Topic: **Updated 5/20/13** In over MY head 1975 cb550 cafe. thanks...Dave500, Twotired

[Greggo]

if i have any problems ill get another frame!!

I thought you've already figured out that there is a problem   

i also do actually have another frame i havent got round to titling it yet. it was on the parts bike i bought and that frame is actually still good.

Boom!  Get the good frame titled, and use it.

[jneuf]

For real? after all the info you were given above, you're still going to go ahead and use the bent frame?

It's not a matter of building a museum quality bike, it's a matter of safety...

[Syscrush]

Boom!  Get the good frame titled, and use it.

I said it above, I'll say it again.  I don't think that the "good" frame is good, either.

[Greggo]

Boom!  Get the good frame titled, and use it.

I said it above, I'll say it again.  I don't think that the "good" frame is good, either.

I must've missed that. 

[xsmooth69x]

well i have this app on my phone that alerts me everytime any of my search criterias are hit

honda cb
honda cb750
honda cb750f
honda cb550
honda cb550f

anyways i got an alert on my phone and boom!!! 1972 cb750 for $300

called the dude and i rented a home depot truck and picked it up. i called him 11 min after he posted it. got it for 300 and the after that he said he got like 7 phone calls about it when i was driving there to get it (about 45 min)

got a 145 speeding ticket in the home depot truck too that was pretty embarrassing..... wasn't speeding for the bike i was just being stupid 79 in a 60









now theres a couple of catches with this bike.

first there is no title, the bikes owner didnt have one its just been sitting around and it was lost in time..... i can get one of these pretty easy i think but if not ill get a 750 frame with a title i think i can get one around $150

also a spark plug broke off and the owner couldnt get it out but i can 

the bike seems to have an SW air ride suspension in the back with the air things even on the front forks

there was some kind of oil cooler on it too but the oil cooler radiator is missing but the bracket thing that fits behind the oil filter is still there so i could add on or just take that part off

the side covers are great but there is a little crack but u cant see it.

no keys to the bike but no problem another ignition and key is like $10

engine turns over

carbs need to be rebuilt

tires are bad

other than that the bike looks good

cables are all loose, controls are all fine, frame is good, rims are good so ya

muffler needs to be changed too

also he threw in a cb350/450 tank... idk kind of random but ok

so ya that was my project today 

so now i have a 1975 cb550 that im about to finish then the 1972 cb750 whahahahaa (evil laugh)

[xsmooth69x]

ok i found the cause of the bend in my frame









and you can see above the rivet joints on the down tube the top section going to the neck has a slight arch in it. very very subtle then the lower part of the rivets are straight

so that part is supposed to be square but there is a little bulge on both sides

this is my other frame. sorry i took the photos with the frame upside down so try not to get disorientated......

this is my other frame and you can see that it is square







now on these photos u can see the section at the rivet on the down tubes are bent like the tube isent circular they are crimped.

from what i understand they tightened the #$%* out of the tubes to put that front pegs on



this isent to scale but you get the idea

[Greggo]

Very lucky find on that 750.  Seriously.  Don't know about titles in MN, but wow, what a score!

[Syscrush]

ok i found the cause of the bend in my frame

Which one is this?  The known-bad one or the supposedly-good one with "aesthetic" problems?

[Roach Carver]

Your bike, Your neck. That thing may do fine for 45 mph. could develop a  bad tank slapper and put you down on the pavement without warning. if the front end is pushed back that much there is no way that it is square with the back tire anymore.

[xsmooth69x]

silver frame is bad

black frame is unknown

[xsmooth69x]

****Updated and put on the first post for convenience****

so i decided to put together a super newb about the newb questions someone who just bought one of these bikes would ask after lurking and looking at cafe threads and stuff

these are all threads i made for myself

dual disk brakes? simple right? just get a double banjo and another stock caliper and rotor... nope!
http://forums.sohc4.net/index.php?topic=88080.msg989960#msg989960

want to fix some big rust holes in your exhaust....  not possible unless you like a tutorial with a beer can
http://forums.sohc4.net/index.php?topic=88088.msg990019#msg990019

want to have the tron tail light? i figured out an exact clone of the tail light and the fleda tail light
http://forums.sohc4.net/index.php?topic=88085.msg990182#msg990182

want some vintage cafe tire ideas? period correct ones? or modern ones
http://forums.sohc4.net/index.php?topic=88133.msg990598#msg990598
^ also about tire sides
http://forums.sohc4.net/index.php?topic=89729.msg1004641#msg1004641

want to know about different carburetor synchronizer to buy?
http://forums.sohc4.net/index.php?topic=89623.msg1004383#msg1004383

crappy wire harness? build a new one? check this out, it has all the places to buy the vintage connectors too
http://forums.sohc4.net/index.php?topic=89181.msg1000058#msg1000058

about capacitors, wires, caps, plugs etc etc
http://forums.sohc4.net/index.php?topic=89800.msg1005547#msg1005547

about wires and ohms
http://forums.sohc4.net/index.php?topic=89878.msg1006386#msg1006386

front and rear sprocket and chain questions, sizes, where to buy, what brands
http://forums.sohc4.net/index.php?topic=89343.msg1001747#msg1001747

want to get an aftermarket speedo and tach? there are ratios...... read
http://forums.sohc4.net/index.php?topic=90214.msg1009732#msg1009732

broken throttle tube read this, maybe a cool aftermarket one.... maybe not
http://forums.sohc4.net/index.php?topic=90220.msg1009774#msg1009774

do you need that metal tube section on the brake caliper? read this
http://forums.sohc4.net/index.php?topic=90638.msg1013213#msg1013213

dont know crap about polishing different metals?
http://forums.sohc4.net/index.php?topic=90793.msg1014871#msg1014871

starter works but makes a weird noise........ (with video)
http://forums.sohc4.net/index.php?topic=91542.msg1022327#msg1022327

some things to know......

