Author Topic: '76 GL1000 Front End and 18" Wheel on CB750K2 -- WHICH SPEEDO DRIVE?  (Read 910 times)

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Offline SOHC4 Cafe Racer Fan

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I'm planning to fit a 1976 GL1000 Front End on my CB750K2.  The twist is that I am going to run an 18" wheel so I can get some more tire choices. 

Which Speedo Drive will provide the accurate speed -- the GL1000 or a CB400f????
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)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline JohnG

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Re: '76 GL1000 Front End and 18" Wheel on CB750K2 -- WHICH SPEEDO DRIVE?
« Reply #1 on: October 11, 2012, 04:04:52 PM »
you would seem to need a speedo drive designed for an 18" front wheel.

That said, you might go back and read some test reviews in Cycle from back then and see how accurate or inaccurate a given drive was  (they always posted the observed and actual speeds).
1976 CB750F - original owner
1971 CB450
1979 CB750F
1982 CB900F
1983 CB1123F - Rick Stetson motor

Offline SOHC4 Cafe Racer Fan

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Re: '76 GL1000 Front End and 18" Wheel on CB750K2 -- WHICH SPEEDO DRIVE?
« Reply #2 on: October 12, 2012, 02:41:29 PM »
The CB400f runs a stock 18" front tire.  I was just wondering if it would render the correct speed and fit onto the CB750/GL1000 hub (same hub).
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)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline fishhead

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Re: '76 GL1000 Front End and 18" Wheel on CB750K2 -- WHICH SPEEDO DRIVE?
« Reply #3 on: October 12, 2012, 04:37:31 PM »
The GL 1000 speedo drive is wider than the CB series speedo drive (to fit the wider spaced GL forks). You will probably need a spacer/spacers on the axle to make the CB drive the same width as the GL drive (the width that the wider spaced GL forks need to have the wheel centered).

Check my old post as I have the GL/CB speedo drive widths/differences listed before.
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