Author Topic: Measuring brake lines  (Read 857 times)

0 Members and 1 Guest are viewing this topic.

Offline Scott S

  • Global Moderator
  • Really Old Timer ...
  • *****
  • Posts: 8,232
Measuring brake lines
« on: April 12, 2017, 04:21:03 AM »
 I'm doing a front end swap (Yamaha R6) and I'll be getting creative on the brakes. How much slack or give should you have in the brake hoses for suspension travel? I'll be getting new lines made, but need to know how much "give" I should allow.

 Right now, I'm leaning towards a stock style master cylinder, Goldwing brake splitter (because that has the pressure switch that will plug right in to my harness and keep the bars clean) and two lower hoses. I need to know how much slack I should allow in the lower hoses.
 For the upper, I can just run a piece of wire or string and get a good idea.
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,362
Re: Measuring brake lines
« Reply #1 on: April 12, 2017, 05:34:26 AM »
When I did mine on my Vintage Mashup project, I got the suspension at full droop then measured up to the fittings. From hole to hole I got a length and I use Goodridge lines which have about every length imaginable especially in shorter ones. That way you can tailor it for a super clean look. Obviously you don't want the lines to ever go taut when riding so I would add just a little (maybe 1") to your full droop distance.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline flybox1

  • My wife thinks I'm a
  • Really Old Timer ...
  • *******
  • Posts: 14,301
Re: Measuring brake lines
« Reply #2 on: April 12, 2017, 07:23:32 AM »
Got an old coil of RG-6 (cable tv cable)?
Hack it up into sections to mock up where you need the brake lines to go, then measure what you end up with.
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mineā€¦"

Offline eigenvector

  • Master
  • *****
  • Posts: 1,949
  • Member of the despondent public
Re: Measuring brake lines
« Reply #3 on: April 12, 2017, 12:07:50 PM »
That's a really good idea.
Rob
--------------------------------
2018 HD Softail Heritage
1979 CB750K Limited Edition
1977 CB550K
1984 CB700SC Nighthawk
1983 VF750S Sabre