Falling into slow corners

[Rols]

Hi all,


I have a weird problem. I don't know if there is something wrong with the bike, or me. Any thoughts on what I describe below?


I have 2015 LC. I have had it over a year and done 8,000 miles on it. It's a good bike. I like the fact that it's a) comfy and b) fun to ride. I like corners and the bike is good at them. I have ride bikes for >30 yrs. I am fast but not crazy.


All was well until recently. I have the bike services around 6-7k. It got a set of new tyres (Michelin Pilot 4s, same as before,I couldn't fault them). Then I ride to Spain. Brilliant ride. I did get hit with a thunderstorm but I didn't really mind, roads flooded,so  I ride slowly, and have a huge moment where the front end washes away. I don't crash, the bike sorts itself out and after about20 mins my heart rate returns to normal. I figure I hit something unseen under the water. But it happens again, later that day, on damp roads and this keeps happening ever since.


In slow speed corners, when I'm being careful, the bike just appears to fall over, like I'd hit gravel or something. I am now being super careful, so I now know this is nothing to do with the road surface. It's either me or the bike.


I have checked and checked again. Tyre pressures are right, nothing is loose, the tyres are on the right way round (I think), steering head turns freely. It's totally fine at higher speeds. Could it be a duff tyre? Iffy damper? Anyone experienced anything like this?


It is properly scary. I am getting to the point where I don't want to ride it any more.

[Casbar]

Why don't you take it to a dealer for it to be checked. Sounds like either tyre pressures, but you have checked them, or a duff tyre. But tyres are normally bad from the start, they just don't suddenly go off.

[exportman]

Look at your front tyre, there have been many posts on this forum about the front tyre cupping,  an uneven undulating wear pattern seen on many heavier bikes,  this can make the front less stable, couple this with maybe you being super cautious and probably still  braking (subconsciously  engine braking) into the corners adding to the issue.  If it is showing signs  then change the tyre.


Also check the tyre manufacturers recommended pressures  not just BMWs. 


If the tyre is in good condition  the wear is smooth and even then get the dealer to look at the bike could be suspension, but I would expect that to give you a problem at speed more than slow.

[gogs01]

My brother had something similar which turned out to be a problem with the suspension - knuckle joint I think.
Might be worth getting the suspension / steering checked. My brother had felt it was a tyre issue too .....

[richardbd]

Rols - I was that soldier...


I have a 2014 LC and had exactly the same experience.  I put my bike away one night no problem, took it out a few days later and it scared me to death.


I was running PR4 GTs.  They had only done about 2,000 miles and both front and rear looked ok to me - and whilst I may not be the most experienced rider, I've probably ridden 150k miles over the last 10-12 years and I reckon I can tell when I've got a tyre problem.


I spent ages analysing suspension, brakes, luggage loads and other stuff.  In the end I concluded it must be the steering damper and sent the bike off to the dealer for their analysis.


They said straight away that the issue was a fried front tyre.  I said "that's ridiculous, who fries a front tyre in 2,000 miles?".  Their response was "it's a fried front tyre".  So, I let them change it (for another PR4 GT) and it was an instant and total solution. 


Strange thing is that the new one has already done 4,000 miles and is fine.


My bet is one of two things - either it was a rogue tyre, or I'd been running it under-pressure and had fried it myself.  On balance, I reckon the former but hear what the guys say.  Change the front tyre...

[guest3954]

Richardbd advice is Spot-on. Take it into dealership. It sounds very much front tyre issue. Sooner the better.  8)

[blokeonthemove]

I agree with previous advice, may be worth checking the wheel bearings as well as the suspension joints, any sort of sudden even though small movement will feel awful.

[gogs01]

Rols,
When you eventually get a definitive answer to this issue, please be good enough to share on this forum - I hate crime thrillers with the last chapter missing .....

[guest3954]

Rols,
When you eventually get a definitive answer to this issue, please be good enough to share on this forum - I hate crime thrillers with the last chapter missing .....

So do I Gogs.
Rols - on 2nd thoughts - get the dealership to collect it.

