What size chainring are you using on your 1x?

What about your cassette largest cog?

10 spd or 11?

Thank you

Sorry to dig up an old thread, but I'm curious about minimum q on a P5 since some people seem to find a lot of aero benefits there. I have 170mm Rotor Flow cranks on mine with 145mm q-factor. There's about 9-10mm space on each side to the chainstay. As long as the arms don't have a weird bulge like the Chorus set on page one, a 127 mm q-factor should fit.

You should be able to fit a set of Miche Pistard Airs* - these are the best option for low Q Factor/1x setups if you're not using a power meter as they come in at 138mm without the pedal washers and have an aero profile. They use a standard Shimano HTII bottom bracket but are quite tight to get in, and just make sure you don't have the back of the chainring bolts sticking out too much.

*I've not personally done it but we've fitted MPAs to a variety of road TT bikes without issue

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AeroCoach UK
http://www.aero-coach.co.uk

Good option, thanks for that info. I couldn't find a q-factor on that set. It looks almost identical to the Vision NS Track, down to the q factor and print design. Have you seen anything in the 130mm-and-under range on a tt/tri bike?

Not on a modern bike - we managed to do 102mm square taper ISO plus old Dura Ace (740x) on a couple of older bikes but you have to play around with offsetting the BB to stop the back of the spider touching.

I actually installed a set of Miche Pistard Airs on a P3C this morning, needed 1.5mm worth of BB spacers on the drive side to give adequate clearance (51cm frame) but apart from that it was fine.

From my published research on Q Factor I wouldn’t shoot for <130mm unless you can test it, 140mm or so for trained riders on average was pretty good. We went down to 90mm and I had to build a whole ergometer to make it possible but there wasn’t anything extra we found (physiologically/biomechanically) when it was that low. Aero wise we’ve found it’s often better narrower however.

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AeroCoach UK
http://www.aero-coach.co.uk

Did you find that narrow and narrower was better for aero?
Or that when you were down at 130 the gains stopped?

Did you ever find that too narrow brought the legs in too close to the frame and disrupted air flow?

As with all things it is quite individual and also depends on the frame. We had one of our sponsored riders in the tunnel recently who had accidentally bought some (second hand) very wide axle Speedplays, which ended up being a few watts slower than normal axle length. It was roughly 20mm extra Q Factor from memory.

Other stuff is normally just a 1:1 comparison from someone’s standard cranks to “a narrower version”, as few people have the ability to fit (or supply) super narrow cranks on their bikes, and it is quite low down the list of priorities for most of our clients.

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AeroCoach UK
http://www.aero-coach.co.uk