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Apr 7, 2016 | 09:51 AM

#21

Mike Lawless

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From: Central California

Thanks all. This ain't my first rodeo by a long ways.

Warp, I didn't know that there was a 7/16 bore MC available. Everything I have seen on the market is either 9/16" or 11/16". I reckon more research is in order!

Apr 7, 2016 | 02:28 PM

#22

Warp Factor

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From: Detroit

Quote:

Originally Posted by Mike Lawless

Thanks all. This ain't my first rodeo by a long ways.

No question, you clearly know a lot about hydraulics and mechanical advantage, or you wouldn't have asked the questions you did.

Quote:

Originally Posted by Mike Lawless

Warp, I didn't know that there was a 7/16 bore MC available. Everything I have seen on the market is either 9/16" or 11/16". I reckon more research is in order!

I don't know for sure either, never owned or worked on a Sportster. But what I found is that a number of places offer rebuild kits for them, so that would suggest that it exists. Maybe the master cylinder itself is a dealer part.
http://www.cruisercustomizing.com/dr...t/DS-1731-0415

Another option might be the Arlen Ness 15" front rotor kit. It probably wouldn't do anything to bring the brake lever closer, but it should provide enough mechanical advantage to increase stopping power quite a bit, since the diameter of the disk is closer to that of the tire.
http://www.revzilla.com/motorcycle/a...tail-2000-2016

Last edited by Warp Factor; Apr 7, 2016 at 02:59 PM.

Apr 7, 2016 | 04:14 PM

#23

chrisj49

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From: Bay Area, CA

You can tell the size of the bore from the size of the banjo bolt, so in the future you don't have to take it off to look inside. Doesn't matter here, as you were headed for another bleeding anyway

I learned this when I swapped cables - I bought the right cable for a Heritage but the banjo bolt was the wrong size for the master cylinder. The previous owner had put an 11/16 bore lever on with a custom cable.

Apr 7, 2016 | 04:54 PM

#24

Mike Lawless

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From: Central California

In my younger days, I spent a lot of time working in hydraulic job shops as a machinist, and I had to learn a lot about fluid dynamics. These days, I have a drag race car with a complete Wilwood brake system. The MC I wanted for that, (because of space considerations) only came in a 1" bore, and I really wanted 7/8". I was able to get the mechanical advantage back by changing the brake pedal pivot point. (custom fabb'd pedals).

I'll have to check in with the dealer to see about that Sportster MC. I haven't been able to find one at any of the online parts places. If it priced as i suspect for a dealer part, it may be a lateral deal to a six piston caliper.

The 15" rotor, although a good idear, is a non-starter for this particular bike. I have 16" spoke smoothies. The discwould go nearly to the edge of the rim,and it would be doubtful a caliper would fit in there. If I had a big-*** front wheel like our friend LA dog....well then!

Thanks for the time lookin' that stuff up!

Quote:

Originally Posted by Warp Factor

No question, you clearly know a lot about hydraulics and mechanical advantage, or you wouldn't have asked the questions you did.

I don't know for sure either, never owned or worked on a Sportster. But what I found is that a number of places offer rebuild kits for them, so that would suggest that it exists. Maybe the master cylinder itself is a dealer part.
http://www.cruisercustomizing.com/dr...t/DS-1731-0415

Another option might be the Arlen Ness 15" front rotor kit. It probably wouldn't do anything to bring the brake lever closer, but it should provide enough mechanical advantage to increase stopping power quite a bit, since the diameter of the disk is closer to that of the tire.
http://www.revzilla.com/motorcycle/a...tail-2000-2016

Apr 7, 2016 | 05:15 PM

#25

LA_Dog

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Joined: Jun 2014

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From: 90210

Quote:

Originally Posted by Mike Lawless

hey bud I hope the EBC pads spruce things up for ya- they've always been my "go to" pad on bikes with stock braking systems. I run them in my Big Dog chopper as well- big *** wheel there too - haha. I have PM 4 piston calipers on that bad boy, braided lines, PM MC and controls, PM rotors - front braking is a three finger affair

Warps suggestion was a good one with a physically larger rotor- that will *definitely* help big time. but about the wheels, yep totally understandable. beyond that- probably do as you stated go with better calipers - braided lines too. although it sounds to me like you have lever force, just no pad to disc bite - at least from your description of things. I'll keep my fingers crossed that the HH pads are the quick / easy fix. make sure you bed the pads initially / break them in. they need the typical break in / heat cycle process. pretty quick to do though.

Last edited by LA_Dog; Apr 7, 2016 at 05:21 PM. Reason: mistake - 4 piston not 6!

Apr 7, 2016 | 05:18 PM

#26

Mike Lawless

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From: Central California

Quote:

Originally Posted by LA_Dog

hey bud I hope the EBC pads spruce things up for ya- they've always been my "go to" pad on bikes with stock braking systems.
I'll keep my fingers crossed that the HH pads are the quick / easy fix.

Got 'em on order!

Thanks for the tip!

Apr 7, 2016 | 05:23 PM

#27

LA_Dog

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From: 90210

^^ one more reason I like them Mike- very little to no dust! I like my big *** fancy wheels to stay clean

Apr 7, 2016 | 06:23 PM

#28

Warp Factor

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Joined: Aug 2012

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From: Detroit

Quote:

Originally Posted by Mike Lawless

I'll have to check in with the dealer to see about that Sportster MC. I haven't been able to find one at any of the online parts places. If it priced as i suspect for a dealer part, it may be a lateral deal to a six piston caliper.

I reckon total bore area would be more important than the number of pistons. Some posters here who have tried 6-piston calipers haven't been very impressed with them.

Quote:

Originally Posted by Mike Lawless

I was able to get the mechanical advantage back by changing the brake pedal pivot point. (custom fabb'd pedals).

Taking a quick look just now, there might be room on the master assembly to re-drill the pivot pin holes offset, and fit a larger pin.