Interested... Would you be changing chains with cassette or letting the derailleur cope with a bit of extra chain? Or do you mean closer ratios for same tooth difference biggest cog?
Why would I need to swap the chain? I'll need to keep an eye on chain wear, and change the chain when it gets close to 0.75% stretch otherwise risk wearing out 2 cassettes prematurely, but half the point of a rear mech is to take up the chain slack. With an 11-36 on one wheel, and probably an 11-32 on the other, it's not having to deal with anything it wouldn't normally have to.
sorry you'll need to explain this. At a guess roadies have big rings and close ratio cassettes on their CX bikes. Grinding up hills on a 53T no idea if that's a roadie or mtb thing, mtbs are used to having low gears but I thought roadies were all "spin it to win it" or is that a new thing.
Spinning up hills on road bikes is a relatively new thing by most roadies standards, introduced predominantly by the drug cheat himself, Lance Armstrong. He continually wore down the likes of Marco Pantani by sitting and spinning a smaller gear at a continuous 100rpm, whilst they were out of the saddle pushing a bigger gear at 65-70rpm going uphill. Chris Froome and Bradley Wiggins both do the same, perhaps even more so, as Bradley Wiggins is known to have used an 11-36 MTB cassette at times to help with his climbing speed in the 2012 TdF!
Next time you see a group of roadies out, check out the bikes. Anything older than 3-4 years old will likely have a 53/39 chainset with probably a 12-25 cassette on the back. Certainly the guys that have been riding for a long time, will tell you that's all they need. But then you've got guys like us, who've learnt to spin uphills on Mountain Bikes with low gear ratios, that have got into road riding, and the market has reacted. More and more you're seeing road bikes not only coming with a 50/34 chainset, but also 12-28, 12-30, or even 12-32 cassettes fitted.
Given that I have a CX bike more as an alternative to an MTB, and will be riding quite a lot of proper offroad on it, I wanted a gear ratio I can just about manage up longer/steeper hills, so fitted a cassette large enough to give me a 1:1 ratio.