A/T tyres for the new MY17 Trailblazer/Colorado

[George Goosen]

Hi

Does anyone have any suggestions on rims and tyres for the new Trailblazer.

Obviously looking for as much tyre can i have without redoing the suspension or loosing road legality.
Also, I guess it would make sense to buy new steel rims?

Thoughts/Tips/Ideas?

Regards

 

[SomeCant]

I have these on my c7 at the moment

they are Kelly 265/75R16 and the tread is pretty chunky and they didn't rub at all on the standard suspension even after I had put a steel bar on, winch with steel cable, 2nd battery in engine bay, bash plates etc.
all that made the front sink pretty bad which forced me to get new suspension but the wheels never rubbed on the vehicle.

I also have a set of coopers at3 which are 265/70/R16 and they are great for long road driving, nice and quiet and grip very well in the wet

anything bigger than 265/75 on a 16 inch rim will probably hit, you might be able to get a 15 inch rim and put a higher profile tire on but make sure the rim clears the brake calipers and discs before buying.
you might be able to fit 285/70R16 on but I would also test fit them before buying as they might hit in the front at full lock of the steering.

I wouldn't go up in rim size they don't do as well when you deflate them to drive on sand or mud(less surface area?) I see people putting 20 inch rims on and then wonder why they cant tackle the beach very well.

anyone with a Colorado 7 if they are going to add the stuff I did to mine you will need better front suspension it sinks pretty bad when you add 200 to 300 kg to the front and would only get worse over time with the constant load on it.

 

[George Goosen]

I have these on my c7 at the moment

they are Kelly 265/75R16 and the tread is pretty chunky and they didn't rub at all on the standard suspension even after I had put a steel bar on, winch with steel cable, 2nd battery in engine bay, bash plates etc.
all that made the front sink pretty bad which forced me to get new suspension but the wheels never rubbed on the vehicle.

I also have a set of coopers at3 which are 265/70/R16 and they are great for long road driving, nice and quiet and grip very well in the wet

anything bigger than 265/75 on a 16 inch rim will probably hit, you might be able to get a 15 inch rim and put a higher profile tire on but make sure the rim clears the brake calipers and discs before buying.
you might be able to fit 285/70R16 on but I would also test fit them before buying as they might hit in the front at full lock of the steering.

I wouldn't go up in rim size they don't do as well when you deflate them to drive on sand or mud(less surface area?) I see people putting 20 inch rims on and then wonder why they cant tackle the beach very well.

anyone with a Colorado 7 if they are going to add the stuff I did to mine you will need better front suspension it sinks pretty bad when you add 200 to 300 kg to the front and would only get worse over time with the constant load on it.

Thanks for this info mate!

I have been looking at the suspension, and noticed the rear suspension is just a spring in this car? It doesn't have any shock absorbers?
Did you upgrade your suspension at all?

I have 18 Inch rims at the moment and tossing up between running the 265 65R18, would you suggest there is enough reason to drop down to the 17s?
If you did do suspension, what did you go for?

 

[Tink]

Thanks for this info mate!

I have been looking at the suspension, and noticed the rear suspension is just a spring in this car? It doesn't have any shock absorbers?
Did you upgrade your suspension at all?

I have 18 Inch rims at the moment and tossing up between running the 265 65R18, would you suggest there is enough reason to drop down to the 17s?
If you did do suspension, what did you go for?

Huh? Better have another look at that rear suspension
Tink

 

[SomeCant]

the Colorado 7 has shocks on the rear, the stock ones are all black so they might be hard to see.

I went for a tough dog 300kg+ constant load setup.
they are foam cell shocks with a 2 inch lift.
at the time they only listed the light springs for the front but I used the heavy springs off the ute and it all came together nice, I notice now on their website they use the heavy springs in the 300kg+ setup.

this is the parts list that are in mine...
41mm Foam Cell Strut (FRONT) FC404200 x 2
41mm Foam Cell (REAR) FC41125 x 2
Coil Springs (FRONT) TDC270H x 2
Coil Springs (REAR) TDC271H x 2

if you plan on adding a winch/steel bar/dual battery/bash plates/full length cage roof rack/awning and carrying a fridge among all the other junk we fill our vehicles with then I would upgrade the suspension in the Colorado 7, the stock suspension is tuned for comfort not really for added weight and being treated like a 4wd.

my Colorado 7 has 16 inch rims so you could go down to 16 that's up to you just make them test fit before you buy and put the steering into full lock both ways and test if there is any rubbing(while not on the hoist).

 

[George Goosen]

Thanks for the update guys!

You were right the shocks are black, for some reason i thought they would be in the springs itself.

Anyone have any thoughts on motivating reasons on why I would drop from 18 to 16?

 

[Tink]

16" will give you a wider range of tyre choices, better availability of spares when remote, be cheaper and give a higher sidewall (generally).
Tink

 

[SomeCant]

I would also think a higher sidewall would allow a larger surface area when you deflate the tires to drive on sand or mud.
if you are not going to be doing much 4wd type driving and just sticking to roads and gravel tracks I would just stick with what you have.

 

[Tink]

I would also think a higher sidewall would allow a larger surface area when you deflate the tires to drive on sand or mud.

Not really. More flex though.

When you deflate a tyre, the width of the tyre only marginally increases. Deflating does increase the tred contact length though. You do not want your tyre's side walls coming into contact with the ground. See this link and the diagrams for a better understanding.
http://www.coopertires.com.au/media/1400/tyre-pressure-guide-extract.pdf

Tink

 

[SomeCant]

yeah that's sort of what I was getting at.
if the profile was lower wouldn't there be less surface area length or width before the rim bottoms out.
one would think the bigger the rim the less you could deflate it before the rim crushes the tire between the rim and the rock.

I have always used 15 or 16 depending on what would fit, my Colorado 7 came with 16s from the factory so I just went with that

 

[George Goosen]

My other option is to keep my 18's and then get steel rim with 16 or 17's for offroading.

Only thing i have a problem is effect on overall speedo readout.

 

[4x4Dog]

My other option is to keep my 18's and then get steel rim with 16 or 17's for offroading.

Only thing i have a problem is effect on overall speedo readout.

George what did you decide and are you happy?
I got bfg k02 265/65R18. Rubs slightly at full lock but after a few 1000 ks no more rubbing.
As said previously with 18" they dont bag out much even at 15psi on sand, i was tempted to go lower but resisted as i did get 1 flat due to tyre bead gapping on a tight corner on sand at Fraser.