[Rols]

I promise to keep you posted. First update should be tomorrow....


Thanks for the interest guys.


Sent from my iPad using Tapatalk HD

[Rols]

I lost a couple of days to the needs of my builders, but then I got some time. This is what I did and what happened:


I make a list of all the possible problems (from above, but also add in "oversteer" as apparently this can feel like the same thing as poor front end grip),i.e. I have: Duff tyre, fried tyre, suspension problem, tyre pressure problem, tyre fitment problem, wheel bearing, knuckle bearing, oversteer or a fault with my brain.


I have a good look and fiddle. The tyres are the right ones, they are fitted properly, the right way round, the pressures are fine (checked with two gauges) and look in excellent condition (see picture below). Too good actually, I was embarrassed to see that they were not scrubbed to the edge. Ahem.


I check all the bearings - heaving and pulling. Everything is tight front and back. The wheel bearing are fine. All the suspension bearings and joints are german good. The steering damper is smooth. Everything is done up tight.


I make sure that the suspension is set up right (apparently oversteer can be caused by having the back end too high - or too big a tyre on the back). So then I'm left with: its me, the tyre was bad when I bought it or it became "fried". I like this last theory as I did have a pretty intense long day at 40C in the mountains before this all started.


To check the "tyre was bad when I bought it" theory, I go back and look at what passes for my diary. This shows that I've had many days of happy riding since the tyres went on. So it can't be a rogue tyre.


So I'm left with "fried tyre" or fried brain. I dress up in leathers and go out to find out which one. I figure that "fried tyre" must mean that the tyre got so hot that some sort of chemical change occurs, leaving it less grippy. I head off from home, with the bike feeling like a steel billiard ball whispering over the finest green baize. [/size]


I take it out to a yet to be built industrial estate, take it up to treble figures, and there on a dusty Spanish dual carriageway, fringed with weeds & spotted with the droppings of construction traffic, do a crash stop. There is a staggering amount of grip available. The bike stops shockingly quickly. Nothing wrong with the front tyre compound. I wizz round the empty roundabouts for a while.


And it slowly starts to dawn on me... if I look ahead, at where I want to be in 5 secs or so, the bike is fine. If I nervously stare a meter ahead at the road surface, madly searching for that next spot of diesel that will have me off, the bike feels very very uncertain and tippy. Duh. The problem is me, not the bike.


So I ride to the beach (see pic) and chillax. On the way back I ride across marshlands. Farmers here are burning off stubble and the flatlands have an erie other-worldly atmosphere. White egrets watch me fly past. I freak out a kingfisher. All is well.


My plan is to ride more and think less. I will also get it booked in for the spanish safety check that I need before I can register it here.


Thanks all.

[gogs01]

..... Nothing wrong with the front tyre compound. .....  If I nervously stare a meter ahead at the road surface, madly searching for that next spot of diesel that will have me off, the bike feels very very uncertain and tippy. Duh. The problem is me, not the bike. .....

So, a brilliant bike with a brilliant tyre and an average (normal) rider. An easy fix now you've identified the problem, and a great excuse for getting out to practice !  Enjoy !

[blokeonthemove]

They call it 'target fixation' in the trade, we have all suffered it at some time, get your vision up to where you want to be, in the distance and you and the bike will get there. I'm told that one should first  check way ahead then a glance for any surface hazards but return to the distant point as you take the bend. Just over a year ago I saw a guy in front of me drive into a recessed gutter because he was looking at it, it reminded me to bring my vision up.

[guest3954]

They call it 'target fixation' in the trade, we have all suffered it at some time, get your vision up to where you want to be, in the distance and you and the bike will get there. I'm told that one should first  check way ahead then a glance for any surface hazards but return to the distant point as you take the bend. Just over a year ago I saw a guy in front of me drive into a recessed gutter because he was looking at it, it reminded me to bring my vision up.

+1. Head up look as far as you can around the bend

[arkmark]

the bike will follow your eyes.  look down, do down.  the other thing that i've noticed on the rt versus a lot of the other bikes I've had is shifting your weight on the pegs smooths out the curves tremendously.