Bike set up................

[Jam]

Right heres the story..................

The rear tyre on my 1100GS is (quite proudly) showing signs of being used right to the very edge BUT the front tyre is still a good 10- 15mm from being fully used..........

I assume (rightly or wrongly) that this is down to the way the bike is set up.................

Question 1
If so what do i have to do use more of the front tyre?

Question 2
Does any of the above have a bearing on the poor ground clearance i am currently experiencing mainly side stand grounding out at what is a reasonable `angle of dangle`

Thanks for your time and hopefully assistance

Jam

 

[(RIP) Geriatric Germ]

Dangle angle

Try this,
on the approach to a bend (left or right) move the body,or CofG right forwards so the speedo is in line with your navel, this puts more weight on the front tyre.

OR Seriously, look at the different Profiles of the tyres.
consider the fact that the rear tyre has deacceleration or acceleration forces acting on it (unless you need IAM to tell you NOT to front brake in a bend) the front tyre has less to do (hence rear tyres wear at least twice as fast as the front).

If it really bothers your street cred., you could always use a high powered orbital sander to 'scuff' the edges of the front one.
Hope this helps.

PS I must make a mental note to sit quietly behind you on runs!

 

[Rob Farmer]

Jam,

It sounds as though you have the rear suspension way too soft. I have the opposite problem with mine I wear the front tyres out before the rear and nothing grounds out. Call round if you need to compare the setup.

Cheers

Rob

 

[Jam]

?

I am a little confuddled by your reply.....................

In the immortal words of Mr Wogan............`is it me?`

Just in case it is me

The wear on the rear tyre is right to the edge of the tyre whilst the front tyre is showing a 10-15mm strip on iether edge that has not had the pleasure of touching the road yet. I am assuming this is to do with cornering as opposed to braking forces etc hence i think it could be suspension set up related...............

`is it me?`

Jam

 

[RussellAisbitt]

As old fart says, look at the profiles of the tyres. Even on sports bikes it is rare (i.e. never happens) for the front tyre to be used all the way to the edge of the tread, unless of course you fall off, then you might even get to use the rim.

 

[THE PICT]

A lot of it can be down to profile,suspension and tyrepressures.
I argree with rob though,my front wears out before the back.Must be to to with the tele-lever.

 

[Greg Masters]

I don't think the query is about wear rate per se, more about where on the shoulders of the tyres wear is occurring.

Jam, is the answer not simply that the front tyre has a higher shoulder?

Greg

 

[Mick Fagan]

Jam, are the tyres a matched set?

I've found that the tyre wear on my 1100 is pretty much as you describe.

If you are grounding the side/centre stands then it would be because the suspension is set too soft, or, you are carrying a pillion.

That said, if you are running out of rear wheel tread then you are pretty much on the limit of what the machine is designed for. BMW have a habit of never over tyreing their machines. When you run out of tread, you usually run out of clearance.

There are ways around this but if you are that desperate to scrub your front tyre to the shoulder, be prepared to step off sometime soon!

Mick R1100GS

 

[Jam]

thanks

That makes sense to me now.......................

Previously with my Aprilia I had this wear occur and i was advised to drop the forks through a notch. This gave me quicker steering and indeed moved the wear lines to nearer the edge of the tyre.

I am not looking for sportsbike performance from the beemer (although the grin factor is on par) i understand the difference. All i am looking to do is understand if this is something i have to live with...........its not the worst problem to have believe me.

It would appear then that most GS`s i see will have an unworn edge to their from tyres.........no problem.

Cheers all

 

[Simon Eassom]

Whilst there may be reasons why your rear end is decking out prematurely . . . all things being normal and set up properly, the front wheel has less angle of lean than the back on any given turn due to the need to counter-steer and the ensuing shifting of the contact area between front tyre and tarmac.

Picture a motorcrosser rear-wheel steering - the front wheel is virtually upright and the back steeped right out sideways leaning over. That's a very exaggerated image of what all bikes counter-steering look like.

Try it for yourself with any round wheel-like object (rubber ring, doughnut, bagel, frisby). Lean the bagel over and mark with a pencil the edge of contact with the desktop (or whatever). Now slightly turn the bagel away from the angle of lean as if counter-steering. The angle between bagel and surface increases and the point of contact you marked before should appear to be slightly lifted away from the surface.

Push your front too much to the edge of the tread (especially with a 19in wheel and narrow section tyre) and you'll be low-siding shortly afterwards.

 

[Simon Eassom]

Re: Dangle angle

the front tyre has less to do (hence rear tyres wear at least twice as fast as the front).

If it really bothers your street cred., you could always use a high powered orbital sander to 'scuff' the edges of the front one.

Under no circumstances sand your tyres! I don't think this was meant to be serious advice, but abrasive papers and discs have very fine pieces of silica in them that will damage your tyres.

On the contrary, the front tyre has the most to do when steering . . . it all depends what you mean by "do". It's never driving the bike because the power goes through the rear wheel, but in turns of grip, friction, whatever, the front wheel matters far more than the back.

Rear tyres wear quicker than front because of acceleration, not because of relative friction when cornering. If you spent as much time front wheel breaking as harshly as you do accelerating, then fronts would wear as quickly as rears . . . GP/superbikes "lay down" their rubber from the rear driving out of corners, not whilst cornering.

 

[Keith Chapman]

I have just tried the bagel thing.... and all my scrambled egg and salmon fell on the floor..

 

[Jam]

Well it started of as a serious question and then............................................who knows

 

[Rob Farmer]

Does anybody know where I can get a 150h70 x 17 bagel? and what are they like in the wet?

 

[judge]

Try it for yourself with any round wheel-like object (rubber ring, doughnut, bagel, frisby). Lean the bagel over and mark with a pencil the edge of contact with the desktop (or whatever). Now slightly turn the bagel away from the angle of lean as if counter-steering. The angle between bagel and surface increases and the point of contact you marked before should appear to be slightly lifted away from the surface.

My Dearest Professor,

You'll have to believe me when I say I tried desperately to carry out this experiment, but try as I might the bagels and the doughnuts kept disappearing before my very eyes - honest

 

[judge]

Does anybody know where I can get a 150h70 x 17 bagel? and what are they like in the wet?

No idea but if its got hot salt beef or cream cheese in it I can't see it lasting very long

 

[TERRY RYAN]

Does anybody know where I can get a 150h70 x 17 bagel?

Rob
what tread pattern would you require

knobbley pattern Judge mk1 bites taken out
slick pattern judge mk2 cream cheese good grip when hot


doughnuts come in same tread pattern put slightley wider

165h70x17 good pattern with a designer pencil mark added
no extra cost

 

[CoolCarbon]

I know someone who may...........

I bet Bakerman could make the required Bagel 160/55 ZR 17 Radial with sticky cheese, just right for a Track Day !

CC

 

[Rob Farmer]

bet Bakerman could make the required Bagel 160/55 ZR 17 Radial with sticky cheese, just right for a Track Day !

Yes I heard his bagels were rubbery.....Hang on I think I've been here before and ended up being called a Tosser!!!