Shudder/Vibration after Tkof

[hyundai]

Hey guys I have a problem one head bolt has stripped in the barrel. Not much room for a helicoil. .????

Good news for me the barrel thread was not stripped, somehow I fitted a shorter head bolt by mistake and it just pulled 2 threads out. I drilled slightly into the thread and retapped it and all is good boy am I a happy Chappy.

 

And this is on my jab 2200.

 

 

[hyundai]

You might be able to go slightly bigger and get away with it. If you go to a metric from AF or whatever it is you can sometime minimise the oversize. Nev

Thanks Nev I did talk to the bolts guy but the next size up was to big. Any way all is good it was not stripped.

 

 

[facthunter]

You can also have a special tap made oversize of the original thread and machine a bolt to suit. (Suttons at Maryborough VIC.) Watch the too short bolts .Those are small enough thread length already. Nev

 

 

[pmccarthy]

It is possible to pull on and lock the park brake by accident when you are doing downwind checks. Depends how the lock works. I pull the brake lever and say brakes free, but now have to think twice.

 

 

[hyundai]

I just bought 2x 10 ply tyres from jab for my j160. The only thing I found don't put to much pressure in them as the are very rough. I have 15 in them still a bit rough on grass strip.

 

 

[Russ]

if too soft, there is the chance of skidding the tyre around the rim, pulling the tube with it, and tearing the valve attachment point. especially on tar. I run 25lbs to be sure......and yes they're a lot harder than 6 ply, double the groove depth etc...........they look real good. ( $90 each wagga bikes )

 

Downside..........bit of a pain fitting them to the split rims, but that's now sorted......and they fit under jab spats too.

 

 

[Guest Andys@coffs]

Get a couple of longer AN bolts to use to pull the hub halves together... Put them in your flyaway kit cause once you have the more ply tyres you can't pull them together with the std fit bolts...at least not easily

 

Andy

 

 

[hyundai]

Hey Russ

 

Yes I know what you mean but they are so tight on the beed I don't think they would slip ????

 

 

[Russ]

Get a couple of longer AN bolts to use to pull the hub halves together... Put them in your flyaway kit cause once you have the more ply tyres you can't pull them together with the std fit bolts...at least not easilyAndy

"AN" bolts............mitre 10 for me

 

 

[Russ]

Hey RussYes I know what you mean but they are so tight on the beed I don't think they would slip ????

Yes, i know they're tight, real tight. i've had a few flats over the yrs, breaking that bead bonding can be a real pain to get the tube out, so i wipe a smear of lanolin along that bonding area to help remove the rim half, when i again get a flat ( i'm a glass 1/2 full guy ) ....so running low air pressures is iffy.

 

 

[billwoodmason]

Great helpful discussion - better than all the Jab negativity that keeps rearing it's head on every thead. I'm over it.

 

 

[Russ]

bill.........this last 12mths we've clocked up 120+ hrs, zero circuit stuff, all point and go, tiger country every time. The times we bump into another traveller it's another jab, apart from GA folks, yet some folks just gob off re jabs. invite them to tag along in their ???, then the excuses begin.

 

Not for a moment do i think i've fluked or just got away with good luck, service them right, control temps, and any point around Oz is yours for the taking.

 

( this is where the fight began )

 

 

[hyundai]

Has anyone had beed slip due to low pressure on 10 ply tyres. By the way jab brakes are not good enough

 

to slip the tyre I am sure. I want to add the extra jab calliper to my jab any secondhand out there.????

 

 

[Guest Andys@coffs]

On my J230 the original single calliper brakes were indeed poor. The double calliper brakes I upgraded to are such that I can lock the wheels..... Anything more than that is pretty much irrelevant....they still fade quicker than I would like but are a vast Improvement over the originals....

 

Some might like even better but the jab's are not really the best machine for short field work..brakes might make them get into a short field but you still have to get out!

 

Andy

 

 

[Russ]

Andy....a jab can get off surprisingly well, full flaps, instant full power, stick neutral, 40ish kts, and heave the stick back,really back, as soon as you break ground level off, stay 1m off the ground, or less, ( ground effect ) increase airspeed to 60+ then commence climbout, nice and steady, don't touch flaps till you get reasonable height, then retract them SLOWLY. ( 100....150m liftoff every time, that's half decent....yes/no )...... well i rekin it's ok.

