Thanks, thats exactly what I want. practical advice backed up by some logic. Top tip. By the way, very envious of you cycling in all that snow. I love cycling in snow. Over here it's below freezing most days but insists on raining. The salt gets washed off every day into the side of the road. It then becames mostly on my bike. Literally just finished cleaning it down. It's still irritatingly about zero but still raining. Spring where are you.