Steel construction the pure fix I have I don't like as well as well at my kona due to the wheel base and over lap but I due ride my pure fix daily at work 5-7 mile and as far as the durability and value it's the best on this planet I've not got the time to check the others and your deep rims are amazing and I've got several stairs I ride down regularly so the bike is awesome and ass far as the short wheelbase and lots of overlap it's for the very few and I'm sure that's why you don't build one Thanks. Rad bike 👍👍👍👍