Author Topic: CB550 Head Shake (Read 4346 times)

jmtuccini · « **on:** September 17, 2012, 10:27:02 AM »

I just bought a 1978 CB550k and realy like it except I cant cure a bad front end shake. I've tried the following:

1. rebalance tire
2. dealer laser balance tire
3. dealer thouroughly inspect whole front end
4. installed progressive springs

Still shakes bad. The dealer said welcome to the 70's, get used to it. I find it hard to believe that this is standard for these bikes.

Can anyone help me solve this issue?

Thanks

jason41987 · « **Reply #1 on:** September 17, 2012, 10:30:59 AM »

check your wheel bearings

jmtuccini · « **Reply #2 on:** September 17, 2012, 10:35:03 AM »

Dealer inspected those too.

Deltarider · « **Reply #3 on:** September 17, 2012, 10:36:26 AM »

Be aware that many front 'unrests' actually originate at the rear.

flybox1 · « **Reply #4 on:** September 17, 2012, 10:46:50 AM »

inspects, and replaced with new (for less than $40) are 2 totally different things

my 38 year old bearings 'looked' new from the outside, but when opened, it looked like something died in there. bearings are always on the list of replacement parts.

did they check for play in the rear swingarm?
true and balance rear wheel? out of round?

when all else checks out, a steering damper can be added for under $30..

steam-powered man · « **Reply #5 on:** September 17, 2012, 10:57:49 AM »

you came to the right place to solve this, and your dealer is a moron btw.

have had a few cb750's, one cb550 -- this is not normal. unless you fiddle with the geometry by dropping the triples down too much these are very stable bikes. and your dealer is a moron, btw.

does your bike track straight when riding? your forks may be twisted in the triples. check 'em out.

get the front wheel off the ground and push/pull the front wheel. should be zero movement/"clunk" at the steering stem. center the bars and nudge them right and left. they should fall to the stops without restriction but not too freely either. replace/adjust head bearings as needed. try to find a bike mechanic with grey hair to help you. your dealer is a moron, btw.

if you're handy with, ah, hand tools download a service manual for your bike from this site. then remove the rear wheel and shocks. attempt to swing the, ah, swing arm left or right. should be zero lateral play. the swingarm should move up/down without restriction but not too freely. replace/adjust swingarm bushings as needed.

replace worn shock upper rubbers as needed. dealer's a moron.

you should have good, recent tires, properly inflated.

more comments to follow, am sure.

strynboen · « **Reply #6 on:** September 17, 2012, 11:13:59 AM »

i put new tires on mine 550...and it runs like a new bike
try to find a mecanic who are same age as the bike..or older

mono · « **Reply #7 on:** September 17, 2012, 11:20:43 AM »

Quote from: steam-powered man on September 17, 2012, 10:57:49 AM

and your dealer is a moron btw.

and your dealer is a moron, btw.

your dealer is a moron, btw.

dealer's a moron.

bwahahhahahahahaaaa

phil71 · « **Reply #8 on:** September 17, 2012, 11:29:20 AM »

swingarm bushings can create a situation like that, but it's probably in the front end.
Before the snark sets in, I'm going to assume this is your first 'old' bike, and maybe even first bike. Taking it to any dealership that services modern bikes will be a frustrating and expensive proposition.
I'm sure you can handle this on your own, and stop giving your hard earned money to someone who's 'guessing' at the problem. You can probably do that on your own for free.
Each fork is held in 2 places by clamps so they can't 'rock' independently. A crack in , or loose bolt on one or more of these clamps will create what your feeling, but so will a really old tire.
You don't say if it's constant, or happens at a fixed speed , or wether you can 'ride through' the wobble till it gets stable again.
I'm not suggesting you ride dangerously, but a little more info can help some of us to point you in the right direction. Also, lets see the ole girl!

jmtuccini · « **Reply #9 on:** September 17, 2012, 11:57:57 AM »

Truly appreciate all comments and will be checking everything as recommended.

Not my first bike but is first old bike.

Dealer is my KTM dealer but has been around and sold bikes for ever. He wants me to buy a new KTM so has bad attitude towards this bike. His son loves the Honda though. Moron is a very fair assessment in this case though! I will be sharing that with him!

Tires are very new.

It happens at all speeds just gets annoying the faster you go. It is the feel of an unbalance tire. Up and down, not a left to right wobble.

I will post a picture of her and list of mods and future plans. I really like this bike and would like to see it last another 35 years.

jmtuccini · « **Reply #10 on:** September 17, 2012, 12:15:30 PM »

Had a pic on the phone.

-new bars
-dime city cycle- speedo and tach, bar end mirrors, fork gaiters, tail light and blinkers
-new progressive fork springs and rear shocks
-brought in stock rear fender

-Looking to do a a slimmer seat and probably raw metal or new paint job on tank after I fix the dang head shake!

phil71 · « **Reply #11 on:** September 17, 2012, 04:18:51 PM »

Whoa. What size tire is that on the front?

jmtuccini · « **Reply #12 on:** September 17, 2012, 07:16:17 PM »

I think it's a 100. Just looks really big from camera angle.

seanbarney41 · « **Reply #13 on:** September 17, 2012, 07:38:29 PM »

Quote from: Deltarider on September 17, 2012, 10:36:26 AM

Be aware that many front 'unrests' actually originate at the rear.

+1, it's not intuitive, but the only thing that has ever made my bike do a similar shake is a dirty, bound up, worn out, or mis-adjusted chain/sprockets...I can't promise you the chain is the cause, but it is one more thing that you need to check

Tews19 · « **Reply #14 on:** September 17, 2012, 07:51:31 PM »

Nice looking bike. Never take the advice of a shop.... Contact them to ask how much fluid they put in when rebuilding your forks. if they say what Honda recommends, I would question how much is that... But red flag is always when they say what the manufacturer states yet can not tell you how much that is... Maybe the rim is trashed. Even though it can look pretty, may not be good.

brooze72 · « **Reply #15 on:** September 17, 2012, 08:10:57 PM »

Quote from: steam-powered man on September 17, 2012, 10:57:49 AM

you came to the right place to solve this, and your dealer is a moron btw.

does your bike track straight when riding? your forks may be twisted in the triples. check 'em out.

get the front wheel off the ground and push/pull the front wheel. should be zero movement/"clunk" at the steering stem. center the bars and nudge them right and left. they should fall to the stops without restriction but not too freely either. replace/adjust head bearings as needed. try to find a bike mechanic with grey hair to help you. your dealer is a moron, btw.

+1 Good advice here, IMO usually steering bearings. Others mention wheel balance but I have found that is usually at a certain speed, speeding up or slowing down will lessen the symptoms if that is the issue. Good idea to check fork fluid, but I have ridden with low oil in 1 fork but didn't experience any head shake.

brooze72 · « **Reply #16 on:** September 17, 2012, 08:11:54 PM »

PS Very nice looking bike.

jmtuccini · « **Reply #17 on:** September 18, 2012, 06:06:12 AM »

Thanks guys. Valuable advice.I'll be busy this weekend running through everything mentioned.

MoMo · « **Reply #18 on:** September 18, 2012, 06:29:54 AM »

Old hard tires can cause that sensation. Get if fixed before you experience a tank slapper. BTW your dealer is a moron---(steam powered man's post was hilarious)...Larry

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Author Topic: CB550 Head Shake (Read 4346 times)