Honda PCX (150) Linked Brakes

[silverantec]

Thank you everyone (almost) for the interest and replies. One or two of you force me to repeat for the 3rd time that the reason for this post was not to complain, nor am I seeking help. I have stated in both my post & subsequent reply that I wished to inform other users and hopefully save them from a nasty accident due to not knowing the facts of the poor rear brake performance.

Sadly gn2 your reply was that of an idiot who did not correctly read my post nor do you understand the subject of it. (Quote: Set up properly the CBS system on the PCX works just fine.Taking the CBS system to bits then complaining the braking system doesn't work... really?) As I have just stated the existence of serious problem, stated that I am a mechanic previously (therefore not without knowledge) & have indicated that a average rider would not normally discover this except under bad circumstances or traction conditions & below state a little more about myself, maybe there is just a chance I know something that you do not and risked sharing that knowledge with others for their safeties sake. And just maybe the CBS (S = system so Centralized Braking System system is redundant.) is not as "properly" setup as you might imagine and it is not the 1st time I have pointed out to motoring dealerships and mechanical workshops that something they have done is actually wrong, faulty or defective.

The left lever operates a primary cable just over 1 foot long (30 cm for the metric inclined) This connects to a compound T bar which on one end activates the secondary brake cable to the rear brake and activates a 2nd master cylinder mounted under all that covering on the steering shaft area. There are no adjustments to control bias front/rear. The only adjustment is a limiter in case of MC failure to cause some secondary cable function. I removed this master cylinder and fitted one long single cable. This 2nd MC does indeed operate the larger (26 mm?) piston of the caliper.

I would not have done this had it been ABS but it is not.(I also doubt I would have bought it had it had ABS but each to his own). I have done as Oyabun indicated and fitted a short braided hose and banjos linking all pistons. The small piston diameter difference is not a hindrance to safe braking any more so than 2 levers controlling 3 pistons. Funny how fitting a bigger disc or different caliper does not raise an eyebrow but separating a CBS system and you find harsh critics come out.

Having the front & rear brakes operate separately is exactly what people have had forever and still on many bikes do have. And if the brakes operation were truly balanced as with a car there would be no reason to have two controlling levers now would there.

pcx man (Quote: I stopped fast 2 days ago and the rear wheel on my 2013 PCX skidded. Also my parking brake holds great as long as the rear brake is adjusted correctly. You can not push it without skidding the rear tire.) Taking it on faith that my information might actually be correct, guess what wheel was doing most of the braking. Have you ever seen you tube videos of sports bikes somersaulting on emergency braking? I have not said the rear brake does absolutely nothing and as the front brake works really hard how much weight do you think was still on the rear tyre.(tire for Americans). Get it almost off the ground and sooner or later it must actually cease rotating in response to what little braking effort is being applied.

I was accelerating on about a 10 to 15 degree incline in rain once at about 20 kph and I got rear wheel spin for a few feet with a slight side slip. Does this mean my PCX is extraordinarily powerful or given the right conditions all sorts of things can happen? (the round smooth stones in the surface get very slippery when wet.) (An old surface type rarely used any more here.)

Mel46: since you do not have the brakes separated you would have to apply sufficient force to the rear wheel to replicate the condition I described of even walking beside the bike(maybe jogging). You might try running the engine against the brake a little. Not enough to heat nor harm the brake or strain anything. I too have tried the brake on the center stand by hand but not with the engine running. I am not certain if I could apply sufficient force to the wheel by hand to adequately test this way & have no one available to operate the brake lever while I might try. No point for me. Riding it proves all I need to.

kramnala58:(quote: Tampering with the brake system) as you put it. There is no law requiring CBS or ABS here. The brake hoses are certified. The cable duplicates the original made by Professionals. (No one here actually certifies cables but original manufacture has been replicated.) No other change or interference by me to the system.

chicaboo: (quote: I guess the drum is just useless for independent braking.) Not useless, but far below what I have experienced on any actual motorcycle with drum rear brake. If I had a decelerometer as I used to use in work experience tells me I get maybe 10% to 15% rear wheel brake effort. You tube videos of a Honda Ruckus also have people stating the standard drum brakes (fitted to both front & rear) are very poor for road use. Hence the modders fit disc brakes front and rear. My bigger worry is not for myself as now I know; but I am truly concerned for people riding with the CBS who have no idea how hard the front brake is working verses the rear wheel not working in corners under imperfect conditions who actually believe they are balancing their brake use.

