Inflating 650b x 47 tires?
 

Hi folks,

For on-the-road inflation, I know a frame-fit pump is the obvious choice, but could CO2 be used as well? How many of the big, 16g cartridges would be needed to get that tire to, say, 55lbs psi? Are there any other options?

TIA

Gas stations, this electric pump from Fumpa.

A 16g CO2 should work fine, although it may not get to 55psi. I usually carry 2, just in case the sealant fails and I need to install a tube.

On a side note, I don't know why anyone would want to run that size tire at that pressure. I have Terrene Elwood 650 x 47 tubeless tires on my gravel bike and I run them at 28psi rear and 25psi front. Even a few psi higher than that and it results in a very harsh ride.

Agreed. There’s no point in riding 650b at that pressure. I’m usually at 20psi, fwiw (I run tubeless and I weigh 150lbs.).

Thanks for the replies!

First off, I have no idea what pressure I should be riding at! Haha! I just got the bike built yesterday, and only rode up and down the street in font of the house to make sure I didn’t bolt something up backwards. I’m 230lbs and used to running 25mm tires at 100psi, so I just pulled the idea of 55psi for the 47mm out of butt; any pressure reccos based on my weight?

The bike came tubed, and I didn’t feel like converting it to tubeless right now, but probably will at some point. My roadies are tubeless, so I have some familiarity there.

It’s great to know a pair of 16g cartridges will be ample, because I have some of those on hand to build a kit bag with! My wife is also getting suspicious about how much I’ve spent already— too many packages on the porch!— and it’s true I’m a bit over the number I had in my head, so I’m not chomping at the bit to throw down nearly $200 on an Impero pump immediately; that can wait until spring.

Awesome! Post pics!

Here is a good place to start for pressure: https://info.silca.cc/silca-professi...ure-calculator

I started riding 650b in the spring and will never go back to 700c. Welcome to the club :)

Don’t worry about tubeless for now. Just enjoy the ride!

My Electra Townie has 26" x 2.0" tires. I keep them at 50psi to reduce the risk of pinch flats.

Though I'm a Super Clyde (315 lbs.), maybe I can reduce the psi a bit to get a more comfortable ride?

Thanks so much! Wow, it’s crazy to consider such low pressures for road riding as 36psi! Lots for me to learn...

I started a thread on the bike, a Breezer Doppler, over in General:

https://www.bikeforums.net/general-c...pler-cafe.html

I run my 650X46 at 60# I ride on the road, mostly and some hard pack gravel MUPs. I can't imagine running so slowly at 20 psi...plenty comfy :)