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

[TwoTired]

how do the forks bend like that?

Hitting an immovable object.

the bike does not seem like it was in a wreak. there is no dents on the rim. how do the just contort?

Assuming the bike was in an accident, it may have had an attempted repair.  Parts could have been replaced to make it drivable, or appear to be drivable.
How do you know it is the original rim?
How do you know they are the original forks?

My biggest fear with that bike is that the whole front end was replaced and the headstock is still bent which changes the rake angle and possibly puts a twist in the head stock, too.
I'm not at all certain what all the driving repercussions will be from reducing rake angle; likely quicken the steering, the bike will be less stable at high speeds and increase the likelihood of head shake, even a tank slapper.

If the headstock is twisted, the front wheel won't track like the rear as the wheel vertical angles will be splayed.  You should be able to check that with a square, and with the wheels mounted to the bike.

Look at the frame down tubes from the side and put a straight edge against them.  They should be straight (must allow for the upper frame "sleeve").

The pics below are from my "parts" bike 75CB550K.  Frame is definitely bent.  When all my other projects are done (HA!), I might take a crack at straightening this one.  Fortunately I have others to compare it to.

[jneuf]

I noticed in the first pic of the bike you posted that the bike looked really short...good spot by TT! Hopefully it's nothing major.

[xsmooth69x]

ok took the forks off but i still have no idea what im looking for.

their are no crumples on the frame or anything and everything else looks fine.....



















fork 1









fork 2

[xsmooth69x]

ok i checked out the frame i hope this is good.....









some others

[TwoTired]

The down tubes look bent to me.  They are convex with your straight edge.

Since you are taking it apart, check out the headstock bearing races and how they fit in the frame.  Check if it's oblong in there.  Top and bottom.
I expect the whole front end was replaced.  But, to check the fork tubes, roll them on a flat surface.  I use my cast iron table saw top.

I know you're in disbelief.  It's going to be tough to restore.  You can just ignore me if you want.
Best of luck with whatever you decide!

[xsmooth69x]

no way twotired you an invaluable commenter. this is what i need and why i came to this thread.

i will take apart the shocks and roll them on my pool table (with some paper  )

worst comes to worst ill just replace them. there are plenty laying around the junk yard. i might even make them replace it i bought the bike with "no major defects" thats a pretty big F'in defect if you ask me.

[xsmooth69x]

so as of now im completely stuck......

i can not remove the hex bolt on the bottom of the forks to separate the top from the bottom...... i fear that if i do it more i will strip out the hex bolt.....

what should i do?

i have literally taken a hex key in the right size and attached a breaker bar to it. it will not let go.

is there some magical tool im supposed to use?

[TwoTired]

is there some magical tool im supposed to use?

An air impact driver.

[MasterChief750]

they can be super hard to get out. i have a giant scar on my finger from doing it. i put the top tree on the tube to keep it from rolling and i put al my weight on it and it finally gave. an impact wrench/driver would work well in this case

[xsmooth69x]

ya i mean i torqued it hard with a breaker bar and i had them on the top tree mount too. the thing is the screw is getting stripped out

[fastbroshi]

A little heat on the fork leg, and an impact driver usually does the trick for me.   About those forks, how long are they?  They look too short.  Considering the seat is from a CB500 twin (I think),  chances are they pilfered other things from different bikes. 

Or maybe the forks are dry?  No oil will cause them to compress down and appear too short.

[xsmooth69x]

looking more into the front forks i really dont think there bent......

i slide a yard stick over the top fork tube slowly and there is no arch or bend..... swear to got i sat there for an hour.

im thinking the same above.... these forks might not be the stock forks???

i was able to take the top bolt off and drained out all the oil and took out the springs. thats pretty much as far as i got since i cant get the bottom hex bolt out.....

i dont think i can stick the forks in the microwave to heat them up.... and i dont own a acetylene torch......

is there any way to identify if my forks are the stockers or off something else?

