Wheel width = Grip

Every major circuit racing series has moved to wider front wheels in an effort to increase grip and reduce track times.  In 2012, DTM increased front wheel diameter from 11 to 12” wide.  A few years before that, Super GT moved from 12” to 13” wide wheels.  In 2017, Formula 1 increased both front and rear tires by 25%.  LMP1 cars moved up to 14.5” or 14.75” while maintaining a narrower 14” or 14.5” in the rear.  Who would have thought that top racing teams would have wider front wheels than rear on a rear wheel driven car?  This goes to show that front grip and braking capability is just as important as rear drive grip.  Over the past several years, the Porsche GT3 RSR has evolved from 11” to 12” and now 12.5” wide front wheels.  From 2009 to 2011, all of the top time attack teams had 10.5” wheels, in 2012 all the records are falling on 11” wide wheels.  In top end racing, wider wheels equal more grip, better braking, less under steer and faster laps times.

1” of extra wheel width is worth ~ 1 sec per min of track time

Over the last decade the Miata racing scene has followed this trend of plus sizing their wheels.  At first the fastest Miata’s were running 7” wide wheels.  When several racers jumped to 8” wheels, many thought they would be too heavy, but seconds were shaved off the fastest lap times and everyone moved to 8” wheels.  When 9” wheels became available, doubt again set in about the weight penalty.  Within a year, all of the fastest Miata teams were running 9” wide wheels.  Then teams moved to 10” wide wheels and times are dropping further.  There is of course diminishing returns and will obviously be a limit, but the diminishing returns is low.  Wider wheels simply allowed the fastest Matias to brake later and carry more corner speed.  At most tracks, carrying 10% more speed in the corners is faster than doubling your HP.

Each extra inch of wheel width is worth roughly one second per one minute of track time.  For example, on a track like Buttonwillow CW13 where competitive laps are around 2 minutes, you should see around a 2 second improvement.   Each extra 1” provides an increase in mechanical grip that improves both low speed as well as high speed grip.  A +1” in wheel width provides a similar improvement to moving up in tire classes, like an Extreme tire to R comps or R comps to Slicks.  Again, the extra grip gained more than compensates for the increase wheel and tire weight.

If the ultra-competitive Miata racing is not a strong enough proof point, where corning speeds and braking make up for lack of power. How about one of the main reasons the Porsche GT2 RS is faster than the Ford GT (best in class aero) and McLaren 720S (best in class power to weight ratio) around a track?  Look at the front wheel widths, the Porsche is 1” wider allowing it to brake harder and turn faster.  The AMG GT-R Pro and Black series front wheel are even wider helping it keep up with lighter and rear engine GT2 RS.  Wider wheels, especially front wheels are faster.

Our goal is to work with you to add 1-2” of wheel width significantly improving grip.  We need to know what wheel widths you have today, current backspacing and detailed pictures of clearances with the suspension, tire well, chassis and fenders.

Helium Wheels for ultimate weight savings and ride comfort

Helium wheels is URGE’s brand name for our Magnesium wheels.  Magnesium is the lightest weight of all the structural metals and >30% lighter than Aluminum while being with in 10% of yield strength.  Taking wholistic wheel design into consideration, Magnesium will save 20% weight vs a comparably designed Aluminum at similar load ratings.

With our design ethos of every pound or kilogram matters, rotational weight at typical wheel diameters has a 4-5X effect vs static weight.  Meaning saving 5 lbs per wheel vs a similar designed aluminum wheel or 20 lbs overall is similar to removing 80-100 lbs from your car.  That is less weight to accelerate, less weight to stop and lower gyroscopic effect allowing the car to turn faster.

Additionally, magnesium wheels have a high dampening factor meaning they absorb vibration.  This is a noticeable effect that improves driver comfort and reduces fatigue from noise, vibration and harshness.

Match your tires with a slight stretch

Another thing to consider is tire width.  Many people believe that wider tires improve grip.  However, this is not necessarily true.  Tires should have a slight stretch on the wheels.  Fitting the widest tires possible on specific wheel sizes will deaden response and create more roll due to unsupported sidewalls.  Additionally, tires wider than wheels will decrease the performance and function of your dampers as you introduce a major damping mechanism into your system.  Extra tire width does not always provide a wider contact patch as the wider tire is pulled up at the edge of the tire by the narrower rim.  The wheel width actually sets the width of the contact patch.  No top tier racing series use tires that are wider than the wheels.  You can clearly see tire stretch to a wider rim in close up television shots.

Custom designs, widths and Offsets

URGE dynamics Grip and Helium wheels are custom wheels that provide you choice of 3 classic and performance optimized designs, a range of 6 diameter combos from a track focused 18/18” to an OEM GT RS 20/21” and the ability to go as wide as possible maximizing mechanical grip, dropping seconds of track time.  Additionally, we can work with you to find the right colors needed to match your paint scheme to simply black wheels that mask brake dust to Gulf Oil or Martini Racing colors.  URGE dynamics Grip and Helium wheels are your high value custom wheel options.

Wheel Styles

Helium Wheels F/R diameter pricing

• 18/18” $6300
• 18/19” $6450
• 19/19” $6600
• 19/20” $6800
• 20/20” $7000
• 20/21” $7500

Helium Wheels features

• Magnesium Alloy
• Targeted <16 lbs for 18x10” width
• Targeted <2x lbs up to 20x13” width

Grip Wheels F/R diameter pricing

• 18/18” $3900
• 18/19” $4050
• 19/19” $4150
• 19/20” $4250
• 20/20” $4300
• 20/21” $4400

Grip Wheels Features

• Aluminum Alloy
• Target <20 lbs for wheels 18x10” width
• Target <2X lbs for wheels 20x13” width

Overall Wheel Design

• Forged & Machined 1 Piece Design
• Maximum BBK Clearance

Colors

• Silver, Bronze or Black Finish included
• Custom colors available for $600 (This will be added to your invoice during the consultation)

Recommend tires per wheel widths

• 9”; 225 to 235mm
• 5”; 245 to 255mm
• 10”; 255mm
• 5”; 65 to 285mm
• 11”; 285 to 295mm
• 12”; 305 to 315mm
• 5”; 325mm
• 13”; 335 to 345mm