The Weight vs. Rigidity Factor
for the true race freak out there and the occasional one as well....
I understand that weight is a key factor when choosing a sports wheel. It’s probably the first thing most people think about. Yet what many may tend to overlook is the importance of a wheel’s rigidity or stiffness.
A recent article in Option Magazine attempted to compare the function of “rigidity” or “stiffness” of a wheel versus its “lightweightedness” and how these 2 factors affected overall performance. Enkei and GT-R tuner MCR together conducted a test using a highly rigid wheel, the GTC 01 and a specially-made, lightened version of the same wheel.
The test was meant to prove that although most people understand the merit of seeking a lightweight performance wheel, most tend to think that as long as a wheel is rigid or strong enough not to crack or bend, it should be fine. What they point out in this article is that when producing a true, race worthy wheel, reputable manufacturers take into account the degree of rigidity depending on the specifications of the particular racecar. The weight factor is taken into consideration only after the rigidy factor.
If you’re interested in reading this article, Jin took the liberty to translate the full article into english. Here’s a summary of the tests and results:
Regular High Rigidity Enkei GTC-01 18×10 +22: 23.76 lbs.
Specially Lightened Version Enkei GTC-01 18×10 +22: 19.8 lbs.
The weight of the lightened version was reduced by 3.96 lbs. Both used Advan A048 (265/35-18 M-Compound). Testing was performed at Ebisu East Circuit using MCR’s Z33 driven by Kobayashi and under the same specs (ie., tire pressure, # of laps, etc.)
Regular High Rigidity GTC-01
Best Lap: 1 min. 4.646 seconds
Top Speed: 147.16 km/h @ 17.83 seconds
Specially Lightened GTC-01
Best Lap: 1 min. 5.045 seconds
Top Speed: 141.46 km/h @ 17.74 seconds
A very rough and quick recap: The surface temperature of the tires for the less rigid, specially lightened GTC-01 were higher overall with extensive wear on the outer portion while not enough contact/usage on the inner portion. The high rigidity regular version GTC-01 showed even usage throughout the inner and outer parts of the tire. Also, the low rigidity, lightweight version wheels gave/bent when taking aggressive high speed turns even affecting the height of the car which even led to scraping and alignment problems. Furthermore, the lighter version accelerated much quicker, but ultimately did not lead to faster times. In summary, Kobayashi expressed that a balanced wheel with both rigidity and lightweight characteristics is important, but he never imagined that the effects of rigidity played such a large role.
link: http://og-made.com/archives/1904
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