Time Trial / Time Trialling / TT

Posted on
Page
of 793
First Prev
/ 793
  • And bigger cogs = more efficient?

  • bigger cogs = more efficient?

    In general, yes, but you weirdos with your dérailleur mechanisms also have to consider chain line, since straight chain is more efficient than bent. Given the alignment of normal road drivetrains, the 62 is probably going to be win both ways, as you're likely to spend more time with the chain straighter.

  • Basically what Gbj said but with graphs and stuff. I knew I'd seen this video before just didn't realise how old it was
    https://www.bikeradar.com/features/frict­ion-facts-free-speed-from-proper-shiftin­g/

  • Found this on water bottle drag there is one real world aero penalty that wasn't possible to account for between the two BTA's tested but it gives you a pretty good idea. My bike set up like this but with acetate sheet fairings attached to form a nose cone broke even in proper aero testing compared to the bare frame. Also I'll try and find some proper data but there seems to be a trend for pro riders who wear very stubby or no tailed aero helmets like your air attack and their riding position. They all have a similar relaxed neck low head eyes down and lowish hand positions and i remember testing well with a Bambino in a similar position in my first ever aero testing session despite the kask supposedly not being very aero in stand alone testing. Obviously everything aero is rider specific and I'm just making assumptions but if your definitely going with the air attack and you said your upping your front end a higher elbow lower head position could work well for you. Hope some of that helps.
    https://www.aero-coach.co.uk/water-bottl­e-testing


    5 Attachments

    • Rotor-Triathlete-Aero-1x13-project_Ironman-Triathlon-World-Championship-Kona-TT-Tri-hydraulic-shift-power-meter-project-with-Ventum-bikes-Profile-Designs-cockpit_David-MacNamee.jpg
    • HwJuxNQAdA3ih795NGDEkF.jpg
    • images.jpeg
    • 70615-largest_wes_greg_no_ad.jpg
    • _20211231_171823.JPG
  • Events are up!

  • Breckland 12hr, Aug 7th. Unlikely if I try and ride the twentyfour12 MTB thing the week before.

  • Well, that was quick. Flatmate just taken delivery of this, got it under £300, and its looking OK. Paired with my tubular Zipp 404 front thats under 1550g for the set. A modern 60-80 combo would probably be just as, if not more aero, but thats also cost about the price of the whole TT bike, sooo...

    Also on the way the profile designs bottle for between the extensions. This, and some more about home-made di2 TT shifters in here.

  • Any interest in a viewspeed Ti front skewer? Super clean front end, infinte watt saving, blah blah blah. Not my pic:

  • Post a reply
    • Bold
    • Italics
    • Link
    • Image
    • List
    • Quote
    • code
    • Preview
About

Time Trial / Time Trialling / TT

Posted by Avatar for hippy @hippy

Actions