Leading Link procured. Want to "float" the brakes. Need help.

[stacebg]

If it was just a weight transfer issue, you'd be right -- braking transfers weight forward. But with the brake caliper under the swing arm and behind the axle there's a physical, mechanical levering that takes place when you brake. The fulcrum is the axle, the force is the rotation of the caliper around the rotor, and the load is the pivot of the swing arm. As the brakes are applied, the caliper (and therefore the swing arm) wants to follow the rotor around its circle. The direction of rotation levers the pivot of the swing arm (and therefore the trike's front end) upward. No "braking" occurs until the levering force of the rising swing arm end is "stalled" by the weight of the trike.

Now if you hit a bump while the the swing is caliper-locked/arm rising, what happens with the suspension? Will the front still rise against the springs, or is the suspension effectively locked up? My imagination says that the front of the swing arm can't rise when the rear is already rising and locked by the caliper. My imagination sees that the entire front end will hop as though there were struts instead of springs at the spring position.

Any thoughts on that (because I can't know . . .)?

never had a problem with it

 

[grandpanystrom61]

Not my usual forum, but searched the floating front brake, and here I am.

I have read over this post, some is on the market now. I will be having to think about this if I want disc brakes, or go with the old drum style.

Waiting on the correct caliper at this moment, than I will finish up I hope.

 

[rodekyll]

I've gotten an adjustable proportioning valve for my linked brakes to make the front caliper less effective. It's too strong and will lock the front up before the rears grab. It is improving the brakes.

My crude floaters work well now that I have proper reaction struts built. I was breaking them. Then I went to 4130 moly tubes and heim joints. No problems since. And the braking is very neutral -- no real rise or drop on the front end under braking.

Why would you prefer a drum?

 

[grandpanystrom61]

Why would you prefer a drum?

Thank you for the heads up on the rod strength, help me get it right the first time I hope.

It had nothing to do with braking function, which works better than the other, rather it has to do with the easy of mounting a wheel with drum brakes compared to that of a wheel with disc brakes. Stock is not an issue, but if you are custom building the front end for the first time, it just seems like a easier choice, but I am into the hydraulic brake system now, have the MC lever, rotor, rim, and caliper comes tomorrow. Yesterday I did discover that how and where I mount the rocker arms off the down tubes could help with mounting of the caliper and what is needed.

So mock up not set in gold yet, but getting ever closer.

​

 

[grandpanystrom61]

rodekyll, do you have picutes of your finished floating brake set up that you can share ?

I did not do enough research, just bought the rotor designed for the rim, than got the caliper to match that, but now I see the reason for the floating caliper. Do to error's I will have to make my own brackets and figure it all out.

Okay, you have talked thru a lot of it, so I just have to figure out how to apply it all to my front end so all does work correctly.

Thank you for the thread and the posted info everyone, again a thread I found that has lead to helping me figure things out. I will post pics of what gets done.

How it starts.

 

[rodekyll]

I've written two very detailed responses, both of which disappeared while posting. Very frustrating.

The nutshell is that you have an axial caliper and I have a radial. The mounts are completely different. The description of what I did is posted earlier in this topic. The essentials are the same, although the mounting considerations are different. You have the right start -- deciding where the caliper needs to be. Now you need a flat plate to act as a mount. It needs to have a bushing or bearing that fits over your axle spacer.

The bushing needs a little play to slide on the axle as well as spin around it. This is because you have a fixed caliper. It has no centering capabilities of its own, so any little deviations in alignment must be compensated for by moving the mount on the axle rather than moving the caliper on the mount. A single-sided floating caliper would simplify that part. If I had to do it again I'd use a SSFC instead of the dual-sided fixed caliper I've got now.

It was attaching the picture that kilt my previous posts, so I'll maybe try doing that with a different computer, later.

 

[grandpanystrom61]

The bracket is part of the caliper assembly, bracket is mounted fixed and the caliper moves side to side, only one side has pistons.



I figured a bushing should be used on the vertical support bracket at the axle area. Thank you for the help.

