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Discussion Starter #1
does anyone know what is the size of the front master cylinder on gs? it is my experience with many bikes that they come stock with too big MC causing wooden feel in brakes. I changed MC in all my bikes, usually to one number smaller. I believe that the MC in this bike is 12.8mm or even 14mm. there is a way to calculate the MC/calliper-pistons ratio to find the right set up. Smaller MC allows more braking power with less force required. If the MC is far too small however, it will cause the brake lever travel too far.
 

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So you are saying most motorcycle and brake manufacturers don't know what they are doing? Seems far-fetched to me. My brakes are perfect.
 

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Discussion Starter #3 (Edited)
So you are saying most motorcycle and brake manufacturers don't know what they are doing? Seems far-fetched to me. My brakes are perfect.
no, please do not misunderstand me. the bike companies design the brake system for people who are not sensitive enough to brake correctly, so that they do not kill themselves. wooden brakes force one to use a lot of force to brake, but they also are safety precaution against locking the front wheel. when you say that your brakes are perfect, are you referring to gs310g?

'perfect' is a relative term anyway. most people are content with their brakes because they do not know that their brakes can be much better. it is a matter of perspective. many bikers think that if they press their brake lever and the brake lever does not move much, this indicates that the brakes are in optimal condition; but this actually means that their brakes are too hard and lack both modulation and power.
 

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Kris,

I have found that simply changing the lever to an ajustable one corrected most of the 'Wooden' feel.
Anyway, for my short fingers, the travel was much too far away from the handlebar to get any kind of feeling.

I doubt that BMW was afraid of front wheel lock since they use ABS.
I think it was a cost cutting measure, easily corrected through eBay and Chinese manufacturers of ajustable levers.
 

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Have you tried changing the brake pads.
Try a Non sintered set it may well give you the feel that you are looking for.
Wemoto offer both 'flavours' by 2 different manufacturers.
 

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Discussion Starter #6
Kris,

I have found that simply changing the lever to an ajustable one corrected most of the 'Wooden' feel.
Anyway, for my short fingers, the travel was much too far away from the handlebar to get any kind of feeling.

I doubt that BMW was afraid of front wheel lock since they use ABS.
I think it was a cost cutting measure, easily corrected through eBay and Chinese manufacturers of ajustable levers.
yes, for sure, adjustable levers are a must. not so much for clutch lever, since you want to open it pretty wide to be able going into the neutral, but for brake side it just a both comfort and safety measure. keeping the brake lever as close to your hand as possible, assuming that the set up is not too soft as for the lever to hit the handlebar, make such a huge difference. luckily, there are many cheap Chinese levers available of very good quality, short or long, which offer such adjustment. however, having this adjustment does not change the general braking feel.

as to the locking the wheel, ABS is the last salvation, which also may fail at times. but the danger of hard, non-gradual braking is that one can lose control over the bike even before the actual lock-up of the front wheel occurs.

I can just share my experience with changing master cylinders. before I had to use three or four fingers to make the bike stop in emergency situation, and now with the smaller MC, one finger is enough and there is much greater modulation. I did that change to Versys 1000, Vulcan S, Tiger 800, CRF 250, and both of my Royal Enfields. If people trust so much manufactures, why the aftermarket companies make so much money? OEM brakes, suspension, seats, and what not, are often produced in lower costs to save money. Well, the bigger vs smaller MC will not make difference in production costs, so it is beyond me (other than the safety measure or the fact that people naively assume that firm lever equals better brakes), why they do that.

the great thing about gs310 is that it is fitted with radial calliper and four pistons. this will no doubt improve its braking capability. sliding two piston callipers are much inferior.
 

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Discussion Starter #7
Have you tried changing the brake pads.
Try a Non sintered set it may well give you the feel that you are looking for.
Wemoto offer both 'flavours' by 2 different manufacturers.
the sintered pads offer more biting but it is only the MC/calliper ratio that change the hydraulic force upon braking that translates into hard/soft feel in braking action. with organic pads you have false sense of softness, because they are just acting more gradually upon the rotor. at the end, you want biting power of the brake pads combined with enough modulation and minimum effort from your hand to stop the bike. the smaller MC the less effort is needed to stop the bike. sport bikes favour bigger master cylinders because they want to have less brake lever travel to save time in racing situation.
 

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Hi Kris, thanks for that clarification. My 310 is the 'R'. I can compare it to 5 other motorcycles I currently own, and a couple more I used to ride. The R's brakes are really great, although I must add that the previous owner (who drove it only 300 miles before selling it) installed shorty levers.
All my driving is on city streets of Los Angeles, i.e. I use the brakes constantly, and sometimes have to stop very quickly.
 

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Discussion Starter #9 (Edited)
Hi Kris, thanks for that clarification. My 310 is the 'R'. I can compare it to 5 other motorcycles I currently own, and a couple more I used to ride. The R's brakes are really great, although I must add that the previous owner (who drove it only 300 miles before selling it) installed shorty levers.
All my driving is on city streets of Los Angeles, i.e. I use the brakes constantly, and sometimes have to stop very quickly.
As I posted in another thread, I fitted 11mm master cylinder. Oh, man, what a difference. Before I had to use my both hands 0:) to stop the bike in emergency situation. Now, i can stop with one finger. It is ridiculous that they fitted 13mm MC on this bike. It is just not safe! On much bigger bikes with double rotors/callipers they use 14mm and even that is too big. For instance, I changed on my Tiger 800 MC from 14mm to 12.7mm, and now the brakes work as they should.

