I typically run 26x3.8 tires on my rigid Salsa Mukluk pretty much year round, and recently rode an extended bit on a friend's Salsa Pony Rustler (full sus 27.5+). Suspension kinematics notwithstanding, it was an eye opening experience. He had upgraded the wheels to Atomik Chubby 43 carbon rims, and the difference in spin-up was immediately, and prominently, noticeable over the full fats. Chalk that up to the 3-4 pounds less rotating mass that he deals with vs. my full fat on alu rums. What I really noticed, however, was that the cushion and muting of trail chatter on the B+ was so near to my full fats as to be negligible. This really has me thinking of building up a B+ wheelset to use for most conditions, and reserving the fattys for sand and snow. Anyone else have similar (or differing) thoughts?
Fat bikes
- Thread starter p nut
- Start date
rruff
Explorer
Reminds me of something I wanted to ask. Are you fat bike riders running tubeless? If you have massive butyl tubes in the tires you will suffer a lot of added weight as well as rolling resistance.
p nut
butter
I like your collection. I haven't ridden a 26" bike in a while (although technically, the fat bike has 559 rims), but I am in the process of building up a dirt road bike. I acquired an old Gary Fisher frame, using some old CK wheels, v-brakes, and .... drop bars! I've got a 60mm stem on there, so I'll have to see how that works out. Cranks--I'm using old Dura Ace 7400. Had to get extra wide BB (122.5mm spindle, I think). It should be a fun bike.
I've not ridden B+ much, but I often switch up fat and 29+ on my Jones. You're right in that the Plus feels lighter/more nimble. For summer riding, B+ would be a great option. Even with the lightest fat carbon rim and tires, you'll still feel a big difference with the B+ set up, I'd imagine. I'd also assume 29+ gets you even closer to full fat suspension effect, at the cost of slower accel.
Tubeless for fat is a must. Difference is substantial. It's so easy with the many options out now. I just use split tube method, but I've heard good things about this fattystripper rim strips.
Eagle05
Adventurer
Or is it the back up camera in your truck that you wonder how you ever lived without?
DaveInDenver
Middle Income Semi-Redneck
Don't have it anything like that so I couldn't say. Actually only saw a vehicle with a backup camera for the first time over Christmas and it seemed pretty unnecessary to me. So I guess I'm sticking with DVD Rewinder for the time being.
Yes, I have been running tubeless since the beginning. Anyone who runs tubes in fat tires, is, IMO, turning extra mass for no reason.
Can you compare thoughts on acceleration, nimbleness, cush, and overall feel compared to full fat? This is exactly the direction I'm thinking of going with my Muk.
Christophe Noel
Expedition Leader
I've spent significant time on fat and mid-fat tires/wheels over the last few years. If done properly, the weight difference between a 3.8 wheel combo and a 27.6+ setup isn't really all that significant or noticeable. The main difference is how they handle and ride. With full fat (4.6) or even regular fat (3.8) you can't really pick your way through rocks and chop, you often have to just commit to rolling over those things. With just slightly narrower 2.8 or even 3.0 tires on 27.5 or 29 rims, you can pick your way around those features far easier, which I find faster.
When driving fat tires hard in a turn, it just takes a bit more force and finesse. The narrower the tire, the less effort and maybe skill is needed to really drive a fast turn.
So much of this really depends on what you demand out of that last 10% of your bike's potential. I have a friend who completely geeks out on all of the nuance of wheels and tires and he rides so reserved, by his own admission, he doesn't ever get to that level of riding where it matters.
deuxdiesel
Observer
I have my Bucksaw set up with 27.5+ tires (Bontrager 27.5+) on Sun Ringle 50 mm rims and keep it like that for all-around riding. You give up some soft conditions handling, most due to not being able to run really low pressures. I routinely run 4-6 psi on my 4.0 or 4.8 fat bike, but with the B+ size, anything below 10 or 11 psi gets unnervingly squirrelly. At 12 psi and the suspension at 25% sag, it rolls over most terrain with confidence except for the softest conditions. I have now settled on a rigid fat bike with 4.6's for beach and fresh snow riding, and the Bucksaw with 27.5+ for everything else.
deuxdiesel
Observer
I still run tubes because at my weight I can still get away with low pressures and not suffer pinch flats, plus the amount of tape and fluid it takes to seal up big tires comes in pretty close to the weight of a light tube, and not all the rims and tires I have are tubeless friendly at really low pressures. I am also not a huge fan of how clumpy Stan's gets in cold temps. I know there are a few others out there, like Orange Seal, but I haven't tried them yet. My new Jamis Dragonslayer B+ bike will definitely go tubeless when the weather warms up.
rruff
Explorer
The rolling resistance of the tube will slow you down more than the weight.
deuxdiesel
Observer
I am pretty liberal with the baby powder inside the tire, which reduces the friction and makes it smell nice as well. I am not alone in still running tubes- many of my riding mates have gone back to tubes after lots of low pressure issues and for the simple fact that changing a tube in the cold is far less complicated than trying to unseat a tubeless tire that is firmly stuck on the bead shelf. But, to each his own.
rruff
Explorer
It doesn't actually help with resistance. The tube doesn't move relative to the tire casing anyway. The loss is from the tube flexing as you roll along the ground. Butyl is a very high-hysteresis material.
But it only matters if you are racing and care about every second.
deuxdiesel
Observer
At the pressures I run, and inside of a 4.6 tire, my tubes do not fill up the casing fully, so that is why I prefer a little talcum powder reduce the friction. I always toy with running the valve stem nuts or not- if I do the tube movement puts all the pressure where the valve is glued to the tube, and if not the stem wanders around a bunch. I've only had one tube failure at the valve stem, but that is on our fat tandem, which is rough on any type of equipment.
p nut
butter
Last weekend, I was running ~1psi. I'm lightweight as well, but I would've definitely pinch flatted running tubes. I use split-tube method, and it's easy peasy. Even changing tires, I can reuse the split tube without issues.
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But that's what works for me. If you're running tubes with no issues, and you're happy with the set up, why change? You're not in a race. Time "lost" due to heavier wheels just means you get to ride longer.
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But that's what works for me. If you're running tubes with no issues, and you're happy with the set up, why change? You're not in a race. Time "lost" due to heavier wheels just means you get to ride longer.