Shimano Introduces the 2006 Dura Ace 7801-SL wheelset
Shimano recently invited a select few “vip” retailers to Solvang for a three-day focus group to test their new 2006 Dura Ace SL wheels. It was a tough decision; three nights at the Royal Scandinavian, free food and a chance to ride. Gee, this was a tough decision.
Road Trip!!!
We arrived Sunday afternoon and immediately handed our bikes over to Shimano’s number one mechanic, Andy. He mounted the new Dura Ace 7801-SL wheels complete with new Michelin Pro Race tires, new Michelin tubes, as well as a new Shimano cassette and chain. I’m thinking, these guys have seen how well bike shop owners take care of our own bikes and were not taking any chances that a mechanical would ruin our experience. The invitation said Campy bikes are welcome and that Andy could make Campy and Shimano work and play together well. You just know we had to see this so along went our Campy Record equipped Moots SL.
The digs were very nice indeed the Royal Scandinavian Inn is a quaint establishment in downtown Solvang, the perfect place to hang out for a couple of days. That evening Shimano booked a banquet room and fed us well, including lots of introductions and instruction about the next two days. The highlight of the evening for us was the hour we spent after dinner getting some quality time with Wayne Stetina.
The next morning the sun was up, the winds were down and the temperatures were perfect. The peloton headed off to ride some of the very same roads U.S. Postal and Discovery have used in their Solvang training camps. The roads in the area are good but not great, just the kind of surfaces to test new wheels.
Steve White aka The Michelin Man had flown in from the East Coast as Michelin’s on site rep and had correctly inflated our tires to Michelin’s recommended pressures. Did you know that you are over inflating your tires? Steve explained the importance of the relationship of contact patch size to tire efficiency and how rider weight must be considered when you determine the correct pressure to achieve that sweet spot. Below is a link to Bib’s page for correct tire pressures.
We immediately noticed how smooth these wheels rode. The rims on the new Dura Ace 7801SL wheels are made from a Scandium alloy, which lends a more compliant ride feel than other aluminum alloys. This is not to imply that there is a disconnected, riding on a cloud feel but the ride is smoother over all. Shimano claims the rims weigh in at 400 grams each. That’s light, almost sew-up light, and the wheelset's acceleration does nothing to make you think otherwise. When pulling away from a stop or making a jump to bridge a gap these wheels wind up quickly. Now of course sixteen bladed spokes in the front wheel and only twenty in the rear together with the 24mm aero profile rim keep the aerodynamic drag low to help you maintain momentum once you are up to speed. The rims’ attributes don’t stop here though, Shimano made the rims 20.8mm wide, which is a little wider than many rims in this class. Their studies showed that the typical 700x 23 tire the average roadie uses mated up aerodynamically better to a slightly wider rim and the extra width spreads the tire out a little wider at the bead improving the ability for the tire to grip and corner well. However, the really big deal with these rims is that they are tubeless compatible! The wheels have reached the market before tubeless tires, but it will likely be worth the wait. The advantages of tubeless will be a more sew-up like ride and steering with weight savings over the traditional tire and tube of 20g to 60g per wheel. If you puncture the air loss should be lower and slower. In the event of a blowout the tire should not roll off the rim providing for a more controlled and safer stop. Mounting and removing the tire should be accomplished without the use of tire levers and roadside repairs will simply use a regular inner tube.
The rims are not the only part of a wheelset and Shimano paid close attention to the hubs also. Rear wheel stability is very important and a common method to increase lateral stability is to tension the spokes very tightly. This approach works but places greater stress on the wheel system and can lead to premature failure. For 2006 Shimano found a way to reduce the side-to-side flex that occurs when you climb or sprint without making the spokes banjo string tight. The Dura Ace rear wheel flanges allow the spokes to be placed further apart which when coupled with the offset rim, dramatically improves the lateral stability of the rear wheel. The nipples are placed at the hub, which helps keep the rotating mass furthest from the axis of rotation lower. In simple terms the weight furthest from the hub is the weight that is the most critical. Rims, tires, tubes, rim tape and spoke nipples are the components of a wheel whose weight you want to keep lighter for the best performance. Hubs and skewers on the other hand are essentially at the axis of rotation and the effect of their weight on wheel’s performance is much less important. What is important in a good hub are things like quality materials, sound design, ease of maintenance, and well sealed bearings without lots of bearing drag. The hub shells are forged and use traditional cup and cone bearings. This means the bearings can be disassembled and overhauled and they can be adjusted so as to not be too tight when the quick release skewer is closed. We were impressed to hear that Shimano uses high tech laser measurement equipment and matches the bearings and cones to provide the best possible match for the longest life and lowest fiction. We mentioned bearing adjustment and with these wheels one cone wrench and a 5mm allen are all that is needed, making adjustments easy and fast.
Earlier we told you that Shimano’s Ace Wrench Andy could make Shimano and Campy work together and indeed he did. Here’s the coolest part, there is nothing to it! Andy simply installed the wheels, readjusted the rear derailleur limit screws as needed and readjusted the cable tension. These tweaks take a good mechanic about five minutes. No special cog spacers in the cassette or other magic just use a Shimano 10 speed cassette and 7801 Dura Ace chain. Shimano of course cannot condone this sort of sacrilege because they have no control over other manufactures’ tolerances or changes in specifications but for now it has been shown that Campy 10 speed shifters and derailleurs can work with a Shimano 10 speed cassette and the new narrower 7801 Dura Ace chain. We have over 600 miles riding this combo and have had zero shifting issues.
At $980 these wheels are well placed from a price point with other top of the line aluminum rim wheelsets and are well below carbon rim wheelsets. We have available demo 2006 Dura Ace SL wheelsets for test rides and yes Campy 10 speed is welcome but fair warning; you’re going to want them after that test ride.
Ashton “AJ” Johnson
Also co-owner of Sundance Cycles, AJ has owned his own shop for twenty years, raced mountain, road and track and was an alternate on the US National Team. AJ has been a certified USCF coach, has completed the Serotta Elements and Advanced Fitting Programs and has performed thousands of fittings for our customers.
