Brake discs: Dual discs, Drum to disc conversion, dual pistons etc..

[ORen]

Hi guys,

 

I have a bunch of questions about brake discs, if anyone has a little bit of knowledge to share it would be much appreciated

 

I understand that the drum brakes are usually recommended for the rear wheel to lower the risks of wheel locking but my stock drum brakes are universally known for their crappy performance so I am looking into changing them and I have no clue what to get or how to get it done. So it got me into looking for more info about disc brakes.

 

1. What's the advantage of having two front brake discs, besides a better braking power? Does that not make the bike more front-heavy ? Is it necessary for a bike with a speed below 120km/h ?

 

2. Can any bike be modified to go from 1 front brake disc, to 2 ? In theory, what do we need to do to get a second disc, besides finding a way to fix it to the wheel ? Do we need to change the caliper and brake cable ? The brake fluid needs change too ?

 

3. I am looking into converting my rear brake drums to disc brakes: What are the things I have to take into account, on top of probably changing the swing arm to fit the disc ? If you've done this conversion, can you share your experience ? What are the risks to the bike's engine or maneuverability ?

 

4. What's the added benefits of having a dual piston caliper ?

 

5. How much does a disc brake cost, the whole thing, all parts ? (let's say you want to put in a whole new set, with the petal disc, caliper, pads, cable, hose, fluid etc..)

 

6. For a 250cc bike, cruising speed 90-100km, day-to-day speed 65-80km, what type/model/brand of disc brakes would you recommend for the front and for the rear ? (Knowing that the bike is front-heavy by nature), I am looking for petal discs.

 

7. Which shop would you recommend for changing stock discs to new ones, and which shop for doing a rear drum to disc conversion ? (I ride a Bajaj Pulsar 200, and the official reseller shop has never done it before)

 

Thanks a lot for taking the time to answer my questions !

[mild_slevin]

Hi guys,

 

I have a bunch of questions about brake discs, if anyone has a little bit of knowledge to share it would be much appreciated

 

I understand that the drum brakes are usually recommended for the rear wheel to lower the risks of wheel locking but my stock drum brakes are universally known for their crappy performance so I am looking into changing them and I have no clue what to get or how to get it done. So it got me into looking for more info about disc brakes.

 

2. Can any bike be modified to go from 1 front brake disc, to 2 ? In theory, what do we need to do to get a second disc, besides finding a way to fix it to the wheel ? Do we need to change the caliper and brake cable ? The brake fluid needs change too ?

 

(Man, you need to change quite some stuff. Left fork don't have a bracket to accommodate 2nd brake caliper your rim don't have another hub to hold 2nd disc, the brake pump need to change, you need a additional brake hose for the 2nd caliper and yes you need to bleed and top up fresh brake fluid)

 

3. I am looking into converting my rear brake drums to disc brakes: What are the things I have to take into account, on top of probably changing the swing arm to fit the disc ? If you've done this conversion, can you share your experience ? What are the risks to the bike's engine or maneuverability ?

 

(For rear, you need to change the rim which has the hub to hold the brake disc. Brake lever might need some modification, since the method they actuate the brake differ slightly. Swing arm, if its wide enough to accommodate the bracket then I don't see why you need to replace it, else you have to look into alternatives to mount it. Like above mentioned, you need brake pump, reservoir, brake hose, caliper and disc)

 

5. How much does a disc brake cost, the whole thing, all parts ? (let's say you want to put in a whole new set, with the petal disc, caliper, pads, cable, hose, fluid etc..)

 

(Wah, brake disc a simple looking metal dish but its costly. My OEM Honda rear disc alone cost me 190SGD (with installation) some more the pad need to be replace as well. Petal disc, usually you can find it on off road bikes. I read an article by Galfer, they claimed that those pattern on the disc can drive off brake dust, dissipate heat, better braking efficiency. If you choose establish brand like Braking or Galfer it can easily go beyond 200++, else you can choose ebay for alternatives. Stainless Steel braided brake hose, previously I was quote around 170SGD for 3 pieces (2 front, 1 rear). For brake pad, choose those made with semi-metallic materials if you are just riding on the street. They provide good braking, at the same time don't wear off your disc that easily.)

 

Thanks a lot for taking the time to answer my questions !

 

My answer in bracket...

Hope it helps.

[Pandoras Kitten 3]

Great answers!

 

As you can see... things get really expensive FAST.

 

There are RXZs puttering around town

 

To increase braking response you may also elect to replace the front brake line with steel braided hoses; these are more rigid than the stock steel lined rubber hoses and provide better and more instaneous braking response.

