Join Date: Oct 2013
Location: Chilliwack, BC, Canada
Can you pull the front brake lever all the way back into the grip rubber?
If you can pull the lever back such that it compresses the rubber of the handle grip then you are achieving all the braking power available from the system as is. If you cannot pull the lever all the way to compress the grip rubber, you are not able to apply sufficient clamping power to the lever to utilize the available braking. It can be most helpful for you to consider this issue.
If you can pull back to the grip, see the following. If you cannot, see the part lower down. I'm typing this off the top of my head, as usual, so may be less well expressed than would be ideal. Apologies.
Assuming that you can pull the lever back into the grip:
First thing is to insure that there is no trapped air or other faults which yield to pressure and so increase the lever stroke. Best to start with the basics and then work on as adding improved components which a more basic problem exists is an expensive way to address. Tom has outlined some of the checks but I strongly recommend that you diagnose the problem before throwing solutions. I also recommend cleaning and lubricating the lever pivot as outlined below in the can't pull to the grip section. Do this every year, IMO.
Changing fluid solves many problems and heads off others. I strongly recommend changing brake fluid and brake fluid in hydraulic clutch systems each year. This can be done quite easily.
See Note *2 below for what may seem to be a counter-intuitive possibility with regards master cylinder swap and also deals with tuning of the master cylinder to increase stroke.
If you can pull the lever back to the grip, braided or other hoses which are less prone to ballooning will reduce the displaced fluid lost to hose expansion which will allow you to achieve higher pressure when the lever does contact the grip or may allow higher pressure/sufficient pressure.
Changing to a larger diameter rotor or caliper offering a larger center radius of pad contact will help in either can or can't scenario.
If you cannot pull the lever back to the grip, installing braided hoses is unlikely to help the problem because you already have more displaced volume than you are using.
If you cannot pull the lever all the way into the grip, there are some things which can help:
Remove the brake lever and clean the end of the lever and the end of the Master Cylinder Piston (I usually use Scotch Brite or similar). Clean the pivot bolt and the bolt hole in the lever, then wipe in a generous coating of good quality waterproof wheel bearing or chassis grease onto the pivot bolt, into the bore and onto the lever tip and end of the Master Cylinder Piston.
FWIW, don't buy some "magic" off the shelf grease from a bike shop because this will be over priced and often unknown quality. Got to an automotive parts store (a real one where the shops buy their parts) and get a tube of general purpose NLGI #2 or similar.
The idea is to "butter" the grease into the pores and irregularities of the metal.
Regardless of whether you can pull to the grip or not, this improves the brakes.
Take care not to break the Brake Light Switch. Gen1 aren't bad but Gen2 and many Suzuki switches are really easy to damage so usually best to remove the switch first and reinstall last.
If you cannot pull back to the grip, try moving you lever position and hand position so that your little finger is onto the center of the lever end "ball" or even off the end of the lever. Doing this is often difficult because we like familiar things so just crossing your arms is easy but crossing with the other arm on top feels "wrong" and is hard to do.
If moving your hand increases braking, then you may have to re-learn how you apply the brake but most people won't like that, IME.
If you cannot pull all the way back, braking can be improved by using brake pads which offer a higher friction so that's a possible. Changing to a larger diameter rotor such as the 320 mm EBC and other brands will offer more braking from the same hydraulic pressure. Problems are: cost and more exposed rotor. You will need to decide.
Note *2: An option which I found to be satisfactory is to install a smaller bore master cylinder with attention to maximizing the stroke. A smaller bore master increases hydraulic apply pressure at the same lever effort but obviously loses volume so attention is required. In the case of the 250 Ninja master I've used, the better lever and some tuning provides more apply pressure with a similar lever arc of movement. I can still pull all the way to the grip but now have greater braking.
Likely have forgotten to add some things but likely few have read this far so will move onto other things.