Alibally: (quote: I can't understand why people muck about with braking systems. Fitting bigger discs and uprated pads I can understand but to tamper with a system that Honda probably spent a load of cash developing and works fine seems daft to me.) Your is the thinking of a person who does not think. You are fine with this, but let a person not interfere with the actual original brakes but just separate the brakes so that they can control the balance of braking and you have a problem.

dasshreddar; (quote: try adjusting the rear drum) They are adjusted all you can thanks. There is a couple of factors limiting adjustment. Not enough and no rear brake effort.(Lever bottoms out against handlebar). Too much and you have to strain the left lever to actually start the engine. The correct adjustment area is actually very small. And in case I had not stated it clear enough previously I reach a point where further squeezing of the brake lever returns no additional braking effort; it just strains the parts for no good reason. Looking from the outside I would have expected much greater braking effort from them. The drum does not appear small given the wheel diameter. But only the Dealership has been in there not myself and it is still less than 1 year old so I expect things to be in good & working order inside.

Again however my original purpose for this post was to try to make people aware of the risk of over using the front brake whilst cornering, particularly in less favourable conditions. I am possibly the only person who has had a reason to discover a potential fault where people may think they have balanced braking but I know that if my scooter has no internal rear brake fault from manufacture then with the CBS intact they actually have almost no rear brake effort going on and just do not know it, as I did not know it. For those who like to pick on me for offering the information, try to remember I was trying to help others. For 20 years I had been employed to fault find and diagnose faults with vehicles, and to explain to mechanics and to dealerships where a fault existed and if possible how it migh be corrected. I am sorry that explaining my past makes it appear like big noting myself but one or two out there need to understand from what I have said I have done to my scooter and the pictures I have shown of my changes to it (all my own work) maybe I am not a complete idiot.

Thank you to every person who showed interest and/or were not derogatory to me, for trying to help others. Sorry also this reply is so long but a fair bit came up to answer.

[chicaboo]

Maybe the only other things you could try are quality shoes and a longer fork (assuming you have the lever travel)?

[relic]

I drove a 1958 Karmin Ghia with only the handbrake
big trucks with adjustable cam brakes and a whole bunch of other vehicles with crappy brakes
I know were you are coming from-did not like the cbs at first on my PCX
but when you think about it is evolution and we are the benefactors

[Oyabun]

Thank you everyone (almost) for the interest and replies. One or two of you force me to repeat for the 3rd time that the reason for this post was not to complain, nor am I seeking help. I have stated in both my post & subsequent reply that I wished to inform other users and hopefully save them from a nasty accident due to not knowing the facts of the poor rear brake performance.

Sadly gn2 your reply was that of an idiot who did not correctly read my post nor do you understand the subject of it. (Quote: Set up properly the CBS system on the PCX works just fine.Taking the CBS system to bits then complaining the braking system doesn't work... really?) As I have just stated the existence of serious problem, stated that I am a mechanic previously (therefore not without knowledge) & have indicated that a average rider would not normally discover this except under bad circumstances or traction conditions & below state a little more about myself, maybe there is just a chance I know something that you do not and risked sharing that knowledge with others for their safeties sake. And just maybe the CBS (S = system so Centralized Braking System system is redundant.) is not as "properly" setup as you might imagine and it is not the 1st time I have pointed out to motoring dealerships and mechanical workshops that something they have done is actually wrong, faulty or defective.

The left lever operates a primary cable just over 1 foot long (30 cm for the metric inclined) This connects to a compound T bar which on one end activates the secondary brake cable to the rear brake and activates a 2nd master cylinder mounted under all that covering on the steering shaft area. There are no adjustments to control bias front/rear. The only adjustment is a limiter in case of MC failure to cause some secondary cable function. I removed this master cylinder and fitted one long single cable. This 2nd MC does indeed operate the larger (26 mm?) piston of the caliper.
.....

Thank you to every person who showed interest and/or were not derogatory to me, for trying to help others. Sorry also this reply is so long but a fair bit came up to answer.

