jefnvk

I guess the paradigm has changed from the first time you don't carry a tube you'll get a flat, to the first time you bother you'll be rewarded for doing so!

Tried taking my tires down to 4.5# this afternoon, and was rewarded with a flat at the furthest point from the parking lot. Thankfully I had just bought a seat bag capable of carrying a spare tube, I managed to change it and proceed, but it got me wondering: are there any good frame pumps for fat bikes? I got by with a Topeak Mini Dual G, which worked and wasn't too exhausting, but took a long time taking 23 min to replace and bring my rear tire up a few pounds to avoid a similar fate. Normally takes me about seven min on a road bike. Would be nice to find one with a gauge, since my fingers aren't calibrated to tell the difference between 3 and 6 psi, but I may be dreaming on that.

I will at some point go tubeless, so I don't need that idea, just looking for advice on pumps!

FrozenK

Blackburn Outpost HV. It ain't small, it ain't light. But it will pump a fat tire with reasonable effort.

ThermionicScott 

Seems like a full-size frame pump would excel here, since you never have to fight high pressures anyway.

CliffordK

I'm not big on the idea of CO2 cartridges for road bikes, but they would be worth considering if you don't anticipate frequent flats with your FAT bike. Perhaps CO2 plus a micro sized pump, just in case.

jefnvk

I thought about that, but how many cartridges would it take to actually fill one? I've got one of the tiny Lezynes that can use CO2.

revcp 

I use the Lezyne Micro Drive HV (HV = High Volume. They also make the HP = High Pressure. Excellent pump. I switch it back and forth between my fatbike and my commuter/tourer. Lezyne - Engineered Design - Products - Hand Pumps - High Volume - Micro Floor Drive HV/HVG

CliffordK

Most of the notes I'm seeing are theoretical, but with grams CO2 and inflation:

https://bicycles.stackexchange.com/q...fat-bike-tiresSo, somewhere around a 20g or 25g cartridge should give you close to your goal of 6 to 8 PSI or so.

Or use multiple smaller cartridges for added flexibility (2 x 16g ==> about 10.4 PSI)

Super cold temperatures may also affect the pressure somewhat.

It probably wouldn't hurt to experiment at home before heading out on the trail. Start with a completely flat new tube?

jdswitters

I carry a 30 gram co2. I can tell you from experience that it takes 450 pumps from a mini topek to get up to about 6 which almost tolerable to ride the pavement home.
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HerrKaLeun

Have the same for my fatbike (never needed, though). You shouldn't use CO2 with sealant (ammonia).

I don't get the CO2 idea at all, it is like throwaway society. And if you screw up the first time, what then? Get the second CO2 bottle, or the third? a pump may suck, but you only need it very rarely and it has endless supply of air.
With a fatbike you will develop extreme leg muscles. Wouldn't you want to also develop arm muscles and pump

taz777

@jefnvk - that tyre looks destroyed? It appears to have a chunk taken out of it! Did you manage to repair it?

Hypno Toad

I have an older version of the Topeak mini floor pump:
https://www.topeak.com/global/en/pro...-road-morph--g

I've never repaired a flat on the road (the last time I flatted, I called AAA - AKA the wife - 'cause I was already running late). However, I have biked to a single-track trails with fresh snow, dumped pressure for the fresh snow. Then added air for the ride home on plowed trails. I found the Topeak good enough that I'm confident I could get a flat fixed in a reasonable time... I'd guess it'd take more time than a road bike, but less that 25 minutes.

I carry an old/check pressure gauge with me spare tube ... likely overkill.

PugPump.jpg

jefnvk

Tire was actually fine, as far as I can tell it was just a tiny pinch flat. I was on packed snow, unless something was poking up through that I missed there was no debris to cut it. Tire just caved in a bit on the top on the pic.

On the plus side, that was literally the easiest tire dismount/install I've ever done!

PedalingWalrus

I ended up almost flat in my front tire two weeks ago on a trip, in the middle of nowwhere ... well not exactly but about 6 miles from parking lot... One cartridge - boom - tire was full instantly and cartridge was empty. My estimates were about 2psi in the tire?

jefnvk

Yeah, the Road Morph is what I use on my road bikes, I took the Dual because it is supposedly better for volume (and the road wont fit on the seat tube). I do have a big Turbo Morph somewhere that I use for touring, as I bought it at a REI Garage Sale and I don't have the holder for it, just gets tossed in a bag, maybe I'll have to give that a go and buy a new one if it works better.

That said, the Mini Dual worked fine, I didn't get tired as it was fairly easy movement, just took a long time.

Hypno Toad

+1 - heck it takes a long time at home to air up a fat tire even with the big floor pump too

rangie

Lezyne micro floor drive is pretty high volume for a mini pump. There's even an XL model intended for fat tires.

The Meister 15psi gauge seems like the most accurate option.

Tubeless makes a lot of sense for fat bikes.

Aushiker

My pump of choice is a Lezyne Micro Floor Digital Drive XL (has a digital gauge). Not frame mounted so you do need a way to carry it. In my case it does in the top section of my Bike Bag Dude frame bag.

I run tubeless so have a reduced the risk of actually requiring it for an emergency situation but in terms of needing to change tyre pressure, say from going from beach riding to back on the road I find that it takes about six strokes per 1 PSI with my 4" tyres.

rangie

What do you think of the gauge?

Aushiker

It seems accurate to me but I haven't compared it to anything else so cannot be 100% sure. In terms of usage I find it easy to read but it does jump around on the down stroke but then settles on the reading.

It also picks up the initial PSI reading quickly as long as it is put on the valve properly.

All up pretty happy with the pump so far.