Steel Braided Brake Lines - Myth or Marvel?

[dorydan]

Hi Guys, I am servicing long-neglected front brakes on my R65LS and wonder if I should replace the rubber lines.  And of course, if I do, should I use rubber or steel lines....  I have read tons of anecdotal stuff saying rubber is more resistant to flying rocks, etc., and has superior flexibility, steel has less "ballooning" and therefore better feel and quicker response. 

Can anyone point me to an objective study on whether steel braided lines actually improve brake performance?

Thanks!

[mrclubike]

I have a Spiegler on mine and it gives a very positive feel.
The original was very spongy and I had a lot of lever travel with my 12mm MC and 40MM caliper
I only wish I had a smaller diameter Master cyl or even a larger caliper piston size 

I think what ever you do you will need to go after market
BMW doesn't seem to have one for our bikes 

[georgesgiralt]

Hello Dorydan,
In 1984 i bought my R65 new. At that time, RT fairing was trendy and the dealer had an offer to put one onto the bike. I took it. *
The bike had dual front rotors. ATE kind.
We used it a lot for our holidays 2 up and camping with a pair of Krauser made for a heavy bike.
Front brake was sponginess and not so efficient. And I had a lot of Adrenalin flowing in my blood sometimes.
So when the master cylinder went south, I exchanged it for a 16 mm one (it was 15 before) thinking it would improve things preventing the lever to touch the handlebar when powerful braking. It did. But it was still rubbery and not so efficient. And I was able to touch the handlebar with the lever if I squeezed it hard enough...
For her 30th birthday, I decided to renew her and remove the RT fairing.
The brake lines were fraying so I decided to put new one in place. I bought locally made SS one. The improvement is more than tremendous. Now I need all my fingers to move the lever and braking power is on par with more modern bikes. It is so that I envision the replacement of the 16 mm cylinder to a 14 mm one...
So IMHO, braided lines ARE the way to go if you have to change the lines...
Just my 2¢.

* : BMW offered the RT fairing but the brake line were identical to the naked bike. A plate was sold to "close" the opening in the fairing. So the dealer did not have to touch the brakes at all during the conversion.

[Bob_Roller]

I would recommend the braided stainless line, I replaced the OEM brake lines on my '81 R65 in '91 with Luftmeister stainless  lines, an aftermarket parts supplier that has long since gone out of business .
So they have been on the bike for 30 years, no degradation in performance as compared to the other R65's .
They improve braking over 40 year old rubber lines, but don't expect a phenomenal change .
I have three sets of Spiegler lines, two other R65's and an oilhead .
One feature of these lines is, there is a slip joint at the hose ends, so you can move it  and remove any twist the line has developed from the  installation process.
Also the aftermarket lines are about the same cost as OEM rubber lines .


https://spieglerusa.com/brakes/brake-lines-accessories-tools/cycle-brake-line-kits/bmw-r-65-ls-front-brake-line-kit-r-65-ls-s-bm0012.html

[Kelvin]

I replaced the original lines on my LS in 2019. At that point there were bumps in the rubber, suggesting imminent failure, and when I flexed them off the bike fluid actually seeped through to the outside. Somewhat overdue(!).

The replacement was Venhill SS lines from motobins. These gave me an improvement in both the amount of pressure required and feel. I wouldn't consider putting rubber lines onto the bike.

[Tony Smith]

Stainless steel lines every day.

BMW fitted them OEM to the GSA models for a reason - they are vastly superior to rubber lines in terms of damage resistance.

[dogshome]

In 1984 i bought my R65 new. At that time, RT fairing was trendy and the dealer had an offer to put one onto the bike. I took it. *

* : BMW offered the RT fairing but the brake line were identical to the naked bike. A plate was sold to "close" the opening in the fairing. So the dealer did not have to touch the brakes at all during the conversion.

Aha! I have the same arrangement and the same wear on the outers. I've struggled to get a set made up even though I am sure the basic parts are the same as the naked R65. You have confirmed that they are the same! The only remaining question is the top hose:- I have RT bars (quite high and come to the height of the mirror mounts when at full lock). I found a height chart and it confirmed RT type. Was that a part the dealer had to change to fit the higher bars?

