Author Topic: Extended Swingarm (Read 29253 times)

Industrial Cafe · « **Reply #25 on:** April 15, 2009, 08:15:59 AM »

It's only a little over an inch longer.

m0rticiansflam3 · « **Reply #26 on:** October 04, 2010, 04:57:15 PM »

so where does puttin a 80' CB750C onto a 78' K8?

Alan F. · « **Reply #27 on:** October 04, 2010, 05:29:11 PM »

Would you please rephrase the question? I think some info is missing.

m0rticiansflam3 · « **Reply #28 on:** October 24, 2010, 07:23:13 PM »

sorry poorly stated. does anyone know here if there is any difference between an early DOHC (79-80) cb750C swing arm and the F model discussed in this topic? i'm asking this because i have an 80' 750c (no title) and i want to run the swing arm on my, titled K8... its more aesthetically pealsin too.

Don R · « **Reply #29 on:** October 24, 2010, 08:04:04 PM »

I think the K8 swingarm is already as long as an F swingarm, the DOHC swingarm may be approx an inch longer. If you have them check it out.

dergs713 · « **Reply #30 on:** February 20, 2012, 09:35:29 PM »

Has anyone messed with extending a Cb550..? or know of what model I can get to stretch it out two inches..?
Matt

Eddie · « **Reply #31 on:** February 21, 2012, 05:12:22 AM »

I extended mine 2". Bought a 750 swing arm, measured from center of the pivot bolt hole back 3" and cut it off. Took a dremel tool and ground a half circle at the cut off part so it will over lap your orig swingarm pivot section...ground enough out that it came pretty close to 2 inches...it has to be the exactly the same on both sides. When you are certian they measure the same weld it on all the way around. After that I welded a 1/8" steel plate to the bottom of the swingarm to over lap the two pieces. The only mod you have to do after that is extended the brake rod.. I'll try to get a picture up...Stupid me, I didnt think to make it a build thread...

dergs713 · « **Reply #32 on:** February 21, 2012, 10:12:22 AM »

Eddie, this is exactly what im looking for!! Please post some pics. Also what year and model 750 you use. Was it off a SOHC or a DOHC? Im wondering what the arm measures up to stock CB550.
Thanks a bunch!! I wanna start ridding here soon.
Matt

Vbled1 · « **Reply #33 on:** February 21, 2012, 11:43:19 PM »

I have a 1980 650 swingarm on my bike. its about 2 inches longer. All i had to do was drill the frame. Everything else bolts up and no trimming one side of the swing arm. It has a 21 in the rear and still has a lot of room.

dergs713 · « **Reply #34 on:** February 22, 2012, 10:12:41 AM »

Vbled, I like that a lot man. Do you have any closeup pic of where you had to drill the frame, and what you needed to drill out...? Thats the exact length im looking for. Did you have to drill it out to fit a bigger pivot shaft or ..?

Also your 21''s, I need to know where you got the rim and what hub you lace it too. Thats a must for my front wheel this season. Please keep me posted, your knowledge can finally get me off this stall of my bike build.!!
Matt

dergs713 · « **Reply #35 on:** February 22, 2012, 10:28:32 AM »

Also CB650 right, not a xs650..? As soon as i get your reply im going to start searching. Thanks a ton!
Matt

dergs713 · « **Reply #36 on:** February 22, 2012, 10:30:38 AM »

Damn...... didnt know you had a 750.... I dont know if thats going to work on my cb550 1975...

Really? · « **Reply #37 on:** February 22, 2012, 10:31:16 AM »

CycleX sells 21's now but they are complete with hub and spokes. Dunno how it will work with a CB550 though.

http://www.cyclexchange.net/Wheel%20Page.htm

Vbled1 · « **Reply #38 on:** February 22, 2012, 01:25:53 PM »

Quote from: dergs713 on February 22, 2012, 10:12:41 AM

Vbled, I like that a lot man. Do you have any closeup pic of where you had to drill the frame, and what you needed to drill out...? Thats the exact length im looking for. Did you have to drill it out to fit a bigger pivot shaft or ..?

Also your 21''s, I need to know where you got the rim and what hub you lace it too. Thats a must for my front wheel this season. Please keep me posted, your knowledge can finally get me off this stall of my bike build.!!
Matt

Sorry didnt meant to thread jack. Yea basically the pivot shaft/bolt whatever you want to call it, is 1 size bigger on the CB650. Meaning you arent drilling out that much. I dont remember the size but once you see both pivot bolts you will see what i mean. Once you drill out the frame it bolts up like stock, that is on a 750, not sure on a 550. Measure and get back to me and i will confirm if you need. side not: the early model chain tensioners bolt up like crap, they are a little wider and when tightened the piece flexes and sits crooked. I got 650 ones of ebay for 20$ and solved the problem.

