Need help

[redneckray]

i have just been contracted to build a trike for a gentleman that is hadicapped,
he has no legs and only 2 fingers on his right hand and a good hand on his left arm and left arm, so it has to be an automatic vw trike, any idea's on how to use the controls to make it stop with his handicapped problems.
Any help would be appreciated.
Redneckray

 

[1550vt]

I've been involved with helping a few folks Ray. I know it will depend on the trike model, but I know some folks that are using the front brake lever to drive the rear and front calipers. Disconnecting one front caliper on an Ultra framed trike with dual calipers will work to stop the trike buy clamping three calipers...one front and two rear. It will depend on the brake caliper and MC volume. There are also some "very expensive" handlebar controls that will drive both front and rears, but the cost is up there around $1700 or so.

Some kits use just one caliper in the center of the rear axle, so I have no doubt that the stock HD brake MC would drive the one rear and one of the fronts. I think the customer will be able to pull the brake caliper with just two fingers.

 

[magusjinx]

Hook a second parking brake lever to the master cylinder and maybe use a D ring welded to it for easier grip with 2 fingers ... And it could be mounted anywhere ...


Just a thought ...

 

[redneckray]

Thanks guys, seems i got my work cut out for me to ponder on this one, it will[trike] have rear disc brakes on it and front disc brakes too, i have heard of using a proportional valve for it to work on all,
i will see how it goes,

 

[FBTRIKE]

redneckray,
I think two fingers may work for bike brakes tied toghether but I would be a little leary of operating VW brakes on the rear and motorcycle brakes on the front with only two fingers. That's alot of fluid to be moving. And the VW brakes generaly require a fairly long lever (brake pedal) and more strength (your leg) to operate. I realize thats to stop a car, but the amount of fluid moving to operate the brake cylinders and move the shoes still remains the same. Maybe a lever that he can pull to operate the brakes?
Not saying it can't be done, I'm sure where there's a will, there's a way, and it sounds like you have some experience with making things work.
Good luck and keep us posted as to what you do.

 

[FBTRIKE]

Redneck, It's early and I guess I can't read. You said it will have bike dics on it.........SO..NEVER MIND!

 

[redneckray]

The front end will have the bike disc brakes, you need your coffee, grinn

 

[1550vt]

Ray...there is one guy named Roger something-or-other from one of the forums that I worked on with this. Maybe he will see it and chime in. The reason I mention it is that he installed a proportioning valve, disconnected and plugged-off one front caliper. As far as I know he said he could stop it on a dime. I did not see the need for the valve, because you can lock-down all three wheels on a trike together. The rear disc will not be in need of adjustment like drums, so there is not that much danger in it pulling one way or another.

I would even suggest to forget the front brakes all together and just make sure you get good disc on the rear. Yes....I know folks are going to say that 70% of your braking power is on the fronts...but this is NOT TRUE for a trike. Most of the rubber and stopping power on a trike is in the rear wheels. If the non-believers will disconnect their rear brakes and try it they will soon discover that itty-bitty front tire will slide if you have to stop in a hurry and is virtually useless on wet pavement.

Look....we are dealing with a person here (not knocking the disability) that will not likely be drag racing anyhow. If a stock HD front MC will stop two front calipers...it sure as heck will stop two rears of the same fluid volume and in this guy Roger's case....one front and both rears.

I have designed and built disc brakes before for trike conversions. It's just a matter of matching the MC to the total caliper volume.

Do you know weight-wise how a VW based trike with the auto-tranny stacks up against the Harley based trikes?

 

[redneckray]

Vw based trikes are a round 1000 lbs in weight, i know nothing about hd 's, only the controls on the front,
i in the past have used the brke lever and hyd resvoir to work very well on the rear of a vw trike setup with disc brakes,
i know this guy will not be going balls to the wall, he just wants to be in the wind after 20 yrs and will use it to better his job placement, got to admire a person like this.
Ray

 

[1550vt]

I think you have your brake problem solved then. If you have used hand controls on the rears of the VW....ought to stop just fine. The lever on the handlebar mounted MC could even be lengthened a bit for this guy with only two fingers to pull it in.

Most HD based trikes with the kits weigh-in at around 1200 pounds or so. Some more some less depending on the frame, as in Ultra vs, Road King vs, Sportster, etc.. This guy is not likely going to need all the trunk storage space either, so you can cut him a streamlined version.

