Inter-tube confusion

kingsknight

Pedelecer
Aug 28, 2018
118
76
42
Hi all,

Hoping someone can help me out. My tyre size on my Crossfuse is 700 x 40c but I cannot seem to find any inter-tubes with a removable presta core. Anyone know where I can find such a tube as all the ones on Amazon seem to be too small. I want a removable core so I can add slime to my tubes! Would be be ok to use a smaller tube in my tyre?

Thanks in advance!
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,993
Basildon
I would forget about the slime. Fit some Schwalbe marathon Plus tyres and you'll be free from punctures.
 

kingsknight

Pedelecer
Aug 28, 2018
118
76
42
They do a 700 x 40c? I thought they only went up to a 700 x 38? Wheel sizes do confuse me as I'm not sure if I could replace my 40c tyres with 38s?
 

soundwave

Esteemed Pedelecer
May 23, 2015
16,899
6,507
get a presta valve tape up the rim with gorilla tape and dump the tubes completely tho could be a right pita to get the tyre to seal with no boost pump or compressor but you could use co2 pump.

if the tyre is lose on the rim add more tape for a tighter fit.
 

kingsknight

Pedelecer
Aug 28, 2018
118
76
42
I would rather just get myself some removable core tubes as my set up has lasted me so well. The slime really done it's job today as I had to pull out 2 pins from my rear tyre and it still didn't go down! Lost some air but it got me home :D
 

flecc

Member
Oct 25, 2006
53,196
30,602
They do a 700 x 40c? I thought they only went up to a 700 x 38? Wheel sizes do confuse me as I'm not sure if I could replace my 40c tyres with 38s?
Yes, there's lots of 700 x 40 tubes available. Even some stretchy ones that reach to 47. But most have fixed valves.

The Tyre size comparison table on this page will answer your questions on that subject.
.
 

Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
2,214
562
78
Hi all,

Hoping someone can help me out. My tyre size on my Crossfuse is 700 x 40c but I cannot seem to find any inter-tubes with a removable presta core. Anyone know where I can find such a tube as all the ones on Amazon seem to be too small. I want a removable core so I can add slime to my tubes! Would be be ok to use a smaller tube in my tyre?

Thanks in advance!
What some people do is to take any old worn out tyre and cut the tread off and insert it, with a few spots of tyre cement, between the inner tube and the outer tread pattern. This reduces the size of the inner tube needed, and adds some valuable millimeters of rubber to absorb any thorns abd the like....plus it costs nothing!!! You were going to throw it away anyway!
A perfectionist would buy a cheap new tyre with a thick tread and do the same....a slight overlap is needed for when you pump up the tyre of course!!
A friend of mine does it just for the rear tyre as he hates repairing it with all the wiring and stuff....As far as I am aware, he has never had a flat!!
regards
Andy