Been having a good lolling at super aero bikes I’ve seen, often £3k+, with 28T cassettes.

But some of the prologue riders seem to be on 25s FFS!

Tony Martin using 11-32 though he is running a 58T single front
http://www.bikeradar.com/us/road/gear/article/tony-martin-canyon-speedmax-cf-slx-gallery-50285/?utm_content=buffer8bdae&utm_medium=social&utm_source=facebook.com&utm_campaign=buffer

Larger chainring and running higher up the block (bigger cog) makes for less friction losses in the drivetrain.

One if the negative aspects about srams mtb 1x system is the 10t cog is something like* 15% worse for losses than an 11t.

*I’m plucking this figure off the top of my head but remember it was a surprisingly large number

Also, aero bikes are not exclusively for flat riding, 28 really isn’t that big for a rolling course. Especially if paired with a semi rather than full compact.

Larger chainring and running higher up the block (bigger cog) makes for less friction losses in the drivetrain.

This. Single 58t up front on my TT bike too and 25t or 28t big sprocket depending on course.

Yup, it always amuses me that people obsess about the slight extra drag of a hub gear, but are happy to run an 11t cog.

cynic-al – Member
Been having a good lolling at super aero bikes I’ve seen, often £3k+, with 28T cassettes.

What should they be running?

Is it possible to get cassettes that don’t start at 11?

I’d like one that was something like 14-30

I’d like one that was something like 14-30

Look up cassettes for youth gearing

Yes, plenty of options finish at a 12.
Think maybe some cassettes for junior racing stop at a 14.

Look up cassettes for youth gearing

Yeah, a “schoolboy block” as we used to call them. I never found one that went over 25 though, so I gave up looking.

One if the negative aspects about srams mtb 1x system is the 10t cog is something like* 15% worse for losses than an 11t.

… but remember a drivetrain is something like 95% efficient.

So if you’re losing 15% extra of a 5% loss, that means a loss of 5.75%.

So the drivetrain is now 94.25% efficient.

These minute marginal gains might make a difference at the absolute top end of the sport, but i’d doubt anyone else would notice.

11=speed 14-28 http://www.bike-discount.de/en/buy/shimano-ultegra-cassette-cs-6800-14-28-447129

10-speed 16-27 http://www.wiggle.co.uk/shimano-ultegra-6600-10-speed-cassette/

It’s still not comparable though is it? 15% extra loss on a highly efficient drvietrain (I thought it was nominally ~98% efficient when well serviced?) is still far less than the losses in a hub gear. Not only that, but you’re only using the 11T cog for a small part of the time, the time when you’re going really fast and the other losses are huge – the rest of the time you’re in more efficient cogs. A hub gear provides significant losses all the time (not that I think it’s that big a deal, just pointing out the difference).