 

[rodekyll]

Sorry, I misread the picture. Yes, I think the single sided floating caliper is a better design than what I did.

 

[grandpanystrom61]

So my metal came in the other day, so I did get a paper template cut and than the wood copy made.

Still not perfect, but I am so close to having the caliper support bracket worked out. It is that fine tuning of correct and proper mounting of caliper with in the bracket so all sit's correctly.

I do not have the shop, maybe not even the ability, to make a bracket that I can actually just mount the caliper into so that if moves freely. I seen it down on another front end, awesome work and so clean.

So I have 3/8" thick 304SS plate for support bracket. I wil just get some things done and take a pic of it all.

 

[grandpanystrom61]

The stages of getting the pattern.



Looking down straight at the front. This is not done......just the first true test fit to see how close I am, or off it is. The front mount hole needs to be up slightly more for rotor clearance.



but the back edge is a little high, again bolt hole mounting location adjustments. Maybe by dropping the rear down some the front will rise a bit, but the center bolt hole will need location adjustment.

One also has to check suspension travel of axle and how the caliper rides the rotor as the rotor moves forward and backwards with the suspension. (remember caliper is fixed to bracket that pivots around the axle )



So I installed the tube and mounted the tire on the rim yesterday. I had to see if all was what I wanted and if my calculation were correct. It looks nice, and still holding air pressure. I did it in about 3 hours time, new tire was getting the better of me, but lots of time spent on getting the valve stem in place along with many break's, but You Tube showed me how the pro's do it and I made all work for me with what I had, a few pry bars and a extra valve with a wire tie attached helped me pull the valve stem in thru the hole and into place.

 

[grandpanystrom61]

Hard metal to soft metal, what needs to be done ?

I must of gotten lost, and so much information on this thread. I figure I will just keep with it so it is a more information thread for others.

I have been slowly working on the floating fender support legs. I used 1/4" thick plate 304 SS and worked and cut out it all by hand. I have been sanding them for the finish, but have a ?????

The legs will ride on the wheel hub bearing spacer's, which are made out of aluminum, all has been made and calculated using these spacers, so do I use a oillite bushing pressed into the fender leg so that the inner side of the busing is rolling freely around the pinched bearing spacer, that is aluminum ??? Pictures, I will see about them.

Plus if I put the flanged side to the inside of the hub spacer, the thickness of the flange holds the leg out away from ever hitting or rubbing on things, just another reason I though of using the flanged bushing.

The left bearing bushing is larger DIA than the right, so had to get to different size flanged bearings.





The forks will be on a 48 degree rake, but that should be the general position of it all. The cardboard template is what I used to make the legs with, which are still a little bigger than cardboard piece...…….arms and feet got worn out working it down to the lines.

 

[rodekyll]

My choice would be a bushing over a bearing, and I'd want something I could inject grease into (zirc?) in order to push out grit. I didn't install lubeable bushings in mine and the floaters stick sometimes. Keep in mind that I'm not an accomplished LL engineer. My experience is limited to the one I built.

Ball and roller bearings really want to go in a full circle rather than a few degrees to and fro. There's not enough travel on the floating brackets to use a roller or ball bearing -- they'll notch and grab like a swing arm or steering bearinng does when the ball/roller travels over the same few degrees .

The brackets look really nice though. I wish mine were as lyrical.

 

[vwbug72501]

Andy,

Looking at the picture of your set up I see one thing that causes concern. The caliper bracket anti rotation link looks a little light.

Consider the lever arm that exists between the axle pivot point and the caliper pads and the axle pivot point and the anti rotation link mounting point. What amount of rotational force do you expect to be applied to these lever arms under panic braking situations? Consider forward weight transfer during a panic stop when figuring the force applied before tire lock up occurs (maximum brake lever arm forces).

My concern is what is the maximum tension force for the threads in the material at the diameter you have selected for the anti rotation link?

You really don't need the "excitement" of having the front brakes go away in a panic stop!

Nice looking front end!!!

