We believe that fine thick merino wool t-shirts are not adequate for use in bicycle. Spending many hours exposed to the Sun they weaken much and just slitting, as you can see in the picture… It is true that it is very suitable for the capacity of dry and not smell, but seen his price, we believe that they are not adequate. On the other hand the t-shirts that have a greater thickness are suitable for cycle with cold. For merino wool t-shirt thickness, you can take as reference measures using the Icebreaker brand. The 150 are the finest and that we do not recommend, gives equal brand that is, all have these features fine Jersey. We have used t-shirts in wool merino from different brands and all we have the same. The 200 tend to be thicker and are suitable in long sleeve for cold days.