Well after what seemed like the longest day ever at work, I was able to get home and see what Peter had sent me. Wheels!
As with everything we've ordered, there were 3 sets of nearly identically built wheels. The only difference was hub/nipple color. We have two sets in red and a single set in black.
All sets are built as follows:
N-SS IP-HR930C Wheelset
- IP-HR930C - Carbon, hookless rim
- Novatec D771SB Front Hub
- Novatec D772SB Rear Hub
- Sapim Delta spokes
- Sapim SILS nipples
This is the profile of this rim:
The weight listed on iPlay's website is perhaps a bit optimistic at 1525g. The three sets I have in my hands averaged exactly 700g (front) and 890g (rear). The range on the three front wheels was 3 grams. The range on the rear wheels was 10 grams. Not bad at all.
So why such a W I D E wheel for an ultra-light XC machine? Well, a variety of reasons. Traditional XC rims have an inner width of 19-23mm. These rims are 26mm, In the past two years, the industry has been moving towards wider rims across the board, from DH to XC. And a lot of this has to do with the advent of tubeless tires. A wider rim has several advantages:
- Allows sidewalls of tire to stay more "vertical", offering more support while cornering, even at lower pressures. As the two beads more further apart, the tire is more supported in the rim rather than pivoting on the rim when the beads are close.
- Allows a smaller width tire to perform as a wider tire. This allows the use of a smaller tire casing for weight savings which can easily offset the small increase in rim width. For example, a 2.2" tire might act as a 2.35" equivalent.
- Increase wheel stiffness.
- Large reduction in "burbing" of the tubeless tire on the rim at lower pressures.
- Increase traction and comfort from reduced pressure needed.
Or at least this is the theory. I will see how this plays out in practice. Perhaps it is all marketing, but it does make good sense on paper, so I suspect there is some truth to it. The above reasons aside, I am looking forward to the reduction in rotational weight over my previous wheelset (~2100-2200g!) and a huge increase in robustness and stiffness over my previous alloy wheels. Opting for a more traditional width rim would have yielded a decrease in weight (marginal), but I suspect the benefits of the increased width will offset the ~100g total per wheelset penalty.
We also decided to try hookless rims on this build as well. Many of the industry players have started to convert to hookless on carbon. Again, there must be a good reason? Well there is. Hookless beads allow for an easier/cheaper to manufacture rim. The rim edge also gets more continuous carbon fibers so it is stronger against impacts than the older hook design.
One last note before the pictures. These wheels were packaged with the utmost care. They were carefully wrapped with protective caps to prevent the axles from damaging rims/spokes on neighbor wheels. The cardboard boxes they were shipped in has custom inserts to hold the wheels in place and fixed relative to one another. My kudos to iPlay.
Rear:
Front:
Front weight:
Rear weight:
The UD matte finish has some neat patterns in the right lighting. Subtle but neat.
Outer width (you can see the hookless profile here):
Inner width:
Rear hub in red:
Front hub in black: