At the risk of opening a huge can of worms, I wanted to ask the forum if someone who has done this before, would you please post a parts list and a few hints on adapting the 1919-25 Ruckstell Axel to hydralic brakes. We have worked our way through all the debate and have narrowed our search to the 51 through 60 Chevy rear brake drum and backing plate. Any ideas and thoughts would be greatly appreciated.
Thanks for your time
Paul this is just my opinion, but unless you are quite mechanically gifted and handy with torches and welders, you'd be far ahead buying a hydrallic brake conversion kit like the one Bill Thorp of Loveland, CO has for sale (rear brakes only). There may be others available. I know some are in developement. With a new kit, you are putting all new parts on and no used or mismatched parts.
Big can of worms. Hydraulic brakes, on the rear wheels only will not stop one bit better than good authentic type brakes. The limiting factor is high pressure skinny tires with not enough weight on them. My center door sedan could lock both rear wheels with only lined inside small drum shoes. You can do no more. Rocky mountain brakes aren't that expensive, are easy to set up, and work very well.
If you want to solve the T's braking issues, You need to beef up the front end to safely handle the braking stresses (like pot holes) and put on wheels and tires that put more rubber on the pavement. If you do all that, Why use a model T Ford? Just get a dune buggy and be done with it. But I think model Ts are a lot more fun, and some of the challenge is handling the old technology.
Just my opinionated rant.
One more point. Unless you are a master engineer, welder and fabricator, all that cutting, offsetting, welding and fitting is usually a lot more time consuming and expensive than restoring it right. And in many cases, it is more likely to fail and may be more dangerous.
I knew a wonderful, master machinist (retired) that many people relied on to fix the unfixable. He once built a pre-1910 4-cyl engine from original factory drawings for a museum's car which the original engine had been lost. His own model T had almost everything done to it you could think of, safety hubs, modern brakes fancy modern bearings in all the silliest places. I saw his car start many a tour. I never saw it finish one.
A hydraulic brake conversion was done for the Model T back in the 80ís but they are no longer available. The Technibrake conversion kit fit into the envelope of the stock brake drums and had very little visual impact. I have set of these brakes on my 13 touring. They stop the car fine and they are not as big an improvement as you might think, however, they do provide a secondary brake system in case something breaks in the drive line and renders the transmission brake useless. The disc brake kits available will likely give more braking than can be utilized but they are not pretty. Truthfully a set of front brakes, even mechanically operated would be the biggest improvement to make a Model T stop well.
I have a nice set of CAD drawings for hydraulic rear drum brakes that my father and I put together. The conversion is similar to the Technibrake setup with a couple of improvements. We looked at the cost of having the parts machined and it was quite expensive. Until we can get time to do the work ourselves the project is on hold. Due to liability issues we never intended to make the drawings or parts available to the public. They are strictly for our own use. I am a hobbyist and feel that I canít really protect myself from legal challenges particularly when it comes to parts or systems that are safety related. My guess is that there are other people who might offer brake kits but have the same concerns about liability. Obviously the manufacturers of the disc brake kits and Rocky Mountain brake kits have addressed the liability issue for now. All it takes is one incident regardless of what caused it to turn things upside down.
A good T driven moderately and defensively stops pretty well. But there is a need for at a backup system in case of a mechanical failure. That is an ongoing challenge and for now the options are kind of limited in my opinion.
Maybe I just don't know what I'm doing, but I feel I must post my experience. I have a 25 coupe with a 26 transmission. This transmission has the wider brake drum. It has kevlar bands. Tony Verschore from Chicago rebuilt my engine and transmission. So I feel quite confident that the rebuild was completed as it should be.
I have toured with the car for several years now, and it would seldom "lock up the tires". After several very close calls with "modern" cars, I switched to hydraulic brakes, and would never want to go back. I used the kit from Colorado. It was an easy, bolt on, project. It can be taken back off if someone ever wants to convert it back. The only modification to the kit instructions, was I put the master cylinder under the driver's seat. I didn't want to open the hood and see it.
I think it all comes down to an individual's preference. When everyone was driving a model t and understood how long it takes to stop one, that is one scenario. When you mix model t's with modern cars and drivers who don't know anything about model t's, that is another scenario.
If you like the challenge of designing hydraulic brakes for you car, and don't mind spending the extra money, go for it. But I have talked to several folks who designed their own and they admitted that they had considerably more money in their design than I paid for the kit. In the end, as a previous post explained, we are all limited by the grip of the tires.
