Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Tandem Cycling A bicycle built for two. Want to find out more about this wonderful world of tandems? Check out this forum to talk with other tandem enthusiasts. Captains and stokers welcome!

User Tag List

Reply
 
Thread Tools Search this Thread
Old 04-23-08, 02:03 PM   #1
brewer45
Senior Member
Thread Starter
 
brewer45's Avatar
 
Join Date: Jul 2007
Location: Salt Lake City, UT
Bikes: Co-Motion Speedster, Giant FCR2, Surly LHT, Surly Crosscheck
Posts: 254
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Inflators

The typical 16 gram inflator cartridge puts a 700x23 tire at about 130 psi. We're riding 700x28 Conti Gatoskin tires. Any guess at what the inflation psi from a 16 gram cartridge for a 700x28 tire might be?
__________________
2008 Red Co-Motion Speedster Co-pilot (Redster)
2009 Surly LHT (captain's commuter)
2009 Surly Crosscheck (stoker's road bike)
2007 Giant FCR2W (stoker's commuter)
1980's NOS Legnano (stoker's toy)
1970's Stella rebuilt as fixed-gear (captain's toy)
brewer45 is offline   Reply With Quote
Old 04-23-08, 02:32 PM   #2
masiman
Senior Member
 
Join Date: Oct 2005
Bikes:
Posts: 1,735
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
by ratios it would guess ~106.
masiman is offline   Reply With Quote
Old 04-23-08, 02:36 PM   #3
72andsunny
Senior Member
 
72andsunny's Avatar
 
Join Date: Mar 2005
Bikes:
Posts: 235
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I've never had a gauge handy when inflating my tires with a CO2 cartridge.

1 cartridge seems to leave my tires a little soft...maybe 100 pounds. Somewhere >1 cartridge is more than enough to blow the sidewall out of a 700x28 Gatorskin (while making the loudest sound I have ever heard).
72andsunny is offline   Reply With Quote
Old 04-23-08, 02:38 PM   #4
brewer45
Senior Member
Thread Starter
 
brewer45's Avatar
 
Join Date: Jul 2007
Location: Salt Lake City, UT
Bikes: Co-Motion Speedster, Giant FCR2, Surly LHT, Surly Crosscheck
Posts: 254
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by 72andsunny View Post
I've never had a gauge handy when inflating my tires with a CO2 cartridge.

1 cartridge seems to leave my tires a little soft...maybe 100 pounds. Somewhere >1 cartridge is more than enough to blow the sidewall out of a 700x28 Gatorskin (while making the loudest sound I have ever heard).
LOL. That's exactly what I would like to avoid!
__________________
2008 Red Co-Motion Speedster Co-pilot (Redster)
2009 Surly LHT (captain's commuter)
2009 Surly Crosscheck (stoker's road bike)
2007 Giant FCR2W (stoker's commuter)
1980's NOS Legnano (stoker's toy)
1970's Stella rebuilt as fixed-gear (captain's toy)
brewer45 is offline   Reply With Quote
Old 04-23-08, 05:33 PM   #5
BreakingWind
BreakingWind
 
BreakingWind's Avatar
 
Join Date: Apr 2008
Location: Colorado
Bikes: Specialized Roubaix, Specialized Ruby Pro, Santana Tandem, Trek MTB, Santa Cruz Blur
Posts: 51
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
All I know is that I accidentally put an entire 16g cartridge into a 700x23 tire the other day and experienced the big bang theory firsthand.
BreakingWind is offline   Reply With Quote
Old 04-23-08, 05:59 PM   #6
lmzimmer
Senior Member
 
Join Date: Aug 2004
Bikes:
Posts: 198
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I use a hand pump to get things started and then finish with a C02 cartridge- works good enough to get me home with 28's
lmzimmer is offline   Reply With Quote
Old 04-23-08, 06:40 PM   #7
regomatic
Cyclist- Bike 'n a half
 
Join Date: Feb 2006
Location: Orlando, FL
Bikes: Custom S & S Bushnell Tandem, Eddy Merckx Ti
Posts: 257
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by lmzimmer View Post
I use a hand pump to get things started and then finish with a C02 cartridge- works good enough to get me home with 28's
What lmzimmer said.
regomatic is offline   Reply With Quote
Old 04-23-08, 08:12 PM   #8
brewer45
Senior Member
Thread Starter
 
brewer45's Avatar
 
Join Date: Jul 2007
Location: Salt Lake City, UT
Bikes: Co-Motion Speedster, Giant FCR2, Surly LHT, Surly Crosscheck
Posts: 254
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks to all for the feedback and cautionary tales. I had hoped to get by without carrying a pump, but it seems that both a pump and a pressure gauge (or a pump with gauge) are in order.

