Question about adding a disc brake on a driveshaft - Brass Era car?

[CatBird]

A friend is planning to increasing his braking ability by adding a disc brake on a driveshaft on a brass era car. He thinks it will stop both rear wheels. 

 

It would seem to me that it could only stop one rear wheel.

 

Question?

[1912Staver]

It will stop both wheels however on loose surfaces they will spin, one forward , the other reverse. It also puts quite a bit of strain on all the driveline components esp . things like axle shafts. It's sort of like having a very grabby clutch only all the stress is reversed.  My Packard truck has a large drum brake on the driveshaft and the parking brakes on the wheels. Most owners recommend reversing things so the brake pedal operate the wheel brakes and the parking brake lever operates the shaft brake. 

 

Greg in Canada

[AzBob]

That is exactly how 15,000,000 Model T Fords left the factory.

Foot brake band is in the transmission. Hand brake operated internal shoes acting on the rear drums.

Edited April 23, 2019 by AzBob (see edit history)

[keiser31]

No matter how much braking you get if mounted on the drive shaft, you will still only get 4" or less per tire/road surface.

[Grimy]

Bill, you can double your braking power by putting disc brakes on the front wheels, replacing NO brakes on the front, but at the cost of judging points if that's important to you.  I've run my 1918 Pierce with 2-wheel brakes on three Modoc tours and up and down from 7,000 ft on the Glidden, and down some other truly serious grades, but I'm careful to downshift (even to first gear on a one-lane, one-mile 12%er near Fort Ross CA, and descend slowly.  If you're talking about your Pierce, I'll tell you that the external contracting hand brake is about 3 times as effective as the internal expanding foot brake (seat of the pants scale).  I use the hand brake routinely to complete a stop even in city traffic--that's why they built the handle to stand so tall and proud.

[C Carl]

Yes, and, particularly in the case of the T Model Ford, your right hand ought to do something. Could even be a  bit of a throwback to steed propelled days when the service brakes were hand lever operated.   -   Carl 

[jan arnett (2)]

No matter what you do you still have bicycle tires on it.  The best was is the way Fred Flint Stone did it.

 

[oldford]

The problem that I see with a drive-line brake is that you have no control when something fails. The Model T's mentioned above had this problem. The only brake was in the transmission and when something as simple as a key would shear, there was absolutely no way to stop the car. I have seen it happen, so it's possible. After watching a pedestrian almost run over by a Ford, I put external brakes on the rear wheels to avoid this problem. I would never rely on simply a drive-line brake...

 

But that's just me...

 

Frank

[West Peterson]

As mentioned by Keiser31 and Jan Arnett, it doesn't matter. It's the tires that stop the car.

[franklinman]

20 hours ago, AzBob said:

That is exactly how 15,000,000 Model T Fords left the factory.

Foot brake band is in the transmission. Hand brake operated internal shoes acting on the rear drums.

Ford wasn't alone in this.  Several examples come to mind, my 1907 Franklin and the T-Head Mercer among others.

[oldford]

4 hours ago, West Peterson said:

As mentioned by Keiser31 and Jan Arnett, it doesn't matter. It's the tires that stop the car.

 

The tires can't stop the car if the stopping force never reaches the tires!

[trimacar]

It's so easy to say, gee, those little tires won't stop a car. Unless you're on water and oil, yes, they will stop you, the tire patch is still gripping the road....

 

Going back in time, even with the bad roads and the reduced stopping power of early brake systems, they do work IF SET UP AS NEW, and PROPERLY.

 

I once was thinking of buying a 1911 Buick, think it was a model 32 or 33, either way it was the only roadster left of that limited production.

 

Two things.

 

One, I drove the car.  With two wheel rear brakes, it absolutely had the best stopping power of ANY early car I've ever driven. Downhill to a stoplight, no problem, stopped straight and true.

 

Second, it had been owned by a master mechanic, who really restored and fixed things, didn't just put them together and say "gosh, that's the best it'll be..." or "gosh, that's good enough". When I asked about spare parts that went with the car, the answer was no spare parts, if something didn't work, it was fixed, period.

 

A lot of modifications to early cars are just laziness, not wanting to spend the time that it takes to make things like new.  Some people may be offended at that comment, but it's true......

[bradsan]

Which is why, as per Frank,  the last thing you want failing on your Model T is the rear end: even excessively worn pinions and bearings can disengage and leave you brakeless except for the handbrake which won't help you much if you have any speed or grade..

 

Favorite accessory for the Model T was, and still, is the Rocky Mountain brake which is a set of externally contracting brakes. They are a definite must with any Ruxstell ( 2speed) rear end or Wardford (overdrive) aux transmission since missing a shift leaves you in the same position as the first point and your brakes become 1) a favourable change in grade , 2)your foot until the shoe wears out, or 3) whatever you end up running into.

 

Brad

[West Peterson]

14 hours ago, oldford said:

 

The tires can't stop the car if the stopping force never reaches the tires!

So fix the brakes as designed, as Trimacar has suggested. Probably less work than designing and engineering a whole new system. Just because you can lock-up your wheels with a better brake, doesn't mean the car will stop any faster. If the brakes are restored properly, you will be able to lock them up... if you want to.

