Fishtailing

[Fulmine]

When accelerating rapidly (not from a dead stop so as not to burn rubber on the expensive run-flat Michellin tires), my Bolt throws in a couple of fishtails. This surprised me. Anyone else experience this?

 

[Eastocean]

That sounds unusual for a front wheel drive car.

 

[user 387]

You are not feeling fishtailing, per say (the back is not swinging around unless you purchased one of the very rare rear wheel drive Bolts) ), but is experiencing something called "torque steer". The Bolt has torque steer.

This is when the two axles going to the two front wheels have different torsional rigidities. Perhaps one is longer than the other or one is a different diameter than the other, or both. This allows different levels of torque to be applied to the two front wheels, effectively turning the steering away from the wheel with more torque. It is pretty common in front wheel drive cars. A few manufacturers have gone to great feats of engineering to effectively eliminate it (VW/Audi come to mind), but most have it.

Another point - the Michelins are not run-flat tires. The will not successfully run flat. They are pretty normal Michelin all-seasons (no-seasons) that simply have a coat of puncture seal under the tread. They are not yet for sale on the aftermarket, so it is unknown how much they cost, but I don't anticipate them being wildly expensive like run flats are.

 

[GetOffYourGas]

You are not feeling fishtailing, per say (the back is not swinging around unless you purchased one of the very rare rear wheel drive Bolts) ), but is experiencing something called "torque steer". The Bolt has torque steer.

This is when the two axles going to the two front wheels have different torsional rigidities. Perhaps one is longer than the other or one is a different diameter than the other, or both. This allows different levels of torque to be applied to the two front wheels, effectively turning the steering away from the wheel with more torque. It is pretty common in front wheel drive cars. A few manufacturers have gone to great feats of engineering to effectively eliminate it (VW/Audi come to mind), but most have it.

Another point - the Michelins are not run-flat tires. The will not successfully run flat. They are pretty normal Michelin all-seasons (no-seasons) that simply have a coat of puncture seal under the tread. They are not yet for sale on the aftermarket, so it is unknown how much they cost, but I don't anticipate them being wildly expensive like run flats are.

That was the clearest / most concise description of Torque Steer I have ever read. Thank you for sharing that!

FWIW, GM did go to great lengths to reduce torque steer in the Bolt. I believe they mounted the motor near dead-center to reduce the inevitable mis-match.

http://insideevs.com/exclusive-inside-the-chevrolet-bolt-with-its-chief-engineer-new-details/

We’ve got some special controls in there for that. Our steering system and our EBCM (electronic brake control module) has some pretty slick calibrations in there to combat torque steer. You can feel a little bit of it but I think it feels fine. There’s a lot of power up there so if you were to remove the controls we put in place the torque steer would be pretty wicked.

 

[roundpeg]

Another thanks for the complete explanation of torque steer. (FWIW I have yet to experience it on my Bolt.)

Traction control should go some way towards reducing it, right?

 

[user 646]

Yipee! Former Saab owners should feel right at home!

 

[michael]

While I have not yet driven a Bolt, I have heard comments about significant torque steer from a friend who has.

Sometimes alignment and tire pressure adjustment can reduce the effect. My Focus Electric had a lot of torque steer when first delivered, and was fine once I had it aligned at a local shop.

First and easiest thing to check is tire pressures.

 

[CGameProgrammer]

I like to accelerate rapidly but the torque steer is not bad. The worst torque steer I ever experienced was with a rented Ford Focus a couple of years ago; the car veered wildly after changing lanes and trying to accelerate. I find the Bolt quite predictable.

 

[Pigwich]

The torque steer on a Bolt is SIGNIFICANTLY less than on the Spark EV, which was arguably, almost bad. I had a friend describe it as "Squirrely, which I kinda like." but it was NOT in fact that great. Please check that your tires are properly inflated, and if you WANT, get the highest speed rated tires you can. They generally have much more rigid sidewalls with more plys. I got some fancy tires for my Spark EV and it greatly improved, but did not eliminate the torque steer problem. I saw in an article this summer that they specifically had to dial back the torque on the Bolt to reduce the torque steer. This kind of makes me sad, but I'm sure it will save me tires, since I LOVE to drive like a dick. Also, I saw virtually no reduction in range with the new tires over the stock Ecopias.

So yeah, get better tires, and make sure they have enough air in them. Also, if your Bolt is SUPER brand new, the tires are going to be slippery for the first couple hundred miles while the mold release wears off.

 

[drdiesel1]

The tires on the Bolt "ARE NOT RUN FLAT TIRES"

They are self sealing tires. They have TIRE GOO (technical term LOL!) inside the tire to seal punctures.

 

[Fulmine]

Thank you all for educating me on "torque steer" and my "self-sealing" tires.

 

[NeilBlanchard]

Torque steering is bit surprising, since I thought the drive unit had equal length driveshafts.

 

[user 646]

Torque steering is bit surprising, since I thought the drive unit had equal length driveshafts.

It's not just driveshafts. Uneven tire traction and suspension flex have a good deal of input here. With this much instant torque at the front wheels, its practically inevitable. Having driven and owned a number of modified FWD turbo cars with over 300 wtq, I can attest it gives the car a lot of character ;]

 

[samiam95124]

I haven't pushed it yet, but the effect seems far less pronounced than the Leaf, which I consider dangerous, since you stand a chance of loosing control if you punch it in a turn.

Yes, this is a standard feature of front wheel drive cars.

 

[GetOffYourGas]

"Feature". Yes.

 

[boltage]

Another point - the Michelins are not run-flat tires. The will not successfully run flat. They are pretty normal Michelin all-seasons (no-seasons) that simply have a coat of puncture seal under the tread. They are not yet for sale on the aftermarket, so it is unknown how much they cost, but I don't anticipate them being wildly expensive like run flats are.

Tire Rack does list the Michelin Energy Saver 215/50R17 91H tires that are the OEM Chevrolet Bolt tires for $139.69 each and availability 1/26/2017.

Note that there are three different variants of this tire in this 215/50R17 size. One of the others is the OEM Chevrolet Volt tire with the same load and speed rating 91H, while the other has a load and speed rating 90V (less load, higher speed).

 

[boltage]

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