Cheers!
__________________
2008 Red Co-Motion Speedster Co-pilot (Redster)
2009 Surly LHT (captain's commuter)
2009 Surly Crosscheck (stoker's road bike)
2007 Giant FCR2W (stoker's commuter)
1980's NOS Legnano (stoker's toy)
1970's Stella rebuilt as fixed-gear (captain's toy)
brewer45 is offline   Reply With Quote
Old 04-24-08, 10:12 AM   #9
dvs cycles
Senior Member
 
Join Date: Oct 2007
Location: SoCal
Bikes:
Posts: 1,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by BreakingWind View Post
All I know is that I accidentally put an entire 16g cartridge into a 700x23 tire the other day and experienced the big bang theory firsthand.
There was something else that caused it. I just inflate my tires to the point that they are just seated with my pump and add a full 16g and don't get over 120psi. No way will 16g overinflate to the point of exceding burst point. You probably had the tube pinched..
dvs cycles is offline   Reply With Quote
Old 04-24-08, 10:10 PM   #10
zonatandem
Senior Member
 
zonatandem's Avatar
 
Join Date: Dec 2003
Location: Tucson, AZ
Bikes: Custom Zona c/f tandem + Scott Plasma single
Posts: 10,858
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
We use a Topeak Mt. Morph pump. Neat gizmo that unfolds into a mini-floor pump; and some come with a guage. 100 pump strokes gets us 100 lbs pressure in 700x25 tire. More strokes = more pressure.
It's 'almost' a pleasure to get a flat with this pump!
Pedal on TWOgether!
Rudy and Kay/zonatandem
zonatandem is offline   Reply With Quote
Old 04-25-08, 11:13 AM   #11
jgg3
Senior Member
 
Join Date: Jan 2008
Location: (BOS + PVD)/2
Bikes:
Posts: 283
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I had my first flat ever on a tandem today. The comments here were well in my mind. It just went soft, no blowout. I was carrying a minipump, a 16g inflator (1), and a spare tube (1). Couldn't find the source of the problem, which was a little worrying. Filled the tube a little for assembly, then a little more after, then went to the inflator. Thought I got it all, but wasn't quite sure, there was some pressure left when I unscrewed the cartridge. Not a whole lot. About 90-100 in the tire (700x28).

This was after more than 2000 miles, so I guess it is ok. Tire is getting thin in the middle, but I will remove and inspect carefully tonight. I still wish I knew what caused it; it would give me confidence that it just won't happen right away (we rode about 8 miles home after).

The thing is, with my wife on the back, I have no one to call! That little safety net has let me just drag one (tubular) tire and inflator around for ages on my single, but I just don't feel confident getting further away from home with nothing left on the tandem. So I probably need to carry two cartridges and two tubes to have some confidence on the tandem. Maybe a good pump is a better idea and I can just deal with the tubes.
jgg3 is offline   Reply With Quote
Old 04-25-08, 02:08 PM   #12
moleman76
Senior Member
 
Join Date: Aug 2006
Location: western Washington
Bikes: Stella
Posts: 604
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
A "cage rocket" in one of your bottle cages could hold several tubes, several CO2 cartridges, etc.
moleman76 is offline   Reply With Quote
Old 04-25-08, 05:09 PM   #13
zonatandem
Senior Member
 
zonatandem's Avatar
 
Join Date: Dec 2003
Location: Tucson, AZ
Bikes: Custom Zona c/f tandem + Scott Plasma single
Posts: 10,858
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Cheapo 'cage rocket' = empty CoffeeMate plastic container.
zonatandem is offline   Reply With Quote
Old 04-25-08, 07:59 PM   #14
justcrankn
Senior Member
 
Join Date: Dec 2007
Location: Minneapolis, MN
Bikes: Trek T2000, Ventana ElConquistador, ElSanto, STP400, 5500, JubileeSport, Scattante...
Posts: 146
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Topeak has a line of 5 different "morph" pumps that work well. After bad experiences with several CO2 inflators and 2 pumps that decided to quit on the ride, I now always carry a Morph pump, tube, patches, and a tire boot. Now we're prepared for most tire problems. While stranded on the side of the road most bikers will stop and help. Several that stopped for us discovered that their CO2 didn't work or was missing something.
justcrankn is offline   Reply With Quote
Old 04-25-08, 08:41 PM   #15
Old Hammer Boy
Senior Member
 
Old Hammer Boy's Avatar
 
Join Date: Aug 2005
Location: Utah
Bikes: Trek, Cannondale Tandem, Surly LHT
Posts: 1,082
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Road Morph, Road Morph, Road Morph.... Use one and you'll never go back!!!
Old Hammer Boy is offline   Reply With Quote
Old 04-26-08, 06:50 AM   #16
brewer45
Senior Member
Thread Starter
 
brewer45's Avatar
 
Join Date: Jul 2007
Location: Salt Lake City, UT
Bikes: Co-Motion Speedster, Giant FCR2, Surly LHT, Surly Crosscheck
Posts: 254
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I replaced one of the bottle cages with a Road Morph. So now I've got the inflator AND the pump. I double dare the road deamons to mess with my tires!

