Tube sizes

Workshop tales, trials and disasters.
Maintenance tips, techniques and myths.
Technical discussion, description and outright lies

Tube sizes

Postby moosterbounce » Sun Apr 27, 2008 11:39 pm

Never thought I'd be posting anything in the shed, but here I am :oops:

Now before I ask my question, I have to point out that I am a) female b) married to a lovely man who has always performed any bike maintenance I needed c) willing to pay a shop to fix stuff, d) completely uncaring provided it looks cool, matches, and is carbon.

Was doing some k's on the trainer the other night and the back tyre goes down. Bugger. Pulled the whole damn thing apart and found a corner of a patch had come loose. No worries - put a "scab" over it, put it all back together and continued riding. My first ever fix!!

6.5km later, it was down again - same spot, scab lifted. Bugger. That's more flat tyres in one night than I've had in my life!! And on the trainer too!! :X

Anyhoo, decided that the scabs I had were old and crappy so got grumpy, chucked it all in and went in search of chocolate :wink: The next day when I was in a better mood, I went in search of a new tube in our "box of interesting and useful bike bits". Found a couple of new tubes and got all excited.

So...these tubes I found. One was 23mm - no worries. That's for the road bikes. The other was 25mm - must be it. Now I was always taught to measure twice, so I checked the tyres on Blade - 28mm. WT? Where does this 25mm tube belong if not on this bike? Not the mtb that's for sure.

This is where my question comes in. What size tubes can fit in what size tyres? Is there some mix that you just shouldn't do?

Being on the trainer, I figured I wasn't going to have a high speed crash if I chucked it on and it blew up so I did, but I suppose I should know these things :)

I should have added a poll: Is the poster of this message stupid? Yes/No :lol:
moosterbounce
Moderator
Moderator
 
Posts: 2493
Joined: Tue May 17, 2011 8:06 pm
Location: Rivervale WA

by BNA » Mon Apr 28, 2008 10:19 am

BNA
 

Postby Birdman » Mon Apr 28, 2008 10:19 am

It should say both on the tyre what size it is and on the tube carton what size tyre it will fit.

I thought you had 2mm either side until saturday evening. Preparing for a Tri-a and i had a flat on the borrowed Giant TCR. So i go to the shed and grab the spare i had and put it all in....no worries. Pumped it up to 110psi so i could recheck in the morning and as i put the valve cap on i hear this clicking sound, look down and the tyre has lifted off the rim and is expanding very rapidly, unscrew the cap as fast as possible and turn the little bit to let it down when BANG, rubber in the face, broke the fudging thing. What did i do wrong. At this stage nothing is open either.

I hope you fixed your problem Moo. I know i didn't, but it feels good to vent.

Mitch.
SOME PEOPLE ARE LIKE SLINKYS. NOT REALLY GOOD FOR ANYTHING BUT THEY BRING A SMILE TO YOUR FACE WHEN PUSHED DOWN THE STAIRS.

Until next time...
User avatar
Birdman
 
Posts: 1704
Joined: Mon Aug 27, 2007 10:25 am
Location: Rutherford, Maitland, NSW....god's country

Postby moosterbounce » Mon Apr 28, 2008 1:47 pm

Bad luck Mitch. Juckily your bum wasn't on the seat when that happened or it would have been more than just lost skin :shock:

Mine is still holding together with the 25mm tube. I no longer have the box it came in as it would have been sitting in a seat bag for a while. That's the problem with having so many bikes - you never know what goes with what.
moosterbounce
Moderator
Moderator
 
Posts: 2493
Joined: Tue May 17, 2011 8:06 pm
Location: Rivervale WA

Postby 531db » Mon Apr 28, 2008 2:53 pm

531db's guide to what works and what dos'nt as far as tube sizes into tyres goes:

*Tubes marked 700 x 18/23 will fit 18C, 19C, 20C, 22C, 23C, 24C, 25C and 28C tyres.

*Tubes marked 25/28C will fit 23C/24C/25C/28C/32C tyres.

*Tubes marked 32/35/38C should only be used in 32C and above.

