Think you have it the wrong way round. I 'thought' I had a 40T according to the website but in fact there was a 44T on the bike. i.e. it came with a 44T from the factory. I was going to put a 38T on it ie step down from 40T by 2T. I have to take 2 links out.A 44T would work on the larger cassette sprockets, meaning the cassette would wear slower. On the other hand, you would lose some climbing gears. You also need a chain that is 4 links longer.
 
 
		 
 
		 
 
		 
 
		 
 
		