Hi all I recently bought a Claud butler ravanna to cycle to work on but having done it twice now finding very difficult on the hills according to Strava it is 10 mile trip with a 1200 ft elevation and some of the hill are quite steep so end up walking a lot rather than riding I have put some road tyres on as I was told the mountain bike tyres will make things difficult and also got some clipless pedals and shoes but how do I know what rear cassette I have on now and what to replace it with to make hills a bit easier