 

Cost - $80 or less from Unique Motorsport. Tested on a Honda Phantom (not mine) with stock piston & caliper and the steel hose upgrade was brilliant.

 

I like to modify with an eye to gaining maximum bang for the buck so that's my 2 cents. Due to weight distribution under braking, the front does the majority of the work. It can be unsafe to have very powerful rear brakes ie, on some Phantoms. Risk of skidding for the unwary, especially in wet conditions.

 

Not sure if the rear drum can be improved - drum brakes reside in the wheel so brake upgrade = new rim compulsory? Last I checked there's not a lot of Pulsar modders locally.

 

Although in India there exist full fairing conversions, Hayabusa lookalikes (Pulsabusa!!), etc

 

There's also the option of having a Brembo caliper but.... I can likely get a used Pulsar for the price. Almost. Or at least the downpayment...

[Cracked]

Go service ur drumbrake.. ask e mech to open up, blow the dirt off, change drumshoe and whateva parts that nid be. Drumbrakes are enuff for lower cc bikes, u dun need rear disc..

 

Somemore, changing to rear disc conversion doesnt necessarily means there b an improvement in braking..

[ulysses_sc]

As suggested by others, replace the stock rubber hoses with steel braided hoses, as well as good brake pads. This will improve braking performance significantly.

 

Unless there are direct bolt on alternatives for you bike, I would stay away from modifications, especially if you are not familiar with brake systems and general bike modifications.

 

FYI, brake calipers and brake pumps need to be matched carefully to function properly. You cannot simply bolt on a Yamaha R1 Brembo brake pump to you bike and expect it to be great. You will simply end up with a very hard brake system that locks up at the slightest touch, reason being the R1 pump is designed to work with dual multi-piston calipers, which will overwhelm your stock caliper easily.

[ORen]

Thanks everyone for the advises and replies, it's very helpful.

I have considered changing the brake cable/hose and pads, but even like that, the braking is poor. I've learnt recently that it could be possible to put a CBR400 rims on my bike, and from there I would be able to put the corresponding braking discs and calipers.

 

Which ones would you recommend for a 200-250cc ?

[mild_slevin]

Thanks everyone for the advises and replies, it's very helpful.

I have considered changing the brake cable/hose and pads, but even like that, the braking is poor. I've learnt recently that it could be possible to put a CBR400 rims on my bike, and from there I would be able to put the corresponding braking discs and calipers.

 

Which ones would you recommend for a 200-250cc ?

 

Are you riding CBX250 "Twister"?

Another thing you can check, the brake caliper/pump if it require servicing or if bleeding is done properly as well.

[ORen]

I'm riding a Pulsar 200cc It's a first hand bike, brand new, got it since April 2010, so I suppose the caliper and pump should be fine ?

I only did about 1500km with it so far. But I will ask the mechanics to look into it, thanks !

[ulysses_sc]

Thanks everyone for the advises and replies, it's very helpful.

I have considered changing the brake cable/hose and pads, but even like that, the braking is poor. I've learnt recently that it could be possible to put a CBR400 rims on my bike, and from there I would be able to put the corresponding braking discs and calipers.

 

Which ones would you recommend for a 200-250cc ?

 

Even if you manage to use a CBR400 front wheel, you will still need to ensure the CBR caliper mounts to your forks correctly, and at the correct distance with respect to the new disc size. For the 2nd caliper, I cannot see an easy solution.

 

The best bet is to also use the forks and triple tree from the CBR400. In that way, you can be sure the entire front end will work in unison.

 

But, front end transplant projects are never simple and straightforward.

 

Good luck.

[ORen]

Hi,

 

Thanks for the advices, this mod has been done on Pulsars. And apparently I can keep my Pulsar stock forks But you're right, I will definitely have to check all these details and it might not work.. so I am prepared to either abandon the idea or to look into other alternatives.

 

Which shop would you guys recommend to do this sort of modifications ?

[ORen]

Photos from fellow Pulsar rider in Indonesia who did the mod - and the funny part is his CB400 rims came from... Singapore

He used aftermarket discs, not original CB400 discs to avoid having to change the forks:

 

http://i655.photobucket.com/albums/uu276/dora343/ibc1.jpg

http://i655.photobucket.com/albums/uu276/dora343/p11-1.jpg

http://i655.photobucket.com/albums/uu276/dora343/kosong.jpg

http://i655.photobucket.com/albums/uu276/dora343/ciwidey1small.jpg

 

http://i655.photobucket.com/albums/uu276/dora343/xtreme1of1-13-1.jpg

http://i685.photobucket.com/albums/vv214/tigersyndicate/S8002755.jpg

http://i685.photobucket.com/albums/vv214/tigersyndicate/S8002754.jpg

http://i685.photobucket.com/albums/vv214/tigersyndicate/S8002760.jpg

 

And what he had to do was just add a bracket for the cylinder :

 

http://i685.photobucket.com/albums/vv214/tigersyndicate/S8002759.jpg

[Pandoras Kitten 3]

That's a cute wee lil beasty. Now to find someone who dares to do that in SG...