if you use NGK caps you need to unscrew the top section of the spark plug

spark plug gaps are .6 mm

you need 20w fork oil for the forks (i used bell ray)

the motor takes 10w40

great places to buy parts....

www.partsnmore.com

www.bikebandi.com

you would be surprised but www.amazon.com has some great prices and shipping on parts i got a great deal on stem bearings

www.z1enterprises.com

www.bkrider.com

[Syscrush]

black frame is unknown

If you can see or measure any crush or deflection in any of the tubes, the frame is bad.  It may well be repairable, but you need to get it to a frame specialist.

[WarwickE36]

LOL @ http://www.bikenadi.com

[hnsimpson]

Good luck with getting a good frame, man...but do get a good frame.

That's not a risk that I would take.

-simpson

[xsmooth69x]

LOL @ http://www.bikenadi.com

link is broken

what is a frame specialist?

do i take it to like a harley store or some chopper shop?

[Roach]

try a automotive frame specialist.. don't go to Harley or a chopper shop they will probably end up sending to out to a real frame specialist.

[Roach Carver]

just get a new frame. generally you can get one cheap. a frame specialist is going to want a lot more than 100 bucks to straighten your frame. I cant believe we are still talking about this. get a new frame, move along and dont look back.

[Bakeoff]

I just picked up a 76 550 parts bike.  After I used it to mock up my exhaust, I'll sell the untitled frame for $75.  I'm right off 394 and 494 if you want to check it out.  Just send me a PM.

[anotherknowitall]

I have the same forking problem on my 750 you had, looks like new ones is the way to go.  That 750 you got was a good deal.

[xsmooth69x]

I just picked up a 76 550 parts bike.  After I used it to mock up my exhaust, I'll sell the untitled frame for $75.  I'm right off 394 and 494 if you want to check it out.  Just send me a PM.

i will possibly look into it thanks for the heads up.

i do have an extra untitled frame too.

it is good other than some small dents in the front tubes due to the PO putting highways pegs on.

of if that frame is junk to i will for sure take you up on that offer 

[xsmooth69x]

I have the same forking problem on my 750 you had, looks like new ones is the way to go.  That 750 you got was a good deal.

ya new frame it is..... and yes im very happy about my winter project 

ill have a build thread made for that one too. and it will probably be better than this one since ill have all the time in the world during the winter

ive been rushing this build and havent been doing a good job logging everything since i want to ride it so Fin bad

[Syscrush]

i do have an extra untitled frame too.

it is good other than some small dents in the front tubes due to the PO putting highways pegs on.

of if that frame is junk to i will for sure take you up on that offer 

Dents in frame tubes means that the frame is NOT GOOD.

[Bakeoff]

Let me know when you want to grab that frame.  I have to tear a few things off it still, but now that I'm done with my bike, I have a bit more time before getting going on my roommate's 500.

[xsmooth69x]

i do have an extra untitled frame too.

it is good other than some small dents in the front tubes due to the PO putting highways pegs on.

of if that frame is junk to i will for sure take you up on that offer 

Dents in frame tubes means that the frame is NOT GOOD.

sorry man im building a cafe bike im not restoring a cb550 to museum quality. the first frame i can understand because it did really throw off the measurements on the rake of the bike.

on the other hand if i was going to make a cruiser and put on the highway pegs myself i would have had to slightly over tighten them so they wouldnt fall off when im going down the road. i doubt at all that the small marks are ruining the integrity of my frame.

but worst comes to worst ill just buy another frame.

[paulages]

I'm surprised no one else noticed this... maybe the confusion over your bent frame distracted people's attention. The compression numbers you posted are wild, because if I understand correctly, you poured oil into the cylinders to perform the test. Am I understanding this correctly? You squirted oil up your wall out of the spark plug holes??

First, cold compression numbers on these bikes are never 200+. 130 PSI would be a good average. Second, the only time you would add oil to the cylinders on a compression test would be if you had low compression and wanted to determine if it is the valves or rings leaking... a few squirts of oil in the plug holes will temporarily seal leaking rings for the test, which will bump the number up a little if they are in fact the problem. Adding enough oil to squirt across the room when you crank the engine over is significantly reducing the compressible space for air in the combustion chamber and could actually prevent the engine from turning over... or squirt everywhere if the plugs are removed.

Your oil gave you high numbers, and since (I'm assuming) you didn't measure the amount of oil put in each cylinder, the differences between the compression numbers you got are irrelevant. Try again, without the oil.