Longtime partner BBS Wheels announced the release of the new BBS CH-R wheels and it immediately sparked an interest for our project A5. Available in silver and matte black, BBS took the classic CH and gave it a new look with a concave face and contoured spoke design. We contacted BBS about the wheel and planned to order a set of 20x9.0 and 20x10.5 for the front and rear , respectively. At the time of the order, a special finish was announced known as "Titanium" and would be special order from Germany. We decided to wait on this "Unobtanium" and we managed to receive one set of only a few wheels to have arrived after a few month waiting period.
Upon arrival, the wheels were inspected and having had a number of wheels sets in various sizes already on the car, we decided to give the 20x10.5 a try on the front of the A5. After initially test-fitting the wheels for clearance, we mounted a 275x30x20 tire and tested for clearance under compression. Passing the tests, we took the A5 out for a test-drive with the wheel setup and were pleased to find that aside from the fender liner clips, the setup did not rub, even on our aggressive stance with the H&R Street Performance coilovers turned all the way down. A quick call to BBS secured a second pair of 20x10.5 CH-R's and completed our inquisition to maximize our contact-patch. in doing so, we have also been able to retain a matching wheel and tire size all the way around our Audi. BBS had previously only fit the 20x9.0 all-around for those that were concerned with Audi's Quattro differentials, choosing to stay away from staggered set-ups.
We then contacted Continental Tire to discuss our tire fitment. The technical specifications of their tires for a 20x10.5 recommends that a tire must be at least 285x30x20 for proper operation. Continental's recently released DW and DWS tires have taken the high-performance market by storm and are popular for both their performance and price. In particular, the DWS is available in a number of custom sizes, including the desired 285x30x20, and carries a 540 treadwear rating. We now had a performance tire that properly fit our wheels.
Before mounting the Continental tires, we examined our wheels to see if we could make adjustments to accommodate the wider 285x30x20 tire size. We measured and compared the backpad depth of both the stock Audi A5 as well as the BBS CH-R wheels and determined that we could increase the offset by 5mm, taking the BBS wheels from a 25mm offset to a 30mm and effectively pulling the wheel inward and away from the fender's lip. Our machine shop carefully removed the excess material from the wheels back-pad.
The wheels and tires were mounted, filled with Nitrogen, road-force balanced and then installed on our project A5. After a number of city and highway miles, we braved the road-course circuit at VIR with our custom wheel and tire package. The car performed extremely well with no major rubbing. However, due to the extremely lowered stance of the vehicle and the comfort specific spring rate of the Street Performance H&R coilover kit, we did experience some rubbing of the fender liners and inner portion of the fender lips. Considering the ride comfort and mileage capabilities of the Continental DWS tire, which was never designed to be a track tire, this wheel, tire and suspension package combines the best elements for a street enthusiast's Audi A5.
