Author Topic: changing to newer swingarm and monoshock. comments or ideas?  (Read 8863 times)

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Offline cb(r)

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changing to newer swingarm and monoshock. comments or ideas?
« on: October 14, 2005, 11:46:31 AM »
My brother in law just gave me a 1974 cb550.  I was going to restore it but there is just way to much rechroming.  I  decided to make a sport classic out of it instead.
I have a complete cbr  front clip for it with rims, calipers etc.  for front and back. 

my question is:
can I put a newer swingarm and mono shock, like the newer sport bikes, on the bike without giving any handling ability  or frame rigidity of the original dual rear shocks?  any comments or suggestions welcome

mind you I will probably stay with the dual rears but I was just curious if anyone has  tried this with any success?

thanks

 

Offline dusterdude

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #1 on: October 14, 2005, 11:51:23 AM »
interesting idea
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Offline Alan F.

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #2 on: October 14, 2005, 12:23:01 PM »
It's been done, There are past posts here somewhere with pics. just do a search and maybe you'll get lucky.

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #3 on: October 14, 2005, 03:22:37 PM »
Anything can be done... but It may be more cost effective to buy a cbr600F2

Offline Alan F.

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #4 on: October 16, 2005, 06:45:42 PM »
I've been thinking about this one...it seems like you'd just have to weld in an upper mount for the shock...across the frame somewhere rearward of the oil tank and maybe some triangular sheetmetal bracing, possibly you'd have some interference from the oiltank, but you could always mount it on some short spacers to add clearance.

Offline Chris Liston

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #5 on: October 17, 2005, 08:26:46 AM »
I've been thinking about this one...it seems like you'd just have to weld in an upper mount for the shock...across the frame somewhere rearward of the oil tank and maybe some triangular sheetmetal bracing, possibly you'd have some interference from the oiltank, but you could always mount it on some short spacers to add clearance.

There are no oil tanks on the 550.
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Offline cb(r)

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #6 on: October 17, 2005, 11:08:36 AM »
well I understand how to mount the monoshock. I quess my main worry is  the frame.  I was under the impression the due to the frame rigidity there might be some twisting and/ or tracking problems once you take away the support of  the original dual shocks?  I was already told to stay away of the single sided swing arm idea I originally had due to possible riding problems.  so I quess this question is directed more towards someone who has actually fabbed a newer monoshock/ swingarm and worked out the bugs.  sorry for any confusion.

Offline Geeto67

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #7 on: October 17, 2005, 12:14:33 PM »
The problem with the frame is not caused by taking away the dual shocks, but by using modern components, such as bigger rims and swingarms that transmit more flex to the frame than the originals. I have a kawasaki h1 with a dual shock setup and fzr400 rear swingarm and rim - the bike's frame flexed because the thicker longer swingarm had more leverage and less give than the tublar steel one that it replaced. Some frame bracing took all that away.

You need to do your research. Find out what suspension geometry racers are running on these bikes and then shoot for similar geometry (usually lowered front raised rear and reduced rim size). The single sided swingarm would have been a pain in the arse to setup but shouldn't have given you any other frame flexibility problems. Your biggest hurdle is going to be chain line, so try to use components that get you close and have a plan. Go to the junkyards often with a tape measurer and see what components may fit your bike or can be modified to fit. I hear dirt bike stuff is pretty trick and easier to adapt to these smaller bikes than sport bike stuff. Some bikes you should look at for for donor parts are ninja 250's and 500's, gs550s, fzr400/600, cbr 600 f1/f2. Most modern sport bikes  bigger than 500ccs will have components too big for your little 550.

Of course you could just build a cafe racer (paint all chrome black, clip ons, rearsets, fiberglass tailsection) and ride the thing instead of taking a year to build it.

BTW, sportclassic is a brand name used by ducati to sell their bikes. What you are trying to do would be more like a cafe racer or streetfighter but who really cares about labels anyway.
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Offline Alan F.

