The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: DgM on March 14, 2008, 07:42:46 PM

Title: Dual Discs
Post by: DgM on March 14, 2008, 07:42:46 PM
Putting right side disc and caliper in my 1983 R65.  Any comment on plumbing from master cylinder all new hoses and splitter or try and find R65LS parts?  Any pitfalls, suggestions?  Thanks
Title: Re: Dual Discs
Post by: Justin B. on March 14, 2008, 07:46:34 PM
The factory setup is a splitter and dual lines but some have used a single line and a crossover hard line to the other caliper.  The crossover is the way the late model Airheads do it (runs under the fender so it's out of sight) and I can't find anything wrong with it.  If you go with the factory type line setup check out Moto-Bins as their price on brake lines is about 1/2 what the dealers over here get.  In fact I bought stainless for less than OEM at the local dealer...
Title: Re: Dual Discs
Post by: Bob_Roller on March 14, 2008, 07:50:55 PM
You will probably need the larger diameter master cylinder, some riders have sucessfully used the smaller one on a dual disc set-up, I guess it will be your call on that.

Other than it could get costly, it's a straight forward installation.

My personal opinion, if you have the old OEM brake lines, it's a good time to replace them, either with OEM rubber, or aftermarket braided stainless lines, again your call.
Title: Re: Dual Discs
Post by: MrRiden on March 15, 2008, 12:21:53 PM
Recently rode an '83 R65 with a single Brembo and rubber hoses. Much better stopping than my '82 w/ dual ATEs and stainless lines. I'm starting to think About pads / rebuild kits as my dual setup is lacking compared to the single Brembo.
rich
Title: Re: Dual Discs
Post by: Ed Miller on March 15, 2008, 03:36:52 PM
Do pads become less effective with age?  I don't know if mine are original.  There's plenty of lining left, so I haven't  bought new ones.  
Title: Re: Dual Discs
Post by: nhmaf on March 15, 2008, 06:52:02 PM
I don't believe that simple aging causes pads to lose effectiveness, but other factors associated with years of use can cause them to lose effectiveness:
1.  surface may become glazed, or possibly contaminated with foreign materials.   Sometimes this can be compensated for by sanding the surface down
a little bit.   Put the sandpaper on a FLAT surface and move the pad (not the sandpaper) to remove any surface glase/issue.  
i'd only do this if the pads still appear to have alot of life yet and just exhibit a surface problem, otherwise, replace the pads - the newer pads can be had with a
newer sintered metal material that "bites" much better when wet than the old 80's era pads.. I can't remember the brand, but there is one out there that will fit these ATE/Brembos...
2. The pads may be legal thickness, but sufficiently worn so that the piston has to travel much further than when new pads are installed, and sometimes there is
oxidation of an accumulation of stuff (or you may be low on brake fluid) that limits its travel near the "outer limits".  More often, the crud accumulation causes the piston
to not retract fully, and you can be left with a dragging brake.. which then wears the pad out faster or glaze it if it gets hot enough.
3.  I used to only change brake fluid after it had turned colors, but I am a new convert to the  "change it once a year" church.  Fresh fluid and fresh brake lines
(brake lines every 5 years or so, depending on type of line and weather conditions) also make a difference.
4.  If the rotor is heavily scored, the pads have less surface area to work with, though at some point the pads may develop ridges to match the 'valleys' in the rotor.
In these cases, one really ought to replace both rotor and pads.
5.  On one bike I owned, I found that a small, very hard pebble (perhaps it was a diamond ?) had gotten embedded in the surface of the pad.  While it hadn't caused
severed scoring of the rotor yet, it WAS causing much of the pad to not contact to rotor surface under all but the most extreme "gorilla-grip" braking conditions.
Removing the pads was necessary to find it - putting new pads solved the problem.
Title: Re: Dual Discs
Post by: DgM on March 15, 2008, 09:01:41 PM
I have Brembo caliper(s) and would like to duplicate LS front braking in addition to esthetics. I plan on using rubber hoses and mounting clips for design continuity.  Anyone know of a complete LS hose / mounting brackets available?
Title: Re: Dual Discs
Post by: tagordon on March 15, 2008, 10:23:12 PM
I suggest you look at your brakes as a system.
Is everything as it should be. As it was designed to be.
If it is, then the understanding of how it works is applied to the application of thesystem.
My R100 and R65 are very different in how they stop.
I have to remind myself this all the time.
I have been through the systems & made sure they are as they should be.
I like the dual systems for the balanced design & application.
It allows the balance of the bike to not effect handling when being aggresive.
If you are only concerned with the pull of the lever then look to why it is as it should not be.
If it is as it was designed & you wish it different. Then expect to alter the entire system.
Or use your knowledge of the system to optimize the results when a using the system as is.
That said, if I did not have duals I would get em.
And make sure they worked as should.
Stopping is more important than going when the are hard objects available for contact. That is my 2 cents.
Troy

