Several silly questions

Aspman77

Had the bike for a little while now but I have some silly questions I can't find answers to.

1 - I got some kit for the bike before I got it. Tube, levers bag etc. The tube I got for the bike is an 18-23mm but the bike tyre has turned out to be 25mm. Is the tube still usable or is it really a no no to push it the extra 2mm even in an emergency?

2 - The tyre is a 25mm but most people seem to use 23mm. Can I get 23mm tyre on the wheels (Alex Rims S500) or would that require a change of wheel?

3 - Folding tyres, are they much different than normal tyres?

4 - Are all Shimano geartrain bits (Sora, Tiagra, 105) interchangeable as long as you keep to the same gearing (9sp, Triple etc etc)?

TIA

CiB

Tube is fine. Blow it up [not too much] outside of the tyre and see how big it gets.

23 tyres will fit.

Folding tyres lack the rim beading that 'normal' tyres have, but will still fit into the rims as long as there's some recess under the rim. Make sure you seat the tyre under the rim properly - inflate it a bit then work round on both sides checking that it's fully & evenly seated in the rim.

Shimano - I can't answer this effectively. Someone else can I expect.

Mettan

Yes, if you can, go for folding tyres - budget ones include Rubino Pros and Michelin Lithions - folders are lighter, better made/better materials, better performing etc - most people use them on here - Folding 23 tyres are the most commonly used tyres - in Winter though, some Roadies will use 24's or 25's - regards inner tubes, 18-23 is a typical size that you'd put into a 23 tyre - regards the Shimano interchangeability, yes they're interchangeable. Some shifters are Double and Triple compatible - others are just Double only etc - just carefully read up on any respective purchase.

Aspman77

Great stuff, thank you.