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #8 on: October 17, 2005, 06:39:31 PM »
Sorry Chris, I forgot that. ;D

Offline cb(r)

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #9 on: October 18, 2005, 08:11:19 AM »
that was some good infomation about the 550 and maybe a tongue lashing on the duc. hopefully I did not snip a nerve.  I was just trying say that I want to use an older look with newer techno.   ducati just happened to be coming out with this new style retro next year and I just happened to see it on the internet.
 none the less, back to the task at hand.   I have some mxer buddies with tons of parts.  I will check that option out.
as far as the clip on stuff.  I am not one to pick up something and put add ons just to ride.  Anything I get, especially bikes, that looks a little beat up  I tear into it and make it my own.  I do not take chances when riding.  So hopefully by spring this bike will be road worthy.  If it takes a year,  I am not worried.   it will make it just that much more enjoyable when puttering around to my favorite hangouts.  thanks again for the input like I said all comments and ideas are welcome.

Offline Geeto67

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #10 on: October 18, 2005, 08:49:38 AM »
that was some good infomation about the 550 and maybe a tongue lashing on the duc. hopefully I did not snip a nerve.  I was just trying say that I want to use an older look with newer techno.   ducati just happened to be coming out with this new style retro next year and I just happened to see it on the internet.
 none the less, back to the task at hand.   I have some mxer buddies with tons of parts.  I will check that option out.
as far as the clip on stuff.  I am not one to pick up something and put add ons just to ride.  Anything I get, especially bikes, that looks a little beat up  I tear into it and make it my own.  I do not take chances when riding.  So hopefully by spring this bike will be road worthy.  If it takes a year,  I am not worried.   it will make it just that much more enjoyable when puttering around to my favorite hangouts.  thanks again for the input like I said all comments and ideas are welcome.

Didn't mean for it to be a tounge lashing, just trying to clue you in to the hip lingo, daddy-o. No nerves snipped here. The thing is if you do a search on the net to find bikes and you type in sport classic you will get tons of duc stuff and not much else. If you do a search for streetfighter you will get a lot of stuff very similar to what you are trying to do to give you some ideas. Sportclassic is a pretty neat name for the not quite cafe not quite streetfighter bikes that are being built now, but unfortunatly duc co-opted it.

 If you are looking for examples of other streetfightered cb550s, you will likely find them overseas where the japanese, english, and germans seem to be building anything they can get their hands on. The japanese espically since the early cb's are highly revered as part of their heritage. In america small displacement bikes are not as popular and people would rather stretfighter newer sport bikes than modernize a bunch of old nails. There are a few of us out there, but more often it is reserved for the bigger bikes like the cb750s, kz1000s, gs1100s, etc...

You three best friends in building your cb550 are going to be your measuring tools (dial caliper and tap measurer), your research skills and powers of observation, and a good local salvage yard and bike community. Take all practical measurements of your existing bike and carry them with you along with your measuring tools. Some measurements that are curcial but you may not have thought about are the distance between the sprocket and the centerline of the rim (this helps in figuring chain line since you will align the centerline of the rim with the centerline of the bike), the distance between the chain and the tire, the width of the pivot, and the diameter of the pivot bolt. Go around an measure as many bikes as you can find, this will give you an idea as to what comes close to your specs (remember those, you should be carrying them around). visit motorcycle salvage yards often. When I was building my h1, I made friends with the local salvage yard and he let me work in the back. I found a frame identical to the one I was building and just played around with different pieces till I had a rough setup, then I paid for what I needed and left the rest behind. if you know a modern sportbike component will fit, read as much as you can about that bike, there might be upgrades or other bikes that interchange as well (for instance I figured out how to use the fzr600 front on my h1, then I found out the gixxer front end is apopular bolt on swap, so just through research I figured out how to put a gixxer front end on my bike). Setting up the front end is easy, the rear end is going to be the tough one so start there.
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Offline cb(r)

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #11 on: October 18, 2005, 01:00:41 PM »
geeto

thanks again I am absorbing like a sponge.   I do not have a good salvage yard here in my midwest town but fortunately,I have a lot of bike mechanics in the family.  I can always have them keep a look out for things.   as far as the measuring thing I have that down.  I have been a tool and die make for almost 20 years so that part is not a problem.  I just have a problem with trial and error.  hate to make errors.  this is why I like to pick the brains of people that have done such things before.  besides it is great to learn new things and ways to do them.  I just rec'd my cbr front end today so I am going home and writing down dimensions for my plan of attack on that issue.  thanks alot for the time

