Author Topic: dual disc conversion for 750 link no good?  (Read 2246 times)

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DH

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dual disc conversion for 750 link no good?
« on: December 12, 2015, 04:46:07 PM »
Anyone know where the conversion thread for twin front disc went? The links for the 750 and 500/550 don't work any more.
thx..

Offline WV_750

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Re: dual disc conversion for 750 link no good?
« Reply #1 on: December 12, 2015, 05:57:33 PM »
There are a few different posts that talk about dual disc conversions. I've had better luck searching the site with google rather than the site's own search function. You can limit google's search to just these forums by following your search terms with site:forums.sohc4.net
Here's a link to save you a little time for this search: https://www.google.com/?gws_rd=ssl#q=dual+disc+site:forums.sohc4.net
73 CB750 K3
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78 CT90
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DH

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Re: dual disc conversion for 750 link no good?
« Reply #2 on: December 12, 2015, 08:55:46 PM »
Should've thought of google first :P.     Here it is................. And thanks for the tip, got me on track.


https://s3.amazonaws.com/sohc4-articles/CB750K/dualdiskconversion-cb750.pdf

EDIT  The article on SALOCAL is the same as above.
« Last Edit: December 12, 2015, 09:10:36 PM by DH »

Offline Mr Freeze

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Re: dual disc conversion for 750 link no good?
« Reply #3 on: December 12, 2015, 09:04:55 PM »
This is the easiest thing and I don't know why no ever brings it up. Get a front end from a 77 or 78 Supersport. Easiest swap there is. No alignment to do and those calipers stop better than the floating ones.
« Last Edit: December 12, 2015, 09:11:17 PM by Mr Freeze »

Offline mrfish2

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Re: dual disc conversion for 750 link no good?
« Reply #4 on: December 12, 2015, 09:22:11 PM »
This is the easiest thing and I don't know why no ever brings it up. Get a front end from a 77 or 78 Supersport. Easiest swap there is. No alignment to do and those calipers stop better than the floating ones.

Because a complete front end from those years is a lot harder to find than an extra caliper arm, caliper, and rotor from almost all the years.
1976 CB550K            1979 XS1100
1980 CB650C - Sold

It's a little motor and likes having the tits revved off it.

DH

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Re: dual disc conversion for 750 link no good?
« Reply #5 on: December 12, 2015, 09:22:34 PM »
This is the easiest thing and I don't know why no ever brings it up. Get a front end from a 77 or 78 Supersport. Easiest swap there is. No alignment to do and those calipers stop better than the floating ones.


Yup, and I''d go that route if not for the fact that I'm trying to up grade and retain stock appearance. Thanks for that note. On a related note..
Does anyone have a good way to get the "reverse flair" fitting out of an earlier 750 caliper? If I'm right, this fitting needs to be pulled out and re installed in the hole where the bleeder USED to be in the REPLACEMENT caliper for the RIGHT side.
So far, I have been unsuccessful using a cut off finish nail.

Offline DaveBarbier

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Re: dual disc conversion for 750 link no good?
« Reply #6 on: December 13, 2015, 05:19:09 AM »
I used a screw. http://forums.sohc4.net/index.php/topic,140833.msg1699993.html#msg1699993

But this might make them unusable. I'm not sure if you can get these things still. I would probably try PB blaster and propane or MAPP gas and then the nail approach again.

DH

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Re: dual disc conversion for 750 link no good?
« Reply #7 on: December 13, 2015, 05:49:24 PM »
I used a screw. http://forums.sohc4.net/index.php/topic,140833.msg1699993.html#msg1699993

But this might make them unusable. I'm not sure if you can get these things still. I would probably try PB blaster and propane or MAPP gas and then the nail approach again.



Thanks for the caliper shots dave. I wasn't sure what the whole thing looked like. I'm going to try salvage another one from a junk
caliper I have, in case I mess up and destroy the current one.

Offline PeWe

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Re: dual disc conversion for 750 link no good?
« Reply #8 on: December 14, 2015, 04:08:17 AM »
What about the cover?
Is there a cover for the right rotor?
Or possible to modify the OEM, left cover? Better if there are dual covers available that look similar and fit.
It will look better with cover for each rotor. My bike need better brakes with OEM look.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

DH

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Re: dual disc conversion for 750 link no good?
« Reply #9 on: December 14, 2015, 05:59:07 AM »
What about the cover?
Is there a cover for the right rotor?
Or possible to modify the OEM, left cover? Better if there are dual covers available that look similar and fit.
It will look better with cover for each rotor. My bike need better brakes with OEM look.



I agree.  I wish there was a shield/guard available. Nobody makes one for the right side as far as I know. Not sure how to modify
a left one to work.

Offline flybox1

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Re: dual disc conversion for 750 link no good?
« Reply #10 on: December 14, 2015, 07:09:49 AM »
Check out the links below  ;)

Branden,
I had a choice to either modify the speedo drive plate to fit the rotor center, or, modify the rotor carriage to fit the speedo drive plate.  Both are shown in this post.  I chose to modify the speedo drive plate as the wheel I bought off a forum member came with one attached  ;D  The mod took maybe an hour with a dremel and hand files.  A sloppy fit here is desireable so the drive plate doesnt bind.
I must have read these two posts 10 times while sourcing parts to be sure I got all I needed and had the mod process in my  mind. 
http://forums.sohc4.net/index.php?topic=53532.0

http://forums.sohc4.net/index.php?topic=38242.msg493516#msg493516

Godffery offers the rotor carriage mod if you get your rotors through him.

Shawn @ Slingshot Cycles made my lines.  Ordered Wednesday. Came Monday.
Right under my lower triple there is a clip where the brake lines sit. 
i'll run both through there to keep them up and off the tire.
i'm running 2 lines up to the MC.  not a splitter like other bikes.
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
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Offline SOHC4 Cafe Racer Fan

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Re: dual disc conversion for 750 link no good?
« Reply #11 on: December 14, 2015, 09:38:51 AM »
What about the cover?
Is there a cover for the right rotor?
Or possible to modify the OEM, left cover? Better if there are dual covers available that look similar and fit.
It will look better with cover for each rotor. My bike need better brakes with OEM look.

None available for the right side.  I bet someone with a 3d printer and time on their hands could make one!
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

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1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
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Wobbly

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Re: dual disc conversion for 750 link no good?
« Reply #12 on: December 14, 2015, 10:23:14 AM »
It's pretty tight as is without the cover--never mind two of them.






Offline PeWe

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Re: dual disc conversion for 750 link no good?
« Reply #13 on: December 14, 2015, 12:48:59 PM »
Tom, your dual brakes look really beautiful! The rotors fits very well, like designed for the bike.
I'll try without cover.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967