Bumpy Ride - Stiff Suspension

[iletric]

Has anyone considered or figured out how to soften that jumpy/bumpy Bolt ride? I drove our Bolt after a month or two break (my family drives it mostly) and I just can't believe how awful it is. It's so bad I actually feel unsafe in this vehicle.

I am specifically referring to 580 east or west through south Oakland and San Leandro. It is a bad piece of freeway. I keep the tires at 38 psi as I do with all my 44 psi max tires on all vehicles, so I know it may contribute somewhat to the poor performance. But the real story here is that the drum-tight suspension does nothing to contribute anything positive to this ride except shaking over uneven surface features. I almost feel like I'm in a boat in choppy waters.

I have fixed my seats. If I can't fix this rabbit suspension, I will ditch this Bolt experiment in 32 months and never look back. I never liked American cars to begin with, they leave much to be desired as compared to the Japanese, so, this just confirms my fahrvergnügen gestalt of them.

Any solid ideas anyone?

 

[boltage]

For comparison, what cars do you consider to be good riding?

 

[EldRick]

The only way you can soften the bumps at this time, is to get some lightweight wheels to reduce unsprung mass. This can make the car feel like it is tippy-toeing over the bumps, instead of slamming into them.
If the aftermarket comes out with some shock absorber alternatives, that could help, but it will be months to years before such products become available.
BTW, some of us like the ride, as being sporty.

 

[jostafew]

Higher profile tires? That would soften things up and reduce unsprung weight. If you do a little googling through the forums I think you'll find the Bolt pattern matches the cruze and volt IIRC. Grab some smaller diameter rims and mount some comfy tires, should improve ride comfort. I'm quite happy with the balance of ride comfort and suspension firmness but there is no one size that fits all. Just be ware you will likely lose 5% of your range by making the above change (losing the LRR tires)

 

[ScooterCT]

Every wheelbase/suspension/wheel setup has a natural resonance frequency. You might be unlucky enough to travel just right speed, across perfectly spaced road heaves, to hit that resonance frequency. You might try changing your speed a few trips to see if that's the case. The Bolt has a wheelbase of 102.4". My Kia Soul has a similar 101.2" wheelbase, but it glides over nasty pavement like it's not there. I'm sure a suspension guru could chime in here. It gets complicated fast. Damping rates. unsprung mass. Suspension travel and geometry.

As a last resort, you could take your Bolt to a tuning shop and have them drive that bit of road. They could swap out shocks for something better suited to your drive. I'd wager GM didn't put world class shocks in that car, just based on what I've seen to date. They spent all their budget on the EV drive train. You can do magic stuff with world-class shocks.

I had a 2 door RAV4 back in the 90s. Very short wheelbase. That thing bucked like a rodeo bronco on choppy road.

 

[iletric]

Shocks of course was my best guess as well. Can anyone look into it?

I drive through this street with speed bumps. My 92 Accord can roll over them at 30 mph with barely a jar. I keep left wheels in the pause between the bumps and the right over them.

Bolt is a disaster. I tried fast and slow, and ultimately I'm down to 5 mph to get over them without jumping the whole car. Bolt has 17" wheels, the Accord is 15". It's just crazy.

 

[DaveInAvl]

Do you happen to know anyone with a GoPro who could get slow-mo closeup video of each car going over the bump?

 

[LeftieBiker]

Shocks of course was my best guess as well. Can anyone look into it?

I drive through this street with speed bumps. My 92 Accord can roll over them at 30 mph with barely a jar. I keep left wheels in the pause between the bumps and the right over them.

Bolt is a disaster. I tried fast and slow, and ultimately I'm down to 5 mph to get over them without jumping the whole car. Bolt has 17" wheels, the Accord is 15". It's just crazy.

Speed bumps are generally intended to get cars to slow to at most 10-15MPH for safety reasons, like lots of pedestrians. Are you saying that these speed bumps are unneeded, or just that you don't want to slow down?

 

[boltage]

I'd wager GM didn't put world class shocks in that car, just based on what I've seen to date. They spent all their budget on the EV drive train. You can do magic stuff with world-class shocks.

Josh Tavel reportedly likes sporty driving. So perhaps it is not a surprise that the Bolt's suspension is tuned to be on the firmer and sportier side of the normal range, more like what you might expect from smaller Fords, Mazdas, and Hondas, as opposed to smaller Toyotas and Nissans which are less sporty.

The Bolt handles the larger speed bumps well in my experience. The worst car for those speed bumps was a really softly suspended Lexus ES that was easy to bottom out the suspension on those speed bumps.

 

[EldRick]

Have a look at the front wheels on the car - there is next to no room for a taller tire, because the shock mount arches over the inside of the tire about a half-inch above it.

 

[tk1971]

I agree with the OP. The Bolt's suspension is teeth-jarringly harsh. My wife's Leaf provides a much tamer ride.

I have some rear window GoPro video of my loaded up hitch bike rack bouncing hard enough that I'm surprised the the handlebar hasn't hit the hatch yet. These same roads never prompted me to record the bike racks moving around with any other car.

I don't dislike it per se. It's just different. I certainly don't think it's a deal breaker though. I can't really say that it's sporty either as the weakest link on the Bolt is the tires, IMO.

 

[boltage]

Have a look at the front wheels on the car - there is next to no room for a taller tire, because the shock mount arches over the inside of the tire about a half-inch above it.

https://tiresize.com/calculator/

You can get a taller sidewall with a very similar diameter to the stock 215/50R17 with 215/55R16, 205/60R16. Obviously, these require changing to a 16" wheel (which requires checking if the smaller wheels clear the brakes and such). This is called "minus 1" sizing (the opposite of "plus 1" sizing that is commonly used to get a sportier, wider, lower profile tire size).