Offline Geeto67

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #12 on: October 18, 2005, 02:08:45 PM »
geeto

thanks again I am absorbing like a sponge.   I do not have a good salvage yard here in my midwest town but fortunately,I have a lot of bike mechanics in the family.  I can always have them keep a look out for things.   as far as the measuring thing I have that down.  I have been a tool and die make for almost 20 years so that part is not a problem.  I just have a problem with trial and error.  hate to make errors.  this is why I like to pick the brains of people that have done such things before.  besides it is great to learn new things and ways to do them.  I just rec'd my cbr front end today so I am going home and writing down dimensions for my plan of attack on that issue.  thanks alot for the time

the cbr front end should be pretty straight forward, grind down the bottom weld, press out the cbr stem, machine a bushing (if necessary) for the cb550 stem to fit in the cbr lower clamp, insert cb550 stem in cbr lower clamp and weld the bottom, adjust top clamp to fit the top of cbr stem. That is how I had my fzr/h1 and cb750/cbr trees done (I had to farm out the machine work).
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Offline Tim2005

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #13 on: October 18, 2005, 03:08:32 PM »
Hiya, I'm in the middle of building a monoshocked 400/4 (finishing someone else's abandoned project). It's not impossible... imo the biggest problem is that the monoshock goes exactly where the original airbox, battery, and all the electrical gizmos used to live, so you have to find a tidy way of remounting all that stuff. At the end of it, I doubt it'll actually handle any better than a stock 400/4, but it's an interesting experiment. Oh, one piece of advice which I was given by another special builderages back & has proved worthwhile, do all the building & get it together & ride it, then take it apart and do all the painting and polishing.

Have fun & keep us posted     

Offline cb(r)

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #14 on: October 19, 2005, 07:18:07 AM »
the cbr front end should be pretty straight forward, grind down the bottom weld, press out the cbr stem, machine a bushing (if necessary) for the cb550 stem to fit in the cbr lower clamp, insert cb550 stem in cbr lower clamp and weld the bottom, adjust top clamp to fit the top of cbr stem. That is how I had my fzr/h1 and cb750/cbr trees done (I had to farm out the machine work)


thanks geeto,

I mocked up the front end last night.  the stem of the new tree is about 2 inches (5cm) longer than the old stem.  It is funny because the new stem uses the same threading  for collars and nuts.  it also has the same diameters for the bearings.  any way I had a couple of ideas of changing over the trees
1) I was debating on whether to weld a spacer with a bearing diameter to the top of the bottom tree and use the new stem.
2) cut the new stem of the lower tree and put new threads on the top.  to make it look like the original.
3) do like you said and change stems.
with no. 1 I will run into probs it will bring the new stem lower to fit the collars correctly but the the for will be either pushed up. (look like crap)  or the front end will be higher and defeat the look I am going for.

I like 2 and 3 for different reasons.  no.1 i think i will run into problems  n0. 2 because I do not have mess with welding and alignment issue.  I just have to make a clamping fixture to hold the lowere tree and stem.  no. 3 i like because it is straight forward the old adage of K.I.S.S or  Keep It Simple Stupid  thanks again.I will try to jump my first hurdle

Offline cb(r)

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #15 on: October 19, 2005, 07:27:44 AM »


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   Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #13 on: October 18, 2005, 06:08:32 PM »
   Reply with quote
Hiya, I'm in the middle of building a monoshocked 400/4 (finishing someone else's abandoned project). It's not impossible... imo the biggest problem is that the monoshock goes exactly where the original airbox, battery, and all the electrical gizmos used to live, so you have to find a tidy way of remounting all that stuff. At the end of it, I doubt it'll actually handle any better than a stock 400/4, but it's an interesting experiment. Oh, one piece of advice which I was given by another special builderages back & has proved worthwhile, do all the building & get it together & ride it, then take it apart and do all the painting and polishing.

