Modern caliper on CB450

jammer415

Been Around the Block
Just rebuilt my carbs, adjusted the valves, changed the oil... Now I realize I need better brakes.

Goal is to install a modern (dual piston) caliper on the stock CB450 fork/wheel/rotor.

I’ve read through a ton of legendary threads of people swapping in entire front-end set ups from modern bikes, but I don’t think I’m ready for that yet. Plus, I’d like to retain the original front fender.

I like the idea of just bolting on an ex250 caliper to the stock CB450 rotor, but I understand that I will need to fab a bracket to make that work?

Wondering if anyone has completed this caliper upgrade? How did you make the bracket? Any other insights?
 

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So as I understand it... The ex250 caliper will just directly bolt onto the stock cb450 rotor, but I would just need to fab up a bracket to get the spacing right.

I was hoping someone would have an image of one someone had already made, but I’m wondering if I just bring the entire front end to a machine shop... could they just look at it and be able to know what to do?
 
Ive seen brackets that allow a 2 piston caliper (AP, Grimeca, etc) to be bolted onto the stock forks using one of the swinging bracket holes and one hole from the fender mounts by the axle.
 
I'm currently working on a swap, using EX500 rotor and cbr600 caliper. I'd think if you're gonna go through the effort of putting a better caliper, why not put a lighter and larger disc on there?
 
advCo said:
I'm currently working on a swap, using EX500 rotor and cbr600 caliper. I'd think if you're gonna go through the effort of putting a better caliper, why not put a lighter and larger disc on there?

are you talking an early cbr caliper? modern uses a floating rotor, wont work with rigid rotor and rigid mounted caliper
 
MiniatureNinja said:
are you talking an early cbr caliper? modern uses a floating rotor, wont work with rigid rotor and rigid mounted caliper

Yeah. 90's. Not sure the year exactly.
 
The issue you will likely run into is there is not enough room between the caliper and the wheel for opposing piston calipers. I had to make spacers for the rotors to fit these brembo calipers on the stock wheel with stock disks. I would look for non opposing (floating) calipers as they require less room on the back side. BTW you can have your rotor ground down and drilled for weight reduction, which will result better stopping power. The difference between a floating caliper and rigid is a floating caliper has pistons on one side only and the caliper body moves to self center on the disk. Rigid calipers have opposing pistons that move to self center on the disk. Either will work on any type of rotor, floating rotors just make the engagement more progressive, with better "feel". If the ex250 caliper will bolt on and just needs spacers, get some washers and shim it out until you know how much you need, then see if you can find a bushing on McMaster Carr or have a machine shop make you some
 

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slikwilli420 said:
Ive seen brackets that allow a 2 piston caliper (AP, Grimeca, etc) to be bolted onto the stock forks using one of the swinging bracket holes and one hole from the fender mounts by the axle.

So would that mean that I would need to lose the front fender? Or just bolt the bracket through there and get a slightly longer screw to also accommodate the fender mount?

(I’d like to keep the front fender)
 
advCo said:
I'm currently working on a swap, using EX500 rotor and cbr600 caliper. I'd think if you're gonna go through the effort of putting a better caliper, why not put a lighter and larger disc on there?

That sounds great... Still single disc, ya?

Do you have a CB450??
 
doc_rot said:
The issue you will likely run into is there is not enough room between the caliper and the wheel for opposing piston calipers. I had to make spacers for the rotors to fit these brembo calipers on the stock wheel with stock disks. I would look for non opposing (floating) calipers as they require less room on the back side. BTW you can have your rotor ground down and drilled for weight reduction, which will result better stopping power. The difference between a floating caliper and rigid is a floating caliper has pistons on one side only and the caliper body moves to self center on the disk. Rigid calipers have opposing pistons that move to self center on the disk. Either will work on any type of rotor, floating rotors just make the engagement more progressive, with better "feel". If the ex250 caliper will bolt on and just needs spacers, get some washers and shim it out until you know how much you need, then see if you can find a bushing on McMaster Carr or have a machine shop make you some

Thanks for your insights. Your brake setup looks stellar! Is that a CB450 also?? How did you get dual front discs? (Fork swap?)

The 2008(+) ex250 caliper is a floating caliper, it’s in the mail and should be here next week (along with the master cylinder and lever). I’ll try it as soon as it arrives.

So you think that maybe I can just shim it flush with some washers and forgo the custom fabbed bracket?? What would I use the bushing for?? (Please excuse my ignorance, somewhat new to me).
 
doc_rot said:
The issue you will likely run into is there is not enough room between the caliper and the wheel for opposing piston calipers. I had to make spacers for the rotors to fit these brembo calipers on the stock wheel with stock disks. I would look for non opposing (floating) calipers as they require less room on the back side. BTW you can have your rotor ground down and drilled for weight reduction, which will result better stopping power. The difference between a floating caliper and rigid is a floating caliper has pistons on one side only and the caliper body moves to self center on the disk. Rigid calipers have opposing pistons that move to self center on the disk. Either will work on any type of rotor, floating rotors just make the engagement more progressive, with better "feel". If the ex250 caliper will bolt on and just needs spacers, get some washers and shim it out until you know how much you need, then see if you can find a bushing on McMaster Carr or have a machine shop make you some

Also, let’s say I’m able to attach the caliper after all, and would like to grind down the stock rotor... How thin can it be??
 
redrover said:
Thanks for your insights. Your brake setup looks stellar! Is that a CB450 also?? How did you get dual front discs? (Fork swap?)

