Author Topic: 750 swing arm on a 550?  (Read 6166 times)

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Offline Roach

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750 swing arm on a 550?
« on: February 06, 2011, 07:21:33 PM »
i posted this question over in the dive bar but thought i would make a thread on the subject.

i really like the swing arms for the 750 that carpy sells but no clue about the width between the 750 pivot points. can someone give me the measurement of the width of the 750 swing arm at the pivot point.

or just answer me yes it will fit or no it wont?

also if i did get a 750 rear swingarm to fit would i have to go to a 750 rear hub?
1978 CB550K Cafe Racer

Offline Roach

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Re: 750 swing arm on a 550?
« Reply #1 on: February 06, 2011, 10:59:10 PM »
anyone i am very curious as to if it would fit dont want to go pay 400 bucks for it and not have it fit ???
1978 CB550K Cafe Racer

Offline bryanj

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Re: 750 swing arm on a 550?
« Reply #2 on: February 06, 2011, 11:18:03 PM »
Well the pivot pin and bushes are the same for the 500 and the 750 BUT the rear of the frame might not be wide enough AND the lower shock mounts might be too far out sideways and/or lengthways
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

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Offline Roach

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Re: 750 swing arm on a 550?
« Reply #3 on: February 07, 2011, 12:13:09 PM »
i new that they were the same bushing ans pivot pin.

anyone know the measurments for the 750 swing arm?
1978 CB550K Cafe Racer

Offline RustyOlive

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Re: 750 swing arm on a 550?
« Reply #4 on: February 07, 2011, 01:35:07 PM »
Roch. I have both swing arms hanging on a wall at home. I'll measure tonight and see for ya.
My understanding is the are the same. I have seen some guys out on the track on 550's with 750 swing arms because they were suposed to be stronger and a tad wider than the 550. If you wanted to run a 140 tire.

Came across this sweet lil race bike last fall at a swap meet.
78 550.
bored out with 750 pistons.
750 forks.
750 swing arm.
140 rear tire.

took 4th place over all at a VRRA race over a year ago..
almost bought it.. but wife said i have to many bikes for now.. LOL
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Offline RustyOlive

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Re: 750 swing arm on a 550?
« Reply #5 on: February 07, 2011, 01:35:46 PM »
750-swing arm. 550 frame.
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Offline turboguzzi

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Re: 750 swing arm on a 550?
« Reply #6 on: February 07, 2011, 02:45:33 PM »
750 s'arm in 500-550's is a common racing mod over here in italy too. The 750 arm is shorter hence reduces wheelbase = quicker steering.

I do not run it in my 500 racer but a friend does, can ask what needs to be done. i believe it's a drop in mod

TG

Offline Roach

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Re: 750 swing arm on a 550?
« Reply #7 on: February 07, 2011, 03:25:08 PM »
thanks guys i need all the help i can get with this one. i think it would be super sexy to have a Dresda styled box swing arm on her... my thinking is if the stock swing arm of a 750 fits on a 550 so should the dresda swing arm.
1978 CB550K Cafe Racer

Offline Flying J

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Re: 750 swing arm on a 550?
« Reply #8 on: February 07, 2011, 03:50:27 PM »
Ok, im watching. Im looking at the dresda arm for my 550. Just so happen to have a 750 rear wheel to drop in as well.

Offline Roach

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Re: 750 swing arm on a 550?
« Reply #9 on: February 07, 2011, 03:56:01 PM »
Ok, im watching. Im looking at the dresda arm for my 550. Just so happen to have a 750 rear wheel to drop in as well.

is there a noticable difference in the width of the dresda and the 750?
 
or is your dresda made for a 550?
1978 CB550K Cafe Racer

Offline Flying J

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Re: 750 swing arm on a 550?
« Reply #10 on: February 07, 2011, 04:04:29 PM »
No, what im saying is I want a carpy dresda to put on my 550 but need to know if it will fit.

Offline Roach

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Re: 750 swing arm on a 550?
« Reply #11 on: February 07, 2011, 04:07:27 PM »
ah so your in the same boat as me cheers!!! ;D
1978 CB550K Cafe Racer

Offline RustyOlive

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Re: 750 swing arm on a 550?
« Reply #12 on: February 07, 2011, 05:37:03 PM »
ok.. so I took some measurements. both 750 and 550 swingarms are 9" across..
oddly.. the 750 arm is 1" shorter than the 550.
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Offline Flying J

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Re: 750 swing arm on a 550?
« Reply #13 on: February 07, 2011, 05:38:38 PM »
Thanks for the measurements!  What is the distance between the shock mounts?

