Rear tire zigzags at a hard stop

[MThomas]

No issues on gradual stops but on hard stops on either a wet or sandy surface the rear wheel zigzags.
I realize the hard stop will cause this but would either a:
- better tire or
- wider wheel&tire

reduce this?

If so what tires are recommended and/or is there a wider aftermarket wheel available for the R1150r?

[towerworker]

I assume you don't have ABS? And by zig-zag do you mean you've locked up the rear and you're sliding?

If that's what you mean (locked up and sliding) that's kinda sorta normal. Depending on which way your leaning (or just putting more weight on your left or right foot peg) you will slightly alter the rear wheel and your tire will tend to slide one way or another. Also any slight direction input into the handlebars will cause the rear to slide one way or another. You need to realize when you do a hard stop much of your weight (you and bike) is transferred to the front wheel and you thereby unload the rear causing it to easily slide. Also you have probably noticed you have dual brake discs on front vs one on the rear. The front typically handles 80% of the braking forces/energy to stop. You may want to play/experiment with braking (in an empty parking lot) to fully realize how powerful the front brake is. The rear brake is very important however. Assuming you don't have ABS learning proper braking technique is very important.

BMW engineers the entire suspension, brakes, wheels and tires for the best overall handling and safety. Good quality tires are a must. But my advice would be to leave the wheels alone and run ONLY the recommended tire size specified in your owner's manual. I ran one size wider one time (got a good deal). No improvement in handling, but it was a real pain to get it back on the bike. Didn't do that again. You can do a thread search and get lots of opinions on tire brands and particular models. I've run Michelin, Pirelli, Dunlop and a couple others. They all make a good tire. Some are softer than others (grip good but wear faster). I'm currently running Shinko. Good price and I've been extremely well pleased with performance and tread life. Hope this helps.

[MThomas]

No ABS, I'm probably forgetting to pump on the brakes in a possible zigzag scenario.
What tire brand is softer/grippier even if it wears out faster?

[peels]

nature of the beast. get used to it. or slow down, and brake earlier.

go watch a superbike race. those bikes hard braking for a corner makes them wiggle like a dogs tail. Remember our bike doesn't weigh much, and not much braking is required to upset the balance, and lighten the rear enough that the tire loses some contact.

Also, put some cases on and load them. that will diminish lol

you COULD get really soft race tires, but then you're replacing them all the time.

[EasyBee]

Or instead of stuffing your panniers with bricks, get somebody on the passenger seat. That way you'll have more load on the rear wheel.
Like Towerworker alreay explained perfectly, if you break hard all the weight will be on the frontwheel and the rear end will lift and have no more grip and slide or zigzag.
One step further and you'll end up doing a stoppie http://www.wikihow.com/Do-a-Stoppie-on-a-Motorcycle

[towerworker]

No ABS, I'm probably forgetting to pump on the brakes in a possible zigzag scenario.
What tire brand is softer/grippier even if it wears out faster?

I think most tire manufacturers will offer some higher performance tires. But remember the trade off.......the sticky tires are more expensive as they're more of a track tire. You're looking at possible tread life under 2500 miles vs 3 to 4 times that for a good sport touring tire. I think I remember you possibly saying in an earlier post that you're a relatively new rider? have you been thru any of the MSF courses? I would soak up as much of their stuff as i could.

http://msf-usa.org/

[MThomas]

I did take the MSF course and it was helpful, I'll just bear this in mind

[sweatmark]

Changing wheel/tire will not change the physics of motorcycle braking. A hard stop using front brake will reduce the z-direction force applied through rear tire contact patch. Brake hard enough and you rotate bike forward, reducing normal force to zero, and thus do a stoppie.

Yes your rear tire should be in good condition to provide stable tracking and braking (when appropriate and traction available), but you should focus on straight-line braking anytime you're on the front brake hard, in order to reduce the squirmy rear end effect, and to prevent a high side should your rear tire lift or slide and then hook up when less than straight.

[peels]

Or instead of stuffing your panniers with bricks, get somebody on the passenger seat. That way you'll have more load on the rear wheel.
Like Towerworker alreay explained perfectly, if you break hard all the weight will be on the frontwheel and the rear end will lift and have no more grip and slide or zigzag.
One step further and you'll end up doing a stoppie http://www.wikihow.com/Do-a-Stoppie-on-a-Motorcycle

I dont put bricks in my panniers! LOL

riding gear, groceries. jogging gear, tools. yada yada.



watch this. its physics.

https://www.youtube.com/watch?v=3obUh-atG2s

and this.

https://www.youtube.com/watch?v=tpI2S3GQ-gA

[swamper]

Your using to much rear brake.

[gregor]

Only using the rear brake is what we used to do as a kid on pushbikes. It seemed impressive then to skid sideways- but we were deliberately being show-offs imitating the motorcycle speedway stars on cinders. Or flat trackers in the USA?
I had my bike tested at the MOT station yesterday. The braking effort was measured on a rolling road device. My bike has the linked brakes plus ABS.
When the rear brake was tested by pulling the front lever the effort was much lower than when tested using the foot pedal. IIRC about a fifth. I rarely if ever use my rear brake as such.
So if your brakes are linked -use your front brake mainly and feed in a little rear brake if you need to.