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Discussion Starter #1
While the overall braking of the CRB250 is acceptable I am quite disappointed with the lack of feel (wooden block comes to mind). I will likely try SS lines but since I like doing things just to do them I thought about installing the ABS caliper, with it's three pistons, on the stock master cylinder to ideally get some better modulation. I don't suppose anyone else has given it a try.

I already have one in transit (thanks to eBay) so I will first see if it even mounts up them i'll snag a secondary line and go to work bleeding it. I figure that even if I stick with the double piston action (single line) the increased surface area of the ABS pads alone should help.

Any thoughts?
 

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Meh.

I think the brakes on the CBR are fine and feel fine, and SS lines would be in itself a good upgrade, then EBC sintered brakes.

Putting an ABS dual line caliper on a non ABS bike is gonna cause issues.


Why didn't you just get ABS to start with? $500 more at the dealer is better off than nigg*r rigging it.
 

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Discussion Starter #3
Maybe I didn't explain what I want to do well enough. I'm not trying to install anti-lock brakes on my non-ABS model. I just want to install the caliper. There are three pistons that need to be moved so there is more fluid movement required and that "should" allow for better feel plus the pad should have roughly 50% more surface area.

And to answer your question; I bought my CBR250r used and even if I bought new it is the Repsol edition which was not available with ABS in the US.
 

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Maybe I didn't explain what I want to do well enough. I'm not trying to install anti-lock brakes on my non-ABS model. I just want to install the caliper. There are three pistons that need to be moved so there is more fluid movement required and that "should" allow for better feel plus the pad should have roughly 50% more surface area.

And to answer your question; I bought my CBR250r used and even if I bought new it is the Repsol edition which was not available with ABS in the US.
You are assuming the pistons are equal sized between ABS and non-ABS. That may be true, but I don't have any idea.
If they ARE equal sized, without changing the master cylinder, going up 50% in area is alot. You could end up w/ alot of travel which would feel like a wet sponge.
 

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Discussion Starter #5
You are assuming the pistons are equal sized between ABS and non-ABS. That may be true, but I don't have any idea.
If they ARE equal sized, without changing the master cylinder, going up 50% in area is alot. You could end up w/ alot of travel which would feel like a wet sponge.
I am actually anticipating that. I know I did a similar change to my other bike where I went from 2 two-piston calipers to 2 four-piston calipers and the lever had too much travel (for my taste). I had to up the MC because the lever almost touched the bar. I wonder if anyone can tell me if there is a difference between the ABS and non-ABS master cylinders? In the end i'm hoping to hit the sweet spot between too much travel and the current setup.
 

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There is a difference between the master cylinders. Honestly, I think you're asking for trouble by modifying the brake system from how Honda designed it.

My bike is a non-ABS version and the brakes work fine. If it's not broken...
 

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Discussion Starter #7
There is a difference between the master cylinders. Honestly, I think you're asking for trouble by modifying the brake system from how Honda designed it.

My bike is a non-ABS version and the brakes work fine. If it's not broken...
Any idea what the differences are? I would imagine there would have to be SOME differences between them but since the rear MC seems to be what articulates the center puck I'm curious if the front MC piston size is actually the same as the non-ABS. By looks alone it would seem that each of the ABS caliper's 3 pistons are approx. the same size as non-ABS's 2-POT.

And yes "If it's not broken..." always stands. But, the stock exhaust is perfectly fine and yet people who want lighter weight and a nicer sound would argue that it's not. The stock seat works just fine as a seat but for certain people it's too firm or too soft or pushes you forward. For me I do not like how the front brakes engage and what might work fine for you does not for others. I also tend to do these types of things because I can as it's a learning process to answer the ultimate question; "what if...".

Thanks for the feedback!!
 

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And yes "If it's not broken..." always stands. But, the stock exhaust is perfectly fine and yet people who want lighter weight and a nicer sound would argue that it's not. The stock seat works just fine as a seat but for certain people it's too firm or too soft or pushes you forward. For me I do not like how the front brakes engage and what might work fine for you does not for others.
Sure, but mufflers and seats are not your brakes. We are talking about the most powerful piece of equipment on your motorcycle. Not to mention the most crucial to your safety. I'm sure I won't discourage you from tampering with it, so just make sure you know what you're doing.

Anyway, IMO I find the brakes very capable with a good bite and "feel." My first motorcycle (1978 KZ200) had mechanical brakes, like a bicycle's.
 

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Discussion Starter #9
Sure, but mufflers and seats are not your brakes. We are talking about the most powerful piece of equipment on your motorcycle. Not to mention the most crucial to your safety. I'm sure I won't discourage you from tampering with it, so just make sure you know what you're doing.
Thank you for your concern but I assure you it's definitely not something I've never dealt with before. I know that likely a large majority of CBR250r owner's are new to motorcycles but I've been around the block a few times, lol.

Anyway, IMO I find the brakes very capable with a good bite and "feel." My first motorcycle (1978 KZ200) had mechanical brakes, like a bicycle's.
I definitely agree that the brakes are very capable. The caliper should be delivered today and I will post up some pictures and proceed with test mounting etc. As is probably mentioned numerous times on this site swapping to a stainless steel line is all that should be needed to get better feel. I'll be doing this regardless if anything to prove to others just how UN-necessary it really is, haha. But I do like the look of the ABS triple-piston caliper.
 

