Handlebar Master Cylinder Conversion

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Norm T R100T R1150RT
Posts: 61
Joined: Wed Aug 04, 2010 5:54 pm

Handlebar Master Cylinder Conversion

Post by Norm T R100T R1150RT »

Can a "single throttle cable" controller be converted to a "dual" cable ? I've been considering the swap from "under the tank" to bar mounted and have the dual cable set up currently. Hoping that with a combination of parts I can accomplish this conversion. Thanks, Norm
Norm Taylor
1980 R100T Airhead
2002 R1150RT Oilhead
1950 HD Panhead
Southern Maryland, USA
2003 K1200 GT
chasbmw
Posts: 765
Joined: Fri Aug 06, 2010 7:40 am
Location: Bath UK

Re: Handlebar Master Cylinder Conversion

Post by chasbmw »

You can buy dual throttle cable 13mm handlebar MCs from motobins. BMW went back to dual cables on the later bikes.
Charles
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Replica 1070 R90/S (based on 82 RT)
1975 R90/6
Garnet
Posts: 3108
Joined: Tue Aug 03, 2010 6:24 pm
Location: Victoria BC Canada

Re: Handlebar Master Cylinder Conversion

Post by Garnet »

Garnet

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captmako
Posts: 42
Joined: Sun Sep 08, 2013 3:03 pm

Re: Handlebar Master Cylinder Conversion

Post by captmako »

Norm T R100T R1150RT wrote:Can a "single throttle cable" controller be converted to a "dual" cable ? I've been considering the swap from "under the tank" to bar mounted and have the dual cable set up currently. Hoping that with a combination of parts I can accomplish this conversion. Thanks, Norm
OK, I'm confused. Of course, that is perfectly normal for me. :P
Nevertheless, Norm are you considering running "single throttle cable" to dual throttle cable? Or, are we discussing
running brake lines? Maybe I'm the only one who is "missing something here." And, that sure could be. The Capt.......
Norm T R100T R1150RT
Posts: 61
Joined: Wed Aug 04, 2010 5:54 pm

Re: Handlebar Master Cylinder Conversion

Post by Norm T R100T R1150RT »

I'm watching, on ebay, a handlebar mounted master cylinder for a single throttle cable. I've the under tank master cylinder controller, cable operated, with a dual throttle cable set up. I was wondering if I could modify the single throttle cable controller to accept my two throttle cables by combining controller parts, possibly using my gear and chain assembly and top cover. Probably created more confusion with this post - sorry. Thanks again, Norm
Norm Taylor
1980 R100T Airhead
2002 R1150RT Oilhead
1950 HD Panhead
Southern Maryland, USA
2003 K1200 GT
Garnet
Posts: 3108
Joined: Tue Aug 03, 2010 6:24 pm
Location: Victoria BC Canada

Re: Handlebar Master Cylinder Conversion

Post by Garnet »

Probably easier to get a one into two throttle cable from a mid 80's bike than modifing the new throttle assembly to take two cables.
Garnet

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chasbmw
Posts: 765
Joined: Fri Aug 06, 2010 7:40 am
Location: Bath UK

Re: Handlebar Master Cylinder Conversion

Post by chasbmw »

Norman.

The most important part of the conversion is getting the size of the handlebar MC right.

I would suggest 13mm and they do come with dual throttles.
Charles
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Replica 1070 R90/S (based on 82 RT)
1975 R90/6
Major Softie
Posts: 8900
Joined: Tue Aug 03, 2010 1:46 pm

Re: Handlebar Master Cylinder Conversion

Post by Major Softie »

Garnet wrote:Probably easier to get a one into two throttle cable from a mid 80's bike than modifing the new throttle assembly to take two cables.
This ^^^
MS - out
sterob
Posts: 148
Joined: Tue Aug 03, 2010 6:16 pm

Re: Handlebar Master Cylinder Conversion

Post by sterob »

I'm in the throws of fitting a second caliper and disc to my 77 R100/7. The single disc, even with a Handlebar mounted M/C was not good.
I'm using two 40mm piston calipers and a 14mm handlebar mounted M/C from Motobins.

It took some bleeding....I used the 'gravity' method first. Did both sides several times....
Lots of air bubbles and no brakes.....
I then used a giant syringe to inject brake fluid into both calipers several times...a few more bubbles and finally the front brakes started to work.

The feel seems quite good, although I have to yet test it on the road. Brakes have 'give' although I can't pull the lever to the handlebar. Will see how it goes.....


Steve
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jagarra
Posts: 896
Joined: Mon Dec 26, 2011 12:42 pm
Location: Reno, Nevada

Re: Handlebar Master Cylinder Conversion

Post by jagarra »

A good way to burp the final air from the system is to pump up the handle until you get a really firm resistance and lash the handle to the handlebar to keep the pressure on overnight. Seems to get the last of the bubbles out.

gg
1974 R90/6 built 9/73
1987 BMW K75S
1994 BMW R1100RS
1964 T100SR Triumph
1986 Honda XL600R
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