Bike Noob

Because I'm Always Learning Something New

  • Home
  • About
  • Contact
  • Partners

How Much CO2?

02.09.2012 by Ray Niekamp // 9 Comments

One of the A riders in the club posted on the Yahoo group that he was making the move to CO2 cartridges, after many years of resisting them. That started online discussions that took two separate tracks.

12g threaded

Another member asked, “How many pounds of pressure does a 12 gram cartridge impart to a 700×23 tire? I use 16g cans and still have trouble getting home with the optimum 92-94 lbs onboard.”

The Internet is a wonderful thing. It doesn’t take long before answers start rolling in. Multiple answers.

“I’ve never checked the actual pressure,” answered a fast rider, “but my 23’s are quite firm after using a 12 gm cartridge. I just did a bit of research and it appears that you get about 100 psi in a 23mm tire from a 12 gm cartridge and about 125 from a 16 gm.”

But that doesn’t allow for individual differences. The fellow who posted that probably doesn’t weight more than 130 pounds soaking wet. The original poster followed up:

“Am I the only one who rides 25 mm tires? What did your research say about the pressures in the larger road tire?”

Cripes. We haven’t answered the cartridge size question yet, and now we’re introducing tire size variations? It’s gonna get confusing.

“I ride 25s too,” chimed in another member, “and am somewhat heaver than Steve so you probably will not be surprised to hear that I only roll with the 16s on the road bike.  However, I also put some Gatorskins on the wheels so I don’t get flats very often any longer [although I just jinxed it and am sure to get a flat on my next ride] so the extra cheese spent on the threaded 16 gram cartridges isn’t a big deal.  If you use less than 6 of these a year, it’s not a major expense.” But he also had a practical suggestion.

“Go buy a 12 gram and a 16 gram cartridge.  Let all of the air out of your rear tire, fill it up with the 12 gram cartridge, and go for a ride.  Repeat with the 16 gram.  Which did you like better?”

I imagined pffffft! sounds coming from garages all over the neighborhood as cyclists took him up on that idea.

16g unthreaded

Then, of course, there’s that complication you get with CO2:

“Bear in mind that CO2 bleeds out of a tire much faster than pumped air,” wrote the 130-pounder, “so if you fix the flat in the early part of a three-hour ride, you will find a lower pressure when you get home. This is why, after fixing a flat on the road with CO2, I always deflate the tire and refill it with a pump at home. However, unless it gets down in the low 80 lbs range, you shouldn’t have any problems short of a pinch flat if you hit a big pothole or rock.”

Okay, this is all good information. But one member had a great idea: Go right to the source. The Genuine Innovations website has a link to an inflation chart.

“Unfortunately there isn’t a measure for the 25mm tire,” said the guy who suggested experimenting. “But there is one for 23 and 28. You should be right in the middle. It looks like a 12gm will get you 90psi in the 23mm tire and 62psi in the 28mm tire or about 80psi in the 25mm. If you want a higher pressure, go with the 16.”

What was the second discussion track? Cost, of course.

The original poster wrote: “If you buy cartridges from a bike shop they can be pretty expensive. I just checked online and it appears that you can get them reasonably cheap if you get a bunch of them. For example you can get a box of 50 16 gram non-threaded cartidges for $50 including shipping. And different prices for different amounts. but 50 for $50 seems about the best.”

Another replied, “Buy a box of 12 gram cartridges at Walmart in the BB/paintball gun section. 15 for $7.97.”

“+1 on that recommendation,” said a third.  “I buy mine in bulk from a discount sporting goods store.  The only thing is that these do not have the threads to screw into some of the smaller nozzles.  I had to use it this weekend and a single Crossmark CO2 cartridge inflated my tire in one shot.”

Well, that was settled pretty quickly. Looks like a bunch of my club pals are headed for Wal-Mart to get their CO2. But one of the previous commenters signed off with some wise advice:

“Even though I’ve had good luck with cartridges, I still have a frame pump attached to my bike just in case Mr. Murphy is drafting.”

 

 

 

Like this:

Like Loading...

Categories // Accessories, Equipment Tags // Accessories, cartridges, CO2, Equipment

CO2 cartridges or a pump? I’ve decided.