Thanks again for the tips.

Cheers!!
__________________
2008 Red Co-Motion Speedster Co-pilot (Redster)
2009 Surly LHT (captain's commuter)
2009 Surly Crosscheck (stoker's road bike)
2007 Giant FCR2W (stoker's commuter)
1980's NOS Legnano (stoker's toy)
1970's Stella rebuilt as fixed-gear (captain's toy)
brewer45 is offline   Reply With Quote
Old 04-26-08, 09:42 AM   #17
Retro Grouch 
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Bikes: Rans Rockst (Retro rocket) Rans Enduro Sport (Retro racket) Catrike 559, Merin Bear Valley (beater bike).
Posts: 26,617
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 89 Post(s)
Quote:
Originally Posted by brewer45 View Post
The typical 16 gram inflator cartridge puts a 700x23 tire at about 130 psi. We're riding 700x28 Conti Gatoskin tires. Any guess at what the inflation psi from a 16 gram cartridge for a 700x28 tire might be?
I don't use a gauge but I strongly suspect that 130psi in a 23mm tire is pretty optomistic.

I generally pump my 23mm road bike tires up to 110psi. When I have a flat I blow a little air into the inner tube to give it shape, install the tire, and inflate it with 1 full 16 gram cartridge. Subjectively I don't think they are any harder than what I get using my pump and gauge. No way am I getting 130psi.

On my tandem I use 28mm tires. It's been awhile since I had a flat on the tandem, but I use the same 16 gram cartridge. My wife and I aren't the lightest team in the world, but that's enough to get us home without pinch flatting.
Retro Grouch is offline   Reply With Quote
Old 04-28-08, 12:07 PM   #18
cornucopia72
Senior Member
 
Join Date: Jan 2005
Bikes:
Posts: 842
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
[QUOTE=jgg3;6583897]I had my first flat ever on a tandem today. The comments here were well in my mind. It just went soft, no blowout. I was carrying a minipump, a 16g inflator (1), and a spare tube (1). Couldn't find the source of the problem, which was a little worrying. QUOTE]

We always mount the tires with the colorful label aligned with the valve. Depending on the tubes being used one can mount them in a way to be able to ID the general location of the problem that caused the flat. We pump a few strokes on the bad tube and run the whole tube very close to our upper lip to find the whole. Then we can go back to the tire and look very closely in the target area and usually (but not always) find the culprit.
cornucopia72 is offline   Reply With Quote
Old 04-28-08, 01:37 PM   #19
specbill
Riding Heaven's Highwayson the grand tour
 
Join Date: Sep 2007
Location: Tehachapi Mtns, Calif.
Bikes: '10 C'Dale Tandem RT2. '07 Trek Tandem T2000, '10 Epic Marathon MTB, '12 Rocky Mountain Element 950 MTB, '95 C'dale R900, "04 Giant DS 2 '07 Kona Jake the Snake, '95 Nishiki Backroads
Posts: 737
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
"We always mount the tires with the colorful label aligned with the valve"
+1 on that..it sure makes it easier to locate the resulting hole and/or remnants in the tire, of the puncture causing intrusion.
Bill J.
specbill is offline   Reply With Quote
Old 04-28-08, 08:08 PM   #20
jgg3
Senior Member
 
Join Date: Jan 2008
Location: (BOS + PVD)/2
Bikes:
Posts: 283
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by cornucopia72 View Post
We always mount the tires with the colorful label aligned with the valve. Depending on the tubes being used one can mount them in a way to be able to ID the general location of the problem that caused the flat.
Yes, sorry I should have been clearer. I do all that, and in fact am sort of anal about it, and known as the cause-finder in our group for mysterious flats. But I had not touched these tires/tubes since they came new in the box from CoMotion, and thus the tube was not marked, and while repairing on the road, we could not find the problem. That was what worried me.

After getting it home, and re-mounting it the next day (with marks and appropriate placement), I was able to find the place. The glass or whatever was gone, so it was good to keep rolling on it. And in fact, we have another 50 miles since then.
jgg3 is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 10:57 PM.