Offline RustyOlive

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Re: 750 swing arm on a 550?
« Reply #14 on: February 07, 2011, 05:44:13 PM »
across? or in length from the pivot tube?
both swingarms are the same across from drop out to drop out..
not sure the lengths from pivot tube. but i imagine if the 750 is 1" shorter.. then I would assume the mounts would be 1" closer as well?
If you want it. I can head back out to the garage a see.. ;-)
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Offline Roach

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Re: 750 swing arm on a 550?
« Reply #15 on: February 07, 2011, 06:06:40 PM »
well all i can say now is get er done
1978 CB550K Cafe Racer

Offline Flying J

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Re: 750 swing arm on a 550?
« Reply #16 on: February 07, 2011, 06:25:16 PM »
This is the distance im looking for.

Offline RustyOlive

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Re: 750 swing arm on a 550?
« Reply #17 on: February 07, 2011, 07:41:51 PM »
both swing arms-shock mounts are 9 1/2" apart.

i could sound like a total dumbass here... but my understanding is that there really is no difference between the 550 and the 750 rear hubs. the axle length, the O.D. and spacers to center the hub in the swingarm are all the same.. I had mocked up this 750 swingarm with my 550 hub before and all fit as good as new.. so unless my $10.00 swapmeet swingarm find is not in fact a 750 swingarm.. i'd say the 750 arm is an easy bolt-on-swap over.. however.. one down side to this.. the 550 swingarm is in fact a little bit wider in the middle. and you can fit a 140 tire with lots of room.. your only going to fit a 130 or maybe 140.. or less in the 750 arm.  oddly, I thought the 750 would have had more room?
« Last Edit: February 07, 2011, 07:44:38 PM by RustyOlive »
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Offline Flying J

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Re: 750 swing arm on a 550?
« Reply #18 on: February 07, 2011, 07:47:59 PM »
Very useful info. Thanks. Im not going to run a 750 stock swingarm but may buy a carpy dresda swingarm and wanted to be sure it would fit.

Offline Duke McDukiedook

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Re: 750 swing arm on a 550?
« Reply #19 on: February 07, 2011, 07:48:18 PM »
well all i can say now is get er done

I wouldn't waste money on the Crapy swingarm unless it is made of aluminum and is way lighter- the 750 swingarm is strong enough for about anything you want to dish out to it.

You would be better off spending money on getting a fairly clean 750 swingarm and powdercoating it and have Hondaman rebuild the collar and bushings and replace the rear bushings. That's my HO.


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Offline RustyOlive

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Re: 750 swing arm on a 550?
« Reply #20 on: February 07, 2011, 08:04:10 PM »
Moore.. your a crafty guy.. why not make a swingarm from scratch like I am?
make it the way you want it..
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Offline Flying J

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Re: 750 swing arm on a 550?
« Reply #21 on: February 07, 2011, 08:28:03 PM »
Yeah, i cant really justify $400 for a steel swingarm. My bike is an alloy style bike so ill hold out for a real dresda or ill have something built. I cant build anything aluminum yet as i dont have a proper welder.....yet.

Offline turboguzzi

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Re: 750 swing arm on a 550?
« Reply #22 on: February 07, 2011, 10:41:50 PM »
well, if you want the real, race proven thing in CroMo, the Bimota replicas are available form motocicliveloci in italy

http://www.motocicliveloci.it/italiano/catalogo/replicabimota.htm




Offline Flying J

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Re: 750 swing arm on a 550?
« Reply #23 on: February 07, 2011, 10:49:26 PM »
I like it but i think i found a similar setup in aluminum for less.

Offline Retro Rocket

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Re: 750 swing arm on a 550?
« Reply #24 on: February 07, 2011, 11:35:35 PM »
well all i can say now is get er done

I wouldn't waste money on the Crapy swingarm unless it is made of aluminum and is way lighter- the 750 swingarm is strong enough for about anything you want to dish out to it.

You would be better off spending money on getting a fairly clean 750 swingarm and powdercoating it and have Hondaman rebuild the collar and bushings and replace the rear bushings. That's my HO.




Carpy's swing arms would be lighter, you only have too look at them to work that out, and it also looks like they have more clearance for bigger tyres.... ;) Just a side note, Carpy's were made using the specs from an original Dresda swingarm he already had .

Mick
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
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