I removed part of the reply to keep mine focused.
The secondary MC controls the central piston, one of the smaller twins. I know as I removed the CBS and followed a different route - I left the cbs cable unconnected and this is the piston that is not moving.
Indeed what could be tried also is to change to some better compound brake shoes and a longer actuator arm (I guess this is what Chicaboo also mentioned as fork in his post). There are some aftermarket manufacturers offering cnc alu arms but I'm not sure if I had seen any advanced compound brake shoes yet.
What I havent seen anywhere so far is a changed rear brake cam ( 43141-KWN-930) when I serviced my gearbox I have removed the whole assebly for cleaning and maintenance and it seemed to me a very crude and cheap design which might benefit from a redesign.

[chicaboo]

Indeed what could be tried also is to change to some better compound brake shoes and a longer actuator arm (I guess this is what Chicaboo also mentioned as fork in his post).

That's right. In my mind it was a brake fork (think clutch fork), but "brake actuator arm" sounds legit.

[gn2]

Silverantec, I believe you're not the only mechanic who has provided comment in this thread.
I said "set up correctly" did you have the rear brake adjusted correctly at the actuator end?
You do know that a locked rear wheel usually provides less braking than a rotating one?
How many miles have you ridden on a CBS equipped PCX?
I've done 19,000 over the course of three years (and Scottish winters) in all weathers on a CBS equipped PCX and am able to inform you that unless you are on ice or snow the left CBS lever will not lock the front wheel no matter how hard you pull it, so based on my experience, your fears are groundless.
I understand that you feel the need to control the brake levers separately, and I undestand why you would want them separate, but to claim you have improved the braking of your scooter is very dubious to say the least.
There's a reason linked brakes are mandated for PTWs up to 125 as of 2017 in the EU, and it isn't because linked brakes perform worse than separate ones.

[silverantec]

gn2: I have offered no suggestion ever that I might be the only mechanic commenting on this thread. I have in my last post if not elsewhere stated clearly that the rear brake is correctly adjusted, and yes even at the actuator end. Also if this were not so then you would have to be suggesting that the dealership got it wrong when they first delivered it to me or returned it wrong after replacing my original wheel which I had earlier stated they missed in their predelivery check and it required me to force their hand and acknowledge the fault existed and to have them deal with it by replacing the wheel. I have at no time had reason to interfere with the actuating lever.

I have also stated very clearly in earlier posts that I have no desire to actually lock up the rear wheel, but unless that were possible to do on a good surface then no one can prove that the brakes actually provide maximum braking potential. Also I provided some info about myself only so people might know I have some knowledge behind my claim. You are just a little insulting stating (quote:You do know that a locked rear wheel usually provides less braking than a rotating one?). I have been involved in the motor vehicle industry as a repairer and the Inspection of vehicles for faults for over 40 years for people who have driven their vehicles for thousands of kilometers who know nothing about how their vehicles work. What other qualifications do you have gn2 since you appear to constantly offer suggestions or criticism that one might offer to an apprentice on his first day.

You seem to confuse miles of riding with an understanding of mechanical leverage and a simple clear stated fact that a wheel is not capable of braking to maximum expected potential. Linked or not linked as per the CBS original setup, the rear wheel brake cannot perform any better than it does right now. I have not reduced the braking efficiency I have simply discovered the deficiency and passed on that knowledge for the sake of others. Take the knowledge those who wish to, and keep it in mind or do not. I only sought to help others. I repeat once again for all I am not seeking answers on how to improve my rear brakes. If I wish to I will do that at my leisure.

I am glad gn2 that you at least understand my reasons (more or less) for wanting to separate the front/rear brakes so that I may control the bike as I see fit, but at no time in any one of my posts/replies have I in any way stated nor suggested that I have improved the brakes. Indeed the only thing I have indicated is that I have achieved separate control of them and hence discovered a weakness in the performance of the rear brake. (I would prefer people do not make false statements of what they claim I have stated.)

