200km/hr

[a2zworks]

Hi all,
Over the weekend some one I know was testing his R1150GS at 200km/hr (it wasn't me, really. I wouldn't do things like that it's illegal)
The bike was vibrating all over, not shaking though.
In control but the vibes were annoying the rider said that it was making his vision blurry.
Again, it wasn't me!
Is this normal for an 1150 or there is more to it.
Shaft out of balance?
What do you think might be?

 

[Robh1664]

Throttle body balance ? Maybe ! (warning, I'm new , so may talk cr*p at any moment)

 

[Ian J Hartley]

You can expect it to get a little rough just before he passes through the 'sound barrier'. It's all due too air compression. Once he passes through the sound barrier he should find everything smooths out.

 

[nick.ct]

Throttle body balance ? Maybe ! (warning, I'm new , so may talk cr*p at any moment)

Dont think it will be throttle bodies, both will be wide open and then some.

200Km/hr................ 125mph
80mph equates to 5000rpm (on 1100GS)
therefore 125mph equates to the best part of 8000rpm

Guessing that if you want things to be smooth at those rpm that you look at
1. the exact positioning of the Hall sensors, and if they are OK
2. balancing the pistons and conrods

 

[Schtum]

What do you think might be?

An optimistic speedo....

 

[newboy]

125! At best I get 110 but I may not be as streamlined.
I blame the Adventure model.


Sent from my iPhone using Tapatalk

 

[a2zworks]

Normal then, I'll let my mate know.
He swears he was doing 200km/hr apparently he installed one of Johns stage 9 chips.
He did not know what revs he was doing or if it would do more than 200, he thought it might but run out of road.
He won't try it again as he doesn't want to risk doing damage to the engine or worse still lose his licence.
Crazy old bastard!

 

[Smug]

Wheels out of balance?

 

[khpossum]

Since the standard speedometer is off by 7 - 8% "your friend" was more likely to be doing around 185 km/hr.

 

[Roger 04 RT]

I would check thethe fuel system and make sure that it can deliver fuel fuel flow. Separate the return line at the QD, and check to make sure ther is 2 liters per minute return to the tank at idle. Here is some info on how to do it at the top of the page: http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=838620#Post838620.

 

[stolzy]

On an 1150, if there's no vibration it means you've stalled it.

 

[uncle dick]

On an 1150, if there's no vibration it means you've stalled it.

Best answer yet.

 

[jaak]

What tyres was he riding? Brand and speed rating?

 

[Hay Ewe]

Need to get up to QLD, your place isn't long enough

 

[GSTourer]

Dont think it will be throttle bodies, both will be wide open and then some.

200Km/hr................ 125mph
80mph equates to 5000rpm (on 1100GS)
therefore 125mph equates to the best part of 8000rpm

Guessing that if you want things to be smooth at those rpm that you look at
1. the exact positioning of the Hall sensors, and if they are OK
2. balancing the pistons and conrods
3. buy a Fireblade

Sorted!

 

[a2zworks]

You can expect it to get a little rough just before he passes through the 'sound barrier'. It's all due too air compression. Once he passes through the sound barrier he should find everything smooths out.

 

[a2zworks]

I would check thethe fuel system and make sure that it can deliver fuel fuel flow. Separate the return line at the QD, and check to make sure ther is 2 liters per minute return to the tank at idle. Here is some info on how to do it at the top of the page: http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=838620#Post838620.

Thanks Roger, I'll look into it

 

[a2zworks]

On an 1150, if there's no vibration it means you've stalled it.

Good point!

 

[a2zworks]

What tyres was he riding? Brand and speed rating?

Michelin Anakee 2 front and rear

 

[a2zworks]

Need to get up to QLD, your place isn't long enough

True Hay, not too many long straight roads down here, before you know it you hit the coast.