I think that Cervelo is the best option all else being equal.

But for "regular" people who aren't hard core trackie's just doing a one off hour record, that's a lot of money to spend on top of everything else. I've used three different road TT frames on the track over the years. I used a Specialized Transition for pursuit and mass start races. I used that bike at the 2008 master's track nationals, kilo, pursuit, team pursuit and points race. I also did my first test hour at Hellyer on that bike. For my second test and the actual event in Aguascalientes I used a BMC Timemachine that BMC loaned me. After giving that back I used my Specialized Shiv for individual and team pursuit at master's worlds in 2017. (FYI, Larry Nolan uses a Shiv for mass start races also. The BB is like 2cm lower than a track frame, but he uses 167.5 cranks and has no issues. With my 175's for pursuit though I can brush my right foot on the track surface at low speed. Not a pleasant sensation...)

All three of those bikes were easy enough to set up with track gearing and no half links were required. The BMC was the hardest due to having the shortest dropout length. (All three are horizontal rear drop out bikes.)

Even still, two or three different chains are going to cost a lot less than a Cervelo T4. :-)

I took two different length chains to Aguascalientes for gear testing and then my "race chain" that I cut down once I had decided on the gear. For the Shiv though that same chain seems to work for all different pursuit gears that I might use outdoors at Hellyer or indoors with a front disk in LA.


The downside to using a road frame is that it is going to be less clean. Neither the BMC nor the Shiv has a removable front derailleur hanger. Also, the various bolt holes for brake mounting, etc. are probably a small aerodynamic hit.

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Kevin

http://kevinmetcalfe.dreamhosters.com
My Strava

That's what I figured, so I got that for pursuit.

....but found that with the Mavic disc being lenticular and the fat chain stays on the T4, that the disc has to sit back to leave a sizeable gap between the tyre and the seat tube. This space is 'protected' somewhat by the front of the seat tube (and air is pretty messy by the time it reaches this point) but I still think that a smaller gap would be a touch more aero.

So I now reckon that a flatter disc (eg Pro) would be a bit more aero.

Have you tested different rear discs in T4's? If so, have you seen much/any difference?