When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
i had heard they are rotary forged like the C7 , but that didnt stop them from cracking on the C7 . i believe the base C8 rims are not wide enough to create a problem though. it seems the C7 grandsport and Z06 had the problems
i had heard they are rotary forged like the C7 , but that didnt stop them from cracking on the C7 . i believe the base C8 rims are not wide enough to create a problem though. it seems the C7 grandsport and Z06 had the problems
Based on their VERY heavy weight, I would find it hard to believe they aren’t gravity cast.
Flow formed wheels (rotary forged or whatever name a manufacturer uses for marketing) are almost universally lighter than the OEM C8 wheels based on my search for a wheel replacement. Like anywhere from 2 to 5 lbs less per wheel. Therefore, my conclusion is the C8 wheel is either gravity cast or is just a crappy flow formed design for weight.
i had heard they are rotary forged like the C7 , but that didnt stop them from cracking on the C7 . i believe the base C8 rims are not wide enough to create a problem though. it seems the C7 grandsport and Z06 had the problems
Yep, like my 2014 Z51 and 2017 Grand Sport wheels (which gave zero problems in 3 1/2 years) the C8 wheels are flow formed by Ronal in Mexico! The 1st C7 Bash showed a video of them being made. My C7 Machined Faced 12 inch wide aluminum rear Grand Sport wheels wheels said Speedline (a Ronal brand) Mexico.
Perfectly good way to make a wheel and the barrel (where some C7 wide wheels had an issue) is made essentially the same as "forged wheels!" Forged wheel barrels are spun formed and made thin and light just like flow formed but start from a forging not a casting. The cold work on flow forming provides about the same grain structure. The difference is the center design can be cast close to finished versus having to be machined with forged wheels. Only some custom designed wheels for folks like Chip Foose are made from a forged aluminum block with 90+% of the aluminum made into chips!
This is a video of who Ronal are:
Tadge said they increased the required test stress on C8 wheels and they added a reinforcement band on the barrel. I saw that band when I replaced a tire on my C8 rear. It was, as expected on the barrel at the high stress hub/barrel interface. That was the issue with the C7 wide wheels on bad roads. It was not a high percentage issue as I and most others had zero issues. Once the C7 Grand Sport was introduced wide wheels were over half of the C7 production. Yep, more wide wheels more issues. In my case with the relatively pot hole free roads we have in Eastern SC no issues.
That compares with the pot holes in the roads when I lived in NE OH, then CT or when I went into NYC! Had fun with my CJ5 Jeep going over the steel plates covering holes and holes in city streets. Felt like when I was off-roading in NE OH. BTW those Jeep wheels were cast! NO issue with strength they were just heavy as were my large all-terrain tires!
Pic shows where the reinforcement band is on C8 wheels. It's not separate as my rough pic gives the impression, it's part of the barrel thickness obviously controlled by the mandrel in the flow forming operation.
Flow Forming Process of Wheel Barrel. Top pic Near Start, Bottom Finished Barrel Formed
