sharkman76

I was told that 17's or 18's will allow a wider wheel and tire combo without offset trailing arms. I guess the larger diamater clears things that hit with 15's any got experance with this and maybe PIC's ?
Thanks as Always
Sharkman76

70 LS1

18's will barely clear the parking brake bracket. However, you can't use the cable unless you move the bracket to the top of the trailing arm. I am running 9.5" rears with 4 7/8" backspacing. You can run 5" with no problems as long as you keep it at 18" diameter.

PatsLs1vette

Also sway bar you have to worry about too,if you have one.

Van Steel

depending on the rim wideth you also have the spring to worry about too.

OHSIXX

I recently changed to 17 X 8 rims and 255/45/17 tires. I think others have had mixed results with 255/50/17.

MYBAD79

Many 17" wheels are not available with the backspacing you need. To correct the backspacing you can install spacers, there are stores on Ebay that sell these for about $150 a set (four).

With a 255-50 tire on a 8X17" the overall diameter of the wheel is very close to the original diameter (27") - looks great...

A 9.5X17" wheel with a 275-50 or 275-45 tire would look awesome on the rear

With spacers you will be able to make almost every wheel fit....

Kid Vette

I'm running 255/50-17s. No problem.

Gordonm

I tried 255 50 17s on mine and they rubbed pretty good on the front. I am running 255 45 17s now and they are great. Some of the earlier sharks have problems wit hclearance others don't. Most of the 77 and later cars don't have a problem with running the 255 50 17s.

68/70Vette

Some of the wheel manufacturers will build you wheel to your own specifications. One such manufacturer is Wheels Vintiques. (Not that I'm trying to say that you should buy your wheels from them, although I did) For example, if you buy wheels from them, you can specify the backspace, the bolt circle, bolt dimensions, etc.

For me, I wouldn't use an adapter. I've already enjoyed the thrill of having my front left wheel come loose and eject itself through the fiiberglass fender. I was driving on the freeway in my 1969 Corvette, I started to notice vibration, and then... boom ..the entire wheel burst the fender and went rolling down the freeway in front of the car. Actually it wasn't because of an adapter. I was using incorrect lug nuts. (I didn't know that at the time). Anyhow, I'm a little sensitive to wheel attachment issues since then. The wheel came off because all of the wheel studs broke, once again because of incorrect lug nuts that were sold to me.

Its a bad day when you see one of your wheels rolling down the road in front of your car. Also, I've also had an experience where I saw, in my rear view mirror, one of my wheels (actually just the circular tread) rolling behind my car. (This rolling circular tread experience occured on a dirt road. I was driving a Toyota Celica at the time.)

Jack71

Wow, you have some bad karma with wheels. I've always been skeptical of adapters and heard stories of them loosening up. << I never lost one on the highway though>>

MYBAD79

68/70Vette:

I agree - there are many low quality spacers out there like the ones that you 'sandwich' between rim and axle.... this is dangerous !!!

Below you can see what mine look like, the spacers are mounted to the axle with the orig. studs/nuts. The rim is mounted on the studs that are pressed into the spacer (just like the orig. studs are pressed in)... the spacer is centric to the axle's hub AND to the rim, note that the spacers has the 'lip' to center the rim...

No other spacer design is safe....

LiveandLetDrive

RedBad, most call those "adapters", and yes, they're definitely the safe way to do it.

Boyd Coddington and CCW wheels are the brands I'm considering. Boyd allows you to choose backspacing in 1/8" incrememnts I believe. CCW is much more expensive, but you can get any rim width and backspacing you can dream up.

As the original post asked, with 18" wheels, is there any benefit at all of using offset trailing arms? Assuming "You can run 5" with no problems as long as you keep it at 18" diameter." is true? Tire width perhaps?

-Chris

MYBAD79

Eventually you will be limited by the frame.... the offset arms give you more clearance in the area where the parking brake cable bracket is mounted but if you go too wide you'll hit the frame or the sway bar with the tire....

If I planned on very wide (let's say 11X17) I'd get the offset arms and take some careful measurements to get the backspacing as close as possible... if it does not fit then I'd add a spacer or adapter... and if it sticks out too far then we're in need of some flares

70 LS1

If you go with 18's there is no advantage to offset arms that I can see. The widest part of the tire/wheel is in the area that is not offset. Offset's are primarily for 15/16" wheels.

I am running 275/40/18 with stock arms. I can post a pic if you want.

MassVette

I switched to 17x8 TTII's & 255/45 ZR17 Goodyears- they clear everything fine- and the handling boost is phenomenal.
IMHO, it's the best handling improvement you can make on a C-3.

mrvette

Course if you are an engineer/fabricator/welder like Norval there, who may chime in soon, you can just offset your own trailing arms, and put what you need where YOU want it....
I just cut the ebrake bracket off, and re routed the cables, and had over with it....I was very close to the VBP sway bar, but it's gone now, no sway bar....and so have another inch to go for the frame, but am ~1/4 inch or so from the otherwise stock T-arm....but I"m nearly centered on my wheel offsets for the increased width....had 3/4 inch to go, and took it...8" to 9.5" width change....

edit....yes and Massvette is right, it's the single most important change to improve handling on our old sharks, or mid years for that matter....hell, ANY CAR....
the larger wheel diameter lessens the chance of the spring hitting the inner wheel/tire surface when changing/altering spring/ride height....

GENE

Matt Gruber

i've had 2 LEO's suggest i corner more slowly w/15" and BFG TA's.
so i see no advantage to possibly harder riding Bling wheels.

DeputyDave

Has anyone tried out 17 or 18 in Billet Aluminum Rallye Wheels? If so what are they like and do you have photos of them installed?

Thanks

Dave

Guru_4_hire

My ultimate goal is some of the CCW wheel track wheels.

17x12 for the rear to fill some 4" rear flares

17x10 to fill the 2" front flares.

335s in the rear and 285s in the front. Should give me a nice 26" tire so I can lower it like all you other people running the 255/45-17s

JRODDVETTE

i run 17 x 9.5 with 275-40-17 tires on the rear, 255-40-17 on the front with vette brakes adapters.
nothing rubs.