Main Menu
|
Active Threads
|
Members Birthdays
|
|

21st May 2019
|
 |
Land Speed Record
|
|
Join Date: Jan 2015
Posts: 734 Sportster/Buell Model: ironhead sporty Sportster/Buell Year: 79
|
|
72xlh....where are ya I need ya...cashh is waiting n did they make headlights like thos 
Sent from my LM-X210APM using Tapatalk
|

21st May 2019
|
XL FORUM TEAM MEMBER
|
|
Join Date: Oct 2018
Posts: 137 Sportster/Buell Model: Sportster Sportster/Buell Year: 1977
|
|
nice bike mike... any thoughts on my master cylinder possibilities... 
|

22nd May 2019
|
 |
Greasemonkey
|
|
Join Date: Jan 2005
Posts: 113
|
|
https://www.joesracing.com/master-cylinder-math/
The link above contains probably everything you could ever want/need to know about brakes.
Basically: Smaller bore's are more difficult to push, and must be pushed farther to move the same amount of fluid as a larger bore.
The bore size on a 1983' that came with dual disc's from the factory is: 3/4" (12/16")
I ran the 70's style Master Cylinder for years, and it was admittedly more difficult to pull, but did the job - It did however, eventually seize up, but that I attribute more to it being a Chinese copy.
GMA makes some fairly priced USA made master cylinders in several bore sizes with various finishes and switch options. When I replaced my Chinese knock-off 70's style MC, I used a GMA with a 5/8" (10/16") bore - It works fine for me.
Here is their part list - Look for the part numbers starting at: GMA-HC
http://beltdrives.com/wp-content/upl...st-For-CCI.pdf
__________________
- 83' Iron -
|

22nd May 2019
|
XL FORUM TEAM MEMBER
|
|
Join Date: Oct 2018
Posts: 137 Sportster/Buell Model: Sportster Sportster/Buell Year: 1977
|
|
Thanks,
I'm not sure what's on there now but the connection to the brake lines is pretty small diameter. Is it advisable to get new connection hardware? I've not done this before so apologies if this is usual.
|

22nd May 2019
|
Custom Bike Builder
|
|
Join Date: Dec 2014
Location: Phoenix
Posts: 2,298 Sportster/Buell Model: xlch Sportster/Buell Year: 1964 Sportster/Buell Model #2: XLCH IR EFI Sportster/Buell Year #2: 1971 Other Motorcycle Model: BMW K1200RS Other Motorcycle Year: 2001
|
|
Single disc requires less displacement of fluid per amount of lever travel---smaller bore
Dual requires more--larger bore
Large bore with single disc will displace more than enough fluid required in less lever travel resulting in very firm short travel
Small bore with dual will result in long travel and softer lever
|

26th May 2019
|
XL FORUM TEAM MEMBER
|
|
Join Date: Oct 2018
Posts: 137 Sportster/Buell Model: Sportster Sportster/Buell Year: 1977
|
|
So, I bit the bullet and got an 11/16 master cylinder. I neglected to get a banjo fitting though. Any idea which size I need?
|

27th May 2019
|
 |
Senior Master Custom Bike Builder
|
|
Join Date: Jun 2008
Location: Cornelius, OR
Posts: 9,510
|
|
I use a small master with dual single piston calipers on the FXR.
If I use more than 2 fingers on it I will lock the front wheel.
__________________
Ryder Rick "I know right from wrong, but sometimes, wrong feels right"
|

27th May 2019
|
 |
Senior Chief Harley Engineer
|
|
Join Date: Dec 2012
Location: Southwest Virginia
Posts: 1,030 Sportster/Buell Model: Xlh Sportster/Buell Year: 1978 Sportster/Buell Model #2: FX Sportster/Buell Year #2: 1983 Other Motorcycle Model: Road King Other Motorcycle Year: 2014
|
|
Quote:
Originally Posted by Roane
So, I bit the bullet and got an 11/16 master cylinder. I neglected to get a banjo fitting though. Any idea which size I need?
|
No way of telling for sure without seeing it. Any auto parts will have what you need and will be able to match your parts.
__________________
I've often run with the devil, but I've never made any deals....
|

27th May 2019
|
 |
Senior Master Custom Bike Builder
|
|
Join Date: Jun 2008
Location: Cornelius, OR
Posts: 9,510
|
|
10mm or 3/8" banjo bolt threads (not interchangeable)
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
|
|
Thread Tools |
|
Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT +1. The time now is 09:38.
|