When changing cassette and chain should i change the unramped chain ring at the same time, in my case a E-thirteen G ring? Or do they get through a few cassette changes.

Can i use any `car’ dot 5.1 fluid in my avid elixir’s ie which you can buy from halfords for circa £12 for a litre?

Cheers.

no, unless it starts chain sucking.

yes, any 5.1 is fine.

Halfraud’s “bike hut” dot 5.1, £5.99/125ml

Halfraud’s automotive dot 5.1 £5.99/250ml

They’re even a rip off when compared with themselves.

Yes, couldn’t beleive my eyes when i saw that, hence my question.

I’ve been using Halford 5.1 in my Hope brakes for years with no problem. Buy the 250ml for £5.99. Assuming you don’t bleed your brakes more than 3-4 times a year this will be plenty, and you shouldn’t keep opened brake fluid for longer than that because it is hydroscopic