Is this a stupid question?

General discussion of the BMW R1200RT/R1250RT
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richardbd
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Is this a stupid question?

Post by richardbd »

I have a sense that my bike (2014 LC) has started turning in very differently, depending on whether it's to the right or the left.  Left feels normal; right seems as if the bike's going to tip all the way in instantly and I feel like I'm trying to stop it turning, not make it turn.


Tyre pressures are normal.  Tyres (PR4s) are only about 1,000 miles old.


The only things I can come up with are that either I'm losing the plot or there's something strange with the steering damper.


Any bright ideas?


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badger
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Re: Is this a stupid question?

Post by badger »

First port of call for me would be check the steering head bearings, if it is notchy that will give you this feeling, also check the steering damper is functioning smoothly
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iRider
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Re: Is this a stupid question?

Post by iRider »

The only advice I can add is to say don't only focus upon the front. Certainly anything out of whack on the rear for any reason can cause steering issues too.


Good luck resolving it whatever it is.

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stelyn
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Re: Is this a stupid question?

Post by stelyn »

badger wrote: First port of call for me would be check the steering head bearings, if it is notchy that will give you this feeling, also check the steering damper is functioning smoothly
+1 on this, Dealer made slight adjustments FOC and ride was better ...... ;)
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guest2360

Re: Is this a stupid question?

Post by guest2360 »

Get wife to push down on back and then swing steering  around to test smoothness. Also with brake on pull bike back and forth to ensure there is no play in the telilever front bearing.  My first port of call though would be a very close look at the tyres. Or have you removed something you shouldn't have for that cool look.
Steve F
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Re: Is this a stupid question?

Post by Steve F »

RTman10 wrote: Get wife to push down on back and then swing steering  around to test smoothness. Also with brake on pull bike back and forth to ensure there is no play in the telilever front bearing.  My first port of call though would be a very close look at the tyres. Or have you removed something you shouldn't have for that cool look.
Sounds more like a Kama Sutra postion!! ;)  Joking aside, as rtman10 says, inspect the tyres carefully then move onto suspension, bearings etc
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k9doc
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Re: Is this a stupid question?

Post by k9doc »

Have you thought about 'camber wear'. As I understand it road camber is generally down to the left creating excessive pressure to RHS of tyre and therefore uneven wear leading to changes in steering characteristics to right and left. Opposite is true for our continental cousins.
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richardbd
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Re: Is this a stupid question?

Post by richardbd »

k9doc wrote: Have you thought about 'camber wear'. As I understand it road camber is generally down to the left creating excessive pressure to RHS of tyre and therefore uneven wear leading to changes in steering characteristics to right and left. Opposite is true for our continental cousins.

Not impossible - but seems unlikely, given the age of the tyres. 


I'm more inclined to the "faulty" steering damper theory.  The tyres look fine and the pressures are ok, according to two gauges and the TPS system.  And even if they were over/under inflated, how would that make them favour one side over the other?



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badger
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Re: Is this a stupid question?

Post by badger »

richardbd wrote:
Not impossible - but seems unlikely, given the age of the tyres. 


I'm more inclined to the "faulty" steering damper theory.  The tyres look fine and the pressures are ok, according to two gauges and the TPS system.  And even if they were over/under inflated, how would that make them favour one side over the other?
I had a damper that was not functioning as it should and caused the bike to wander, turned out to be the rose joints that were sticky for the damper, freed them off and job done.

Check the tyres are seated correctly in the rim, sometimes they can be of centre wnen fitted, the tyre must be sitting symmetrical on the rim.

What mileage has the bike done then?
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richardbd
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Re: Is this a stupid question?

Post by richardbd »

badger wrote: I had a damper that was not functioning as it should and caused the bike to wander, turned out to be the rose joints that were sticky for the damper, freed them off and job done.

Check the tyres are seated correctly in the rim, sometimes they can be of centre wnen fitted, the tyre must be sitting symmetrical on the rim.

What mileage has the bike done then?

Bikes done 7,500.  Tyres about 1,000.  Problem came on "suddenly" - put bike away one evening, np problem.  Get it our a few days later, noticed it straight away...
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badger
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Re: Is this a stupid question?

Post by badger »

Have you checked anything yet, steering head bearings, steering damper, brakes binding/sticking piston in caliper etc?

Did you hit a pothole hard or anything similar?
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richardbd
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Re: Is this a stupid question?

Post by richardbd »

badger wrote: Have you checked anything yet, steering head bearings, steering damper, brakes binding/sticking piston in caliper etc?

Did you hit a pothole hard or anything similar?

Am away at the moment, so just hunting for ideas.  Didn't hit anything.  Superficially at least, everything looks/feels normal apart from the weird feel to the turn-in going right.
jon23505
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Re: Is this a stupid question?

Post by jon23505 »

Hi, have you checked your cables, and brake lines for snagging or are they getting trapped.
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richardbd
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Re: Is this a stupid question?

Post by richardbd »

jon23505 wrote: Hi, have you checked your cables, and brake lines for snagging or are they getting trapped.

Yep - nothing like that...
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richardbd
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Panic ye not...

Post by richardbd »


So, the RT's back from a good going over by the top chaps at Bahnstormers, Alton.


They've fixed the non-functional LED spot lights in the traditional dealer way - by replacing them.


Much more importantly, they've cured the rather bizarre handling gremlins - they replaced the front tyre. 


The tyre was a Pirelli PR4 GT; it was less than 2,000 miles old; to the casual observer (me) it looked to be in decent condition and repeated efforts at playing with the pressure made no difference to the increasingly disconcerting steering.  I was convinced there must be something wrong with the bike itself but the boys at Alton were convinced all was well, apart from the fried tyre.  They suggested that I must have been riding it in a rather "progressive" manner to do this to a tyre.  I reckon it was a dodgy tyre.


Having given the bike a decent work out today though, I can report that the chaps at Bahnstormers appear to be right and normal service is now resumed.


All that's left to ponder is:


a)  how can a PR4 GT front tyre be "fried" after less than 2,000 miles?
b)  is there something in the bike's set-up that's contributing to the tyre wear?
c)  how can a (reasonably) experienced rider fail to identify the physical damage to a tyre?


Oh - and I also grumbled about the fact that my BMW Nav 5 satnav won't connect to my mac.  Most dealers will fob you off with a "oh, they never connect properly to macs".  Bahnstormers said "that's ridiculous" and despite the unit being 18 months old, pushed BMW to replace it under warranty because they believed it was faulty.  They won and now I have a brand new satnav unit.


And finally, when the bike was delivered home, it was IMMACULATE.


Hats of to Bahnstormers, Alton...
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