Sunday, February 1, 2015

Gravity Bullseye Monster Update

I've had my Gravity Bullseye Monster fatbike out for a few rides so far, venturing out to the local parks in both the snow and the dry.

If I had to sum it up my fatbike experience so far, I would describe it in just one word:


Occasionally it's slow and fun, such as when I can go off trail and ride across the snow. But mostly it's slowness of the painful and frustrating variety, where I'm working hard for not much forward speed. Today's ride was a good example. We had an inch or two of new fallen snow over a couple of crusty inches. Riding the paved bike path to the trail was painful, more work than when I'm towing the kids and a trailer full of groceries against a headwind. I kept looking down, hoping to see I was plowing through a drift, but it was just a light dusting:

(actually, this picture was from later, with a bit more snow. Most of the paved trails I rode were even more clear than this)

It was fun to get into the woods and putter around, but it's still not as if I can float gracefully above the snow, like Legolas running over snow in Lord of the Rings. More like Gimli bulling his way through. Perhaps I can blame the tires, but I would quickly spin out going up any hills, just like riding a regular bike in the snow:

Fortunately, I found a fix for the ponderousness of the fat tires:

Yep, skinny tires, or least skinnier. I ordered up a cheapie $100 fat bike wheelset, meant to convert your fat bike into a reasonable all around machine in the dry season. It's generally not recommended to put 3" 29+ tires on such a skinny rim, but that didn't stop me from trying it out:

The narrower, lighter wheels transform the bike. When I got home after today's slog, I removed the 4" fatbike wheelset and put on the 29+ wheels. It was like getting a new bike: where I previously had to grind out forward motion, now I could just... ride. Like a normal bike:

It didn't have the stability of the fatbike where the snow got deeper, but the overall balance of the bike is so much better. I need to give the fatbike a trial in some deeper snow, but so far, a 29 plus bike looks like a much better package for my riding.


  1. Hi how has the bike been perfoming since you wrote this post? Still a good buy for the money? I like the idea of being able to get different tires/rims for it. and does it have place to mount rear/front rack or trailer? Thanks, Ed

    1. Hi Ed,
      I was feeling pretty negative about the fat bike experience at this post, but if you look a couple of posts later, it started to get better. Two keys: tire pressure, and tires. I was running my pressure too low (= slow), and the stock Mission Vees aren't worth much. On One Floaters made this into a new bike.

      So, overall, I think it's still a solid buy, but budget another $150 for some better tires. I'm not sure if any bike in this price range doesn't come with the Mission Vee tires, but if so, that might automatically make it worth checking out.

      I also like that this frame has relatively short chainstays (460mm) for a fatbike. Most others in the price range are more like 467mm. Not a huge difference, but something to think about.

      The frame has brazes on for racks, but I'm not sure what racks are out there to fit the 170mm spacing. If the trailer mounts to the QR (like the newer Burley design), it should be fine.

      Overall, I liked it well enough that I'm already ready to upgrade :)

  2. Grrrr Nice review but this doesn't help me much. :) If anything. I am more confused. hah!
    I have a geared 29er fun, but I thought I wanted a 27.5 ss. No real big hills here. Mostly what I want is house to barn which is bean/corn field or grass or root covered trail. It is around a mile loop. Just looking for that maintenance free yet FUN bicycle. I really enjoy my ss road bike.
    I decided to skip the $399 Gravity 27five, I can get the $299 Gravity Deadeye 26"x3.0 (close enough to a 27.5) Or I can get the $399 Gravity Deadeye Monster 26"x4.

    If the 4" doesn't really float on snow, and it is just all around slower. Maybe I want the 26x3" but the 4" looks so fun! I am the guy that likes to go fast though. I am 5'8" I like acceleration. hence dropping to a 27.5 from 29er.
    I'd bought the 29er for the road commute part. Now I'll just commute on road bike and leave whatever ss bike at parents farm.

    1. My $0.02:
      - a single speed fat bike in the snow is going to involve a lot of walking
      - if you're going to deal with the oddity of a wide bottom bracket and fat hubs, you might as well get the payoff of 4"+ tires to go with it. The Gravity plus/mid fat bikes use these fat bike standards, but don't follow up with the fat tires.

    2. curious If I bought the bullseye monster, it comes with 50mm drilled rims. I can mount 29+ 3" tires on those right? As in I don't want the gears... I don't my 5th bike to have a derailleur.

      I am still leaning towards the Deadeye though, thinking it will be a better summer bike, and just running the 26x2.75 all winter (its just a fun bike to go 1/2mile to the barn do chores) Walking is fun to if snow is deep enough ;)
      Anyways I'd be tempted to run a 26x4 surly knard up front for snow. It would fit on deadeye non-monster fork. With a 26x2.75 dirt wizard on rear. Lots of traction and running in the wider track left by a 4" knard up front.
      I only have about a week of not ridding last year offroad. It snowed a lot 5" I rode in it left a bunch of tracks with the 29er and then it froze hard. It was fine until I hit old tracks. It was like having front tire fall into drain grate in town.
      The rest of it was painful. but I was also putting in Large miles on indoor trainer same time from. The 2 were not intermixing! lol
      so I took a week off on the snow riding.

    3. The Bullseye Monster will fit a 29+ tire, but you have to buy a new wheelset:
      29" wheel: 622 BSD
      26" wheel: 559 BSD (2" or 4" tire, the rim diameter is the same)

      Have you thought about the BD Plus models? Those might be a good compromise, and they have single speed versions. Though you still have to deal with the wide bottom bracket and hubs.

    4. oh duh!! I wasn't even thinking about rim Diameter! I feel stupid now! lol
      I have pretty much ruled out SS for fat or 29+.

      So I am browsing Craigslist.. and your Bullseye pops up! hah congrats on your Salsa Mukluk. too bad I am 16" on that bike. which ironically is on bike Island for $450 for a 16"

      I Originally started this with the idea of a SS 27.5, but by the time I add a suspension fork. It is way more $ to invest in a SS than I want to. All roads lead back to the Deadeye non monster $299 + 26x2.75 Dirt Wizards (set for $110) on ebay at moment. It is kind of a win/win I get my 27.5 diameter tire, SS, and the volume of a half fat gives me a little suspension. and $410 is pretty inexpensive for a 5th bike to just play around on.

      thanks so much for the conversation! Dayton Ohio here btw.

  3. What wheelset did you get and from where? 135 front spacing and 170 rear?

    1. I got the Framed Fattie Slims, 135 front spacing front, 170mm rear. I still have this wheelset for sale:

  4. I've tried my gravity bicycle on thick sand. I did not enjoy my ride much since I got stuck every 20 m. I lowered the pressure to 3 psi and put it into easy gear but still I got stuck. I'm currently thinking to convert it to an ebike now. Any tips you can help me with?

    1. Sorry, no idea about an e-bike, but it seems like you would still get stuck, even with a motor assist, if you don't have enough flotation. I'm not sure even 5" tires (which wouldn't fit in the rear, anyway) will help with soft sand.

    2. Can you fit 4 inch tires on this bike?

    3. Sure, it comes with nominal 4" tires. I think they were more like 3.8", but there was still extra clearance.


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