Oversteer on 04 R1150R

[peter1951]

Has anyone experienced oversteer on the R1150R. Im fairly new to the bike and find that particularly on fast RH bends I have to lift the bike upright to hold a good line, otherwise the bike tracks towards the centreline of the road. I have new dunlop roadsmarts fitted and am running at the BMW recommended tyre pressures with the rear shock set to solo rider (please note that Im riding on UK roads, we ride on the left hand side)
If you have come across this, any tips on how to cure it? or is it a characteristic of the bike?

Cheers

Pete

[iowabeakster]

hmmmm

I don't think that the bike has any inherent steering problems. At least, I've never heard of any particular problems with the r1150r. I am in no way insulting your ability to ride, but I believe the problem is with your turning technique. It is something that I am perpetually trying to improve myself.

It sounds like you are "double-apexing". You lean into the curve, get to close to the center line, straighten it out, then need to lean again to finish the curve. This is a common problem for people of all experience levels. We all do it sometimes, really good riders do it very infrequently. We reflexively want to keep our distance from the edge of the road, so we start leaning too early.

Here's how to deal with it... start your lean LATER in the curve (or farther along in the curve). Set yourself up in the outside part of your lane, and keep the bike upright for as long as your can (I know... you're headed off the road!). Then make a single, smooth, late turn. It makes no difference whether the turn is right or left. It make no difference which side of the road you drive on (in different countries). In the US, I do the dreaded "double-apex" more often on fast left-handed curves.

In a right hand curve (in your country), if you are starting from the outside of your lane, you can cut towards the centerline a good distance, without fear of crossing over. This also has a benefit of giving you a visually better perspective to see the road, around the curve. It also gives you a bit of cushion if a driver, coming the opposite direction, wanders into your lane. Confidence in this technique will be achieved through practice.

In your case, for a right hand curve, start on the left side of your lane. And wait as long as you can before leaning over. If you are too nervous, slow it down, you need to practice. Once you've got confidence... then speed it up.

For a real thorough explanation... I recommend David Hough's Proficient Motorcycling and his second book More Proficient Motorcycling. He explains in dozens and dozens of pages, with many pictures, what I tried to explain in a couple sentences. He calls this technique, "delayed apexing".

[f4tweet]

I have new dunlop roadsmarts fitted and am running at the BMW recommended tyre pressures

You should be running 38-40 in the front tire, and 40-42 in the rear tire. Ignore the book. You are riding with too low tire pressure.

[Jed]

I have new dunlop roadsmarts fitted and am running at the BMW recommended tyre pressures
You should be running 38-40 in the front tire, and 40-42 in the rear tire. Ignore the book. You are riding with too low tire pressure.

This has been my experience. Higher tire pressure = better / faster / lighter handling. I suspect the book pressures are about maximizing traction for lateral acceleration and stopping distances. Oh yea, and the tires wear more evenly with higher pressures. I run the same pressure ranges that f4tweet lists above ever since I destroyed a set of tires in 7K miles using the pressures from the owners manual. So far I've got 5K miles on the new tires / higher pressures and not a hint of tread wear.

cheers,

[sweatmark]

Has anyone experienced oversteer on the R1150R. Im fairly new to the bike and find that particularly on fast RH bends I have to lift the bike upright to hold a good line, otherwise the bike tracks towards the centreline of the road. I have new dunlop roadsmarts fitted and am running at the BMW recommended tyre pressures with the rear shock set to solo rider (please note that Im riding on UK roads, we ride on the left hand side)
If you have come across this, any tips on how to cure it? or is it a characteristic of the bike?

It's not the bike oversteering. R1150R has neutral handling when ridden solo; with pillion and/or cargo, the bike pushes (understeers) more than I'd like.

IMHO your tire pressures are fine at the book recommendations, at least for regular road riding. As comparison, I've ridden trackdays with 30psig in front and 26psig in back, using a range of tires from old Scorpion Syncs to DOT Pirelli SuperCorsas. Even with a low 30psig in front tire (and some fellow riders run lower in order to get heat into DOTs), the steering at speed is still neutral. I'm referencing a trackbike different from R1150R, FWIW.