[John_Mereness]

Perhaps mention exactly what the brass car is and see what other people have done - there is a lot of knowledge here.  

 

Been there done that twice now via converting internal expanding to hydraulic as linkage could not be converted/re-engineered due to obstructions.  

 

Generally speaking, it is a lot of re-engineering and fabrication to get the brake pedal to work the brakes on the axles - but worth it car design allows. 

[CatBird]

I especially agree to get the original brakes working properly. Perhaps with softer "grab-ability" with modern linings like Moose sells. I also know that others are adding "juice" hydraullic brakes inside the rear drums. The bottom line is that only stopping ability is the amount of rubber you put on the ground.

 

On a Model T, the bands in the transmission can clamp and stop the car. I am in the thought that the brakes are a matter of prayer and hope! Obviously the handbrake operates the rear drums. 

 

These Brass cars were made when the speed limits could have been as low as 10-20pmh. To me that pushing a brass car at 60-70-80mph is dangerous.  I consider it disrespectful to the car. Enjoy waht it was made to do. My 1908 Thomas Flyer has a 100mph speedometer. I think this is for "bragging rights." Obviously the wooden artillery wheels were not made for that speed!

 

In my 50s cars, I have friends installing front disc brakes. Not me. I find that the original brakes are sufficient unless pushing the car beyond its original limits. I remember disc brakes became all the rage in the 1960s when they were popular on race cars.

 

My original question was that since only one wheel drives the car, through the differential, how would a disk brake on the driveshaft would only stop that wheel?  It seems logical that a differential must allow one wheel to freewheel when cornering. I seem to remember that the concept of a "limited slip" differential came about in the 1960s for the muscle cars. Though it were possible in Brass Era cars, I can find no research it was done. Even if that were true, I would assume that gearing down would still only slowing the driven wheel.
 

To me it seems illogical to add a disc brake to a driveshaft and an unnecessary expense. Better to put better brakes all around would be the best idea, especially for touring. 

A local guy seems to have the most driven Duesenberg in the USA at10,000 miles a year. He has disc brakes on his front wheels.

[edinmass]

If he has a Duesenberg with disk brakes.........IT IS NOT A DUESENBERG..........they had hydraulic drums when new, and stop fine from 100 MPH..........no question about it. 

[mercer09]

 

Bill, you can double your braking power by putting disc brakes on the front wheels, replacing NO brakes on the front, but at the cost of judging points if that's important to you. 

 

 

Fella at Hershey years ago had an 05 Maxwell, with front discs from a motorcycle. Stopped the car wonderfully!

 

looked like hell.

[CatBird]

On 4/26/2019 at 6:31 PM, edinmass said:

If he has a Duesenberg with disk brakes.........IT IS NOT A DUESENBERG..........they had hydraulic drums when new, and stop fine from 100 MPH..........no question about it. 

 

I completely agree.  He offered to sell me the car, not a bargain anyway, but I didn't like it. I think he had the old drums. If he like his discs, I am not to dis his car or him. 

Disc brakes don't look good on any car that was not made for them. They also dirty up your whitewalls with brake dust. We have disc brakes that came on several of our modern cars.  IF I wanted to add front brakes, I would add drums that look like the rear. 

But the older cars need to be driven respectfully and at the conditions at the time they were made. Our old cars have lived a very long time with the factory brakes.

 

We are very fortunate that we live next to Stone Mountain Park. 25mph in the Park and has 15 miles of hard surface roads. We feel fine with our two wheel brakes. 

[CatBird]

On 4/27/2019 at 6:56 AM, mercer09 said:

 

Bill, you can double your braking power by putting disc brakes on the front wheels, replacing NO brakes on the front, but at the cost of judging points if that's important to you. 

 

 

Fella at Hershey years ago had an 05 Maxwell, with front discs from a motorcycle. Stopped the car wonderfully!

 

looked like hell.

 

Not that I care that much about judging points, but I have heard that you may not lose points for adding safety features. And if touring, might be a good idea. But I don't like the looks of disc brakes and for the most part (unless racing or mountains) don't see the need. If I were to add front brakes, they would be drums and would look like the rear.

[Chris Bamford]

Interesting post on the HCCA Forum from a fellow who installed a driveshaft disc brake on his 1910 Buick. Many photos included.

 

https://hcca.org/BOARDS/viewtopic.php?f=6&t=1095&sid=3e0918878629a141b5a775f6c1c2e57e

[trimacar]

I have a Model 16, and know the weaknesses of the drive shaft and rear end.  I can't imagine what a panic stop would do with that set-up, lock the driveshaft at speed?

 

The Model 16/17 has large brake drums, I would have thought hiding discs inside them and converting pedal brakes to activate them would be the way to go, if one was going to add different brakes. Many people convert and change the pedal to the drums, and the hand brake to the driveshaft brake, the reverse of factory set-up.

 

I would also repeat myself, if one takes the time to do the original brakes correctly, then there's plenty of stopping power.  Instead of assuming original brakes would work, a lot of people just assume they won't, and change them.