It is a cheap modification that will transform your braking experience. I am sure, you can get second hand 11mm MC on ebay, and brake lever to match. For instance, you can look for MC for 250KLX kawasaki, or Rebel 300 Honda.
 

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Sorry Kris, but I have to once again disagree with you: the stock brakes are extremely safe, there is absolutely no need to replace the master cylinder with anything different. I suggest you have your stock brakes examined under warranty by BMW because they may have been defective in your case.
 

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Discussion Starter #11
Sorry Kris, but I have to once again disagree with you: the stock brakes are extremely safe, there is absolutely no need to replace the master cylinder with anything different. I suggest you have your stock brakes examined under warranty by BMW because they may have been defective in your case.
Klumper, well, if you are content with you brakes, this is a matter of personal preference. there is nothing to examine by the dealer, this is the stock set up, which in my option is wrong. the only way you can see the difference, is if you try a smaller master cylinder. and the difference is like between day and night. I did this conversion with many bikes, so I gained some sensitivity on the subject. there is zero modulation with the stock set up. the MC to calliper ratio is way too hard. it is basically designed to suit beginners, preventing them to stop too abruptly, or it is just designed based on sheer stupidity. I usually use a mathematical formula to calculate the ratio, but since i did not measure the size of the calliper pistons, i went just by feeling.

just out of curiosity, can you stop the bike in emergency situation from the front brake using just one finger, or you have to press hard to make the bike stop? 'one finger' is just a metaphor to how much force needs to be applied to properly engage the brakes. i usually cover the brake lever with 2 or even 3 fingers....

https://www.vintagebrake.com/mastercylinder.htm
 

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Discussion Starter #13
Thanks for the explanation.
I've visited the link you posted; which is the row of the table relevant for G310 GS? i.e. the diameter of the calipers?

For your info, in the MotorradOnline test, they substituted OEM brake with a 12mm Magura radial HC-1 pump, and it did not give significant improvement...

https://www.motorradonline.de/motorrad-dauertest/bmw-g-310-r-im-50000-kilometer-dauertest.851494.html
this is rather strange. they say that the original lever had very long travel, reaching up to the handlebars? in my bike, the lever had very little travel, and the feeling was annoyingly wooden. in your bike, does the lever travel a lot?

with my 11mm MC i am very happy, and feel safe because I can stop instantly without effort. But I would think that 12mm would be a great improvement too, or even better. I would try it, but I have only the 12.7mm MC, which is very similar to the stock.

But keep in mind that they speak of g310r, which is a sport bike. people who ride sport bike like very firm lever, especially on track because with less brake lever travel they can react faster. however, as counterintuitive as it may seem, longer lever travel means that less effort is required to stop the bike and there is more modulation. Of course, too small MC would result with brake lever hitting the handle grip. With my adjustable lever, on the lowest setting, I am close to touching the handlebar hence I use the middle setting. In my personal opinion, 12mm MC would be optimal.
 

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I agree that with the problem experienced by MotorradOnline (long travel of the front brake lever), reducing diameter of MC would not solve the problem but rather amplify it, even if a radial pump should improve if compared to OEM one.

I have the problem of lack of modularity, not long travel one
I also will change OEM the brake pads with the ones pointed by you

By the way, the online shop is italian, are you also from Italy?
 

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Discussion Starter #16 (Edited)
No, I was born in Poland but live in Asia, India and Thailand. You can order Brembo in many places. In my experience Brembo and Galfer are the best. Don't have good experience with EBC pads. I don't know what pads are in the stock set up, but they seem to work just fine, even though I am sure they are inferior quality. Living in India for long time, I have to say that everything here is made with low quality. On the other hand, products made in China are getting much better; like the brake levers are excellent.

As to MotorradOnline report, it just does not make sense. The gs brakes are hard as a rock. But I do like the rear brake, and it is quite effective.
 

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No, I was born in Poland but live in Asia, India and Thailand. You can order Brembo in many places. In my experience Brembo and Galfer are the best. Don't have good experience with EBC pads. I don't know what pads are in the stock set up, but they seem to work just fine, even though I am sure they are inferior quality. Living in India for long time, I have to say that everything here is made with low quality. On the other hand, products made in China are getting much better; like the brake levers are excellent.
As to MotorradOnline report, it just does not make sense. The gs brakes are hard as a rock. But I do like the rear brake, and it is quite effective.
FYI Front stock pads (on my bike at least) are actually Brembo.
 

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Discussion Starter #18
FYI Front stock pads (on my bike at least) are actually Brembo.
Good to know! From what I see they are still made in India. I could not find anywhere the part number. Are they sintered? 07W00320. On top it says HH, so they are probably sintered... the one that I ordered are 07GR18.SA
 

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Discussion Starter #20 (Edited)
I agree that with the problem experienced by MotorradOnline (long travel of the front brake lever), reducing diameter of MC would not solve the problem but rather amplify it, even if a radial pump should improve if compared to OEM one.

I have the problem of lack of modularity, not long travel one
I also will change OEM the brake pads with the ones pointed by you

By the way, the online shop is italian, are you also from Italy?
I read you message again, and as I pointed out, the oem lever has hardly any travel, hence the lack of modulation, or lack of the sense of progressive braking. the person who wrote that article either had no biking experience, or the brakes were faulty. if you install a smaller MC, you will not believe how great of a change it is! the bike stops immediately without any effort if you wish it to stop. however, my set-up for some riders maybe felt as too soft, even though I personally love it. a compromise would be going for 12mm MC. brakes are more important than expensive aftermarket exhaust, and second hand MC's are dirt cheap.
 
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