Fat Bike Thread
 

There seem to be a few of them floating around, so I figured they could use a thread.

It seems one of the trickier aspects of these beasts is the tire pressure. I was out for a ride today at 9 psi rear / 5 front and it was handling great on the snow covered road. Then I decided to ride along some snowmobile tracks through a field and the back end was sliding around all over the place. After a bit more road riding I lowered the rear pressure to 6 psi and gave the snowmobile tracks another go, and it was much easier going. But that pressure was a bit low for the bare pavement on the MUP, but it was less than a km back to the snowy streets and a short ride home.

Tweaking pressure on the road is something that will probably be necessary if transitioning between vastly different terrain. One day at school I needed to raise my pressure a few psi and it didn't seem to need an excessive amount of pumping with my Topeak Turbo Morph. I might get a high volume mini-pump if I can find volume per stroke specs somewhere that show a different pump would be an improvement.


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Well, as a fat bike rider I can tell you that matching the PSI to the conditions is something that I always do. It makes sense to prioritize the tires when they are such a significant component of the bike. Fat bikes are designed around the tires in most cases.

The tread also makes a big difference in snow. Now that there is a selection available, I'm not the only fat bike rider who hates the Endomorph, although it looks like you don't have that problem.

All that gear on the back of your bike may also be a factor. Fat bikes are made to float over the snow, which isn't so easy if you are carrying a lot of weight.

As far as the winter conditions are concerned, there might be a "feel" aspect to it as well. I bought my fat bike before winter hit and rode it on some wet, muddy MTB trails to get used to it before the snow fell. I found that fat bike tires will slide in the mud but they "catch" before the slide goes too far and results in a loss of control like what would happen with a regular MTB tire. The fat bike tires are so large that in sloppy conditions when turning a corner, the first half of the tire slides and clears the way for the second half of the tire which catches the newly exposed earth and digs in. You just have to develop a patience and "feel" for it because such a thing is counter-intuitive on a regular bike. When in heavy snow, however, the snow can pack in the tire treads and then everything is lost. The newer treads which have come out recently are designed for just such a thing, but I haven't tried them yet.

That picture was from earlier in the week, today I just had a light trunk bag. Its amazing the difference in tire feel over the range of 4-12 psi. The large volume makes the pressure sensitive to changes in temperature. My pump seems to be one of Topeak's highest volume mini pumps, so I'll probably stick with it.

I've got a pair of Dillengers on order so I'll be able to ride faster on hard packed / icy roads. I also ordered a Bud to replace the Larry just in case the demand for Dillengers outstrips the ability of my LBS to get a hold of them.

I ran Nates last winter and they were a lot of fun. I ordered Husker Dus to use in town on the bike paths and horsetrails as they roll easier.

pre nates...

http://farm8.staticflickr.com/7159/6...8c6869a62c.jpg

For some reason I can't get a pic to load, but I run my Muk around 5 for single track and 25 on the paved road. I haven't ridden in the snow yet. Tire pressure is critical with these bikes and for the terrain you are using. I just have the stock Larrys as I'm not sure what tires I need. Kinda like the Knards though as they might work for single track and the road.

The only thing hard for me is that at times I lack the physical strength to ride it. Hauling myself and a 30+ fat bike can get tiring pretty fast. I see you guys going at high speeds for miles but I'm hanging on around 10mph average for my rides. Did 16 miles on a "Rails to Trails" path and 1 mile single track today around a lake so I'm not bad. Just slow.

Picked up a Moonlander this summer and I have to say I love that bike more than any other bike I've had since my '71 Schwinn Sting Ray. Nothing but smiles. I've been riding a lot of single track and some commuting on it since. There is no question that understanding and adjusting tire pressure is essential to the proper ride for any given surface. I'm usually running 9-10 psi for off-road, and 20+ psi for on road commutes with Big fat Larry's.

I've also got a set of Bud and Lou's and they are scary aggressive tires which grip like nothing I've ever ridden before. They're too much tire for dry conditions in my mind, the rolling resistance is notable. BUT, I can't wait to get them in some real snow. So far we've had a mere dusting. I'll update this thread with the snow report on those, if we ever get any....

Picked up my Pug this spring and love the bike... was especially fun to ride in the river valley along the river and on the single track and it has been great in our recent snow at 10-12 psi which offers a nice balance for soft snow and harder packed snow.

It rocks a simple 3 by 1 drive and I have a new rear wheel on the way to add an 8 speed cassette wheel which will work better for single track and harder climbing.

http://www.ravingbikefiend.com/bikep...erpugsley1.JPG

Right now it is off at the frame shop as we are in the process of laying out designs and making templates for dedicated front and rear racks.