As for the wheels. I had custom spokes made by buchanans and they laced and trued them to my stock hubs, cost me about $450. Added with tubes $30, tires about 150$ (dont remember) mount and balance about $40. CycleX has a cool front wheel for like 325, its simple if you just want a front wheel, and then you could recover some cost by selling your stock one. Again since you have a 550 im not sure any of this info is useful.
PM me if you want any other info.

dergs713 · « **Reply #39 on:** February 22, 2012, 05:32:35 PM »

Hey man thanks for getting back to me. The measurements on my stock swing-arm are: 10'' wide from center of arm to arm, pivot point is 9'' wide, and length (from center of pivot point to the closest the rear axle can go in the plate) 17.75.'' Ideally I would be to stretch it two inches. I heard a honda 750 sohc arm is about and inch shorter.. So thats where im at.. If not I might just chop the existing arm and add a 2'' plate right behind the pivot point.
Matt

Vbled1 · « **Reply #40 on:** February 23, 2012, 02:47:29 AM »

Quote from: dergs713 on February 22, 2012, 05:32:35 PM

Hey man thanks for getting back to me. The measurements on my stock swing-arm are: 10'' wide from center of arm to arm, pivot point is 9'' wide, and length (from center of pivot point to the closest the rear axle can go in the plate) 17.75.'' Ideally I would be to stretch it two inches. I heard a honda 750 sohc arm is about and inch shorter.. So thats where im at.. If not I might just chop the existing arm and add a 2'' plate right behind the pivot point.
Matt

Hey matt, i measured the swing arm and its essentially the same as the DOHC posted above minus the width of the pivot area which is the same as the sohc 750 posted above. the Length from center of pivot bolt to the very first part of what i call drop outs (bmx mentality) is 18 3/4. I had run my rear axle all the way up against the drop out when had the stock one. with the extra inch and some, plus running my axle in middle of drop out i gained about 2. I hope that helps.

KRONUS0100 · « **Reply #41 on:** February 23, 2012, 05:14:12 AM »

I am running a 1981 CB750C swingarm on my 1976 CB750F. it is 2 inches longer, and tubular steel instead of stamped. fairly simple install, shaved 12mm off right side, had new sleeve made for stock 76 pivot bolt so i didnt have to drill my frame out. also am running the shock of an 1981 CB900F as they are about inch longer, still bottomed out 2 up. So i will remedy this and weld in a spare set of lower shock mounts in front of the existing ones. overall added about 1 3/4 inches to wheelbase, bike is smoother handling and tracks straight line easier. still turns pretty decent.

Seeparkfly · « **Reply #42 on:** May 31, 2014, 10:58:57 PM »

Quote from: KRONUS0100 on February 23, 2012, 05:14:12 AM

I am running a 1981 CB750C swingarm on my 1976 CB750F. it is 2 inches longer, and tubular steel instead of stamped. fairly simple install, shaved 12mm off right side, had new sleeve made for stock 76 pivot bolt so i didnt have to drill my frame out. also am running the shock of an 1981 CB900F as they are about inch longer, still bottomed out 2 up. So i will remedy this and weld in a spare set of lower shock mounts in front of the existing ones. overall added about 1 3/4 inches to wheelbase, bike is smoother handling and tracks straight line easier. still turns pretty decent.

I have a 76 CB750F as well and looking for a longer swing arm. That 81 CB750C swing arm, did you weld a mount for the rear brake caliper arm?

Seeparkfly · « **Reply #43 on:** May 31, 2014, 11:14:39 PM »

Forgot to ask. Does anybody know of a longer swing arm for my 76 CB750F that is tubular with a disc brake mount? Hope so.

KRONUS0100 · « **Reply #44 on:** June 01, 2014, 07:18:59 AM »

im using a 1981 cb900f swingarm, cut 13mm of the right side of pivot area, and had sleeve made for stock swingarm bolt. otherwise you have to drill out frame for the larger pivot bolt

754 · « **Reply #45 on:** June 01, 2014, 08:22:20 AM »

77/78 for arm is longer than earlier K models by about 1 1/4 inch.
Not sure on your length, if it has the bolt in ends, it's likely the shorter arm.

seat cover man · « **Reply #46 on:** September 10, 2014, 12:07:05 PM »

Is the right side of the swingarm the oil tank side? Just to make sure thanks. Don't wanna grind 1/2 inch off the wrong side thanks!!!

754 · « **Reply #47 on:** September 11, 2014, 09:10:13 AM »

Right side is oil tank, just lay one swingarm over the other, then you know which part lines up. If arm has thicker pivot bolt , you can machine shims to use the smaller bolt.

Not going with the single sided arm, looks like..

seat cover man · « **Reply #48 on:** September 11, 2014, 09:44:55 AM »

Yeah ya scared me. With needing to make parts and stuff lol

70CB750 · « **Reply #49 on:** September 11, 2014, 09:57:09 AM »

Quote from: 754 on September 11, 2014, 09:10:13 AM

Right side is oil tank, just lay one swingarm over the other, then you know which part lines up.

Frank, that's brilliant!

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Author Topic: Extended Swingarm (Read 29253 times)