 

Wait, that's you!

[ORen]

lol... yeah..well, if I could take my Pulsar to Jakarta I wouldn't hesitate ! But yeah, I need to find someone here who's willing to do this

[Pandoras Kitten 3]

Time to surround Ah Chong @ Planet and 'convince' him with biker diplomacy tmw

 

I can imagine this scene:

 

Ah bengs walk into planet like bengs, go to Dr Chong

 

"HARLOW BRO, I GOT SPECIAL PROJECT FOR U AH."

 

Well it is worth a try - till you find a proper Pulsar modders club. Lots of other bike shops @ ubi too.

[ORen]

My Ah beng style sucks. I'll try the Fussy Ang Moh style, closer to my character

"Hi... How are you ? (You have to be Ang Moh to ask that to a mechanic, busy on bikes, barely interested in anything else at the moment and wondering if you're lost or mental) So.. I'm looking for someone who can help me with my bike.. (The poor girl lost always works - specially after the previous line).. can you please come have a look ?"

 

If he doesn't follow, or look for someone else to save him from this, we got a winner, thick skinned enough for me to then go nuts and explain how I bought an Indian bike to change it into a 400cc bike, instead of just buying the damn CB400 from the start.

 

Yeah, I can see this working in my head - the guy has to be in an excellent mood for this to work, goes without saying.

[Pandoras Kitten 3]

"Dear Sir I fully know what I'm talking about. I didn't stay up all night looking at the experts' websites for nothing. Now would you kindly get me my parts or do I have to look at your competitors to do the work?"

 

 

Don't bring me to any local restaurant, I will talk like this LOL

 

ps. will bring printouts of your pulsar example to chong @ 9am tomorrow. Lets see what he says or if it's possible locally. Have to deal with inspection by LTA yearly too y'know?

[ORen]

Yeah but not until in 3 years ! And if this works out, I will put back my stock rims or cry until they clear it

[Pandoras Kitten 3]

I can't even take out my carburettor without professional assistance and you're swapping out your rims for yearly inspection *respect*

[Pandoras Kitten 3]

Super 4 parts costing:

 

I stopped before I even began the survey, at item no.1

 

1 set of CB400 tyres... $265-300

 

By the time we're done with the mega-pulsar, there might be enough capital spent to buy a second pulsar. Or Take a big bike license and get a pre-loved CB400.

 

I'm also leery of the mechanical aspects of the big wheels - more stress on that little Pulsar chain is bad, plus the consideration of reduced performance from the heavier wheels.

 

The front forks of the Jakarta bikes also look too thin to support the big wheels. Won't want to think of hitting a bump at 100kph on those little fork springs plus the mass of the big wheels. Have heard of certain-generation Pulsars having broken forks from normal street riding. Safety factor may be reduced even more with the big wheels.

 

Not a word of discouragement (on the contrary, I admire your creativity & willpower) but in terms of bang for the buck, a real, live CB400 or equivalent may be a better investment

 

A low risk upgrade would be to get the rear rim and part of the braking system of a new model Pulsar 220 - that one comes with a rear disc brake standard.

[Blahhh]

You wish to convert your front pulsar's disc from single to double disc brake by putting cb400 rims? Have you considered how your bike will be aligned on the roads with a front tyre bigger then the rear? Or if the forks can support the bigger tyre at all? Is there enough space around the fender to allow some debris like small pebbles to roll thru with a tyre that big? Have you stopped and think why they designed the braking system to only have 1 disc brake in the first place?

 

I suggest you work with your braking technique instead.

[ORen]

Keep'em coming !

 

Well Blahhh, although I can sense a little (tiny tiny) annoyance from an experienced rider to a baby rider like me who's all about dumb ideas as loing as they are exctiting, thanks for sharing

 

I am stopping to think and consider, this is what this thread is for, and I believe this forum too : an opportunity for me to learn more, and have better brains picked with my nonsense.