*The general principle is that you can use a smaller diameter or 'C' tube in a slightly larger tyre than the indicated range as the tube will safely expand to fill the larger tyre envelope.

*In practice, use of a slightly larger tube than tyre size will work if care is taken during instalation not to create a pinch flat situation with the tyre bead, eg I've use tubes marked 25/28C in a 23C without problems, the actual extra width of the tube compared to a 18/23C was only about 3mm.

*Birdman, your problem is more likely to be an incorrectly seated tyre bead sitting over(pinching) the tube. As you have taken it to 110 psi, the tube inflating has lifted the bead from the bead seat and then blown off the tyre/out the tube. Unless you are using an el cheapo tyre not rated for 110 psi, the bead should hook the rim ok at that pressure.
531db
 
Posts: 969
Joined: Mon Nov 20, 2006 6:25 pm
Location: Riding a real steel bike - somewhere!

Postby MichaelB » Mon Apr 28, 2008 3:02 pm

531db wrote:*Tubes marked 700 x 18/23 will fit 18C, 19C, 20C, 22C, 23C, 24C, 25C and 28C tyres.



Have had no issues in 3,000km with an 18/23 tube in a 28C tyre :D
User avatar
MichaelB
 
Posts: 6837
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

Postby MountGower » Mon Apr 28, 2008 5:20 pm

Birdman wrote:

look down and the tyre has lifted off the rim and is expanding very rapidly
Mitch

You have a loose fitting tyre. I have been in this boat aswell. What you need to do is put the tyre and tube on, pump it up part the way and roll the wheel around leaning on it as you go to ensure that the tyre sits evenly as it's pumped up. You can do this as many times as you need to, maybe three times at the most. So as you are increasing the pressure, you are ensuring that the tyre sits evenly on the rim.

At first I worried about the tyre and was alarmed about the ease at which it came on and off, bit it never peeled off. This is no guarentee, of course, but that is how it went for me, anyway.

If it bothers you try putting on a new Continental GP4000 and you may go back to the loose tyre with pleasure.
MountGower
 

Postby stryker84 » Mon Apr 28, 2008 5:22 pm

When you say "rubber in the face" I'm hoping that's tube rubber, and not tyre rubber?
stryker84
 
Posts: 1817
Joined: Thu Sep 28, 2006 8:38 pm
Location: Warrnambool

Postby Hawkeye » Mon Apr 28, 2008 5:27 pm

MountGower wrote:If it bothers you try putting on a new Continental GP4000 and you may go back to the loose tyre with pleasure.

Ha! I think that goes for anything with "Conti" on the sidewall sticker.

I have a set of Sport Contact 1.3s on the mtb, and I chewed the ends off two sets of plastic tyre levers before I got smart and bought some steel-cored ones. :lol:
Hawkeye
 

Postby Birdman » Tue Apr 29, 2008 9:29 am

It was tube rubber not tyre rubber luckily.

I am using Maxxis reFuse tyres and conti tubes, cost me a pretty penny each so i wasn't expecting it to happen. I can't ride to work until i get it fixed and nothing is ever open when i am off work so it may have to wait.

I did pump it up half way and push it into the seat and everything looked fine. I dunno i guess i'll have to try it again. Them tubes are just so damn expensive.

Mitch.
SOME PEOPLE ARE LIKE SLINKYS. NOT REALLY GOOD FOR ANYTHING BUT THEY BRING A SMILE TO YOUR FACE WHEN PUSHED DOWN THE STAIRS.

Until next time...
User avatar
Birdman
 
Posts: 1704
Joined: Mon Aug 27, 2007 10:25 am
Location: Rutherford, Maitland, NSW....god's country


Return to The Shed

Who is online

Users browsing this forum: No registered users



Popular Bike Shops
Wiggle Wiggle UK
Ground Effect Ground Effect NZ
Ebay Ebay AU
Chain Reaction Cycles CRC UK

“Bicycles BNA Twitter
“Bicycles BNA Facebook
“Google+ BNA Google+
“Bicycles BNA Newsletter

> FREE BNA Stickers
> BNA Cycling Kit