Topic: Wobbly front wheel at stoopid low speed - brake?

[Gene]

Ladies and Gentlemen,

I have this "wobble" going on at extremely low speeds, literally creeping into a parking slot.  It usually happens when I am turning the wheel to the right at like - 1 mph. Wobble wobble wobble.  Almost like a wobble-shake.  The front brake is fine, I've never messed with it - but it can become squeaky, typically after I've topped off the fluid.

Do I need to bleed the line and maybe mess with the puck/disc/whatevah?  Curious if this is common, which I think it may be.  Never any shaking/jiggling/wobbling at speed, and never when I'm leaning into a turn.  typically only when I'm totally upright (perpendicular to the ground) and twisting the bars to the right.

Any info is helpful.  Don't think it's dangerous, I'd just like to make sure it's not a big issue and maybe fix that squeak when I have full reservoir.

Thanx.

[goldarrow]

How old are the steering bearings?

[ekpent]

Brake,wheel bearing or steering bearings. If it feels notchy when turning on the center stand the steering bearings are shot or need grease. Front brake is fairly easy to clean/service and should be done anyways periodically. On the center stand turn the front wheel slowly and look for an anomaly.

[trueblue]

Headstock bearings that are too tight will do just that, tapered bearings are the worst for it as they can handle more preload without becoming notchy.

[oldhatt45]

Gene,
You might also look at the axle clamps.  Make sure they are on correctly (any space should be to the rear).
What shape are the front wheel bearings in???  Replaced recently?
You don't say what kind of tires you are running.  I seem to recall there was something about tires that might cause a wobble.
(Not 100% sure on the tire thing.  I maybe having a senior moment on that.)

Hope you find the cause.

Charlie

[70CB750]

Front tires on the end of their life span could do that.  How many miles on the tire?

[Stev-o]

Only does it at 1 mph? Ride faster!

Just kidding, the guys gave you good suggestions above to check.

[HondanutRider]

Front tires on the end of their life span could do that.  How many miles on the tire?

Cupped tires (even very slight) can cause a wobble at slow speed.  This  the common complaint of heavy bikes like the latest Goldwing model, which causes the front tire to wear with a cupped profile.  The cupping occurs on the outer edges where the running weight on the tire causes the outer edges to squirm and wear unevenly.  Although not really that heavy, perhaps your CB750  been run with low tire pressure that allowed the front tire to start squirming and cup.

[Gene]

Thank you gentlemen.  The tires are a year old, bridgestones. Wheels were balanced when I changed the tires. The bearings (all) quite probably date from 1975. I have never replaced them.

I'll check everything suggested and prepare myself a more reasonable maintenance schedule on those bearings.

Thanks again.

[Retro Rocket]

Thank you gentlemen.  The tires are a year old, bridgestones. Wheels were balanced when I changed the tires. The bearings (all) quite probably date from 1975. I have never replaced them.

I'll check everything suggested and prepare myself a more reasonable maintenance schedule on those bearings.

Thanks again.

If its bearings, get on to it straight away, if that wobble manifests itself at 40, 50, 60 MPH you'll be changing more than your bearings....   Been there, done that....

[Gene]

Yikes Retro! 

Steering bearings seem in good shape - smooth, no freakiness, I need to check the front wheel bearings - no time this weekend.  No cupping or uneven wear on the tire.

So it's down to the wheel bearings or the front brake, which has been an issue since I picked this bike up a little over a year ago (just little stuff, nothing major like my 360 w/seizing - never again - carry a rubber mallet just in case).  She stops fine, but there's some quirk in that area.

Thanx again, fellas.  I've dodged some major old-bike bullets (chain coming off at speed, melted points, ah the list goes on) but the last thing I need is for the front wheel to lock up or fall off.  That's the sort of thing that keeps one up at night.

Until next,
Gene

[Gene]

I never finished this, turns out the tire pressure was simply too low in the front.  Happened again, pumped up the tire (tyre for you Brits and Aussies), no prob. Didn't want to leave this hanging in case someone else comes along.

Still need to repack the steering bearings tho, just on the verge of notchy.

[Stev-o]

What pressures you run, Gene?


