snow floatation setup
Will wide rims and low pressure make a big enough difference for the expense or should I just go skiing and stop being silly? I have been commuting on Nokian M&G for a few years now up here at 9500ft in Colorado and am toying with the idea of a wide rim setup for pure snow riding. I could get snowcats for my commuter or go for the 29er makeover. Just put weirwolf LT 2.55 on the 9er and road up a packed road that gets lots of snowcat travel and they didn't float so well. There just isn't enough safe plowed roads up here to keep me entertained. I was hoping I could ride snowmobile packed trails and such.
Good questions, I'm of the opinion that in the Rockie's the temperatures are mild enough that even snowmobile packed snow is often not hard enough to support bike riding. Especially when it is deep snow. If it is just a few inches on a hard surface underneath, sure, no problem. But if the snow is pretty deep there has to be pretty heavy snowmobile traffic to pack it down hard enough. And because the temperatures are mild enough and the snow is pretty dry in the rockies the snow does not usually get real hard on it's own.
Of course, the bigger the tire footprint is the better the bike will get some flotation and the wide 4 inch tires are going to be the best choice. They have significantly more contact area and can be run at much lower pressures than a 29'er tire. A 29'er tire has only a slight contact area advantage over a standard 26 inch tire of the same width. In fact, a 4 inch wide 26 inch tire has such a high profile that it is probably almost as big as a 29'er mountain bike tire on it's outer diameter.
Then there is always the option of the cross country skis if the snow is not hard enough to support the bike. I think the 4 inch tire and wide rims are the better choice for a snow bike.
Last edited by Hezz; 12-14-08 at 07:46 PM.
Dog is my co-pilot
You won't be able to float on deep snow with any bike tires, unless there is a frozen crust. What you do get from very,very, wide tires is more work pushing them through the snow. In hard packed snow from cars, studded tires grab extremely well. When you get to 6" deep snow your pedals go down into the snow a little. It's a lot of work to go very far. Over 6" is so much work it's not worth it unless you want a work out. It also depends on how sticky the snow is, fresh powder is much less work than sticky snow. Wider tires do handle a lot better and low psi is a big help. 25psi in 2.1 tires is great on slippery snow. If there is no ice for the studs to grab studs don't help in the snow.
Fat low pressure tires do let you ride where you couldn't otherwise go. You won't float on top of powder snow, but you will get traction in loose snow and be able to get through sections that you'd be walking with normal MTB tires. There is a limit in terms of snow depth and how much effort it takes to chug forward. If you want to ride packed snowmobile trails some 3.7" snow tires will do the trick.
The trouble is most bike frame do not have clearance for fat rubber. I have a MTB that lets me run 2.4" tires - which are pretty huge for XC riding, but it doesn't have near enough clearance for 3.7" snow tires. A Surly Pugsley will take snow tires, but that may be more of an investment than it's worth depending on your goals.
I built up a Pugsley this year with the goal of getting in lots of winter riding, including some touring. I've been out several times in the last few days cruising around with ease while most other cyclists are struggling with the aftermath of a winter storm.
Vik, Have you taken out the BD yet? It would be slick to put a Pugsley fork on your BD for the winter. No stopping it.