Tyre Sizes 18-23 or 18-25

[thesaintjason]

Hi,

Just a quickie (did search but couldn't see an answer to this simple question).

In the process of putting better tyres and tubes on my fairly new bike which has had a couple of P's already after only a couple of hundred miles.

Now the bike came fitted with 18-23 Bontrager tubes. I did get a cheapo tube from Decathlon as a spare which was 18-25 which I tried to fit but it seemed too big. Do I need the 18-23 again OR should 18-25 fit and my bad experience with the Decathlon tube was down to it being rubbish/my bad fitting?

I am concerned that the larger accommodating tube may cause me to fit the tube badly and increase my chances of a P.

Thanks

SJ

 

[youngoldbloke]

18-25 means the tube should fit tyres from 700x18 up to 700x25, so the Decathlon tube should be fine, in theory. IME some brands of tube are narrower than others before inflation. Can't see why fitting the Decathlon tube could cause punctures unless you trap it between the tyre and rim - after you have fitted the tube (I assume you put a little air into it when you do this - just enough for the tube to take shape) and before inflating it fully, turn the wheel pushing the bead away from the rim and look to check that the tube is not trapped. Do this both sides. Also push the valve up into the tyre to check the tube is free.

 

[thesaintjason]

Thanks for the reply and for the helpful tips too. I think my inexperience is most likely to blame