And lastly the reason that lots of laws and rules are made is because in the eyes of the law every person is as stupid as the stupidest person ever to exist so they make laws and rules so that stupid person does not have to think. This takes away in some cases from having better self control which many people have and has nothing to do with something performing better as a result of whatever that law or rule was made about. ABS is an exception. No person can control brake lockup as well as a good working modern ABS however we are not talking ABS here & CBS is nothing like ABS, and CBS does nothing to either improve nor reduce the efficiency of the maximum braking of a wheel, however it most certainly can hide a inefficiency problem such as I have tried to point out in my first post.

Starting this thread was an effort to inform others. I am not seeking help from those offering it. I am willing to discuss anything about it with those wishing to discuss it.

[silverantec]

This 2nd MC does indeed operate the larger (26 mm?) piston of the caliper.

Sadly I must correct an incorrect statement I had earlier made. Somebody else pointed it out to me and they were indeed correct. The CBS master cylinder actuates the middle piston of the 3 which is also one of the two smaller two pistons fitted. I was myself misinformed and had previously had no reason to doubt the information or the source. Although I previously knew it was the middle piston operated I had also thought that was the larger piston. Thank you for the earlier caliper picture and the person who pointed out my mistake.

[alx123]

I stopped reading at " i have 1000 years of experience as a mechanic so I am the smartest guy here."

At topic: PCX's CBS seem to be working fine for me. Couple it with progressive braking and you'll be okay.

[Alibally]

I stopped reading at " i have 1000 years of experience as a mechanic so I am the smartest guy here."

At topic: PCX's CBS seem to be working fine for me. Couple it with progressive braking and you'll be okay.

+1.

[you you]

Silverantec, I believe you're not the only mechanic who has provided comment in this thread.
I said "set up correctly" did you have the rear brake adjusted correctly at the actuator end?
You do know that a locked rear wheel usually provides less braking than a rotating one?
How many miles have you ridden on a CBS equipped PCX?
I've done 19,000 over the course of three years (and Scottish winters) in all weathers on a CBS equipped PCX and am able to inform you that unless you are on ice or snow the left CBS lever will not lock the front wheel no matter how hard you pull it, so based on my experience, your fears are groundless.
I understand that you feel the need to control the brake levers separately, and I undestand why you would want them separate, but to claim you have improved the braking of your scooter is very dubious to say the least.
There's a reason linked brakes are mandated for PTWs up to 125 as of 2017 in the EU, and it isn't because linked brakes perform worse than separate ones.

I don't want to get into an argument with you, apologies for silverantec, but as an aside I've been riding quite a few different bikes recently. I'd normally agree with you but my recent experience has been that a locked rear wheel does give much better braking and turning sometimes. Low to medium low corners. Counter intuitive I know. Especially if you hold it just before it locks, bit of counter steer, lock it and turn in, goose it out. Modern tyres?

Doesn't translate to a scooter I know.

[gn2]

I'm not interested in arguments either.
I know what I know.
Properly maintained CBS on a PCX works perfectly well in all circumstances.
Two master cylinders are better than one.
The rear wheel of a PCX can be locked solid with the rear brake to allow the rear wheel nut to be undone.

Just a note for forum members in the UK (possibly relevant elsewhere too)
In the UK any modifications to braking systems such as described in this thread require to be advised to your insurer who may well cancel the policy when you explain what has been done.

[honkerman]

I stopped reading at " i have 1000 years of experience as a mechanic so I am the smartest guy here."

At topic: PCX's CBS seem to be working fine for me. Couple it with progressive braking and you'll be okay.

Precisely. I use the CBS lever as step one of the progression. the way it actuates its single front piston makes it perfect for the job.

[honkerman]

I've withheld comment on the main just of this topic since I've been mulling it over in my brain. I mean no disrespect nor wish an argument, but I'm wondering if there isn't something that got screwed up in the process of changing up the braking system. When the rear brake tension is properly adjusted on my PCX, it will lock the rear wheel so that the axle nut can be removed. The rear wheel will not move with the brakes fully applied.

Drum brakes in general pretty much suck. It's a reality of the technology. That said, the rear drum on my PCX doesn't seem to suck as badly as you seem to be experiencing (though it still sucks).

Even mechanics with years of experience can still have a bad day.

