Since I recently moved to the Northern Rockies, I have been excited about getting in to snow sports. (For a guy from Texas, this is all still very new. The heat kept me inside this whole summer, and I'm not about to let the cold do the same.) Snowshoes and XC skis were on my wish list.
When I saw the MSR Lightning Ascents on sale at Backcountry.com, I went back and forth between getting the 25" and the 30" models. I ended up buying both, figuring I could compare them and send the pair I didn't want back for a small penalty. I thought I'd share what I found, pictures included. I got the yellows because that is what my wife likes.
First, here are the weights:
25" listed weight: 31 oz per shoe
25" measured weight: 31.3 oz per shoe
30" listed weight: 36 oz per shoe
30" measured weight: 36.4 oz per shoe
5" Tails listed weight: 4.5 oz per tail
5" Tails measured weight: 4.7 oz per tail
One of the things I've seen people on the forums wonder when comparing the two is the placement of the bindings on the 25" versus the 30" models. You'll notice that the bindings on the 30s are set back a little farther than on the 25"s--they're more centered on the shoe.
Not only that, but the bottoms of the shoes are a little different as well. The 30"s have an extra traction bar on the tail of the shoe to compensate for the increased surface area and for the increased weight rating. That's probably a big part of the weight jump from the 25"s to the 30"s (5.1 oz per shoe). It's not all decking.
It's also worth noting that front end of the 30" shoes is raised higher than the 25" shoes, given the extra length on the front decking. They both continue up at the same angle.
I measured the front part of the decking at 3 5/16" on the 25" shoes and right at 5 1/2" on the 30" shoes. Basically, the bindings are set back about 2" on the longer model.
When I added the 5" tails to the 25" shoes, they do come out right at the same length as the 30" model. But again, as you can see in the picture, the bindings are 2" farther forward than they would be on the 30" model. I'm not sure how much difference this really makes, but it might explain some of the reason that people are finding that the tails only add marginally extra flotation. For 7.2 oz carried or worn, I guess that's up to you.
And just for good measure, here is a picture of the tail attached to the shoe. The end piece hooks into a slot on top of the shoe, and the very burly rubber keeps the tension with the bottom pin. It was somewhat difficult to get on at first (the rubber is very stiff), but I imagine that will change with a little practice. Regardless, the tails feel very secure, and this can all be done with gloves on.
Let me know if anyone wants me to take any more pictures. It will probably be a few more days before I send a pair back to Backcountry.com. (I'm still trying to decide which ones to keep!)