[fastbroshi]

   The lowers look like Honda items, but not sure if they're different from a 70's CB500/550 four.  How much oil did you drain from that leg?  Did you drain both?   
   Back when I didn't know any better I drained one leg on mine and the front end dropped down nice and slow, I barely caught it before it fell over! 
   That said, my second 550's forks were pretty dry and they didn't sag that far.  Maybe they have the wrong springs...  Might have to disassemble everything and inspect.  Even if all your components are correct, you probably need to rebuild them anyway. 
   And you don't need anything as hd as an acetylene torch, a small bottle torch from Lowe's or Home Depot will do the job. 

[xsmooth69x]

heres some more pics if it tells anyone anything

forks are fully extended







see the hex bolt is messed up.... im afraid anymore will have irreversible damage.

[xsmooth69x]

other than this hiccup with my front end i made some more progress

heres some parts i had to get from the bone yard



i spent $117 <----- bought with store credit of $150 with the purchase of my bike

1 carb                                 $50 (not pictured)
throttle cable                       $10
exhaust sleave things 2x for $10
speedo cable                        $10 (not pictured)
rubber seats for the tank      $10
flasher with rubber craddle    $5
misc tubes (all for the carborators, they where in good shape) $5
air box boots                       $10
                                           $7 tax

so now i have 4 happy rebuilt carbs 



now my pride and glory the 2hrs of searching....... my new tank!!











not that much rust on the inside and not to many dents and the gas latch works perfect. the gasket even looks good.

i got to swap out my crappy tank for another one i found for free (i kept the petcock off my old tank and took the one with this tank  )

[xsmooth69x]

   The lowers look like Honda items, but not sure if they're different from a 70's CB500/550 four.  How much oil did you drain from that leg?  Did you drain both?   
   Back when I didn't know any better I drained one leg on mine and the front end dropped down nice and slow, I barely caught it before it fell over! 
   That said, my second 550's forks were pretty dry and they didn't sag that far.  Maybe they have the wrong springs...  Might have to disassemble everything and inspect.  Even if all your components are correct, you probably need to rebuild them anyway. 
   And you don't need anything as hd as an acetylene torch, a small bottle torch from Lowe's or Home Depot will do the job.

the amount of oil that came out of both are maybe half a quart between the two.... it was a weird purple color smelled rank too

[fastbroshi]

  Nice tank.  Kinda GB500-ish with those pinstripes.  Are you sure you used the correct size allen bit?  If you used the hand wrench, that was your problem.   With those allen bolts, if you EVER encounter resistance past hand tight, you need to used a bit designed to be used with a ratchet at the least. 
 
If you've determined what the correct size bit is, maybe 5 or 6mm, you may still be able to get it out with heat. 

Put the fork lower in a vise, and hold that torch up to it and warm up all around until your spit sizzles on it.  Then if you've got an impact use it.  It's the only thing I'll use on them now.   Others have used a broomstick shoved into the fork lower, but if the fork lower is super hot that's going to be more difficult. 

If someone has some CB550 forks not installed and they wish to chime in, we'll know more.  And that actually sounds like too little oil. 

[xsmooth69x]

ya it does not seem to be factory paint. so someone must have painted it that way.

im going to sand it completely down anyways.

there is not a diff between a 500 or 550 tank is there...... swear it was the same size as my original tank.

i used an 8mm hex..... it fit perfectly

ill get a torch and try it again. hope it gives

and ill grab a replacement bolt for it too at the bone yard

[Oddjob]

so now i have 4 happy rebuilt carbs 

Looks like you've made a minor mistake on the carb rebuild.
Bottom carb is clearly No1 cylinder as it has the choke lever on it. Top left looks like No2, middle top No3 and top right No4. However it that is correct it looks like you've fitted the float bowls from No2 onto No3 and vice versa. The drain plugs on the bowls always point outwards so No1 and No2 should point to the left of the bike and No3 and No4 to the right, can't see No1 due to shadow but as No4 is correct it must be ok.
Also make sure the new carb has the same stamping number on the body as the rest, IIRC it's on the front where the inlet rubber connects on the small webbing just above that area. The number must match the original carbs, there are carbs which look identical to yours but aren't off the same model, CB500 carbs are a prime example.