[GatorGreg]

Good article about the PCX's combined braking system for those that haven't seen it:

http://world.honda.com/tech-views/motor/cbs/PCX/

Interestingly, the prior gen VFR Interceptor also had a combined braking system, but for whatever reason they decided to get rid of the combined braking system for the 8th gen 2014+ VFR Interceptor. This change was greeted with nearly unanimous applause from the motorcycle press reviewers, most of whom seem to favor having more individual control like the OP. I'm curious to see if Honda also ditches the cbs on the upcoming 2017 CBR1000RR. I believe the '08-'15 ABS equipped 1000RR's had a combined braking system as well.

Personally, I thought the system worked great on my old PCX, I would typically use the left lever first and then apply more gradual pressure with right lever when needed. Seemed to me to be a nice feature to have, especially on a scooter with no abs where grabbing too much front brake could land you on Homie's sig list

[gn2]

The NC range also went from linked brakes to separate ones.
Separate brakes have lower manufacturing costs than linked.

[dasshreddar]

"Again however my original purpose for this post was to try to make people aware of the risk of over using the front brake whilst cornering, particularly in less favourable conditions. "
EXACTLY

OOps It's been so long since I took the cbs off... I changed the rear brake cable
I used a longer(1 piece cable) off of a GY6... try that and then your rear brake will work.

[you you]

I'm not interested in arguments either.
I know what I know.
Properly maintained CBS on a PCX works perfectly well in all circumstances.
Two master cylinders are better than one.
The rear wheel of a PCX can be locked solid with the rear brake to allow the rear wheel nut to be undone.

Just a note for forum members in the UK (possibly relevant elsewhere too)
In the UK any modifications to braking systems such as described in this thread require to be advised to your insurer who may well cancel the policy when you explain what has been done.

Do you ever have what other people call fun?

And I'm not talking about condescending stating the obvious for your own satisfaction and for your own enjoyment. Just fun, maybe making other people happy?

[JohnL]

Do you ever have what other people call fun?


Bazinga

[silverantec]

honkerman: (quote:I mean no disrespect nor wish an argument, but I'm wondering if there isn't something that got screwed up in the process of changing up the braking system. When the rear brake tension is properly adjusted on my PCX, it will lock the rear wheel so that the axle nut can be removed. The rear wheel will not move with the brakes fully applied.)

Fair comment; but in essence the only real change to the entire bike is now one cable works the rear brake instead of two (in line), and with the front wheel no longer included in the braking effort by the left lever I now know what the maximum braking capacity is from the rear brake.(in terms of on road effect). How would the brake effort required to hold against undoing the wheel nut compare to the unladen weight of the bike with more than 50% of its weight on the rear wheel on a good surface and the wheel already turning & trying to make it lock up. I have not done that comparison. I have not altered the leverage ratios that activate said brake. If people have read this post and are happy with their brakes I have done them no harm. And if they are thinking about it and ride with it in mind I may have done someone a service. The PCX is a great overall scooter. I would hate to put someone off them. My rear brake does provide reasonable modest braking. I simply pointed out the "fact" that I now know it has limitations greater than I might reasonably have expected.

GatorGreg: I myself had seen that post prior to purchasing my scooter. I think I let it cloud my judgement and with the dealership not actually having a demo bike for me to test ride took it as fact that a big dealership like Honda would get it all right.

But I am not actually picking on the feel of the bike as manufactured with the CBS operating. I thought the bike "felt" ok under brake. But can anyone state that a lot of that good feel in braking does not come from the reassuring effort the front wheel brake is putting in. Maybe there is in fact a certain balance to it that is ok.

Hundreds of (rear wheel)Handbrake tests I have performed on cars has proven no handbrake on any vehicle exceeds 25% effort before rear wheel lockup. Many do not reach 20%. I have estimated with me riding the bike I may be achieving 10 to 15% at the rear wheel in my situation.

Realising that for on road purpose your front brake may in fact be doing more of the work than the rear so your "Balancing" your front/rear brake use with additional effort by your right brake(front wheel) lever may not in fact be as "balanced" as you thought was the only purpose of this thread starting. It is also possible that Honda realise that under emergency braking in a straight line on a wet road they do not want you to lock up your rear wheel. If that means that on corners your front brake is also working harder than you thought and you add to it with the right brake lever I have sought to offer a caution not to overdo it.