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


Go Back   > >

Folding Bikes Discuss the unique features and issues of folding bikes. Also a great place to learn what folding bike will work best for your needs.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 09-23-09, 03:53 AM   #1
giskard
Senior Member
Thread Starter
 
Join Date: Jan 2007
Location: UK
Bikes: Kona Jake the Snake
Posts: 328
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Replacement inner tube for Dahon Mu

I need to replace the inner tube on the front wheel of my Mu P8 and was wondering how I determine which size tube I need given that the bike is fitted with Schwalbe Marathon racer tyres. My lbs has sold me a Schwalbe AV7A tube - it's labelled 20*1 3/8 Schrader which looks okay to me except for the 1 3/8 which I guess is the tube diameter when inflated?

Can anyone tell me if I have the correct tube for my bike?

tia

Johno
giskard is offline   Reply With Quote
Old 09-23-09, 09:18 AM   #2
HGR3inOK 
Senior Member
 
Join Date: Apr 2009
Location: Oklahoma, U.S.A.
Bikes: Brompton H6L-X, Dahon Curve D3
Posts: 750
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 15 Post(s)
What size are your tires? The AV7 is correct for 20" tires from 1.5" to 2.5". The AV7A may work, but it may not be the best fit. See:
http://www.schwalbe.com/gbl/en/produkte/schlaeuche/

Last edited by HGR3inOK; 09-23-09 at 09:21 AM.
HGR3inOK is offline   Reply With Quote
Old 09-24-09, 03:27 PM   #3
giskard
Senior Member
Thread Starter
 
Join Date: Jan 2007
Location: UK
Bikes: Kona Jake the Snake
Posts: 328
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by HGR3inOK View Post
What size are your tires? The AV7 is correct for 20" tires from 1.5" to 2.5". The AV7A may work, but it may not be the best fit. See:
http://www.schwalbe.com/gbl/en/produkte/schlaeuche/
Thanks for your reply.
Referring to the chart in your linkie, I can see that the AV6 40-406 and AV7 40-406 should fit - my existing Kenda inner tube is a 20x1.5
The only difference is between those two tubes that the AV6 is lighter than the AV7 (I guess the AV7 is a more robust tube?) so I'm guessing I need the AV7?
The ETRTO number on my wheel is 406 x 17 - how does that relate to the tube size?
giskard is offline   Reply With Quote
Old 09-24-09, 03:40 PM   #4
HGR3inOK 
Senior Member
 
Join Date: Apr 2009
Location: Oklahoma, U.S.A.
Bikes: Brompton H6L-X, Dahon Curve D3
Posts: 750
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 15 Post(s)
Whoops, wrong language. What size are your tyres?
HGR3inOK is offline   Reply With Quote
Old 09-25-09, 05:49 AM   #5
giskard
Senior Member
Thread Starter
 
Join Date: Jan 2007
Location: UK
Bikes: Kona Jake the Snake
Posts: 328
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The existing tube is 20 x 1.5 so I guess that's what I need. The 1 3/8 tubes I bought were way too big for my wheel even though the wheel is 20" and the AV7's are 20".

I'll post some pics when I can
giskard is offline   Reply With Quote
Old 09-25-09, 08:05 AM   #6
HGR3inOK 
Senior Member
 
Join Date: Apr 2009
Location: Oklahoma, U.S.A.
Bikes: Brompton H6L-X, Dahon Curve D3
Posts: 750
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 15 Post(s)
Anyone know the size for the Marathon Racers on a stock Mu P8?
HGR3inOK is offline   Reply With Quote
Old 09-25-09, 11:10 AM   #7
HGR3inOK 
Senior Member
 
Join Date: Apr 2009
Location: Oklahoma, U.S.A.
Bikes: Brompton H6L-X, Dahon Curve D3
Posts: 750
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 15 Post(s)
I'm pretty sure your tyres/tires are 20"x1.5". If so, you should use Schwalbe AV7 tubes.
HGR3inOK is offline   Reply With Quote
Old 09-25-09, 11:28 AM   #8
vmaniqui
Senior Member
 
Join Date: Jan 2009
Location: Bay Area, SF California
Bikes: Citizen Tokyo, A-Bike, Dahon Boardwalk D6, Dahon Boardwalk D7, Dahon Curve D3, Dahon Mu XL, BF Tikit2, Dahon Speed TR, Dahon Curve SL.
Posts: 1,504
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by HGR3inOK View Post
I'm pretty sure your tyres/tires are 20"x1.5". If so, you should use Schwalbe AV7 tubes.
yes. correct. the size is 20x1.5
vmaniqui is offline   Reply With Quote
Old 09-25-09, 11:51 AM   #9
giskard
Senior Member
Thread Starter
 
Join Date: Jan 2007
Location: UK
Bikes: Kona Jake the Snake
Posts: 328
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks for your responses guys.

After following the link provided by HGR3inOK a few days ago, I did conclude that the AV7s were the correct ones, my tyres are 40-406 (20" x 1.5) so that's what I need. BTW, I still don't know what the 40-406 means - I'm guessing the rim diameter is 406mm, but the 40? Wassat?

Just out of interest, here are a few pics (not great quality) of the original Kenda tube and the AV7A's that Evan's Cycles (incorrectly) sold me - you can see that the 20" x 1 3/8 AV7A is way too big, even though it's supposedly a 20" 1 3/8 tube which to me would mean that it should be the same diameter but a wee bit smaller than the 20" x 1.5 that's correct for my bike.

I'm confused by all this tyre/tube sizing as it doesn't seem to make sense to me, even after reading Sheldon Brown's pages about tyres and tubes.
So just to confirm, I need these, but do I need to specify the exact size (i.e. 20" x 1.5) or is that size covered by the tube that is 1.50/1.75/2.00?

Thanks again
Attached Images
File Type: jpg IMAGE_051.jpg (90.4 KB, 10 views)
File Type: jpg IMAGE_050.jpg (87.9 KB, 12 views)

Last edited by giskard; 09-25-09 at 11:58 AM.
giskard is offline   Reply With Quote
Old 09-25-09, 11:58 AM   #10
HGR3inOK 
Senior Member
 
Join Date: Apr 2009
Location: Oklahoma, U.S.A.
Bikes: Brompton H6L-X, Dahon Curve D3
Posts: 750
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 15 Post(s)
Quote:
Originally Posted by giskard View Post
... So just to confirm, I need these, but do I need to specify the size (i.e. 20" x 1.5) or is that size covered by the tube that is 1.50/1.75/2.00?
Just specify that you want the Schwalbe AV7.
HGR3inOK is offline   Reply With Quote
Old 09-29-09, 06:42 PM   #11
jobtraklite
Senior Member
 
jobtraklite's Avatar
 
Join Date: Jun 2009
Location: Quincy, IL
Bikes: too many
Posts: 108
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The maiden voyage on my MuP8 was to the train station to pick up tickets for a train departing at 6:00AM the next morning to go on tour. On the way back from the station, I had a pinch flat and through stupidity, blew out the tube. The LBS was closed for the day; so my only choice was a generic 20" tube from K-mart. That was over 700 miles ago; and it's still going strong.
jobtraklite 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 06:31 AM.