Have fun & keep us posted     

glad you brought that up about the electrical because I was thinking about cutting the seat section and makethe seat lower and then that leaves me with less room.  hmm delema.  I think a mono shock is still the way to go  I think I am going to hold of until I get this front end under control (hopefully only a weekend project) and then check out the sprocket spacing for my new rear rim and tire.  I will keep ya updated on the swingarm project when I get back to it.  good luck with yours.  keep me updated

Offline ProTeal55

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #16 on: October 19, 2005, 09:04:03 AM »
Make sure to post some pics of your progress.

Seems to be a killer idea for a project..........
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Offline hahnda

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #17 on: October 19, 2005, 12:21:15 PM »
Here is a CB360 that had a monoshock added in.I think he used the stock swingarm and modded it though. Not my favorite color for a bike but it does look interesting.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4582682779

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Offline Egil

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SV: changing to newer swingarm and monoshock. comments or ideas?
« Reply #18 on: October 19, 2005, 01:18:11 PM »
I have this page from a  magazine ( if the tekno is nice) the tekno was not nice at all >:(
got some tekno problems whit the photo   :'(  , ask me for the photo and I mail it to you 8).
If it can help  8)!

« Last Edit: February 05, 2006, 01:05:38 AM by Egil »
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Offline GoatBaSS

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #19 on: October 19, 2005, 03:51:17 PM »
There is a 750 super sport in the old gallery that has the look you lust after. Mighty fine. Good luck.L
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Offline cb(r)

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #20 on: October 20, 2005, 07:17:35 AM »
egil and hahnda,

thanks for the pics guys.  that mono shock look is pretty cool.  better than I had imagined.  well I do not know when I will have pics of my build but I will definitley take some.  I have the front end mocked up and put the rear wheel on but I am running into alignment probs with the rim and sprocket.   thanks to geeto67 I think I have a pretty good plan of attack.  there seems to be a lot of machining in my future.  there is alot of design challenges ahead as well

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #21 on: February 04, 2006, 09:56:50 PM »
I just got a 97 CBR600 rear suspension assembly.  I put a 77 750SS swing arm, that I have because I was going to change to
comstar rims and 78 79 front end with double disc in front and single on the rear, but I want to go modern on my front and rear,
and the swing arm mount seems to me to be VERY similar in side to side measurement but the bolt bearings for the CBR is larger. Can you say DRILL IT OUT.  It is about two inches longer than the stock swing arm as well. It will be a journey for a minimal wrencher.  I have a 03 CBR front end coming and that will be a lot easier.
Plus I WILL BE ABLE TO STOP AN A QUARTER.
  Here are some bike that are badass and what I will be going for.
   

Offline cben750f0

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #22 on: February 07, 2006, 07:24:59 PM »
heres one with a cbr600F3 swingarm...
you are never to old, to act like a kid... be safe
funny thing,chasing someone down hill on a bike 30 years older than theirs..
he said \\\\\\\'it was like watching a 250kg unguided weapon getting stuck up you bum\\\\\\\ http://www.bikepics.com/members/trixtrem/

Offline Egil

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SV: changing to newer swingarm and monoshock. comments or ideas?
« Reply #23 on: February 08, 2006, 09:13:23 AM »
Thats a real racer you have there , it`s superb ;D ;D

Is it your bike , have you more photos , how did you do that , how did you connect the mono shock and the frame  together , ???
« Last Edit: February 08, 2006, 01:26:14 PM by Egil »
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Offline cben750f0

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #24 on: February 08, 2006, 03:43:54 PM »
na its not mine... found it when i was searchin for parts for mine.... looks really understated, if you didnt know better you wouldnt really see it, but a CBR F3 front and rear really sets i off... i think i looks brilliant... anyone know who it is?... peace
you are never to old, to act like a kid... be safe
funny thing,chasing someone down hill on a bike 30 years older than theirs..
he said \\\\\\\'it was like watching a 250kg unguided weapon getting stuck up you bum\\\\\\\ http://www.bikepics.com/members/trixtrem/

Offline KB02

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Re: changing to newer swingarm and monoshock. comments or ideas?
« Reply #25 on: February 08, 2006, 05:21:52 PM »
There was a 750 on ebay a while back that had been built up with an SV650 front and rear (mono shock) end. It looked pretty sweet. It also looked allot longer than a stock CB, but that was probable a matter of making room for the rear suspension.
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