Interesting thread, I'v been thinking also about putting on wet brakes. This kit from Bill Thorp, How do I contact him? Is there any others making brake kits for the T's
I am working on a solution PERHAPS. I am developing a bolt on front brake kit. It will be available in a hydraulic version, perhaps in a cable mechanical version. It will be a drum brake using readily available components for the wearing parts. The drum is being cast as one piece with the hub and will be offered for both Ford wires and wood wheels and perhaps for some of the more popular after market wires.
This old saw about the narrow tires just cracks me up. The force of friction is dependent on 2 things;
1. the weight of the car
2. the coefficient of friction
Area of the friction surface never enters into it. Certainly in the brakes themselves area can have some effect due to the brakes getting hot and some minor effect on the coefficient but mostly it is due to the drum getting larger as it gets hot.
Our tires are probably not of a particularly sticky compound or "sipped" very well but actual effect on braking force in normal road conditions would be minimal.
So why front brakes; Simple; the weight on the front end of the engine etc PLUS the weight transfer as the car rocks forward in a hard stop (unloading the rear wheels. Average estimates for modern cars is that 70% of your braking force comes from the front wheels.
People have been running front brakes on T's for years.. One popular version has been Nash Metro and they have been welded to the spindles. Couple of obvious issues. Not too many Nash Metros around to scavenge for brakes. The welding makes me cringe if not done right. The wishbone needs to be re-enforced which is do-able. Experience has indicated that the pan appears to be strong enough.
What Alan says about defensive driving habits is accurate, however it won't protect you from the text messaging distracted person cutting in front of you and slamming on their brakes after they have just passed you. If Wayne has solved this then please educate those of us who having driving T's for years
I figure the liability issue is manageable.
Les I assume you got the Wire wheels from Stan Howe by now, hope all is well, and keep me in mind for a set of those front brakes, I've not driven my 23 rdster since I lost my disc brakes several years ago, until I have some fronts to help stop it, it has a full length A crank, A rods, balanced, lightened flywheel ported block headers, alternator, distributor , dropped front axle 26-7 wire wheels Ruxstell set up w/ ball bearings, safety hubs on and on, go's fast, can't stop it when actually needed, as the parts man on some tours, I need to be able to run the tour and get back to the parts trailer to help all the ones who have broken down. I'm not a mechanic, so must rely on others for my repairs and modifications.
Yes I picked them up about a week later. One of the first odd ball will be the Phelps spline. I want to run those on a speedster I am building for my wife.
What is the story on the disc brakes you "lost".
Here are some Nash Metropolitan brakes on a 1922 Speedster.
The old hydrolic brakes were very good when they were working well. The main advantage was equalized pressure to all wheels. You cut the advantage in half when you install on only the rear wheels. As stated above by Wayne, once you lock the wheels, they work no better than the Ford brakes. The transmission brake also has the advantage of equalizing the pressure, as does the Rock Mountain brake.
A big disadvantage of hydrolic brakes is that any leak in the system can cause instant loss of brakes. The modern cars with 4 wheel brakes have made a safety feature of dual master cylinders so that if one half of the system fails you still have the other. This won't work with two wheel brakes because if only one side works you will lose control of your car. With the Ford transmission brake in tandem with the Rocky Mountain brake, you have a dual system which is much less likely to leave you without brakes.
If you convert to 4 wheel brakes, you need to beef up the front suspension, and then it would work best if your front wheels cannot be locked up, but just apply a heavy drag.
The bottom line is that if you don't do all 4 wheels and use a dual cylinder, you could end up with an unsafe brake system. Unless you are a mechanical engineer, it would be best to use a system that has been designed to work on a Model T or to use the Rocky Mountain or equivalent system.
The kit you said you were developing for the front axle, is this something you will be selling? Can you give any more details? Thanks
One more thing I would like to comment on. Norm says "then it would work best if your front wheels cannot be locked up, but just apply a heavy drag"
The first ABS (Ford offered electronic ABS as early as 1969 on the Thunderbird and Lincoln MK 3) systems were designed to eliminate lock up on the rear wheels because if you lock up the rear wheels the back end will come around. If you lock up the front wheels you slide in a straight line. Obviously you achieve maximum stopping force just BEFORE lock up as the coefficient of static friction is significantly greater than for sliding friction as well as maintaining steering control is always nice.