 

[redneckray]

can you use a hyd cluth off a HD TO WORK WITH THE REAR BRAKES?

 

[1550vt]

I promise that I am not trying to talk over your head here Ray, but it all depends on the ratio of the area of the MC to the total area of the calipers. The piston area relates to "volume" of fluid moved and there is a certain ratio that gives one a certain feel on the brake. Some folks like a wooden (hard) brake and others like a softer brake. I use the stock HD front (foot) master cylinder and two Tokico rear 4-piston calipers and this set-up works very well. The foot brake HD MC is a 5/8 and the handlebar mounted HD MC is 11/16, which is bigger than the foot brake MC.

Measure the diameter of the VW caliper piston bore and if it is an inch (i-inch) or smaller....the stock HD handlebar MC should work very well. If the VW pistons are larger than 1-inch...I'd look for an aftermarket handlebar mounted MC in the 3/4 size.

You should be able to use the box-stock VW rear calipers and rotors...it's just a matter of having a handlebar mounted MC large enough. 11/16 may be marginal, but I am sure the 3/4 would work and I am also pretty sure that Hayes and others make one for the older bikes that ran the banana front calipers....as in the Shovel Heads.

In reality...I think this guy would want a softer (spongy) brake anyway with only the 2-fingers to pull the lever.

 

[redneckray]

thanks for the info, for a moment there you were talking over my head for a REDNECK, GRINN
But I UNDERSTAND WHAT YOU ARE SAYING AND THANKS FOR YOUR HELP,
I AM STILL WAITING TO SEE WHAT HE WANTS TO DO AS FAR A TRIKE BUILD,

 

[1550vt]

U got me to do a little digging around and I went back and found a Master Cylinder Ratio Chart. It is an easy way to tell how the brakes will "feel" based on caliper piston area vs. MC piston area and it looks to me like you could go up to a caliper piston diameter of around 1.5 inches and be just fine with the HD 11/16 handlebar MC. A lower ratio means a harder brake and a higher ratio means a softer brake. Two rear caliper pistons of around 1.5 inches in diameter used with a 11/16 MC would result in a ratio of around 10, which is the middle of the road.

Rears are usually HARD at a ratio of around 8-10, but the fronts are usually soft at a ratio in the upper end of the teens

Now....I know some brake engineer expert can come in here and work me over with the math, but we are keeping this to "generalities" for simplicity sake.

I think the stock HD MC will push the VW calipers and feel just fine....as long as the VW calipers do not have a piston bore larger than 1.5 inches.

I'll leave you alone for a while now and let you get back to some other important thinking you need to do on this build, but I think the 11/16 front brake MC will work out just fine for this guy and give him enough stopping power to clamp the two rear calipers.

 

[redneckray]

Lollll i'm glad you are helping me with this, cause i don't have a clue about it all and i really appreciate your help. I will be starting on this project soon and then get to the brakes and bars and etc,
once again, thanks for your help
ray

 

[1550vt]

I like to help people make conversions from drum to disc. I wanted to convert mine from drum to disc and Lehman told me I have to give them $4,000 for a new rear end and would have to have a dealer make the install. They told me that it was just not possible for an untrained person to make the conversion and nobody but a Lehman dealer would be qualified to do the install. Of course, I told them where they could best use their $4,000 rear end...which was to stick the thing up their rear end.

Hot Rod and street car builders do conversions like this all the time and it is not some science only bestowed upon Lehman. Any wheel out there can be safely converted to disc.The trikes use standard automobile bolt hub patterns and once you discover what they use....you can find rotors to fit that wheel. The rest is just coming up with the right caliper, master cylinder and brackets to mount it all up.

That's what got me started on brakes....I just hate to be told that I can't do something. Mine cost me around $300.

I am a "tinkerer"....just like you!

 

[redneckray]

I love it, when you say you like it when someone tells you it can't be done, as i love it too, i love it when some one tells me it can't be done, lol
you are right there are people that do the conversions all the time and it works,
maybe i can pick your brain along the way to build some trikes as time goes on, lol
thanks again for you help,
ray

 

[oldnewby]

this is just an idea, you might research the ADA, Americans with Disabilities Act for some ideas. you could probably adapt some of the controls for cars.


Old Newby

 

[oldnewby]

I picked up a copy of trikes maqgazine. there was an ad for this company, and
I remembered this thread.

West Performance - PFM Performance Motorcycle Brake Systems

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