11.11.2008 by Ray Niekamp // 10 Comments

After my fumbling experience with a flat tire last month, I decided to rethink my practice of carrying CO2 cartridges for dealing with flats on the road. I still think the cartridges are a neat solution to the space and weight challenge bikers face. But I’ve never felt that they worked the way they’re supposed to — that the tire inflated as much as it needed to (Yes, I know — it’s not the tool, it’s the carpenter). So I decided to go in the other direction. I bought a mini pump.

Actually, it’s kind of a hybrid between a frame mounted pump and a mini pump. It’s a Topeak Road Morph. And sharp-eyed readers will recognize that it’s not exactly new. On my first ride carrying the pump, it was the indirect cause of my fall.

The switch to the pump was not without some adjustments. Fall aside, I had to deal with two other problems: mounting it to the frame and a quality deficiency.

The Road Morph is not really a mini-pump, which some riders carry in their jersey pockets. It’s a little too big for that. So it must be mounted on the frame. Topeak gives the owner two options for that: fastening it to the top tube with zip ties, or attaching to the seat tube using the water bottle braze-ons.

I opted to zip tie it to the top tube. That turned out not to be the best solution, at least for me. The zip ties kept catching on the inside of my thighs when I dismounted, even after trimming the ties back as far as possible. I was concerned they would tear my riding shorts. Then, the hose popped out of its cradle when I rode on a rough stretch of road.

The second deficiency was a quality issue. The bezel that attaches to the tire valve was missing. It’s not an obvious thing, because the end of the hose looks pretty normal even without it. I didn’t discover it was missing until the morning of my century, when I had to scramble to find a floor pump to top off my tires. I rode the century with the pump zip tied to the frame, but pulled it off as soon as I got home after the ride.

pumpThe LBS was happy to exchange the pump for a new one — one that had the bezel. I decided I didn’t like the zip tie attachment, so I took off one of the water bottle brackets and mounted the pump there. Now it not only works the way it’s supposed to — it looks better, too. I think.

Yeah, I know, I’m down to one water bottle per ride now. Not a problem. One bottle is good for about 20 miles for me, and when I run low, I look for a gas station or some other place where I can fill it up. Since I’m not planning on riding another century anytime soon, I can get along fine with one bottle. And if I really need a second one, I can put it in one of my jersey pockets.

So far, I’m happy with my decision. The little pump has several features that make it act like the big guys. It has a little flange that flips out so you can hold it under your foot, just like a floor pump. Its handle can flip sideways to resemble a t-shaped handle for pumping. It even has a rudimentary pressure gauge.

I have yet to try the pump under battlefield conditions. It’s only been used to pump up some spare tubes in my garage. But it worked just fine on them, got them to full pressure without a hassle, and when my next flat comes (knock wood) I’ll be ready.

Like this:

Like Loading...

Categories // Accessories, Equipment Tags // Accessories, cartridges, CO2, Equipment, pumps

CO2 cartridges or a pump?

07.29.2008 by Ray Niekamp // 39 Comments

I’m probably flirting with danger here, but it’s been awhile since I’ve flatted.

Even so, I try to be ready if it should happen. My seat bag has a spare tube, a patch kit, and what I would most likely use in the event of a flat — a CO2 inflator and several CO2 cartridges.

The CO2 is convenient, but it’s not a panacea. When I have flatted in the past, I’ve found it’s not easy to get the right amount of air into the tire. I’ve resorted to a series of short bursts on the inflator trigger, and try to determine by feeling the tire whether it’s got enough pressure. When I first started using it, at a time when flats were much more frequent, I sometimes wasted a cartridge and needed two to fill the tire. And sometimes, I only managed to inflate the tire enough to make it home.

Another concern is the cost. The cartridges run about $3.50 each, so if one or two are wasted by fumbling around, the tire repair is suddenly costly. I usually carry four in my seat bag, so I can give one or two to another biker who might be flatted with no air.

Then there’s the environmental issue. Carbon dioxide is a greenhouse gas. Do I really need to contribute to the Earth’s problems?

What’s the alternative? A pump. The choice is between a frame-mounted pump and a mini-pump that can mount to a frame or even fit in your jersey pocket.

A Zefal frame-mounted pump.
A Zefal frame-mounted pump.
A Blackburn mini pump.
A Blackburn mini pump. It's actually less than one-half the length of the Zefal.

