Steering head bearings

[OB_terra1]

I took my Busa to the large, high volume dealer who sold it to me. After taking off alot of weight, mostly off the front, the front end started to wander off line and get really vague out of corners under power, or sometimes just under power in a straight line.

I took it to a speed shop that's been doing the exhaust, etc. mods, and they said the steering head bearings were ridiculously loose, three quarter turn out from tight, and would respond differently in every corner as they took a different set.

So...I don't know what happened to Frank, but at 100+ under acceleration, the front end becomes disinterested in rider input.

Check 'em out. If you jab the brakes at a stop light and hear a knock, they're probably loose. Don't assume your're dealer has a clue, you don't want to find out the hard way.

 

[OB_KawAbuser]

Terra how did you remove weight from the bike, and where just from the front end?

Exactly how did you achieve your weight loss.

 

[OB_terra1]

Kawa: I know exactly how much, but unfortunately, not exactly where, because the shop lost the breakdown sheet!

Pretty standard stuff:

- Akrap ti/stainless pipe
- Dymag cast mags
- 86 smog pump/plumbing
- 86 fan [near 10 lbs]
- took off reflectors, little crap [6lbs!]
- Dunlop 207GPs - ran 'em 300 mi. on mountain roads, 170mph on highway, they stick great, save @ 2lbs
- grab handle [2lbs]
- shave/drill rear disk [4.6lbs - see Trick Brake thread

The bike is transformed -- immediately obvious just pulling it off the sidestand.
I also dropped it 5mm in triple clamps to shift weight forward, it worked well but the overall handling difference is so unbelievable that I'm going to keep going and end up having to revalve/spring the front [again - but it's worth it]. Ohlins rear increased ride height 1-2 inches.

Next move: I have a line on some ceramic/alloy matrix 320mm discs that weigh 70%+ less than stock, real poundage. Along with ti bolts for the carriers, and whatever else I can think of [or afford -- any idea where I can get a reasonably priced ti axle?] I may have a front end I can really trust. Did some serious trail braking this weekend, the front is already good.

 

[OB_KawAbuser]

Terra, have you gone beyond changing the fork springs with the forks?

Did you weigh the whole bike before and after you changes? Any thoughts on weight distribution changes, stock I believe to be (51 front and 49 rear).

What happened to Frank(frank adams?)did he crash or something?

[This message has been edited by KawAbuser (edited 04 October 1999).]

 

[OB_crazy bill]

you took your fan off ? i hear mine kick on an awfull lot . doesnt your bike run hot sometimes..in traffic maybe?id really be interested in knowing this. i noticed a couple local guys decided when they installed chrome wheels not to reinstall one side of thier front brakes. i didnt think that was a very smart thing to do but i would be interested in anyone elses thoughts .

 

[OB_KawAbuser]

Crazy Bill those guys with the single front rotor are drag racing most likely.

 

[OB_terra1]

Kaw: Changed the fork springs, revalved by PPS here in San Diego. I think they're too stiff, but since I'm going to peel more weight off, I'll wait to send them back.

Crazy: Fan seldom cuts in, I don't ride in traffic much, I use Golden Spectro [better at high temperatures] and will switch to full synthetic soon, and I switch off the bike at stoplights. Rode the crap out of it this weekend in the [pretty damn hot] desert, never went over the mid-gauge red mark.

Weight distribution? I'm not sure -- It definitely got light, moved it down 5mm in the triple clamps, much improved, but if I switch rotors I may need another 2-3mm. I don't know any other way to shift the weight forward except ride height, which will raise my CG. Going to have to experiment.

 

[Frank Adams]

do not even ride your bike if you suspect the beerings to be loose in your steering head.
it'll cause your bike to get into a wild uncontrolable wobble.
if you keep it at low speeds you should be alright. but if you pin the throttle and run up through the gears like i did then be prepared!
i was luckey, i had a full set of leathers on and helment when it happened to me...