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Discussion Starter · #1 ·
After disassembly, hydro sonic cleaning, and rebuilding of my front brake caliper with new gasket and brake cable I've come to realize my work was in vain. The caliper was a flawed design with a 3 part pressure disk using pin bearings in the center that always slip out of their groves and cause the brake pad to brake unevenly which causes a horrible squeal. It's now time to upgrade to hydraulic (I knew it was inevitable, I just wanted to delay it for a couple more years) I'm attaching a link to the Honda twins site that show how a guy came up with a pretty ingenious 3 part bracket design using relatively common tools and equipment anyone could have access to


My idea is to come up with a 2 part design that, instead of joining with fasteners, I'll weld the plates together. And as much as I respect how he managed to hack the steel into an attractive shape, I feel drawing the design on CAD and letting the CNC do the cutting is the right way to go. Luckily I work in a steel warehouse and plate is plentiful and free around here so I got lots of fuck-up room. Any ideas for specific caliper and brake lever/reservoir would be appreciated

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Discussion Starter · #3 ·
Thank you for the input trailsrider, I'm attaching an exploded view of the original caliper that shows that it floats on a swivel.
Font Circle Auto part Pattern Drawing


I imagine I could recreate this with a piece of stock cut to size and milled to the correct I.D. although it looks like the pin is shaped as a grease trap and probably means the stock would need to be counter sunk, seals fitted, ect. Which makes a fixed bracket much more appealing. The guy in the link made his into a fixed bracket in 3 pieces, one bolted on forks, one bolted to caliper, and one "sandwiched" between the 2 in order to compensate for the caliper placement on the disk. Chances are I'll have to mimic this technique.

I'll take your advice about using aluminum since it's just as plentiful and seems reasonable that I wouldn't want to throw the weight off on the front. I imagine ¼" thickness should suffice for this application? Also these calipers that you speak of, they operate with Pistons on both sides pushing towards each other and only require one brake line correct? Seems silly to ask but I like things laid out nice and simple.
 

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Discussion Starter · #5 ·
Ok I figured that's how they worked. I've done brakes, calipers and rotors on cars and trucks, and mechanical brakes on old japanese bikes both disk and drum. But I've never had to service a hydraulic motorcycle brake so I had to ask.

I plan on setting the caliper in the same orientation as the original one was. Both the bike and myself don't weigh much and it only tops out at 75 mph, with that being said the placement should be fine and the caliper can be small. But if I'm using aluminum then I wanna make sure it's thick enough to handle the stress. ¼" should work right? For you Canadians that's about 6.35 mm
 

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Discussion Starter · #8 ·
I've been searching for different conversions and found this beauty. It's a 2 plate design and located on the other side of the disk like modern bikes. Brake is a sliding caliper with 2 pistons on one side, which gives the other side adequate clearance for the spokes. By the looks of it from the back view I'd say the plates are identical in thickness and simply welded on both sides one on top of the other with the fork plate inside and caliper plate outside. Best part is I saw this caliper, hose, and lever on ebay for around $50
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Discussion Starter · #11 ·
You're right the bracket in the photos is too long and give leverage for shearing the bolts, but I was gonna reduce its size drastically not only for that reason but also so it can fit between the fork and the lower fender mount (see photo of original cb200 front end)

Wheel Tire Automotive tire Bicycle tire Synthetic rubber

I know what you mean that the closer to the axle the better, I've got another photo of a gentleman who fabricated a mount that is attached at the axle, if I was more experienced with the break press at work I'd try my hand at cutting and bending a plate in a similar fashion.
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I'm gonna try to build it with the 2 plate method and sliding caliper first and see how it works, even if it causes the break pad on the piston side to wear faster I'm content on spending a little more for new pads.

Just so we are clear, this is not a racing motorcycle. I've had this bike since my dad gave it to me on my 14th birthday and had less than 3k miles. I've babied this thing and did my absolute best I can at keeping it as original as possible, so you can imagine I'm somewhat sad at having to do any upgrades and ruin it's authenticity 😭
 

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Discussion Starter · #14 ·
I can understand your reasoning for wanting to redesign things for better performance, infact it's bulletproof logic. But if I had a choice I would wish my original caliper would be refurbished rather than upgrade to hydraulic only because sentimental reasons. There's lots of bikes out there I like, but only one I love.

I'm gonna try my hand at the prototype I had in mind. I'll use 1/4 aluminum, flip the caliper on the other side, and shorten it to reduce leverage. This should well out perform the original design. And just for you I'll take measurements of the pads every 100 miles to see if the wear is drastically different. Oh and I don't like how he drilled out the disk either, but that photo doesn't do the caliper bracket any justice there were other photos that showed a better view of it, but because the zoom in is crap I see no reason to post them
 

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Discussion Starter · #17 ·
Have you ever ridden a motorcycle that has a one finger front brake? I'll give you a heads up it takes a little practice.
Lmao no I don't believe I have, and I can assume it's not a fun experience.

I'm at work now, when I get home I'm gonna take a picture of the distance between the outer edge of the disk to the spokes, when I did it yesterday I measured 1 ³/¹⁶" which I can't imagine an opposing piston caliper can fit between. My cb750 with gsxr front end has calipers with opposing pistons now that I think about it, but it's a mag wheel with plenty of clearance

I'm starting to assume I'm gonna have to design this like a car, take a fixed caliper like #3 in your diagram and figure out how to make the whole thing float
 

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Discussion Starter · #18 ·
Or if i was desperate I could swap the front end off a CL200, but lord knows I'd be hunting down the tank, side covers, and pipes to complete the look 🤣
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Discussion Starter · #20 ·
I don't think I'd want to ride a bike with one finger stop. My little ass would fly right over the handle bars.

That's crazy you have a 4 pot caliper that is that small, I bet something like that is expensive though. Looks like what a majority of people use in their conversions is just a cheap caliper for a 50-150cc mopeds. That being said, if an effective bracket can be made, then there's a potential for mass producing so-called "hydraulic conversion kits" and make some decent money as there is a demand for them.

But I digress, do you have a model number for that 4 pot caliper? Or a bike that it comes on stock? I'd at least like to see it
 

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Discussion Starter · #22 ·
Man I just took a peak at braktec, looks like really nice high quality equipment, especially the reservoir levers. But with that comes high prices. Add a new disk to it (which the right thing to do would be to take a piece of stainless steel round stock, probably 10-12" diameter, and have it lathed and milled to a precise shape that fits the original mounting bolts) and you would have a front brake unmatched by any vintage rebuild. But just the price of stainless steel... Oooo sends shivers down my spine 😱

999 out of 1000 people are gonna look for an economy option. But I see you have fine taste for motorcycles, way outta my budget lol
 

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Discussion Starter · #29 ·
I actually found a lever and caliper that works for me, just gotta get around to making my template for the bracket and then fabricating it. Its gonna happen, just that motorcycle season is in and I can suffer a squeaky brake for enjoying the ride at the moment
 
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