 

[grandpanystrom61]

I did read another thread that stated they had used underrated material for the brake pivot stay. I will check and make sure that I did get a stronger stay, and if not, I will get that corrected.

Thanks for the heads up, no one wants shit to happen when doing a "panic braking"...…………….

 

[grandpanystrom61]

The 6" thread shaft is Carbon Steel, did not find any strength rating on the website, McMasterCarr, but I believe I wanted 4060 steel rod, need to read back, my bad ordering when I want to do things. The swivel joint is 303SS and the static radial load cap., lbs, is 2100. The shoulder bolts that mount the swivels are High Strength 17-4 PH SS with a tensil strength of 130,000psi and the note that spe.'s met are ASME B18.3, guess further searhing could teach me what that all means..... Yes I did jump into it, but I think I am getting the help needed to be sucessful with this project...

Thank you all very much for your input and help.

 

[vwbug72501]

Didn't you post a while back that you had a family member that worked at at machine shop? They should have access to the properties data that you need. I would be interested to find out how much stretching force could be applied to the stay rod threads before they fail. Check out the data on fine threads vs coarse threads mild steel vs 4060 steel, and also look at the same data for larger diameter rods.

As for the expected lever arm forces and tire coefficient of friction, etc calculations, maybe your local high school physics teacher (or one of his students) could help. This kind of information isn't always easily available and that is why a lot of people adopt the "Bigger is Better" design approach. Your forks have a light and streamlined look that is appropriate for your trike so I understand your wanting to keep everything minimal.

 

[grandpanystrom61]

Didn't you post a while back that you had a family member that worked at at machine shop? They should have access to the properties data that you need. I would be interested to find out how much stretching force could be applied to the stay rod threads before they fail. Check out the data on fine threads vs coarse threads mild steel vs 4060 steel, and also look at the same data for larger diameter rods.

As for the expected lever arm forces and tire coefficient of friction, etc calculations, maybe your local high school physics teacher (or one of his students) could help. This kind of information isn't always easily available and that is why a lot of people adopt the "Bigger is Better" design approach. Your forks have a light and streamlined look that is appropriate for your trike so I understand your wanting to keep everything minimal.

Wow, my mind did not even go that way. I just ran with my mind and some input helped me this far.

I really do see your point, a math head (but not that deep) so I will have to search out the help in figuring it out. I do agree it will not be a waste of time, I just hope that I only have the one issue.

I thought I had it, was getting excited, still am, just wondering how all will work out math wise. Need to get a new total weight of the trike, or a very close estimate, so the math can be done. More to do...…….

 

[TomyJ]

Springer disc

Found these when I was looking for RebelRouser's rear, right side, 11.5, .210w rotor to a caliper, not to much different from the chrome one, hope this helps, If NOT? I tried. I really like your work...

 

[stacebg]

View attachment 78818View attachment 78817View attachment 78819Found these when I was looking for RebelRouser's rear, right side, 11.5, .210w rotor to a caliper, not to much different from the chrome one, hope this helps, If NOT? I tried. I really like your work...

that what i was talking about lol

 

[grandpanystrom61]

View attachment 78818View attachment 78817View attachment 78819Found these when I was looking for RebelRouser's rear, right side, 11.5, .210w rotor to a caliper, not to much different from the chrome one, hope this helps, If NOT? I tried. I really like your work...

Yes that would have been a nice way to go at it, would have been done a long time ago. I jumped the gone making the brake stay, thought of it as a challenge, than one thing lead to another and I am almost done now.

Granddaughters came to stay in the our house, so I lost my play room and moved out to the garage, shit is tight, so have to get the projects done and trike put back together so I can breath, LOL.

The oil-lite bushing are to thin for a grease fitting, and they are suppose to be self oiling, but agree a thin layer of grease may help all keep moving freely.

Family talks more than helps, it does hurt some, but I can still get things done, just takes me a bit longer.

The family here has given much more help than I ever imagined, even gave me the confidence boost I needed. Thank you all so much.