Author Topic: Dry weights for cb750 based road racers  (Read 14465 times)

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Offline slikwilli420

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Re: Dry weights for cb750 based road racers
« Reply #50 on: June 20, 2018, 06:40:41 AM »
Chassis changes are out in this class. If I bump then I can move things around in a custom frame. I could lengthen the swingarm but would lose the handling. It may be ideal for endurance racing, but mine are 6-8 lap sprints, so corner handling is more important. Rider position aside, save for moving the oil tank to the front of the engine a la Bimota, I dont see how I could shift much weight around without frame alterations that would be outside of class rules.
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Offline simon#42

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Re: Dry weights for cb750 based road racers
« Reply #51 on: June 20, 2018, 08:31:27 AM »
you dont want to lengthen the swinging the bike is already to long  , moving the oil tank is a good idea its a pity you are not allowed a proper fairing you could make a tank to fit in the nose .
most people put longer rear shocks on which does work but it causes more problems than it solves

Offline slikwilli420

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Re: Dry weights for cb750 based road racers
« Reply #52 on: June 20, 2018, 09:03:44 AM »
No room to make it shorter either. Fairing is a no go, unless I bump a class. There isnt much motivation to do so either since there are only a few Formula 750 guys but grids of Sportsman regularly top 10 guys. Lets continue this in my thread. Sorry for the departure regarding weight.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
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AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
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Online scottly

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Re: Dry weights for cb750 based road racers
« Reply #53 on: June 21, 2018, 08:07:24 PM »
So I ask Willi and Scott... how much do you figure the street legal and charging parts accounts for.
 
 I am guessing 20 to 30ish lbs..
The charging system, including the field, stator, and rotor, plus the starting system, including the motor, gears, clutch and solenoid, plus the muffler, headlight, mirrors, grab-bar, fairing, kick starter and kick-stand add up to about 33 pounds.
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Offline 754

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Re: Dry weights for cb750 based road racers
« Reply #54 on: June 21, 2018, 09:31:47 PM »
So that is what I was thinking  subtract from yours, and add to his.
 And you should be quite close.
 I think Scott has around 10 lb advantage frame wise.
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Offline slikwilli420

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Re: Dry weights for cb750 based road racers
« Reply #55 on: June 22, 2018, 04:13:17 AM »
A lot more than just removing this components got me to where I am now. Every part I replaced is lighter than stock and that's nearly everything.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
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Online scottly

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Re: Dry weights for cb750 based road racers
« Reply #56 on: June 23, 2018, 08:33:35 PM »
How much does your oil tank weigh? How much for the hoses from the tank to the engine?
Your wheels might be your biggest single advantage? My Morris front, with no tire or brakes is about 13.5 pounds, and the rear with no tire, but including the sprocket and brake rotor, is 20 pounds.
Don't fix it if it ain't broke!
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Offline slikwilli420

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Re: Dry weights for cb750 based road racers
« Reply #57 on: June 23, 2018, 09:27:02 PM »
Oil tank plus longer lines and cooler is probably similar to suck tank and lines but I never did weigh them. The rear is 17.6lb which includes caliper and master cylinder. I can't find the note on the front but lighter than my old wheel with aluminum hoop.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html