My system will be designed to work with your stock T rear braking system as Henry built it and add hydraulic front brakes. If you want to add accessory rear brakes that will certainly be your choice.
I plan to have limited run ( maybe 10 sets) of production prototypes available in the new year. After these have been thoroughly tested then mass distribution is possible. The people buying these realize that these are untested production prototypes built to the best industry practice with the finest materials available.
The Model A had 4 wheel brakes and that's the way Henry made it. As long as the front wheels turn, you have control of the steering, but when they lock up, you will keep going straight ahead. I once had to make a panic stop in a 53 Ford and I thought I was going to hit the car in front of me. The car 2 cars ahead was stopping to pick up a hitchhiker. The car ahead tried to pass, but had to pull back in front of me because a semi was coming from the opposite direction. I turned the wheel to go off the road rather than hit the car. The car skidded straight and fortunately I stopped about 2 inches from the other car, but my tires had flat spots on them. I suppose you could turn if you pumped the brake, but who thinks of such things in a panic? Same thing could happen on a curve, If you apply the brakes you could go right off the road.
So it is good to see that we are on the same page.
Les they were a set of (and still are on it) motorcycle disc, that were advertized in the late 80's or early 90's, by some fellows in Kansas, I have set 2 of 4 built, I've lost the small brake linings twice, the first time was on a tour in the country and just did a circle or two in a field, the last time was in Rolla Mo coming down a street to a 4 way red light (heavy fast traffic crossing) we were in the straight thru lane, again lost linings, and ate the end out of the plungers, dropped all oil from set and had only low, and reverse, if I'd had 5-10 more feet would have not bounced off the new Mustang in front of me, only left tire prints on the rear bumper, ruptured my electric fuel pump, and have not fixed brakes yet, I have a friend who builds street rods that's agreed to help me
Terry, Wayne Alan and all who responded, thanks for all your thoughts. Our goal is to have a break system the will be as effective as they were in 1925 but still work in the event of drive line failure, rolling backwards, or if the brakes become wet or muddy. We plan on driving the car as we would in 1925 but with all the defensive skills of 2009. Reliabilty would be better than stoping a T on a dime after it was driven faster than it was designed for. Our car is a coupe that I promise to stay under 35mph while keeping all eyes on the other drivers around us. I promise.
Thanks again all
A comment. You are designing around relatively obsolete parts (51 through 60 Chevy rear brake drum and backing plate).
In working up my front brake system I looked at Dexter hydraulic trailer brakes. They are available in 7", 10" and 12" sizes and the cost of complete backing plate assemblies will amaze you. Check it out.
One more thing (yeah, right Columbo), I'd recognize that speedster anywhere! The Nash Metropolitan brakes are not too objectionable looking. It is just my preference to keep my cars closer to original era accessories. There were both hydraulic and mechanical four wheel brake sets offered for the T in the mid '20s. I have seen a really nice mechanical set on a speedster and would love to do that, but I can't bring myself to do it on a car that is supposed to be from about 1920, because they were not available yet. Just silly me.
Sorry, Les Schubert, the coefficient of friction is divided into several parts. One of the two main parts IS the surface area of contact.
And whomever can, say hello to "Humble Howard" for me!
"The coefficient of traction is defined as the usable force for traction divided by the weight on the running gear (wheels, tracks etc) ie:
Usable Traction = coefficient of Traction x Weight"
Note, surface area is not in the equation.
"As the coefficient of traction refers to two surfaces which are not slipping relative to one another it is the same as Coefficient of static friction, also known as limiting friction..."
"In some applications, there is a complicated set of trade-offs in choosing materials. For example, soft rubbers often provide better traction but also wear faster and have higher losses when flexed -- thus reducing efficiency. Choices in material selection may have a dramatic effect. For example: tires used for track racing cars may have a life of 200 km, while those used on heavy trucks may have a life approaching 100,000 km. The truck tires have less traction and also thicker rubber..."
The tradeoff is traction vs. wear. A 4.5" balloon tire, like on the Improved Ford, has 50% more contact surface area than a 3" tire, so it has the potential for 50% greater traction - if a softer rubber compound is used that yields the same total mileage.
Do the balloon tires go more miles on a T than clinchers? If they go 50% more miles, then the rubber compound - and the traction - is the same in both tires, which I suspect.
