Topic: K8 750 dual brake conversion

[MilehighCB]

Hello all,
I know there are a million posts about converting to dual front brakes and I have read many of them.  I would like to stop my head from spinning from all the different applications and posts and see if I can get it right. 
The K8's differences in front end braking leads me to a few questions specific to the K8 and I will address those as well as a few other questions.  Here goes.

Can I use  K model front rotors or does it have to be from a F model?  I am looking for a 77/78 setup to match my caliper on the other side.

I would prefer to use my orignial K8 MC step up, as it is all nicely polished aluminum, and it contains the brake light switch.  Can this work, using a double banjo fitting for the two lines at the MC?  I read the GL1000 is a easy swap, but the resivoir is plastic and I would like to not have that if possible.

If I went to a GL1000 MC, do I have to use an external brake switch, or is it similar to the K8 and contain it in the MC/switch?  Again, I would like to use a double banjo fitting at the MC instead of a splitter down stream if its possible?

Is it the pistion size of the MC that needs to be increased for a dual setup and not the resivior volume, and if so, am I right to figure the stock K8 may not up to the task?

The rest of the swap seems pretty straight forward for any year, mounting the rotor, modifying the speedo etc, etc.

Thank you for indulging me on these questions, having a K8 things do not always fit into the norm of the masses!

[MilehighCB]

Ok, I think I have found all the answers to my questions.

I have bought another 77/78 rotor, and brake caliper and mounts.
I will double banjo at the MC and use two seperate SS brake lines. 

I will attempt to use my stock K8 master cylinder and if it isn't up to the task, I will upgrade.  Give it a try first, maybe it will have enough to work.  If not, either a GL1000 or the upgrade to the GL1000 listed on the GL guru's site(forget the name).  I would like to keep it stock/vintage looking thou.

I am debating on upgrading to a GL front end, but honestly my stock setup is in great shape and I spend many hours cleaning and polishing my forks, so I would hate to go thru that again for more work and slightly bigger tubes.

Overall, its a bit more weight, but I think for the added weight I should have much better brakes then stock.  With the mods done to my bike, I would like to be able to slow the bike better.  Not to mention, dual brakes will look bad ass, so its worth the weight!

[scottly]

I'm in the process of adding a second K7 caliper, also planning on using the stock MC. I know that the earlier 38mm calipers work well with a stock MC, but I'm also wondering a bit about the 43mm 77/78 units. A bit of advice: don't base your impressions on the "feel" of the hand lever, but rather on the actual braking force used on the road. Even though the lever may feel as if you can pull it all the way to the grip, this may be enough force to stand the bike on it's front wheel! 

[MilehighCB]

I am finally getting my dual brake conversion wrapped up.  I have another question..

I bought the dual banjo bolt from Z1 Enterprises that fits the brake line fittings that they sell.  I want to know if I need to place a copper washer between the seperate brake lines?  I know that I need a washer on the outside fitting to the bolt, and then one on the inside fitting closes to the MC. 

Any thoughts?  I don't want to bleed the entire system only to find out I have a leak, or can't keep an air tight system.
Thanks....

[voxonda]

Yes, a copper washer is needed between both lines.

Cheers, Rob

[MilehighCB]

Thats what I thought.  My concern was that with a washer on the outside, the first brake line indexes perfectly with the hole and then the notch in the middle of the double banjo bolt.  When I put a washer in between the first and second brake line, it #$%*fs everything past mid point.  I test fitted it and I think when the copper washers "crush" the distance is less then before they "crush" and probably line things up better.

Regardless, I will use a washer on each side of the brake fittings. 
THANKS!!!