I am willing to buy some cycling gloves from an online store, but can't seem to find any details about the sizes. They range from S to XXL, but how do I know which best fits my hands? If it helps, I am willing to buy the Cube Teamline gloves.
Try some other gloves in a store, to see what size fits you on average.
E.g. in a shirt I'm a medium or a large.
However I bought my gloves in a store, after looking at the whole range on display, and trying on a few of them for feel.
They 'fit me like a glove'.
When I was looking for winter gloves (with full-length fingers and an inner lining, which are more difficult to fit that finger-less gloves are), in an outdoor sports store with a cycling-clothing department, I found a great variation in the quality of the design, and in the quality of the manufacturing (i.e. the stitching).
Most I tried were not comfortable. I chose the best for me.
There are somethings that are best bought localy.The variation in sizes of shoes,gloves and helmets between brands makes trial fitting almost a necessity.Some online sellers do a better job than others of helping you decide if someones product runs true to size.Contact the sellers customer service department for guidance. If they have product ratings check them as it is often the reason for comments.