We'll be answering that question in the coming weeks and months. We installed a set of new Khamsin wheels tonight on the Campy Only Sachs--no time to ride them, but rest assured they'll see some miles soon.Khamsin's are Campagnolo's least-expensive wheelset, sitting at the bottom of lineup that includes (from most to least expensive) Shamal, Eurus, Zonda, Scirocco, Vento, and ... Khamsin. They're based on Campagnolo's "G3" spoking pattern, which arranges the spokes in groups of three--two spokes on one side pulling against one on the other. For the front wheel, there are eight of these pairs, alternating between the sides with two spokes. On the rear, all of the two-spoke pairs are on the drive side and all the single spokes are on the non-drive.
A very smart rocket scientist friend of mine (no kidding ... he works for NASA) once told me that the G3 pattern is bunk. He said there is no engineering reason for the pattern, and that it shouldn't be any stronger or better than a "G2" pattern with one spoke on each side.
That may be true, but the Scirocco wheels we've had for some five or more years, also based on the G3 pattern, have been tried and true (no pun intended) through thousands of miles of riding.
So, let's see how the Khamsins hold up. Check back and see.
Some stats below. The total weight of a Khamsin wheelset is 1,895 grams. That's about 140 grams more than Ventos (about 5 ounces) and a whopping 400 grams (more than 14 ounces) heavier than the top-of-the-line Shamals. But really, how many of us need Shamals for daily riding ... or any riding? And keep in mind that a pair of Khamsins will set you back about $400 (less on eBay and other places), while a pair of Shamals is on the far side of $900. That's right--with the money you save, you can almost buy the new Apple tablet computer when it comes out!
Khamsin front wheel: 855 grams (all weights per www.campagnolo.com)
Khamsin rear wheel: 1040 grams
Vento front: 810 grams
Vento rear: 945 grams
Scirocco front: 770 grams
Scirocco rear: 955 grams
Eurus front: 660 grams
Eurus rear: 890 grams
Shamal Ultra front (clincher): 605 grams
Shamal Ultra rear: 790 grams
I would certainly agree using G3 on the front wheel is bunk.
ReplyDeleteOn the rear wheel using twice as many spokes on the drive side makes spoke tension more uniform. The high dish on modern rear wheels translates to drive side tensions more than twice that of non-drive side. With equal number of spokes on both sides it is difficult to get the wheel tight enough so the non-drive side spokes will be tight enough not to back off.
The old Roval wheels (not to be confused with the more recent wheels by Specialized also called Roval) used equal spoke spacing much like Fulcrum's offerings. It would be interesting to see an engineering analysis of using equally spaced spokes vs. grouping them together as Campagnolo does.
The biggest reason I have been able to figure out for the G3 pattern, is spoke tension. I just had my Rolf Dolimites repaired and trued, and the mech kept stressing how much tension a paired spoke wheel needs. I believe I read on Campy's website that the adding the third spokes means much less tension. Now for a 140lb person, this may be a moot point, but for me at 6'2" and 225lbs (right about 100kg), this could mean a longer lasting wheel, more comfortable ride, and possibly less flex (?). I've had my Khamsin's for 2 years now, and have beat them hard on both my road bike and cyclocross/commuter bike. They are still true, and tough as nails, but a bit heavy on the road bike on the steep (but short) Maine hills.
ReplyDeleteIt's not just weight-savings you're paying for with the more expensive wheels, I believe the seals are better.
ReplyDeleteMy (up to then) lightly used 2007 Khamsin failed to cope with a rain-sodden 1400km randonnee this summer. The seals went, and the freewheel stopped working properly, although fortunately it didn't completely fail to engage. Result was new bearings and a new freewheel mechanism which with labour cost half the price of a new set of wheels!
My heavily used Swiss DT 1450s have behaved impecably through similar conditions.