For trackdays at PIR, my favorite organization runs a long straight to avoid a rash (literally and figuratively) of high-sides at the conventional track layout's Festival Turns (corners 1-2-3)... this means the first turn for moto trackdays is Turn 4 in the following maps:

http://www.portlandraceway.com/index.ph ... &Itemid=45

The corner 4-5 sequence is ridden as a unit, truly a double apex configuration, but I somehow "turn" C4-C5 into a triple apex all too frequently with a bad/early/slow turn-in at entry of C5. As a result, I find myself looking down at the berm next to my front tire and mentally exclaim: "Damn! Yet again I've slowed down too much in the previous corner, entered this corner too early, and now I'm condemned to motorcycling mediocrity and insufficient turn-speed for C6... which of course will make me double-apex THAT turn too!" (OK, I don't rant the whole thing every lap, but a single hearty F-bomb seems to cover it).

Trust me, I can triple-apex that double-apex with a variety of tire pressures, bikes, weather conditions, and times of day. The only constant is my feeble brain.

So, back to the original question and "Tips to Cure":

(1) increase turn entry speed if you dare!;
(2) make your turn-in later (the bike's got good brakes);
(3) apply throttle earlier in turn to maintain/increase velocity and better "balance" the effects of your counter-steering turn-in.

Note: I plan to ride my Rockster goat (nicer term than "pig" or "cow") for the 1st time at PIR sometime this season. If I can actually scrape the valve covers in Corners 4-5-6, then my life quest will be complete.

[AirForceDirt]

If you're new to the telelever front end of BMW's (some at least) then you may notice the front likes to dive into corners more when compared to a conventional front-end setup. Its much more noticeable at lower speeds. Its not much at it likes to fall into corners, but that normal bikes are more difficult to turn, so it takes more effort, while the R is pretty balanced. I had the same issue with cornering when I first got the R after riding a DR650 and F650GS (single) since I got my license. Now that I've gotten used to it, i don't notice anymore, and usually do a pretty good job of avoiding early-apexing (other than when Its either necessary or easier for the particular corner).

In short: "They all do that, you just get used to it."

[Sunbeemer]

Perhaps you are experiencing unfamiliar torque reaction of the bike to the inline crankshaft as you accelerate through a RH curve, which twists (leans) the bike over farther leading, in effect, to oversteering. On the other hand, a LH corner will have the opposite effect so that the torque of acceleration will decrease the lean angle causing an (apparent) understeer. You get used to it, then use it to advantage.

[momentman]

I have found it is worth experimenting with preload for different tyres. Effectively I get some more ride height at higher preloads, and the bike wants to turn in better. Of course if you have an adjustable length paralever arm as some do, then you can adjust the ride height that way.

On a ride the other day I thought I was riding like a pussy, and tried some more preload, and found it much easier to hold a line.

Tyres are Pirelli Diablo rosso

By the way airforce dirt I reckon that our bikes dive less than the average bike, not more

Reg

[sweatmark]

Reg - What kind of wear rate are you getting with the Diablo Rosso?

I'm using the R1150GS Paralever strut/arm/link part like many folks here. The shorter link does quicken turn-in a bit, but I haven't experimented with additional tweaks via rear shock pre-load or length (using adjustable Ohlins).

[peter1951]

Thanks for all the information guys, just back from completing several passes of my favourite twisty road. Based on advice offered after eash pass I made small adjustments to the settings and found the bike handles best with the following settings (solo)

Tyre pressures increased from book recommended settings to :- Front tyre 34 psi rear 38psi. (bike fitted with dunlop roadsmart tyres)
Rear preload increased and set to first line after the red spot
Rear rebound 2 turns out from hard
Front rebound 1 turn out from hard.
The bike is much better, its lost that vague feeling in the bends.

Could anyone out there advise how much backlash there should be at the rear wheel with the bike in 1st gear and on its centre stand? Ive got a couple of inches lash on mine.

Cheers

Pete

[momentman]

Sweatmark
Answering your query about Diablo Rosso
Have only travelled about 3000km on the front so far, had a diablo on it before that
Probably wont get huge mileage but it sure grips
I like to have the braking capacity of a softer one on the front....

i have found the pirelli and metzeler to be very similar - same factory?

Cheers
Reg

[monstrous]

I would have to agree with some other comments here, I too find the bike understeering (pushing), not oversteering, I have never had the bike step out. I almost didn't buy a r1150r based on the comments I had read from various sources about a lack of front end feel. I find this to be false as well, I have slid the front multiple times in turns and found it to be very predictable and as drama free as that experience can be. None of those slides resulted in losing the front. As predictable as any bike I have ridden at a sporting pace.