As for the fork problem, I seem to recall when I was a Honda mechanic in the 70s and 80s that the damper rod at the bottom of the fork sliders which the allen bolts screws into has a 17 or 19mm bolt shape in the crown of it, I do remember using an engine bolt which was welded to another to hold this in place whilst someone else removed the allen bolt. Even with air guns sometimes they used to spin in place, I may be wrong on this and it may have been later Hondas I used that trick on, not having any spare forks in pieces right now I can't say for certain but if anyone can check they'd be able to tell you. You may have to use the broom handle trick if I'm wrong or if that fails to work you could drill off the head of the allen bolt and remove the rest when you have the damper rod out of the slider.

[Bakeoff]

Another Minnesotan with a 550!

Check out my build thread.  http://forums.sohc4.net/index.php?topic=81214.0 
I saw you bought a throttle cable.  Too bad, since I'll be replacing mine with a shorter pair once it goes back together.

If you need a hand with the forks, give me a shout.  I'm right over near Ridgedale Mall in Minnetonka.

And honestly, I'm surprised you got a deal of any sort out of Sport Wheels.  That place is...a huge headache. Over priced, sitting on a gold mine of parts that are slowly rotting into worthlessness.  Finding a clean tank there is like finding a unicorn in the back seat of your car. It just doesn't happen. lol

[zedteamk2]

In regards to the stuck Allen Bolt.
I had good luck on my yamaha using an impact wrench and a Torx bit that fit nice and snug.
The allen wrench would just slip, but the Torx bit into it.
You definitely need the impact wrench for this method.
I got one cheap from harbor freight.

[Bakeoff]

I've seen way too many allen bolts stripped out with torx bits. I'd only use it as a last ditch effort, making sure to pound it in.  Cause after that, you're drilling it out.

[xsmooth69x]

ya i love impact wrenches but i use them as a last resort too. idk maybe its my lead finger but i usually end up stripping things out.

im going to try the blow torch and nicer tools.

[xsmooth69x]

Another Minnesotan with a 550!

Check out my build thread.  http://forums.sohc4.net/index.php?topic=81214.0 
I saw you bought a throttle cable.  Too bad, since I'll be replacing mine with a shorter pair once it goes back together.

If you need a hand with the forks, give me a shout.  I'm right over near Ridgedale Mall in Minnetonka.

And honestly, I'm surprised you got a deal of any sort out of Sport Wheels.  That place is...a huge headache. Over priced, sitting on a gold mine of parts that are slowly rotting into worthlessness.  Finding a clean tank there is like finding a unicorn in the back seat of your car. It just doesn't happen. lol

dude you have a sweeet build and you have so many bikes 

well i guess im just a mean person when it comes to negotiating for $$$$

i make sure to get prices off ebay and other websites for the parts i need before i go there. then i #$%* about how its cheaper on fleabay and i dont have to pull the parts myself and that giving everything X amount of dollars cheaper saves them money for not having to post or pay shipping and im still pulling parts. also when i bought my bike i pointed everything and its mother out wrong with the bike.

i try and deal with the lady at sports wheels idk maybe she just thinks im cute becuase she pretty good on giving me prices. thier daughter is kinda hot too and its her families junk yard...... could you imagine the inheritance  and she actually knows stuff about motorcycles which just give her another +1

finding that tank though it was nuttz but when i found it i #$%* you not the skies opened up and a beam of light came down and pointed it out. it was crazy

[Bakeoff]

The last time I went there was last summer and the yard seemed bare of anything worth any value.  It was just broken wheels, rusty frames, and deteriorating seats.  Have they collected a bunch more?  Wait, daughter?  Probably too young for me anyway.  lol

I have two roommates, so the bikes aren't all mine.  There's also an old Yamaha being added to the garage and a Honda scooter in the shed.  I'm running out of room fast!  At least I own the house, so I can tell them to go to hell.  lol

What area are you in?