to disc brakes when the right pieces become available. I have been in contact with Mike for many months but he is suffering delay after delay. That said. Do I have to justify my choice? No. Do I care if you don’t like my choice? No, last time I checked it was my name on the title. All that out of the way, I like the pedal feel of disc brakes, it’s hard to describe but it’s there.

[jeepguy1948]

And, for those of you that think Hot Rod is blasphemy; if I had space for additional cars I would have one Model A “hot rod”, I would like a 40’s-50’s style car with a flathead V8. Also to those who don’t like hot rods, do you run a B or C motor? Do you have a balanced crank? Do you have insert bearings? 12 Volt? Electronic ignition? I could go on and on, one man’s ‘Stocker” is another man’s “Hotrod”.

[Patrick L.]

Deleted

[MALAK]

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Originally Posted by Kevin in NJ

Some basic science here.....

So Model A brakes properly rebuilt do a wonderful job stopping it from 65-70 MPH. The limiting factor is the tire contact patch on the pavement.

The best you can do force wise is keep the braking force just below where the wheel locks up. Once it locks up the braking force is greatly reduced. Factory brakes have no problem locking the wheels when they are rebuilt properly.

In all the posts I've seen about mechanical vs hydraulic (or in this case disk) brakes, IMO, this is the crux of the matter.

As has been previously stated, for normal daily driving, properly maintained Model A brakes are fine. Occasionally, however, our brakes are called upon to stop a vehicle as quickly or in as short a distance as possible to prevent rear-ending another vehicle or running into someone or something. In these situations, modulation is key. Modulation is being able to feel the braking effort and modulate the brakes to the threshold of skidding, without skidding.

For some this would make no difference, being in a panic situation would just mash the brakes, hold on, and hope for the best. For those who know how to feel and modulate the brakes the difference between hydraulic and mechanical brakes makes a very large difference.

I’m an avid cyclist and have ridden many 10’s of thousands of miles, both mountain/trail, and road. Mountain bikes have used mechanical or hydraulic disk brakes for years but the road bike industry has only recently started using mechanical or hydraulic disk brakes, relying on the age-old rim brakes. When I bought a new road bike with disk brakes I noticed the feedback and modulating abilities on the first ride. The ability to modulate the brakes has on more than one occasion saved me, and with hydraulic disks, it’s much more positive and controllable than rim brakes.

I would be very interested in seeing two similar Model A’s (same body style tires, weight, and preferably driver) one with properly maintained/adjusted stock brakes and the other with Hydraulics, tested for stopping distance at various speeds.

This may be something I’ll try in the next couple of years as the PU I’m currently putting together has relatively new, stock brakes, but I have a Clings hydraulic conversion I planned on putting on it. We’ll see, no promises.

Tom

[Flathead]

If you choose to use disc brakes with original Model A wheels be sure that the wheel center is properly supported. Just having the right bolt circle is not enough.

[Karl]

Originally Posted by jeepguy1948

And, for those of you that think Hot Rod is blasphemy; if I had space for additional cars I would have one Model A “hot rod”, I would like a 40’s-50’s style car with a flathead V8. Also to those who don’t like hot rods, do you run a B or C motor? Do you have a balanced crank? Do you have insert bearings? 12 Volt? Electronic ignition? I could go on and on, one man’s ‘Stocker” is another man’s “Hotrod”.

In Answer No ,No ,No, No and No

Runs fine 60mph and I can lock up the wheels whenever I want
BUT everything has been rebuilt to as it left the factory.
Each to there own but in my opinion disc brakes may well be a solution looking for a problem -but again your car so do as you wish

[nkaminar]

I have posted this before but here it is again. The Rolls Royces of the same vintage had a clutch disk that ran off the transmission, geared way down. The mechanical brakes would activate the clutch which would then apply the braking force. It was power brakes. But here is the genius of the design: As the rear brakes started to skid the braking force would be diminished and a skid avoided. Sort of like modern ABS brakes but without the computer. Saved my dad from running into a school bus that pulled in front of him.

[redmodelt]

Oh hell you can even buy disk brakes (rear only off the shelf) for the Model T.