Title: Re: Dual Discs
Post by: DgM on March 16, 2008, 01:37:41 AM
Mounting bosses on right fork leg begging for caliper, in addition to familarity of dual disc system on LS, leads me on quest to dual disc my now single disc Brembo caliper R65.  Hence request for opinions as well as hoping to find existing LS BMW engineered Brembo caliper hydraulic system for dual disc setup.  Have seen home made installs that left much to be desired.  Would like to install as designed for R65LS.
Title: Re: Dual Discs
Post by: Justin B. on March 16, 2008, 07:11:58 AM
DgM, are you just wanting a list of part numbers, then?

<SOAPBOX MODE ON>

People, let's not fall into the boxerworks trap of answering straight-forward questions with opinions, derisions, etc.  That was always frustrating and irritating to me and one of the reasons I hardly ever go there anymore.  I would rather gut it out and find my own solution/answer rather than sort through a bunch of responses pointing out why what I was trying to do was stupid, unnecessary, unwise, not the way somebody else would do it, etc.  I have had PMs from new users thanking us for not traveling that path.  

</SOAPBOX MODE OFF>  [smiley=beatnik.gif]

Of course, once the question has been properly addressed let the "thread degradation" begin!  ;)
Title: Re: Dual Discs
Post by: DgM on March 16, 2008, 01:19:52 PM
Thanks.  A list of part numbers would be very helpful.  A complete group of existing hydraulic parts for sale would be like Christmas in July.
Title: Re: Dual Discs
Post by: donbmw on March 16, 2008, 02:18:11 PM
You can go to any of the online parts fiche and get the numbers needed. Keep an eye on ebay  and check some of that use bike parts sellers.

Don
Title: Re: Dual Discs
Post by: tagordon on March 16, 2008, 02:26:01 PM
Recently saw a dual disc & fork leg setup on eBay.
Just looked and its gone.
But there's caliper:
http://cgi.ebay.com/ebaymotors/BMW-Brembo-Front-Brake-Caliper-Right-R100-7-R80-7-R65_W0QQcmdZViewItemQQcategoryZ35604QQihZ012QQitemZ220211309899QQrdZ1QQsspagenameZWDVW
Good Luck
Title: Re: Dual Discs
Post by: tagordon on March 16, 2008, 02:30:15 PM
Here's a link to Max's parts fiche for the brake parts:
http://www.maxbmwmotorcycles.com/fiche/MainDiagrams.asp?mospid=47853
Title: Re: Dual Discs
Post by: Justin B. on March 16, 2008, 04:57:08 PM
This is from the ETK, I'll post another "page" with the lines and stuff later:
Title: Re: Dual Discs
Post by: DgM on March 18, 2008, 11:06:57 PM
Thanks for your assistance.  Christmas came in July.  Picked up complete R65LS hydraulic - master cylinder to calipers - with brackets etc.  However, I could use some clarification on the bushings used to mount Brembos to fork leg.  I've seen ATE calipers with mounting holes that match bolt diameter.  The mounting holes on my Brembo are larger than the bolts, and on the schematic gracefully posted there are parts #4 and #12 that seem to be the bushings needed.  Anyone have the parts numbers for the bushings?  Are they top hat section or cylindrical?
Title: Re: Dual Discs
Post by: nhmaf on March 19, 2008, 12:05:48 AM
The bushings are top-hat shaped - unfortunately I don't have access to my photos right now - I think that they can still be ordered, though someone may have an alternate (And cheaper) source to use for them.
Title: Re: Dual Discs
Post by: Bob_Roller on March 19, 2008, 02:15:22 PM
Those bushings, called 'sleeves' in the parts catalog, to complicate matters, are available in different thicknesses in the flat flange area.

I think this is to get the caliper 'centered' over the rotor.

I don't know how critical this is, as the left caliper does not have the bushings or 'sleeves' installed, at least on my '81 with dual ATE calipers.
Title: Re: Dual Discs
Post by: DgM on March 20, 2008, 02:00:23 PM
Thanks for info.  Will have to wait to mount disc on wheel, then position caliper to determine centering over disc.  Scientific.
Title: Re: Dual Discs
Post by: Bob_Roller on March 20, 2008, 02:36:50 PM
I can't tell from your profile, as to where you reside, but if you are in the US , or somewhere that uses the non-metric system, the sizes shown in the parts catalog under the supplement category like : 1,2  2,35  3,5 are the thickness of the flange area in millimeters,  3,5 would be 3.5 mm.

These parts catalogs take a little getting used to if you are not familiar how to use them.