[georgesgiralt]

Hello,
It took me a long time to figure what you meant. And I had to call the local BMW  Guru who made the braided lines for my "naked" bike.
Now I remember that the top hose from BMW was somewhat short for the RT handlebar fitted (I also have RT handlebars). So the dealer moved the brass interconnect tube from it's designated place to the top of the triple clamp under the rubber pad. And the Guru confirmed that they should have put a longer rubber tube in order to maintain the original placement.
Frankly, this doe not make sense to me because if you move the Y connecting pipe higher, then the two caliper hoses will be too short...
I've long binned the old rubber hoses so can't mock up or ascertain this...
So maybe my dealer was cheap and did not want to change the upper rubber hose and installed the brakes in a way everything fitted but marginally ? I do not know.
Hope this helps.

P.S. : check on Realoem the parts for the fairing and brakes. You'll see they are the same for the naked bikes.

[dogshome]

That all makes good sense. Thankyou! I will have another go at sourcing pipes now 

[drhooves]

Had my bike in the shop yesterday ('86 R65), and after looking at the (original) rubber brake lines, and the front brake being rather "slow" to recover (the brake light stays on for several seconds after releasing the front handle, and sometimes requires moving it manually back to the "off" position), the recommendations were:

- replace the front brake line, as it may be restricting flow back to the master cylinder after being engaged (steel braided hoses recommended)
- replace the master cylinder

How difficult is this task?  I may try to do it myself, as the shop is booked up through the fall.

[georgesgiralt]

Hello,
It is not a difficult task per se, but...
It is a case where you must think about it twice. Are you up to the job ? Because lacking brakes on a motor vehicle is not so fun. Specially on a motorbike.
And if you replace old rubber line having deteriorated, you *also* have to clean and rebuild the front calipers and the master cylinder and put new brake fluid in the circuit...
So, if you never did this kind of job, either let it to a trained mechanic or ask for help and supervision of a knowledgeable person  while doing it ....
Just my 2¢
By the way, old rubber lines peel inside and make valves that, if you are lucky, let the brake fluid go from the master cylinder to the caliper and block it back or if you are unlucky block the fluid when you apply force on the brake lever and prevent you from braking... So your situation is quite serious and need immediate attention...

[Burt]

The original BMW brake lines deteriorate over time, so I would have them replaced with the SS ones.  As it is a safety issue, the cost is irrelevant.  You will notice the difference straight away 

If you are having difficulty determining the size, then use a piece of string to measure the length of the current brake hose.  It may be easier to tape the string to the current brake hose.  Then take three measurements at full left lock, bars straight and then full right lock.  Use the longest measurement, then look at Motobins, Motorworks, etc and find a brake hose that is about the same length as there can be minor differences.  Purchase with confidence, fit and bleed. 

[dogshome]

I would also take the calipers apart and replace the rubbers. My slow-to-return front brakes actually stayed on one day! Why am I not accelerating....!!! Luckily I was doing about 30 having just turned off an island. They quickly cooled and I took it very steady the last mile to home. 70 or more in the outside lane of the A1 in a pack of lorries with ever-tightening brakes would not have been funny 

The backs of the pistons were  full of gunk, also the little bleed hole in the master cylinder. You can clear this with a fine wire (0.3mm or less) though the top of the fluid reservoir. Doing these things is straight-forward. The bleeding with twin discs just takes patience moving from left to right until it all suddenly works as it should.

I didn't replace master cylinder as the bore and seals were good. Hoses are next on my list and I'll get a set of master cylinder seals in whilst I've got the fluid out to do that. Currently they are not causing any trouble, but they do have wear marks.

Oh, the only bolts that need any kind of torque are the ones that hold the calipers together. Bleed nipples, unions etc have to be snug but use a short spanner. Torque wrench if you worried. I always upset the younger engineers at work when I say I've been servicing and repairing my own brakes for about 40 years. I trust me to get it right whilst taking my time, not the garage who want it out the door!

[mrclubike]

Like everyone is saying you should rebuild  the caliper also
Bleeding can be the most frustrating part of the job