With Bromptons, I've seen people extend the gear range without an IGH by adding a 58T chainring. Also, the T-Line will be offering a 12-speed soon but that could defeat the purpose of the 16.4 pound lightweight titanium bike. Your response has been helpful. I wish I could examine a Helix and take one on a test ride. I did feel every bump and jar on NYC rough roads on the T-Line. It got tiring. The skinny 16" wheels didn't help. It's still a great bike on smooth roads. Hmm...