I got my Surly Bud front tire yesterday and it is huge. I had to notch my fender near the fork to raise it to make room for the tire. I don't think a Lou will fit on the back of the bike. It raised the front of the bike up enough I'm going to need to adjust my saddle.

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Lets file this one under, "complicated solution to simple problem". I needed to true my rear wheel but it wouldn't fit in my truing stand, so I rigged up something to attach my dial indicator to the bike. An spare skewer happened to thread into a Manfrotto 035 Super Clamp. To get enough reach I used a piece of square aluminum tubing, to which I attached my gauge holder which I unscrewed from its magnetic base. Most of the stuff I had laying around, I just needed to pick up an M8 bolt and some nuts.

http://i969.photobucket.com/albums/a.../bIMG_0043.jpg

Hello gecho. You're running the Bud on your Rolling Darryl rim? I've read the 82mm rim doesn't give the tire the ideal shape. Can you comment on this.

I've only been out for 1 ride so far and the shape seems ok.

A zip tie attached to the stay or fork makes a great indicator for truing... I have built entire wheels this way using the frame as my stand.

Thanks for the input. I've been reading it was designed to work best with the 100mm clown shoe rim. I got my lbs to order a rim and hub etc to build me a clown shoe front wheel. Can't wait.

I went for a global fat bike day ride with a few people. We started with an intense ride along the creek, some of the guys with us are in incredible shape. One guy had a cross bike without studded tires and was able to fly through the snow (though not always in a straight line). That guy had some crazy bike skills, when we switched to the MUP he was riding no hands uphill on snow while removing a pullover sweater.

About 27km and over 2 hours of riding. I packed too much, expecting a longer ride on more packed surface, and had it all over the rear wheels. I need to take less and move some of the weight forward. Maybe a frame bag for light yet bulky stuff like spare clothing, so I can make due with just a trunk bag.

Gecho..... What fenders are you using? I have been looking at fenders for my Necromancer and I love the look of yours.

I modified a pair of Planet Bike Cascadia 29er fenders based on what I'd seen other people do. Some photos and information on how I made mine are on the 4th page of the 2nd link.

http://forums.mtbr.com/fat-bikes/cus...rs-672314.html
http://forums.mtbr.com/fat-bikes/yet...ad-744695.html

I recently modified the front fender to fit a Surly Bud up front by notching the sides to allow the fender to be raised a few inches. The part in front of the fork is a bit floppy now, so I may reinforce it some time.

http://i969.photobucket.com/albums/a.../bIMG_0073.jpg

Excellent..... Thanks for the links.

MadCityCycilist,

How do you find the fatbike works on our ice? I'm running 2.0 studded tired right now and am thinking of making the leap to a fatbike for snow, mud, and sand, but was wondering how well they work on ice.

Thanks,

Jon

I put a deposit down for 45Nrth studded fat bike tires two months ago, and it turned out as I half expected it would. The Canadian distributor got 8 tires for the entire country and decided to kill my LBS' entire order. Its crap like this that lets me feel not the least bit guilty bypassing shops and ordering stuff online.

It sounds like people that ordered the 45Nrth boots will be equally screwed over. Since 45Nrth said all of this years stock has shipped and there will not be another production run.

Tired out a necro pug at my local shop and compared it to my normal winter ride with studded tires. I was pretty darn impressesed with how it handled in all of our fresh snow, crud, and ice compared to standard studded tires. I don't know that it can blast through everything, but it certainly works better than anything I've used so far.

Anyways, I talked itmovermwithmmy wonderful wife and she decided that I needed one. :)

Jon

Since I'm running a 4.8" Bud in the front and a 3.8" Nate in the rear, the back of my bike doesn't have as much floatation on soft snow. Having a trunk bag on the back makes the rear end sink even more. Today I experimented with wearing a back pack instead of using a trunk bag to move some weight toward the front which seemed to help. I ordered a cheap frame bag and may also get a handlebar bag for days when I'm riding off the beaten path.

I decided to bite the bullet and order some very pricey carbide grip studs for my tires. They are removable, but I might just leave them in permanently since during the summer I'll put the Larry back on the front and might get a smoother rolling Knard for the rear.

Snow Bikes? Where? I can't imagine that this can be any fun.

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I'm only half fat, looking at a moonie next year though. Running a Nokian W294 aired up to a Gordo tubeless.

I screwed 148 Grip Studs into my rear tire and 60 into my front tire so far. I'll have to finish up the rest tomorrow and take it for a test ride. They feel very sturdy in the 27 tpi tire. The smaller knobs on the 120 tpi tire aren't quite as meaty as I had hoped.

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I was out on the unplowed MUP this morning after we had a bunch of snow and wind on the weekend. The narrow channel made by people walking makes for fun but slow riding. It took me over 2 hours to go 20km. I've taken to calling my fat bike riding "quality miles", since it takes much more effort to accumulate them.