Rubbermount_EVO Front brake combination not working well. Suggestions?

[Glamazon]

I find the twin discs on my 883R superb. I rode a friend's 54 Triumph T110 with a half width single leading shoe brake in 1979, now that was a bad brake! You could always look for a front end from a chop builder. Try braided stainless brake lines, they perked up the brakes on my Honda 500/4 & Triumph T140 Bonneville for a relatively inexpensive improvement

[sml1226]

14 883R would be the newer style brakes. I thought the 16 CX was great with that setup. I don’t know if they just paired the master and caliper better, or if the new calipers are really that much better. The old style never felt as nice as the two bikes I’ve been on with the 14+ setup.

I’m not sure of the piston bore on those, but just going to the newer Sportster caliper is probably an option too. It may need a different master cylinder, and those are meant for the newer 300mm rotor size, but the new Sporty brakes definitely do feel better to me than the older ones.

[jzink0883]

Originally Posted by Folkie

I think the stock brakes on my '15 CB are pretty good.

+1

These are the stopping distances of three bikes tested in the June 2012 issue of Motorcycle Consumer News:
- 2012 Harley-Davidson Sportster 72 (560#): 120.7’
- 2012 Kawasaki Versys (460#): 122.4’
- 2012 Triumph Speed Triple (480#): 128.7’

A reader asked MCN how the single-disc Harley with a skinny 21” front tire could have better stopping numbers than the lighter dual-disc bikes. MCN’s answer was that the Sportster’s weight distribution and low center of gravity meant the rear tire could contribute more to braking and that enabled the short distance for a single stop.

[jammantoo]

Originally Posted by jzink0883

+1

These are the stopping distances of three bikes tested in the June 2012 issue of Motorcycle Consumer News:
- 2012 Harley-Davidson Sportster 72 (560#): 120.7’
- 2012 Kawasaki Versys (460#): 122.4’
- 2012 Triumph Speed Triple (480#): 128.7’

A reader asked MCN how the single-disc Harley with a skinny 21” front wheel could have better stopping numbers than the dual-disc sport bikes. MCN’s answer was that the Sportster’s weight distribution and low center of gravity meant the rear tire could contribute more to braking and that enabled the short distance for a single stop.

This is very true and important to remember when working with the brake system

No matter what, the NORMAL sportater just does not have a performance designed brake system.

I have had a sporty in the remuda since the 70s, along with the sportster has always been a sportsbike of some type and I also ran 250 two strokes in club races on roadrace tracks in the 80s and 90s.
There is a huge difference in both the design of the master and slave cylinders of the Sporty and a sportsbike.

You actually did improvements with the full floating disc and the SS line, it is just your Master cylinder does not give the feedback that other ones do. that is not an issue to most riders so HD does not have a need to improve it. And those who it is an issue with normally go with some aftermarket brakes anyway such as Performance Machine.

My current sporty has a single disc up front, with all sporty cylinders, it works as good as I push the sportster and I have only once complained. And that was a panic stop when I first got the bike. I now know the bike good enough that I could shut it down a lot faster.

If you want more feeling out of the brakes you will need to change the master and slave, and get a matched set, too many guys get masters with the wrong bore size. IT IS IMPORTANT to get the correct bore for the calipers, and number of calipers that you will be using. Sportster brakes are really not that bad for what the bike is designed for. But if you want to be able to get the feedback of a performance brake system, then you are not able to use stock sporty parts, they are not designed for that.

Being able to have brake feel such as the OP describes comes from having a complete system designed for EACH ITEM in the system. Just hodge podging a system together is dangerous as mismatched parts can result in brake performance being degraded not improved.

Full floating disc will improve any disc system, it smooths out any imperfection in the disc

SS braided lines are only as good as the design of those lines, cheap SS braided lines can actually be worse than well designed ones. make sure you are not getting cheap look good SS braided lines. Buck up and get a good set if you want performance.

ON A PERFORMANCE brake system.........
Calipers and masters need to be matched in so that the bore and stroke of the master is sufficient for, and will not over power the slave units, that means a single master be used with a single slave and a master designed for a double slave system be used with double disc.

I used GSXR masters and slaves on my sportster track bikes, I also beefed up a lot of items on the bike so that the thing did not get squirrelly in corners when braking that hard. I really do not see the need of those kind of brakes on my 48 as I do not push it that hard. And the stock swingarm tends to twist when you hang out the rear end spinning the tire tucked into a curve to get it to step out and square out a corner.

Good luck straitening out the brakes. One thing I love about sportsters is they are just a canvas, it is up to each owner to paint his own picture.

[Diogenes415]

As jammantoo mentioned, matching the master cylinder to the caliper(s) is a must. At the risk of redundancy from another thread here is a page that helps explain what ratios to look for and a ratio chart... I used that these past few decades with great success both on and off the track.
http://www.vintagebrake.com/mastercylinder.htm

Also, many riders overlook the fact that road grime and detergent residue left behind after washing your bike greatly reduce the effectiveness of your brakes. Even some brake specific cleaners sold on the market can leave contaminates behind. Acetone is easily the best solution to keep your brake contact surfaces absolutely clean.

[sml1226]

Originally Posted by Diogenes415

As jammantoo mentioned, matching the master cylinder to the caliper(s) is a must. At the risk of redundancy from another thread here is a page that helps explain what ratios to look for and a ratio chart... I used that these past few decades with great success both on and off the track.
http://www.vintagebrake.com/mastercylinder.htm

Also, many riders overlook the fact that road grime and detergent residue left behind after washing your bike greatly reduce the effectiveness of your brakes. Even some brake specific cleaners sold on the market can leave contaminates behind. Acetone is easily the best solution to keep your brake contact surfaces absolutely clean.

That’s the ratio I was running with in making the recommendation to not change the master and pick up a touring caliper. Of course, that doesn’t account for stroke, but as was mentioned, with HD parts, these aren’t going to be performance systems, where that stroke change makes a big difference to your feel. You probably won’t see that without using performance parts end to end.

Stock 06 single disc is 1/2” master. The ratio is going to be something like 25.4:1 with that caliper, without touching the master. A 12mm bore would be a little better for that “ideal” ratio, but both are going to be close.