74 R90 – bar mounted master cylinder – how to

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Major Softie
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Joined: Tue Aug 03, 2010 1:46 pm

Re: 74 R90 – bar mounted master cylinder – how to

Post by Major Softie »

Ken in Oklahoma wrote: But even that list didn't mention what the Major mentioned, which is the leverage ratio of the hand lever to the master cylinder piston size.
Ken
Actually, the article DOES mention it, if only in passing:

"The hand lever ratio counts too: witness the adjustable master cylinders from Lockheed and Brembo."
MS - out
frasse
Posts: 2
Joined: Wed Feb 10, 2016 5:28 am

Re: 74 R90 – bar mounted master cylinder – how to

Post by frasse »

Hi,
Looking at this mod and I'm interested to do it myself. In the initial post the eurobars were extended, but could the MC be mounted without the extension?
If going with the 13mm, would that be sufficient if later I would add a second brake disk on the front?
Br, Frans
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Airbear
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Joined: Tue Aug 03, 2010 10:02 am
Location: Oz, lower right hand side, in a bit, just over the lumpy part.

Re: 74 R90 – bar mounted master cylinder – how to

Post by Airbear »

G'day Frasse, and welcome to the forum.

Re the extensions - yes, the MC will fit, but only just. Something I failed to mention was that the right side of my handlebar was badly bent in an argument with a cow a few years ago. I used oxy-acetylene to reshape it and though I took care to get the end of the bar into a correct symmetrical position (I made a jig for the purpose) the tube at the bend is a bit flattened. Others who have done the mod haven't had that difficulty. Check the ADV thread linked in the first post.

As to running two disks, I have no personal experience but my brake lever is still well away from the grip at maximum squeeze and my feeling is that two disks would work. The improvement with the single disk in terms of feel and effectiveness is so great that I haven't felt the need to consider adding a disk.

Asking your questions on ADV > Old's Cool > Airheads might get a more definitive response.
Charlie
and Brunhilde - 1974 R90/6
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Graduate, Wallace and Gromit School of Engineering and Design (Pending)
frasse
Posts: 2
Joined: Wed Feb 10, 2016 5:28 am

Re: 74 R90 – bar mounted master cylinder – how to

Post by frasse »

Thanks Charlie! That was the info I needed. Looking at the space "available" I estimated it would fit but would have been a bummer if it doesn't work.
Cheers!
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