I have asked Coker and Universal about their rubber compounds but never received a reply.
If you're using relatively new clinchers, and not ancient Riversides, then the surface area of your tires is not the limiting factor in braking.
As I just wrote in another thread going here, the high CG, Center of Gravity is the limiting factor in stopping a T, and not skinny tires.
I have tried measuring the traction of almost new clinchers, but got distracted before getting meaningful data. It looked like they have a coefficient of near 1.0.
Far more important than coefficient of friction is the percentage of total weight on the braking wheels. Look at the formula above. The harder you try to stop with rear brakes, the less weight on those wheels. That is your limit for stopping.
At the same time, shifting more weight onto the front wheels gives them more traction. I haven't yet slid the front wheels on the ol' brass picup, or on the Speedster it used to be, and I've made some really panic stops. Seatbelts have kept my passenger aboard, and not into the windshield or over the front of the car.
For example, I got caught at 30 mph between stoplights 50 feet apart recently and made a panic stop. It would have tossed the wife into the windshield, had she not been belted in.
I've driven without front brakes, and I'd rather not.
Wikipedia quote that Ralph quoted above:
"As the coefficient of traction refers to two surfaces that are not slipping relative to one another it is the same as Coefficient of static friction, also known as limiting friction..."
When a tire is loaded in braking or cornering, the rubber flexes. As it flexes, it IS SLIPPING!
This is why during cornering there is a slip angle - the tire is not breaking loose by any means, but there is more steering angle required than the resulting direction change.
Braking is exactly the same thing, though in a different direction, obviously.
If everything that Ralph said above (that he chose to quote from Wikipedia) was true, all our cars today would be riding on 30 x 3 clinchers or 4.40 x 21" balloon tires.
The auto manufacturers would love it because rolling resistance could be reduced dramatically and it would be far easier for them to meet their CAFE targets.
Now, in the case of SMOOTH surfaces such as the inside of a brake drum where the friction material (the shoe lining) doesn't ENGAGE with the surface like a tire does on a road suface, the above conveniently quoted Wikipedia information IS true - surface area has NOTHING to do with it.
Sorry, last line should read "surface", not "suface".
Well, I have seen a Cadillac SUV with 23" really low profile tires.
Everything I quoted from wiki is true, Seth. It's just that traction is not all there is to tire design and selection.
"When a tire is loaded in braking or cornering, the rubber flexes. As it flexes, it IS SLIPPING!"
To keep this from getting too complicated, I'd rather discuss just dry, straight ahead braking. Drifting is a whole 'nuther subject on wiki.
How do you relate flexing to slipping in straight ahead braking? Clinchers at 55psi flex precious little, anyhow. Once a tire starts slipping, traction is greatly reduced and you have wheel lockup and skidding.
Radial tire construction is a big factor in treadwear. You can buy Michelin clinchers for maybe $300 each, and they may be a softer compound and still have less treadwear than bias ply clinchers or balloon tires.
Tires play a large role in absorbing bumps, so ride comfort is one more factor in modern cars. Score one more for radials, and one against skinny, high pressure tires.
A T equipped with front brakes has plenty of traction for the job. Tires with Too much Traction could cause a T to Turn Turtle in a Tight Turn. Too much Traction could be argued as a factor in Ford Exploder (Explorer) rollovers. Lots of them have rolled over without tire failure.
Without front brakes, the best you can do is really soft compound tires and equalized wheel brakes with all the weight you can add as far aft and low as possible. A rear mounted spare is a big help. If I couldn't have front brakes, I would consider Michelin radial clinchers for the rears.
The tranny brake in a T is near useless when one wheel has less traction than the other, as when going off the shoulder into gravel. Wheel brakes will tend to pull the car back onto the pavement.
The flexing I'm talking about Ralph is in the rubber between the plies and the road surface. The net effect is that the plies don't keep up with the road surface during braking. This is slip, though it isn't skidding.
But I won't argue with you any more and I knew better when I did earlier because you have all the answers.
So if I may sum it up. Maybe the skinny tires are not optimal for stopping but adding front brakes would make a HUGE difference. I don't think anyone can argue with that!
Thanks again for the good information. The trailer brake is something I had not thought of. We were not set on the old Chevy design, more that was the only thing we and heard of that was possible available. Again our goal is to have a closed brake that will work effectively forward or backward and be protected from wet or muddy conditions. Hopefuly it would not look like a modification on the 25 coupe. When the group starts the Speedster project, then that is a completly different application. Now you are talking about a truley modified Model T in every way.
