Thursday, January 26, 2012

The Oasis

Concrete jungle
Wednesday I went for a morning ride to test out a theory I had regarding the Larry 3.8" vs the Big Fat Larry. I was wondering if I would have made more progress through some deep, granular snow on the BFL's than I had on the smaller 3.8"ers.

I also was wondering how the inertia of the heavier wheels might affect all of this. The overall weight of the two bikes might also come into play as well.

So I left to go ride a couple of stretches I had ridden earlier this week where the snow had not been plowed. Temperatures were similar for each day, but there had been some warmer weather where the snow may have firmed up some over what I had originally experienced. As I reached the unplowed sections, I had high hopes that the Big Fat Larrys would float up a bit better, despite the bike weighing more.

I found out that even though I had bigger tires and that the snow was maybe better, I didn't see any real advantage. In fact, it may have been a disadvantage really. I think a couple of things were working against me on The Snow Dog.

Big ruts!
Those Big Fat Larrys push more of a "wake" than the skinnier tires do, so I was working harder when the tires did sink in. Secondly: Those big tires didn't float up like I thought they might, so I was fighting the higher resistance to the wheels more with the wider tires. Part of this was due to the heavier wheels/bike overall.

By-Tor the Titanium Mukluk has much lighter wheels, tires, and tubes which gave it a big advantage in the inertia department, as far as overcoming wheel weight. I also found that the skinnier tires seemed to deal with the snow in a similar manner to the BFL's, but since the weight of the front end was so much less, the titanium Mukluk would float over stuff better, leaving the rear to dig down and get traction.

Either way, the rides were both exhausting exercises. I had to go at a high torque, low speed setting and my legs and body were working hard to keep either bike going straight and moving forward. I think things were a bit more successful on the titanium rig, but that's splitting hairs. Dealing with ruts on The Snow Dog made life harder, which I didn't have to do with By-Tor.

Rest stop at The Oasis
The Wednesday ride saw me taking a break underneath a bridge for Highway 218. The bike path goes underneath here and on either side the snow was very deep. Both bikes were grinding in the snow near here, and my body was working way too hard to keep it going, but I was having fun seeing what I could ride over.

I stuck around a while to cool down, took some images, and then lumbered home with legs that were shaking when I got home from all the hard work. It was fun to figure out which worked best for what, and technique was honed as well.

Obviously, Big Fat Larrys are better suited to situations where trail/snow has been packed down some and skinnier tires are punching through a bit. I would probably find that on snowmobile trails, but the snomo folks must be sticking around to the country, because I can not find a snomo track in town yet to save my life. Guess I'm going to have to head over to Mitchell Sand Pits next, if there is any snow left this weekend!


Joboo said...

Did you play around with PSI? I didn't see mention of it; although it's early, and I'm at work!! Lol
I know that's what makes the difference in my FatBiking adventures.


Vito said...

Interesting...I've kind of been thinking the same thing all along. Bigger is not necessarily better. At what point does "Fat" actually become a disadvantage. I know there is a mindset out there that believes the possibilities with fatbikes is endless and they will take you anywhere no matter what the conditions. I tend to strongly disagree. It's physics...and I'll bet that in heavy wet snow without a packed trail you will not get very far on those BFL's no matter how much float you think you will get. I'm not sold...I love my Pugsley and the 3.7s or 3.8s, but I also realize that there are limitations. There are times that I also wish I had gears. I'm running ss which adds a whole new dimension to the game. I'm looking forward to hearing or reading more on this topic.

Guitar Ted said...

@Joboo: I had low pressure in both bike. I'm sorry, but my gauge isn't accurate down this low, so I only use it as a reference point between the two bikes and go by feel. (I really probably should have an accurate gauge!)

That said, I had the bigger tires of the Snow Dog at what I felt was an optimum for float vs. rolling, and By-Tor's tires were set the same. I did try to make both the same/similar feel to eliminate that from my parameters as much as I could.

I wanted to know, in these conditions, what worked best. I think narrower, (in these odd, and what most wouldn't ride in), conditions is better than wide.

mw said...

haven't had the op for deep snow at all here. but i'll be sure to report how my front and rear bfl's do. yeah buddy.

what i'm curious about are some high mountain and/or rocky ledgey western slope mountainbike rides on my new floatation bike. which yeah, i'll also report when it happens.

Joboo said...

I do have a low pressure gauge, but I find myself not using it much. For whatever reason it seems like i use the squeeze method more. I mean really, if I adjusted the pressure all the time for the conditions....... I wouldn't be riding much!! Lol
If I bog down, I don't have a problem pushing to where I can pedal again, and again, and again, and again!! ;)

gotta agree with your statement Bill!!
When does the wideness over play the pure fun the pedal??!!


Lance H Andre said...

GT, is correct, if the snow conditions are not favorable to getting float then there is very little advantage to the large tires (we have seen that at prior years of Triple D when the winners were half fat and half skinny).

Float can be improved by three factors: 1. Total bike weight, 2. Contact patch (tire width, rim width and psi), and lastly 3. Weight distribution. However, in fresh snow, only option is to follow someone else or work your ass off… still beats a day at the office!

Vito said...

"Still beats a day at the office." Amen to that!!

Doug said...

@Lance H Andre

I disagree that total bike weight has any affect on the amount of float you get. If you look at the total wt of a 200lb rider plus the weight of the bike, the difference is minimal. A 35 lb bike vs a 30 lb bike plus a rider is a total difference of 5 lbs, or only 2% of total wt.

I agree with Vito. Float is everything. when you're looking for a do it all snowbike rim and tire. When the new 100 mm Clownshoe was announced, I found myself uninterested. I've put in 1,000's of miles on snow with my Pugsley since 2006 with 65mm Large Marge's and 3.7 Endomorph's. I ride mostly on packed snowmobile trails in northern Minnesota with hard pack conditions most of the time. Anything wider would not give me any additional advantage.

Also, get a good gauge. Conditions change daily and as little as 1 psi difference in psi can make huge differences.

Doug said...


Float ISN'T everything.....

David O'Sullivan said...

Might that be why surly made the clownshoes for the BFL? there must be quite some difference between 100mm rims and 65/80mm in term of float...

Same as squeezing a 29r on a road rim, it works (just), but not as well as a nice wider 29r rim

retroscool said...

My experience has been that in some snow conditions I have been better off riding my "fat bike light" set-up which has a setback seatpost and a shorter stem with H-bars then my pugsley. The rearward weight bias and narrower rear tire (2.4 racing ralph on a P35 rim) digs in better and I also find it easier to spin. I find that as long as the snow isn't actually deep enough to "float" on and I have the steering control of a fat tire up front (Larry on an 80mm wide rim) The narrower back tire works better. That being said when snow conditions do get deeper or on sand where more floatation is required the larger tires do work better. It's a tough subject with too many variables.

rideonpurpose said...

5 lbs if 5 lbs... being lighter in all ways will increase your float.

In GTs example here of fresh snow I would bet my CX bike with 46mm deep rims and flexus cubus 32s would have been the clear winner... It's a real world test/situation but not what most people are really using fat bikes for. It would probably take a 37" wide tire to actually "float" on unpacked snow.

So far as flotation in conditions where it can be reasonably expected- Another major factor is rider weight. At Triple D Spinner was on big fat larry's @220 lbs and I was on larrys @170 lbs... I bet we had a similar end result. Seemed that way on our pre-ride at least.