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It could be done by getting the right master cylinder and the ratio correct for power and feel.

Would never bother for a road bike though, there is no instance that a standard cbr needs any more braking, it does stoppie swith a decent rider, / or locks the front killing noobs easy enough.

Start with fixing what is wrong with your brakes or riding first.
 

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Without measuring the diameter of the pistons, i would hazard a guess that the amount of fluid need to move 3 pistons is going to be 1/3 more. If the master cylinder pistons on the R and the RA are the same size then you are going to have 1/3 more travel on the lever to compensate and it will feel mushy in operation.

However if you do know the diameter of the twin piston caliper pistons and the three piston caliper pistons, you would add the surface area of the twin pistons together and see if its the same as the area of the 3 piston added together. If not then you will need a master cylinder with a bigger piston to shift more fluid.
 

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Any idea what the differences are? I would imagine there would have to be SOME differences between them but since the rear MC seems to be what articulates the center puck I'm curious if the front MC piston size is actually the same as the non-ABS...
The size of the pistons sets are different (and have different part numbers)... The ABS master cylinder piston would have to push more fluid.
 

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... I also tend to do these types of things because I can as it's a learning process to answer the ultimate question; "what if..."
... I'll be doing this regardless if anything to prove to others just how UN-necessary it really is, haha. But I do like the look of the ABS triple-piston caliper.
Sorry OP, but I can't help but wonder if this is another case of "mod fever" trumping the idea of "leave well enough alone"?

Why not try a set of performance brake pads, as others have suggested?

Although not as outright crazy, this thread does remind me of the thread a while back where the guy was convinced that installing a cheap $6 pressure relief valve on his front brake caliper would give him the "effect of an ABS brake system"... I wonder what happened to that guy?
 

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As I stated before and will say again -
Changing that stuff is a waste of $$. The best upgrade you can do is SS brake lines, and sintered pads. It'll do a stoppie on a dime.

But yeah Mike, When I seen this topic for some reason I was thinking about the other guy that wanted to put that cheap ass valve on that makes it ABS. This guy seems to be a little smarter than him, but still pretty boarder line.... I have a feeling that one guy ended up crashing and giving up MC's, if he lived it.

But yeah @ OP, If you want to put $$ into your bike that will be well spent, then get the suspension setup.. I love how people spend a lot of money on these pointless "mods" because they have mod fever, but they don't even change the stuff that needs to be changed.

If you care so much about looks, and you're doing it because it'll look better like you said, then yeah, its a case of mod fever.
 

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Before I started putting on different calipers I'd find out why the stock setup doesn't feel rite, maybe your pads or disk is glazed up? Maybe your fluid has excessive moisture, maybe the master cylinder is leaking or the pistons ain't moving back correctly.
As you see there can be a few simple fixes to make the stock setup work.
Ss lines front & rear feel great & are not expensive.
Try that first then if your not happy still maybe the caliper/bracket & master cylinder from the non abs 500 will fit?who knows? Once you start messing with 2 lines into 1 & different size pistons in the same caliper your setting yourself up for heartache.
As a mechanic my professional opinion is find out what's wrong with the stock setup first, I use ss lines & stock pads & have almost double your hp & mine stops perfect every time.
 

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Master Cylinder Bore
R = 11.000 mm
RA = 12.700 mm
Front Caliper Pistons Bore
R = 25.400 mm
RA = cyl A = 22.650 mm
RA = cul B = 27.000 mm

Modding without an OEM Service Manual. Talk about a Lack of Information. Also Known as the School of Hard Knocks.
 

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Discussion Starter #20
Thanks for the feedback I really do appreciate it all. I am not so set in my ways that I HAVE to do this or that and am one of these people that post up looking only for reinforcement of my sometimes whimsical mod choices. I really do enjoy brainstorming especially when those few folks that actually know what they're talking about chime in; it makes the world go round. Plus I know that I'm new here and you may assume that this is my first bike and there's no way to confirm that I actually know what I'm doing.

From what I can tell the outside two pistons (27 x 35) are independently controlled by the front master cylinder. The center piston (22 x 27) is controlled by the rear MC. So based on Soul Searcher's specs the increase in fluid displacement is ~33% (lemmy99 got it!). In my experience increasing fluid requirements on a same size MC piston softens the lever. And this is where I have an issue with the current setup; it's the lever feel and travel. Nothing more.

Also it seems that folks are jumping to conclusions and making assumptions that I want more overall braking power. This is not the case. As many have stated the brakes are "just fine" and can no doubt lock up the brakes at will. What I do not like is the feel and lack of, to me, modulation. I would like more bite and for that a sintered pad is the answer. The SS lines are of course going to provide consistency and by reducing expansion and thus sponginess but with the MC/piston ratio the way that it is I can't see how an SS line would have much effect on the lever feel.

A side benefit to the ABS caliper is the larger pad. An even smaller benefit is the increased surface are for more heat dispersion which of course has a downside of more weight.

But back to my goal if someone has a suggestion on how to soften the lever and improve modulation without changing out the caliper or master cylinder than please let me know. Ideally I would like to go with a 4-piston caliper but that would almost certainly require a new, larger, MC. So to me, for now, the triple piston caliper that is already molded to (hopefully at least as I haven't checked) mount to the fork tubes of the CBR appears to be an ideal option.
 
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