The 2008(+) ex250 caliper is a floating caliper, it’s in the mail and should be here next week (along with the master cylinder and lever). I’ll try it as soon as it arrives.

So you think that maybe I can just shim it flush with some washers and forgo the custom fabbed bracket?? What would I use the bushing for?? (Please excuse my ignorance, somewhat new to me).

Sorry I should have specified. that is a kz750, but what is needed to make those calipers work there is likely similar to what you have to do.

If the bolt holes do align on the ex250 caliper, I would use washers to determine how much offset (if any) the calipers need. The washers might work for the final product, but I would be worried about flex and chatter because its not a solid piece. If you can't find a bushing online that has the dimensions of the stacks of washers you can have something like that made fairly inexpensively. If that caliper doesn't line up perfectly with the fork mounts its not too difficult to make an adapter either. I had that hanger water-jet cut out of a piece of 7075 and drilled, tapped it myself. I did use a mill for some recesses, but all the chamfering and finish work was done by hand with files. Somewhere on here a member generously offered a to run some small stuff though his (laser?) cutter for very cheap. most disks will have a minimum thickness stamped on them. Its best practice not to go below that. The single disks are usually thicker than duals to act as a heat sink to prevent fading but some vintage disks are crazy thick. for example i toyed with keeping the single disk that came on that kz750 which was 7.5mm thick and having it turned down to the stamped minimum thickness of 6mm. that would have resulted in a significant weight loss somewhere where it really counts. if you use organic brake pads the wear on the disk is minimal, and modern organic brake compounds are fantastic.
 
Curious if this is an option for you. On my CB360, I drilled out the rivets and separated the outer disc from the inner ring, then bolted an EX500 rotor onto it, since they have a matching bolt pattern...
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doc_rot said:
Sorry I should have specified. that is a kz750, but what is needed to make those calipers work there is likely similar to what you have to do.

If the bolt holes do align on the ex250 caliper, I would use washers to determine how much offset (if any) the calipers need. The washers might work for the final product, but I would be worried about flex and chatter because its not a solid piece. If you can't find a bushing online that has the dimensions of the stacks of washers you can have something like that made fairly inexpensively. If that caliper doesn't line up perfectly with the fork mounts its not too difficult to make an adapter either. I had that hanger water-jet cut out of a piece of 7075 and drilled, tapped it myself. I did use a mill for some recesses, but all the chamfering and finish work was done by hand with files. Somewhere on here a member generously offered a to run some small stuff though his (laser?) cutter for very cheap. most disks will have a minimum thickness stamped on them. Its best practice not to go below that. The single disks are usually thicker than duals to act as a heat sink to prevent fading but some vintage disks are crazy thick. for example i toyed with keeping the single disk that came on that kz750 which was 7.5mm thick and having it turned down to the stamped minimum thickness of 6mm. that would have resulted in a significant weight loss somewhere where it really counts. if you use organic brake pads the wear on the disk is minimal, and modern organic brake compounds are fantastic.

Wow a lot of good information there, thank you!

I’m excited to try the ex250 caliper on and see how it fits. I’m also contemplating custom rotor applications, otherwise will grind mine down to the minimum thickness (since heat dissipation is easier where I live due to a constant icy wind blowing pretty much all-year round).

When you had your bracket made out of 7075, did you have to design it yourself? Or did you just go to a machine shop, show them what needed to be bolted together, and they figure out what to do?
 
irk miller said:
Curious if this is an option for you. On my CB360, I drilled out the rivets and separated the outer disc from the inner ring, then bolted an EX500 rotor onto it, since they have a matching bolt pattern...
7064cce9f2fdc4344b292d492c36a9ce.jpg

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a375e9ac26105d45f0597c605e126175.jpg

That’s awesome. Although it looks like the ex500 rotor won’t work for the 450 (since it has nine rivets vs six on the cb360/ex500), but definitely a possibility from a different bike? Maybe an fzr1000??

How much lighter is the ex500 rotor, as opposed to the stock 360 rotor?
 
I didn't put anything on a scale, so it's just speculation, but they have to be half the weight. Plus the EX rotors being drilled, I gained some cooling and stopping.
 
redrover said:
Wow a lot of good information there, thank you!

I’m excited to try the ex250 caliper on and see how it fits. I’m also contemplating custom rotor applications, otherwise will grind mine down to the minimum thickness (since heat dissipation is easier where I live due to a constant icy wind blowing pretty much all-year round).

When you had your bracket made out of 7075, did you have to design it yourself? Or did you just go to a machine shop, show them what needed to be bolted together, and they figure out what to do?

I designed them myself. It took a couple versions laser cut out of acetate to get the spacing correct. A competent machine shop should be able to make something work for you. The hard part will be finding a shop that is willing to take a project like that on. I don't know if EBC makes their "pro lite" rotors for your cb450 but if so that is a high quality floating disk
 
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