Saturday, January 19, 2019

Improving Your Motorcycle's Brakes... Cheaply.

As the lever fades...
With a few miles, or years, under its belt, most bikes start to feel a little bit lacking when it comes to the feel at the lever. And I, for one, am not keen on riding bikes where the lever almost touches the bars. Now, if money is no option, there are plenty of easy fixes:
  • New discs and pads
  • Braided brake lines
  • Rebuild the calipers with new seals, maybe pistons if damaged
  • Brembo adjustable master cylinder 
But this gets expensive, and changing parts could be masking an actual problem — something that could be easily fixed. So what if you could improve your standard brakes where things have deteriorated over time? Well read on...

So how does it feel?
Personal preference for me is to have the span adjustment at 1, furthest away from the bars. I don't like it to get anywhere near the grip, especially important if you're using one or two fingers for braking. If the rest of your fingers are still on the throttle, they could prevent the lever moving far enough to provide the braking effort needed — and that's a bugger when you're horsing into a corner!

There are things I like to do to make sure the braking systems on my bikes are working somewhere near to how they came out of the factory. Here's the quick list:

  • Brake pads - clean them, deglaze them, replace if worn.
  • Brake pad pins - clean/polish them, replace if worn.
  • Calipers - clean them in soapy water with toothbrush and very fine wet & dry paper on the pistons if you can't remove the dirt build up. Pump the pistons until they nearly pop out to make sure they are spotless.
  • Check the pistons now move freely - push in with fingers, pump out with brake lever. Do they move together?
  • Brake discs - check for wear, deglaze and clean them.
  • Brake hoses - visually check for damage/bulges.
  • Brake fluid - change it anyway, especially if the bike is new to you.

The CBR's lever is a fraction too close to the grip for my liking. That's on position 1. 

Bearing in mind I've already changed the brake fluid and pads on this bike, and also cleaned up the pistons in the calipers with a toothbrush and soapy water (this is well worth doing when you change pads), there is another thing I want to try before going down the route of new discs and braided lines. 

There are a couple of pistons in the calipers that don't move quite as easily as the others, but not enough to warrant a strip, clean and new seals. A spray with silicone once there're clean and dry helps them to move freely.

I previously used a racing brake fluid, but will now go back to standard DOT4 as required. The fluid is still clean which shows there's little, or no, seal degradation. Cleanliness is uber important when it comes to the brakes, and covering the tank and paintwork before taking the reservoir cap off is a must.

The fluid is still relatively clear, in fact the reservoir is more yellowed than the fluid. I use a syringe to suck out the fluid, then use a new rag to clean out the rest. Finally, a spray of brake cleaner on another rag will clean the inside.

Perfect. The reservoir can now be topped up with fresh fluid.

Give the reservoir cap a good clean, along with the rubber boot. Make sure they're all dry before refitting.

Having flushed the fluid on this bike already, there is one method I haven't used. Can't say for sure if it'll make any difference, but worth a try. On a bike with a single brake hose to one side of the wheel, there will be another shorter hose to feed the other caliper. Because this goes up and over the mudguard/fender, there is a possibility of leaving air in the system at the highest point. 

Only a slight chance maybe, but it's worth checking. To eliminate that issue, I'll take the caliper off and bring it down to the same level as the other.

You'll need a flat bar to go in between the pads to prevent the pistons from dropping out, and then somewhere to sit the caliper on. Like a bucket. 😀

Now the hose is at the same level, or lower, than the brake line splitter, I'll bleed them as normal. There was no notable difference when bleeding, everything seems normal.

First road test and I could feel the lever was definitely further away from the bar, and the brakes were slightly more responsive. This maybe just a fluid change difference, but I'll keep an eye on this to see how it goes. For now, happy riding.

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