Topic: 1975 CB550K1 - Stock-ish Restomod - More Mods

[SOHC4 Cafe Racer Fan]

Is it possible maybe the wheel itself moved on the rim?

Seriously doubt it.  No burn outs or rear lock ups to torque it.

[Tews19]

Is it possible maybe the wheel itself moved on the rim?

Seriously doubt it.  No burn outs or rear lock ups to torque it.

WEAK! Just playing!

[SOHC4 Cafe Racer Fan]

I guess I didn't catch the tire trueness comment and thought you were referring to the wheel. 

So does anyone have any real suggestions.

[nvr2old]

I had a couple of questions that may stir up a hopeful solution..

I read back through an earlier post that said you took it out for 5-6 hrs. and rode it pretty hard.  Did it display the shake then..?  Does it happen only in a straight line?  You also mentioned it was a little unsettling going into corners.  Is that at slow speeds or fast sweepers?  Could it be something as simple as a slightly over-tightened steering stem nut?  Just throwing things out there..

[SOHC4 Cafe Racer Fan]

Good questions and suggestions.

The hard riding was in twisties and I don't recall having the wobble.  Only on the straights and on the freeway.  The unsettling was a corner or two where the pavement was rough and I lost some traction on the front end.  I am not entirely positive but I think the wobble is coming from the rear.  I'll check the tension on the nut, too.  Thanks!

[bwaller]

Are the wheels aligned? A weave can start from a tight or loose steering stem. After installing often times they will need to be retightened a couple times. Are the shocks longer than stock, front end taller or shorter than stock? Spokes tight, tires seated properly, pressures correct? No fairing of any kind?

Did you have the S/A bushings made or did you buy them from a supplier? Some bushings tend to be slightly oversize. If I may I would suggest a different solution to torqueing the swingarm pivot bolt. With the shocks & wheel removed, and the pivot well greased, lift the arm to full travel top. Tighten the nut until the arm drops slowly (smoothly) under its own weight to the bottom of the travel. Often I found this method takes a bit more torque than Honda recommends.

Good luck, you'll find the cause.



 

[SOHC4 Cafe Racer Fan]

Are the wheels aligned? A weave can start from a tight or loose steering stem. After installing often times they will need to be retightened a couple times. Are the shocks longer than stock, front end taller or shorter than stock? Spokes tight, tires seated properly, pressures correct? No fairing of any kind?

Did you have the S/A bushings made or did you buy them from a supplier? Some bushings tend to be slightly oversize. If I may I would suggest a different solution to torqueing the swingarm pivot bolt. With the shocks & wheel removed, and the pivot well greased, lift the arm to full travel top. Tighten the nut until the arm drops slowly (smoothly) under its own weight to the bottom of the travel. Often I found this method takes a bit more torque than Honda recommends.

Good luck, you'll find the cause.

Brent.
Thanks for all of the ideas.  Now for the process of elimination.  I'll get to checking the pivot.

The bushings were sourced from a legit supplier.  They went in normally -- nuts and washers method.

[SOHC4 Cafe Racer Fan]

So I rode the bike yesterday and notice another distinction.  The wobble/oscillation only seems to occur on grooved freeway pavement, and not on asphalt.  My 750, however, doesn't do this.

[bwaller]

Very likely different tires.

[Retro Rocket]

Very likely different tires.

I agree, some tires track lines and grooves way more than others, thats where those crappy Firestones really fail...

[Tews19]

That's normal if I'm thinking of the same road distinction. Lately around here the highway and more driven on roads have these like 1/2-1" creases. You can hear the pitch of the tire humming more as well on these newer roads.

[SOHC4 Cafe Racer Fan]

Interesting. 

I run Avon RoadRiders on my 550.  Bridgestone Spitfires on my 750.  I am planning to replace the Spitfires for something stickier.  The Spitfires feel like I'm riding on hard plastic hoops -- lack of feel in the corners, but no wobble.  I was thinking of swapping to the Avons, since they have better feel, but maybe I should try Bridgestone BT45s instead.

I'd be better off oiling up my tires than using Firestones in corners!

[Tews19]

I've used BT45s on a few CB's. I really like them and will continue to use them. I did however only get 5500 miles out of the rear. The middle is worn bad and I don't do burn outs.

[SOHC4 Cafe Racer Fan]

I've used BT45s on a few CB's. I really like them and will continue to use them. I did however only get 5500 miles out of the rear. The middle is worn bad and I don't do burn outs.

I don't mind so much about getting a ton of miles out of them, as long as they give decent traction.  I'm not used to getting a huge number of miles on my sportbike tires S20s.

[Tews19]

They have plenty of grip/stickiness. I ran Dunlop 404s and the BTs are much better imo.

[SOHC4 Cafe Racer Fan]

Damnit!!  Base gasket leak!!   

I'm going to swap to APE HD studs.  Hopefully, the extra torque will create a better, lasting seal.   

[SOHC4 Cafe Racer Fan]

No.  This is an original base gasket.  Have only changed the sump gasket and rotor gasket.

[Lostboy Steve]

Interesting. 

I run Avon RoadRiders on my 550.  Bridgestone Spitfires on my 750.  I am planning to replace the Spitfires for something stickier.  The Spitfires feel like I'm riding on hard plastic hoops -- lack of feel in the corners, but no wobble.  I was thinking of swapping to the Avons, since they have better feel, but maybe I should try Bridgestone BT45s instead.

I'd be better off oiling up my tires than using Firestones in corners!

I had the Spitfires. Now I have the Sport Demons. I like them a lot better. Not that the SF wasnt sticky but these are far superior and look nicer.

[seanbarney41]

No.  This is an original base gasket.  Have only changed the sump gasket and rotor gasket.

no reason not to try torguein' her down a little more

[goldarrow]

I torque down to 18 lbs

[SOHC4 Cafe Racer Fan]

I torque down to 18 lbs

On stock studs?

[goldarrow]

I torque down to 18 lbs

On stock studs?

Yes. Manual tourqe specs if I recall correctly is between 16-ish to 18-ish.  First time torque down to about midway, leak after 1000 miles.  Retorque to upper limit, leak magically disappeared.

[SOHC4 Cafe Racer Fan]

I torque down to 18 lbs

On stock studs?

Yes. Manual tourqe specs if I recall correctly is between 16-ish to 18-ish.  First time torque down to about midway, leak after 1000 miles.  Retorque to upper limit, leak magically disappeared.

I've heard you can torque down to 18.5 with APE studs but didn't think you could go up to 18 with stock studs.

[goldarrow]

Sorry about the numbers I posted earlier.  Specs in the manual is between 14-ish and 16-ish.  I went with lower number.  I did retorqe to 18, or close to it though.  Dave500 also suggested in my bulid thread

go a little higher final torque,like 16-18,you wont need to retorque,yeah turn the engine over a few times to make sure theres no binding or valve to piston smash,plenty of oil down the bores.

double check your cam timing marks,and make sure the ignition is set up correctly,it must fire up first time and dont let it idle,blip the throttle untill its warm enough to ride,youll have to vacuum sync the carbs once its run for a little while,change the oil after the first tank of fuel.

[SOHC4 Cafe Racer Fan]

Cal,

Thanks for the tip.  The head was re-torqued a second time (way before) when I replace the head gasket to eliminate a leak.  Will try again, but if that doesn't work I think I'll be pulling the stock studs, and using the APE HD's I previously purchased.

Does anyone know for certain the specs for the APE studs?