Forum

[Clement]

Bullet comrades

I worked my way through all the recent comments re wheel alignment. At moderate speeds, quickly pulling the handlebars towards and away from me, my old thumper produces a real wobble and shake - more than I have experienced on other bikes; I re-checked the wheel alignment by the string method with strings as high up under the centre stand as I could get it; all seems to be okay aligned; I then tried, with some trepidation, the hands off method at around 50 mph (without additional texting thrown in). To my surprise the bike was extremely steady, neither pulling to the right nor to the left. I have at the moment a fairly large American chief style seat - wonder if this (for a Bullet) oversized seat is partly to blame for the unnerving wobble effect mentioned above.

[Gwilly]

Maybe steering head bearings need adjustment or replacement...

Put a 2x1 under the centre stand to lift the front wheel clear of the ground.

Stand astride the wheel and try pulling and pushing the front forks..

Any undue movement or knocking noise requires attention..

[Clement]

Thanks Gwilly; I put 2 blocks of 4*2 under the center stand which lifted the back wheel; then a heavy battery on the rear carrier which lifted the front wheel; no play in the forks so steering bearing seems to be okay. Back and front wheel bearings also okay: no side shifting in the vertical plane.
By the way,with pulling the handle bars towards me I mean just quickly pulling say the left handle bar towards and away from me; there is just too much wobble; I wonder if the new (but soft) Indian springs on my large chief style seat are to blame......?

[PeteF]

"By the way,with pulling the handle bars towards me I mean just quickly pulling say the left handle bar towards and away from me"
I would have thought that would be a very good way to get a big wobble.

[Clement]

matter of degrees Pete - Bullet seems to jump around a lot more than my previous bikes; if there are no complaints about the indian springs or bigger saddles then I have just to learn to live with it.

C

[Dennis C]

Pulling or pushing the bars like that is "counter steering" and a well known way to make any bike change direction very quickly. "Makes the bike wobble", why am I not surprised?.

[jefrs]

Wot DennisC said, yes! - pushing one side of the bars will make the bike drop quickly into a bend that side. Feathering the rear brake with the power on will make the bike drop further into the bend, which is useful if you've over-cooked entry to the bend.



Imo the induced wobble is basically old bike design with upright riding position, if we put more of our weight over the front, ace bars and rear-sets and lie on the tank (ouch), it doesn't do it nearly as much. Part of it is short wheelbase, a heavier bike with a long wheelbase has less sensitive steering response, a short wheel base can change direction quicker.

The later C5 does have revised steering geometry, trail and rake. I've tried waggling the bars, the bike shimmies like a fish but doesn't do anything peculiar, and stops wobbling as soon as I stop waggling the bars..



I've substituted solid brackets in place of the springs on the C5 solo seat to lower it, a side effect is that the disconnected pogo-wibble sensation went away, I feel far more connected to the bike.

[Mark B]

What are the other bikes you are used to? The first time I rode a Bullet I nearly fell into the first corner I came to because the steering seemed so light and direct after the Ducati which I had at the time - you really had to boss that around and tell it what to do. The faster you go, the more a bike will try to stay upright because of the gyroscopic effect of the wheels, hence the need to countersteer. Although I'm not sure why you'd try to induce a wobble...

[Clement]

thanks for the comments; have a better understanding of the mechanics causing this feeling of "disconnectivity" ...... so not the springs at all;

C

[jefrs]

MarkB - me, I learnt on old british bikes, knackered ones not pristine restorations. So getting on a bullet again was like coming home. So much so that I still keep trying to change gear with the brake pedal. Yes they are rather different to a modern sports bike, not as precise but personally I find the set-up far more forgiving if you make a mistake.