 

You're making excellent points, and they are helping me deciding so thanks a lot

Regarding improving my braking technique, I agree and am not looking for a compensation to my skills (although that sounds good too from a new rider's perspective, until I gain enough experience) but rather for efficiency improvement, given that my bike's drum brakes are widely recognized for their poor efficiency.

 

 

Kalyan, yeah I wanted to go with the P220 option at first: much safer choice, and will probably do the wonders I'm looking for. But importing the parts isn't guaranteed, have not yet had a response on that by our official distributor but I'm chasing that lead too.

 

Cost wise - yeah pretty stupid hun.. I haven't looked into it, thinking if that's a show stopper, I'll find other rims / other solutions. For now I'm more interested in the different options available. The front forks of the first gen of P200 or I think the latest P180 *some* had issues with pretty scary pictures floating around the web of broken forks.

 

I don't know how bigger rims and tires would affect the forks and if they can take it. I don't know how it would affect the engine. That's why I started this thread really and I'm glad all this has been mentioned. Will add this to my brainstorming, thanks a lot for all the help and time spent to reduce a little bit my cluelessness

[dark_angel]

best is not to meddle with the braking system of ur bike, it may feel ok and even work ok but

1) it doesn't come with the bike so might had some insurance claim issue dwn the road.

2) damn expensive as wanna customise

3) lots of after installation issue if screw up

4) lots of time n effort +$$ waste if cannot wrk in the end

 

If wanna those with 3 brakes one, can always get S4, lots of them in market.

[Guapo]

1) Upgrade ur front brake pump for a single caliper....Example will be Aprilia RS125 , Honda Hornet 250 , KTM 250 EXC , Suzuki DRZ400 etc.

 

2) Upgrade the caliper from one of the above bikes and custom make a bracket at Seng Kwang.

 

3) Upgrade to stainless steel brake hose.

Hel & Speilger. Cheap and good.

 

4) Get EBC brake pads or Gold Fren if available .

 

Get 3 & 4 first.

If not good enough then get 1.

Not enough add 4.

 

Really not enough get a Ducati.

[Pandoras Kitten 3]

I think O'Ren's thread is one of the more funner ones I've encountered since I've joined the forums. While it's a bit of a "buy and throw away" market in terms of our bikes due to Singapore's licensing system there's no stopping us from wanting to improve our rides' performance to the limits of cost and common sense.

 

I don't doubt that the stock Pulsar parts can be improved with some tinkering ; there won't be an "aftermarket tuner" thing going on in India and Indonesia for no reason. However we've realised that the bang for the buck issue needs to be considered, same for the logistics base.

 

I love Pulsars for the overoptimistic technology / marketing but skipped the Indian bikes for now because there isn't a huge parts and knowledge base unlike the common and trusted Japanese brands - known to be overengineered, run 7 yrs on crappy grease and never break down, somehow etc.

 

I don't know how bigger rims and tires would affect the forks and if they can take it.

 

Hehe easy one - you know our dear local and Malaysian lightweight sportsbike (NSR SP, KRR) riders with the "bicycle rims"? They're using little tyres so as to reduce rolling resistance to a minimum for maximum straight line acceleration.

 

Now imagine the Yamaha TW200 with something like Phantom sized tyres on a tiny body. I know it's meant for a different purpose (off road etc) but part of the reason I love Pulsars is that it's built for efficiency. Adding drag to it with huge wheels that will no doubt drag down the drivetrain and already overworked motor (at highway speeds) may not be a wise idea.

 

It being a class 2B and all, you might go with the Singaporean flow and replace her with a bigger, better street machine in a surprisingly small span of years.

 

Well of course, if you're like a desperate person like myself, then class 2B forever

 

I got a Phantom to live with just because it's a "heavy iron" style design with huge wheels, decent brakes (actually, too good, Tokyo Drift fun in the rain!), and enough trademark Honda durability to survive whatever DIY modifications I can throw at her!

 

But worry not, given the legal challenges faced by mass manufacturers (of bikes and whatever), we can safely assume we have more or less functional and modern bikes.

 

I suggest you work with your braking technique instead.

 

Indeed, we have to live with our respective limitations and in doing so, max out the potential of the bikes with time. Better brakes does not necessarily mean automatically increased safety; we must of course, anticipate the oncoming dangers in time to use them

 

And by realising the limitation of the stock braking systems and expanding our defensive riding skills to cover this limitation (while finding a customisation solution), that's how the safety riding culture should develop.

 

Don't tell us newbies to ride like ah peks, but know how the bikes work. Hats off to O'Ren for bringing up the topic in the first place, so that I can poke at it