I had a little shimmy on my 550 last week.  Checked pressures, and they were a little low. 
Pumped em up and no shimmy yesterday on a ride....

[Gene]

I actually try to go around 36-38 rear 39 front.  That is approximate.  I wear BT-45s which call for 41, but they're meant for tubeless rims, so basically I try to mitigate the difference between the  manual and the tire specs.

Am I way off?  Please let me know.  It hasn't been a major issue, but it would be nice to dial it in.

[ekpent]

 If you feel any notchiness in the steering bearings then the race is probably already shot. For 25 bucks or so those roller bearings are a very nice upgrade if your in there with it torn down.

[Lostboy Steve]

My front rim was never perfect from the factory. Where the seam is has a pretty crazy run-out that spoke tension wont fix. I just live with it. Eventually I'll have to get another rim. Funny, that a rim of that quality would slip through the cracks. By the time I noticed it on the truing stand it was already powdercoated and I wanted to ride...

[Stev-o]

I actually try to go around 36-38 rear 39 front.  That is approximate.  I wear BT-45s which call for 41, but they're meant for tubeless rims, so basically I try to mitigate the difference between the  manual and the tire specs.

Am I way off?  Please let me know.  It hasn't been a major issue, but it would be nice to dial it in.

I run the same pressures.  Most think 32 is the majic number but is wrong. 

[seanbarney41]

I actually try to go around 36-38 rear 39 front.  That is approximate.  I wear BT-45s which call for 41, but they're meant for tubeless rims, so basically I try to mitigate the difference between the  manual and the tire specs.

Am I way off?  Please let me know.  It hasn't been a major issue, but it would be nice to dial it in.

I run the same pressures.  Most think 32 is the majic number but is wrong. 

+2

[Gene]

If you feel any notchiness in the steering bearings then the race is probably already shot. For 25 bucks or so those roller bearings are a very nice upgrade if your in there with it torn down.

I intend to tear that out - replace with the tapered bearings (study first - sounds like the right thing to do though).  And, at the same time - I need to have my rims relaced with stainless spokes, so at that point I'll do the wheel bearings too.  I know I'm probably on borrowed time with a lot of this stuff, but, it'll get done. 

Until joining this forum I was a points, plugs and oil guy.  I can't thank you all enough.

I still need to add my blog here "Confessions of a daily rider: Commuter maintenance on a budget"

[scottly]

I actually try to go around 36-38 rear 39 front.  That is approximate.  I wear BT-45s which call for 41, but they're meant for tubeless rims, so basically I try to mitigate the difference between the  manual and the tire specs.

Am I way off?  Please let me know.  It hasn't been a major issue, but it would be nice to dial it in.

Stock specs are 28 front, and from 32 to 40 in the rear, with the higher pressures for higher loads, such as a passenger and luggage. The tire sidewall rating is a maximum pressure, and has nothing to do with the recommended pressure from the vehicle maker.   

[seanbarney41]

and the recommended pressure from the vehicle maker probably worked great for the tires the bike came with...fortunately, those tires are not made anymore

[scottly]

Why would today's tires require more pressure? Anything over 32 pounds in my front tire and I can feel the paint on the road at crosswalks.

[BomberMann650]

In an odd turn of events, bloo developed a wobble after I put the rising sun slicer on. 
I also changed the brake pads at the same time.
Tire was overinflated some, and I went searching for a long straight edge verify rear wheel alignment.  Still searching...
340mm shocks hadn't caused a wobble before.  Even doin the ton down a lonely farm road.
The only noticed the wobble when I took hands off the bars to adjust a glove.  As she decelerated below 40mph, It began.  So I gave up on adjusting that glove right away!

I have fork seals and head bearings waiting to go in.  I had hoped to find a headlight bucket before tearing the front end down and do it all at once.

Is there anything else (beyond lack of steering damper) that I should look for?

[jonda500]

Since the eighties I have run 30-32psi in the front and 34-36psi in the rear, have never heard of using 40 in the front??
Low pressure in the front tyre makes my bike want to stand up right and reluctant to lean,
John

[BomberMann650]

My gs-11 front had 41psi cold stamped on it