The issue with the pumps is also one of convenience, and efficiency, too. I’ve had occasion to use a mini-pump, and I’m not crazy about them. They have trouble supplying enough air pressure, especially to a road tire that may take over 125 psi. But I like the convenience of the CO2 inflator, and I’m not sure if another gizmo fastened to my bike frame would be worth the bother.

For now, I’ll continue to go with the cartridges and inflator. I’ve had enough experience with them that I’m confident I won’t waste them in future situations. And for every day that I go without a flat, cost becomes less of an issue. But I’d sure like to hear your opinion. Inflator or pump?

(Since this post last July, I’ve resolved the issue to my satisfaction.  Here’s what I decided.)

Like this:

Like Loading...

Categories // Accessories, Equipment Tags // Accessories, C02, cartridges, Equipment, pumps

Get Email Updates

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join 257 other subscribers

Categories

  • Accessories
  • Bike fit
  • Bikes
  • Blogging
  • Books
  • clubs
  • Cold weather
  • Community
  • Commuting
  • Components
  • crash
  • cycling
  • Equipment
  • Favorite rides
  • fitness
  • food
  • guest post
  • Heat
  • Injury
  • logs
  • Maintenance
  • Mental
  • Nutrition
  • Odds 'n ends
  • People
  • Poll
  • Racing
  • Records & stats
  • Review
  • Rides
  • running
  • Safety
  • soreness
  • Specialized
  • Technique
  • Technology
  • Tips
  • tires
  • training
  • Travel
  • Uncategorized
  • Home
  • About
  • Contact
  • Partners

Recent Posts

  • Getting Back on the Bike: Road Cycling Tips for Older Cyclists
  • Are BCAAs and EAAs Good for Cycling?
  • How to Fix Numb Toes When Cycling
  • How to Find and Vet a Bike Club
  • Celebrate Pearl Izumi with Big Savings in the Memorial Day Sale

Categories

  • Accessories
  • Bike fit
  • Bikes
  • Blogging
  • Books
  • clubs
  • Cold weather
  • Community
  • Commuting
  • Components
  • crash
  • cycling
  • Equipment
  • Favorite rides
  • fitness
  • food
  • guest post
  • Heat
  • Injury
  • logs
  • Maintenance
  • Mental
  • Nutrition
  • Odds 'n ends
  • People
  • Poll
  • Racing
  • Records & stats
  • Review
  • Rides
  • running
  • Safety
  • soreness
  • Specialized
  • Technique
  • Technology
  • Tips
  • tires
  • training
  • Travel
  • Uncategorized

Archives

  • May 2024
  • December 2023
  • November 2023
  • March 2022
  • October 2020
  • November 2018
  • May 2018
  • September 2017
  • November 2016
  • October 2016
  • January 2016
  • July 2015
  • June 2015
  • May 2015
  • April 2015
  • March 2015
  • February 2015
  • January 2015
  • December 2014
  • November 2014
  • October 2014
  • September 2014
  • August 2014
  • July 2014
  • June 2014
  • May 2014
  • April 2014
  • March 2014
  • February 2014
  • January 2014
  • December 2013
  • November 2013
  • October 2013
  • September 2013
  • August 2013
  • July 2013
  • June 2013
  • May 2013
  • April 2013
  • March 2013
  • February 2013
  • January 2013
  • December 2012
  • November 2012
  • October 2012
  • September 2012
  • August 2012
  • July 2012
  • June 2012
  • May 2012
  • April 2012
  • March 2012
  • February 2012
  • January 2012
  • December 2011
  • November 2011
  • October 2011
  • September 2011
  • August 2011
  • July 2011
  • June 2011
  • May 2011
  • April 2011
  • March 2011
  • February 2011
  • January 2011
  • December 2010
  • November 2010
  • October 2010
  • September 2010
  • August 2010
  • July 2010
  • June 2010
  • May 2010
  • April 2010
  • March 2010
  • February 2010
  • January 2010
  • December 2009
  • November 2009
  • October 2009
  • September 2009
  • August 2009
  • July 2009
  • June 2009
  • May 2009
  • April 2009
  • March 2009
  • February 2009
  • January 2009
  • December 2008
  • November 2008
  • October 2008
  • September 2008
  • August 2008
  • July 2008
  • June 2008
  • May 2008
  • April 2008
  • March 2008
  • February 2008

Copyright © 2026 · Modern Studio Pro Theme on Genesis Framework · WordPress · Log in

Go to mobile version
%d