I picked up an old Dawes Lightning that was converted to fixed. Beautiful bike. The reynolds steel is lightweight, and the bike is really comfortable to ride. The comfort is making me a little uneasy.

Part of the reason it is comfortable, is that it has a 41 inch wheelbase, and the bottom bracket is only about ten inches from the ground. These are the same dimensions as my Surly Long Haul Trucker. I can't find too much information about the old Dawes line, but I believe the Lightning to be a sport touring bike.

With 175mm crank arms, I am a little nervous about the geometry. I didn't flip a pedal quickly enough the other day, and broke off the tab on the bottom of my MKS GR9 pedals.

I have had pedal strike on my Surly and I have taken it easy enough on the fixed gear.

I tried to search, but it is broken.

How high should the bottom bracket be? I know that 175 seems a bit long for cranks already.

switching them out for 165 could give you a little bit more clearance, and you could try to run slightly taller tires.

I don't know that any of these are going to raise the bottom bracket all that effectively.

How high off of the ground is the BB typically on a specifically designed fixed gear frame?

Wider tires will give a little more clearance against pedal strike, and 165 cranks will raise your pedals a centimetre further away from the ground. Between the two of them you'll have a bit less to worry about