Hybrid bike innertubes

[chillyuk]

My bike has 700x38c tyres. Following a puncture yesterday I went to buy a new tube. Years ago when I used to cycle you bought a tube to suit the tyre/wheel. Now it seems one size fits all! I bought Continental tubes (3 for 2 from Halfords), and the size range is 700 x 32/47.

This morning, the first time I have ridden with it fitted, the bike seems to be all over the place, almost like riding with a very soft tyre. It is also very sensitive to minor ruts in the road and white lines that seem to throw it off track. I didn't notice it with the old tube. It's the rear wheel by the way. The tube fitting is fine and the tyre is properly fitted and inflated. I wouldn't say it is dangerous, just a little disconcerting. Probably wont even notice it after a few rides.

Could this be a less than ideal match between the tyre and the tube?

 

[TheDoctor]

Wouldn't have thought so. You're pretty much in the middle of the range, and Conti know a bit about tyres.
I hesitate to ask...but is the tyre at the recommended pressure, and was it beforehand? Is the front tyre OK, fully inflated and properly seated?
I have had this, where a bike didn't feel 'right' and I never did get to the bottom of it. Possibly it just felt a bit 'different' and I hadn't been on it for a bit.

That's not all that helpful, is it?

 

[Ivan Ardon]

Have you put the wheel back in straight and done the QR / nuts up securely?

 

[chillyuk]

Everything is put back correctly. I suspect it is probably just a difference in pressure, as I don't use a guage, I just pump them up till they feel hard. I have a track pump in the shed so perhaps I will dig it out and have a look at the pressures.

 

[ASC1951]

I don't use a guage, I just pump them up till they feel hard.

Perhaps I've misread your post, but you can't get road tyres anywhere near hard enough with a standard frame pump. I don't use a gauge because after many years of practice I can get them pretty close, but I do always use a track pump.

'Hard' on my 23s means I can only just dent the tube with full thumb pressure on the top. You might want it a bit softer with 38s, but not much.

 

[Mr Pig]

I suspect it is probably just a difference in pressure.

I think so. I've used tubes covering different size ranges in tyres many times and never noticed an issue. Used Conti tubes too and they seem good quality.

 

[byegad]

Maybe the tyre isn't seated properly. Even if it's only slightly out it will wriggle the front wheel around on every rotation.