Low rolling resistance tires are likely to be available in the other sizes. The self-sealing feature is less common and is less likely to be available in the other sizes.

 

[jostafew]

Regarding the taller tire, it was assumed that one would drop the wheel diameter in order to allow the greater sidewall without affecting the overall tire diameter. Eg. go to a 15" (might have brake clearance issues) or likely a 16" wheel.

 

[iletric]

Speed bumps are generally intended ... for safety reasons, like lots of pedestrians. Are you saying that these speed bumps are unneeded, or just that you don't want to slow down?

I make no judgement on the need of the bumps.

There are 2 ways to ride rough road, slow or "fast." In my Accord the optimal crossing of these particular bumps is 25-30 mph. I tried it with Bolt. It was a jarring experience.

I used to hate driving behind the kind of cars/drivers who I thought didn't or don't realize or understand the above principle. Now in Bolt I'm one of THEM. Ergo, I feel sorry for the guy behind me who has to slow down for me to 5-8 mph so I can crawl over the stupid bump b/c I have this idiotic suspension.

 

[HotPotato]

Determinants of ride quality (arguably in decreasing order of importance) include spring rate, shock/strut valving, suspension design, amount of sidewall cushion in the tires, and unsprung weight.

Softer springs are almost unheard of in the aftermarket. Softer shocks are more common: the best of the breed is Koni FSD: brilliant valving produces a considerably better ride without sacrificing any handling.

The Bolt's rear suspension is a very basic design that's good for minimizing cost and weight and maximizing cargo room, but skittery on rough surfaces (the back of the car can step out in a mid-corner bump). It's common for the class, but not ideal for ride/handling.

You probably can't find aftermarket springs and shocks for the Bolt yet. And obviously you can't change the car's suspension design.That leaves you at doing a minus-one or minus-two wheel fitment: you use a one or two inch smaller diameter wheel with a tire with a taller sidewall so that the total outside diameter of the tire remains the same as stock. Theoretically that taller sidewall will flex more and absorb bumps better. You can also specifically shop for a tire designed for good ride. But a wheel and tire swap sounds like a lot of money to spend...and, what if you get a flat?

It may also help ride if the wheel is on the narrow side for the tire; a GM suspension engineer once said you get the best ride by putting the widest 60-series tire that will fit on a given wheel. (The number on the side of your tire will say something like 205/50/17: that would mean the tire is 205 mm wide, the sidewall height is 50% of the tire's width, and the wheel diameter is 17". The sidewall height or aspect ratio is what's referred to when someone talks about a 50-series tire, 60-series, etc. In the old days, 70-series was standard on comfort-oriented models, but today nearly everything on the road is running ridiculous tall car-show rims with rubber-band sidewalls: 50-series used to be only for the highest performance cars but it's pretty standard now.)

Those wheel/tire tricks, by the way, will likely make the car less fun to drive: steering response will go from sharp to sluggish, as the car rolls on its tire rather than abruptly changing direction.

It's a shame we can't always get a long-term test drive to try vehicles where we drive them. I loved my Mazda3, but the road noise over rough surfaces was deafening...but without such a road near the dealer, I didn't know until I owned it. You may want to trade the car for something more refined; a Nissan Leaf has a very soft ride, if your commute is short. A Ford C-Max Energi is like a bigger Bolt but with a plug-in hybrid drivetrain: not much EV range but a very nice, soft-riding car that still boasts precise, if not sporting, handling.

 

[iletric]

Thanks for the in-depth. I guess, I have no recourse.

Waiting for Leaf 2 though, like for salvation. At least I have the seat issue resolved. Will have to take my lumps on suspension. Plus I really don't want to put more money into the lease.

 

[flamaest]

Please let me know if you decide to replace your rims / tires. I would like to buy a lightly-used OEM rim/ tire so that I can put that in my bolt for long trips just in case I get a flat. I don't believe in the self-sealing tires, I think that that is marketing hogwash.

I also believe that the ride comfort in the vehicle is questionable. a few weeks ago I drove going south from San Jose and there is a off ramp from 85 to 101 which has a mild dip. When I take that ramp in any other car , they handle this dip just fine. When I take this off ramp with the bolt, at a mere 65 or 70 miles an hour, the car almost takes flight and I feel like there is a moment where I'm out of control. Keep in mind, everyone on those roads is doing 90 miles an hour. Speed limits be damned. They will run you over.

 

[iletric]

When I take this off ramp with the bolt, at a mere 65 or 70 miles an hour, the car almost takes flight and I feel like there is a moment where I'm out of control.

That's exactly my complaint...

 

[LeftieBiker]

Has it been established that the LT and Premiere both have the exact same suspension parts and damping/spring rates? GM seems to have made yet another unnecessary mistake by not softening the Premiere's ride a bit.

 

[bravo]

I don't find the Bolt the least bit jarring, rough, or bumpy. Not even close. If you want those traits, try an i3 Rex!

However, since you do, these are the steps that I would take (in order):

1. Try to get the dealer to trade for a Volt. That's a cushy ride. This is unlikely to happen – Volts are in short supply and Bolts are abundant.
2. Check your inflation levels. 2 PSI makes a big diff in ride quality in many cars.
3. Enlist the aid of TireRack to go -1 or -2 on the wheel/tire setup.
4. Stay away from that speed bump.
5. Look into coilover shocks (or maybe the Koni's that a previous poster mentioned). I don't think that the Bolt is overspung or overdamped. But it's possible that it's underdamped. In which case to shudder that you feel over your speed bump is the suspension bottoming out.

I honestly would be very reluctant to do suspension work, esp on a leased car. Nor do I recommend lighter wheels (if they exist). The theoretical advantages if wheel lightening will not be felt in this class of car.

Good luck to you and sorry that the Bolt isn't working out.