Good summary Les. In my opinion anyway....
For your entertainment on tire width. Winter got away from me and so today it was nice and I am putting winter wheels on my Smart car. The fronts are 145-55 R 15 with a tread width of about 4 1/4"
This car weighs a little over 2000 lbs and will run all day at 80 mph.
The rear brakes are little drum brakes and much wider tires.
This is purely for your entertainment, nothing more!
For your entertainment on tire width. Winter got away from me and so today it was nice and I am putting winter wheels on my Smart car. The fronts are 145-55 R 15 with a tread width of about 4 1/4"
Do you have any contact informaion for Bill Thorpe in Loveland Colorado? I would like to take a look at his setup amoung others.
There is a photo of Bill Tharpe's brakes in this video slide show: http://www.youtube.com/watch?v=bSUrsh3nq9E
Just my personal observations, not trying to influence anyone one way or the other, so don't jump on me please, I am listening to continuous Christmas music and enjoying life. I have been around T's since they were almost new, and lived through the change over from mechanical to hydraulic, and will be the first to tell you, hydraulics are good. My initial driving experience with T's and other mechanical brake cars and trucks, was mainly on the dirt and caliche roads of the day. In the main, very poor roads, and you sure couldn't get up any speed and very little traffic. The first time I ever drove 60 mph (solo) in a '37 Chevrolet pickup, I blew out a front tire, and that scared me back to slow driving. Anyone here who is old enough to remember those cars back then, know that they had poor brakes, but certainly good enough for the traffic and roads of the day. As to sliding the rear wheels, I think that was considered by my generation as being a bit show off and not good technique. I spent a good deal of time driving trucks moving big machinery and oilfield equipment, saw logs, hay, cattle and etc. The trucks mainly had hydraulic brakes, a few air, but the trailers universally had no brakes, finally electric, but a long time coming. We (I) learned to drive defensively doing this, and we looked way ahead, knowing we would be lucky indeed to even stop in a regular manner. We learned very quickly about gearing down in regular traffic and on hills. I "opened up" the Rocky Mountains to the Company I worked for at the time, and established a driving school for us specifically tailored for mountain driving. When I would certify a driver or trainer, he would get a very poor grade from me if he ever used the brakes, they learned early on to use the transmission and Jake brakes. If you know anything at all about Wolf Creek Pass in the winter in a blizzard in a very large oilfield truck, you know what I mean. I have always driven defensively, and that is the trick to a T or anything, always expect some fool to do something foolish, and sure enough, he will. I have gotten to the point that I don't like ro drive here in my small country (tourist) town, there are too many folks out there who don't have a clue. I have worn out lots and lots of vehicles, and was known to turn in a Company Car with 100,000+ on it with the original brakes, just look way ahead down the road. My current pickup, a 2000 Chevrolet Siverado Ĺ ton is used for everything, including pulling a 16' trailer with electric brakes, it still has the original rear pads, the fronts were replaced due to a recall. what I am saying is that one can drive without hydraulics on a T, just depends. I have purchased a set of Mr. Tharp's, and hopefully will get a set from Mr. Schubert, and God willing, will get someone to help me put them on, not a pure T certainly, but one I will feel safer in driving with my family aboard. The old parts are going to be kept in a good box, and will stay with the car, and anyone later on that feels like it can put it back in a heartbeat. Like I said, just my thoughts and experiences, mostly for the younger folks who are just getting into our Hobby. In my experience, pumping brakes is the way to go anyway, I will very seldom ever hold the brakes on all the way from the initial application to final stop. I also have quite a bit of time in all types of aircraft, and learned early on not to trust them, but to taxi slow, the man in front of you doesn't have stop lights. Now back to my Christmas music, and Merry Christmas to all.
If you are taxiing a REAL plane, you are doing "S" turns to see over the nose anyway! ;-)
Thanks Grady ........ easy does it.
Grady and I grew up in the same school of driving. My F250 has 163,000 miles on the original brakes.
T front brakes.
I may have a solution on the front spindles. Looks like I am going to be able to get them made in cast STEEL (and made in North America to boot). Yeah it will take a couple more months but they will look just like Henry made them and significantly reduce the cost. I am still going through the final design phase on these but the numbers look really good now.