I have a bmx bike with the tire size being 20" x 2.4. Will a 20" x 1.5- 2.125 fit or should I get a 20" x 1.7 - 2.25 instead. If I get a slime inner tube will it be noticable on the weight or just a bit.
I see this as a two part question.
- A 1.5- 2.125 width tube will fit in a 2.4" tyre fine.
I carry 2" wide tubes in my seat pack when I go cycling as a spare tube for my 2.35 tyres. I do so purely as it fits nicer in my pack and my tyres are tubeless. So if I get a puncture, I put the tube in and fix the tubeless when I get home.
- You won't notice the weight but Slime might not work as well with over streched inner tubes.
When you fit a slimmer inner tube in a wider tyre, it streches more. So if you get a puncture with a slimmer inner tube, the slime has to work harder (than with a correct size tube) to plug the hole as it is more likely to burst bigger due to the over streching.
Personally I would rather invest in a more puncture proof tyre than in using Slime.