 

Short field stopping..........not so good, and too good brakes are bad at times.....grass, you lock up, and just shudder like hell down the strip, knowing you should release all that pressure.......but hey, that fence is getting reeel close, pull even harder, stop ya barstard, stop. ( should i shut the engine off to aid stopping, should i power up and get airborne, why the hell did i try landing here.........please god, let me stop, promise i'll never do this again. )

 

 

[jetjr]

Believe theres a new brake kit from Jabiru, saw it on Rod J430 last year?? and selling in RSA, only listed issue is extra force can be applied can break console.

 

Theres some better brake pad and rotors out there too

 

I have a pair of spare calipers if you want to buy them?

 

Slipping of tyres on rim could happen simply on touchdown - little wheels going from zero to 60mph instantly, heavier the tyre more inertia

 

Be careful with lubricating beads, most oils and greases damage rubber, use detergent.

 

 

[facthunter]

It's only the wheel weight and inertia that will make a tyre creep on touchdown. The lighter the wheel the less the effect The tyre weight will retard the acceleration of the tyre but that helps.. Keep your tyres inflated helps stop tyre creep. Nev

 

 

[jetjr]

Yep and thats the problem, the 10 ply are a lot heavier

 

 

[facthunter]

I meant the wheel centre . The tyre has to spin it up. Nev

 

 

[Russ]

Andy....a jab can get off surprisingly well, full flaps, instant full power, stick neutral, 40ish kts, and heave the stick back,really back, as soon as you break ground level off, stay 1m off the ground, or less, ( ground effect ) increase airspeed to 60+ then commence climbout, nice and steady, don't touch flaps till you get reasonable height, then retract them SLOWLY. ( 100....150m liftoff every time, that's half decent....yes/no )...... well i rekin it's ok.Short field stopping..........not so good, and too good brakes are bad at times.....grass, you lock up, and just shudder like hell down the strip, knowing you should release all that pressure.......but hey, that fence is getting reeel close, pull even harder, stop ya barstard, stop. ( should i shut the engine off to aid stopping, should i power up and get airborne, why the hell did i try landing here.........please god, let me stop, promise i'll never do this again. )

tried to edit this.....but missed the opurtunity.

 

So.....i am in no way advocating my short field takeoffs technique as SAFE........it works for me, better experienced folks here may shoot me down, so be it.

 

 

[biggles]

...but hey, that fence is getting reeel close, pull even harder, stop ya barstard, stop. ( should i shut the engine off to aid stopping, should i power up and get airborne, why the hell did i try landing here.........please god, let me stop, promise i'll never do this again. )

Russ , as long as your directional control etc. is stable , and you are absolutely sure you can continue a safe landing, apart from going through the fence ,shutting down the engine will considerably shorten your rollout ...... Bob

 

 

[Russ]

Can vividly recall enroute .....wife's bustin for a pee, so i divert emerald, make all required calls, join circuit downwind **, notice RPT taxying from terminal towards holding point, me being an obliging gentleman, i call him and offer to extend my downwind leg to let him get away......he says its Ok, he'll hold, so onto base and finals i go, thinking here, i decide to land looong, rather than normal and putt putt along the runway........holding him up. Touchdown fastish, tar strip, zip past the RPT that's holding, brakes applied.....SHYTE, pull harder........bigger SHYTE, runway end is looming, brakes fading bigtime, anyway all ended good........just.

 

Memories / nightmares............don't ya just love em.

 

 

[hyundai]

Yes, i know they're tight, real tight. i've had a few flats over the yrs, breaking that bead bonding can be a real pain to get the tube out, so i wipe a smear of lanolin along that bonding area to help remove the rim half, when i again get a flat ( i'm a glass 1/2 full guy ) ....so running low air pressures is iffy.

I will keep mine at 15 psi will post if I have a problem.

 

 

[Russ]

Currently 25psi........yes, still hardish ride on grass, intend trying 22 but no lower.

 

 

[SDQDI]

Not trying to hijack the thread...... But can't help but insert a little about my wheels (not on a Jab)

 

I used to run them at ten but lately have gone down to 6 psi, it is so awesome and even makes my landings soft:thumb up:

 

Have I mentioned before that I love bushwheels?