Did I do something stupid?

[hobbsic]

Well hello there!
Long time lurker who spontaneously bought a 1974 R74/6 last fall. I'm really just working my way through the, I guess, normal steps of bringing a sleeping beauty back on the road. Anyhow. After rebuilding the forks I moved over to the leaking master cylinder under the tank. Not a pretty sight. Anyhow, after search the interwebs for general information about that, I stumbled upon the "switching to handlebar mounted MC"-solution!

I bought an old throttle assembly, bad in all the right places, and cut it up. Well, in the middle of that process I stepped back, thinking, of life's inner meaning and my latest.. uhm, mistake? The throttle part of the sliced one is shorter than the one original on the bike. I guess it won't be able to pull the throttle cable as far as the original would..? Am i screwed?

Them things:


That bike:


So, whaddya say, is it a ?

[Plaka]

Originally Posted by hobbsic

Well hello there!
Long time lurker who spontaneously bought a 1974 R74/6 last fall. I'm really just working my way through the, I guess, normal steps of bringing a sleeping beauty back on the road. Anyhow. After rebuilding the forks I moved over to the leaking master cylinder under the tank. Not a pretty sight. Anyhow, after search the interwebs for general information about that, I stumbled upon the "switching to handlebar mounted MC"-solution!

I bought an old throttle assembly, bad in all the right places, and cut it up. Well, in the middle of that process I stepped back, thinking, of life's inner meaning and my latest.. uhm, mistake? The throttle part of the sliced one is shorter than the one original on the bike. I guess it won't be able to pull the throttle cable as far as the original would..? Am i screwed?

Them things:


That bike:


So, whaddya say, is it a ?

I'd say the picture is utterly confusing. What do you have? What are you cutting up and why?

[elite-less]

Can't say I've ever seen a throttle cam with a shorter arm like that. You'll need to remove the tops and compare/measure the inner cable channels.



.

[hobbsic]

Originally Posted by elite-less

Can't say I've ever seen a throttle cam with a shorter arm like that. You'll need to remove the tops and compare/measure the inner cable channels.



.

Hmm, yeah, I did, and it's like 1cm shorter than stock. Maybe it's not even a BMW part from the beginning?


Plaka:
Heres a link for you!
http://forum.boxerworks.com/viewtopic.php?f=1&t=5461

[Mista Vern]

Originally Posted by Plaka

I'd say the picture is utterly confusing. What do you have? What are you cutting up and why?

What he said.


PS: What's in the boxes?

[Plaka]

BTW, from what I can see, that's a special tank. Get it off the petcocks.

[tradern]

Lever broken off the tip?

[ericrat]

Looks like a generic aftermarket Magura master cylinder and a BMW throttle assemply with the brake cable portion "sliced" off.

No point in worrying about it too much now that the deed is done. ASSUMING you have the carbs and throttle cables, wire it up and make sure the butterflies open all the way to the stops, it should be obvious enough. Note that cams inside the throttle assembly are not all the same. You may wan to use the cam out of your original throttle assembly.

Eric

[Plaka]

Originally Posted by hobbsic

Hmm, yeah, I did, and it's like 1cm shorter than stock. Maybe it's not even a BMW part from the beginning?


Plaka:
Heres a link for you!
http://forum.boxerworks.com/viewtopic.php?f=1&t=5461

Gotcha. Thanks!

I really like the paint on the tank in the pic (at the link). Wonder what it is?

[danedg]

That would be a 1974 R75/6.....

The shorter cap probably won't work. But you should be able to switch caps to "stretch" the cable correctly.

[garthg]

Originally Posted by Plaka

BTW, from what I can see, that's a special tank. Get it off the petcocks.

On that point, Chris Harris mentions, but doesn't show, a tank stand he built to hold tanks off the bike.

Does anyone know what this looks like?

[Brun]

Originally Posted by hobbsic

...The throttle part of the sliced one is shorter than the one original on the bike. I guess it won't be able to pull the throttle cable as far as the original would..? Am i screwed?

G'day Hobbsic. I'm responsible for that Boxerworks 'how to', and am still delighted with my front brake. I'm wondering why you used a replacement throttle housing - which I think comes from a R60/5 - rather than the one you had. I'm sure you can get or make throttle cables to suit the new one, and it is probable that there would be less throttle movement, but I would be more concerned about getting a smooth throttle operation.

When these things get old they get very lumpy. My suggestion would be to test both by assembling them on the handlebar (with cables) and test the feel while applying tension to the cables. You can also measure cable travel at the same time. Go with the smoothest operating one. I replaced the twisty part and the gear and chain part on mine with new parts. This greatly improved things but the wear in the housing is still causing lumpiness, though it's acceptable to me.

You will love the new brake. Good luck with it.

[Plaka]

Originally Posted by Brun

G'day Hobbsic. I'm responsible for that Boxerworks 'how to', and am still delighted with my front brake. I'm wondering why you used a replacement throttle housing - which I think comes from a R60/5 - rather than the one you had. I'm sure you can get or make throttle cables to suit the new one, and it is probable that there would be less throttle movement, but I would be more concerned about getting a smooth throttle operation.

When these things get old they get very lumpy. My suggestion would be to test both by assembling them on the handlebar (with cables) and test the feel while applying tension to the cables. You can also measure cable travel at the same time. Go with the smoothest operating one. I replaced the twisty part and the gear and chain part on mine with new parts. This greatly improved things but the wear in the housing is still causing lumpiness, though it's acceptable to me.

You will love the new brake. Good luck with it.

What kid of paint did you use on that project? (the tank)

[Plaka]

Originally Posted by garthg

On that point, Chris Harris mentions, but doesn't show, a tank stand he built to hold tanks off the bike.

Does anyone know what this looks like?

A coupla two by fours?

[Brun]

Originally Posted by Plaka

I really like the paint on the tank in the pic (at the link). Wonder what it is?

You mean this?



It's matte black Wattyl Killrust Epoxy Enamel, from a rattle can. Not sure if Killrust is available elsewhere than Australia. I baked it by my woodstove between coats, and it is wearing well. Here is the rest of the bike.