Bontrager R4Aero versus Specialized Mondo Open Tubular

Triathlon Forum
1

Does anyone have any insight into which of these two tires might be optimal for a Zipp Firecrest 808 and Hed C2 Clincher Disk? I’ve seen the AFM chart and the 23mm Specialized Mondo has the second lowest rolling resistance on the chart. However, the 21mm Mondo has not been tested yet and may not test as well. The R4 aero is a bit further down the RR chart and is 22mm wide. I know the Bonty tends to be a tire designed for aerodynamics, anyone know if the Mondo has a decent aero shape? How about a 21 Mondo upfront and a 23 out back? Or, if the Mondo does not have a good aero shape, Bonty R4s on both ends. This will be on a Speed Concept that does not seem to shelter the rear wheel as well as a P3 does for example.

Tom A., AFM, anyone else have any insight.

Thanks.

2

if the discontinued mondo open tubular is anything like the bontrager rxl pro i would go with that. the 220tpi casing has been reported to be more fragile than the 290tpi.

3

How about running the R4 up front for aero and decent RR and something else on the back like a CONTI 4000S.

4

How about running the R4 up front for aero and decent RR and something else on the back like a CONTI 4000S.

Because the Conti 4kS is only “meh” in the RR department. Great for training, not the fastest for raceday.

I’m rolling with the R4 Aero up front (Jet 90 C2) and my trusty old Bonty RXL Pro in the rear.
They seem plenty fast.

5

Right but aero is part of the game as well. If you remember the aero charts on bontrager it turns out that CONTI 4000s ends up being pretty dang aero as well. Plus it doesn’t flat. Sure it might not be the best in RR but it is a good all around tire.

6

Right but aero is part of the game as well. If you remember the aero charts on bontrager it turns out that CONTI 4000s ends up being pretty dang aero as well. Plus it doesn’t flat. Sure it might not be the best in RR but it is a good all around tire.Aero hardly matters in the rear, and the RR for 4000s is pretty terrible.

7

So what matters on the rear then? If aero doesn’t matter then maybe we should all be rolling 25cm tire then.

8

So what matters on the rear then? If aero doesn’t matter then maybe we should all be rolling 25cm tire then.

funny you should mention that… as I’m now 100kg I thought that I’d try some 25mm Ultremos… very sweet, and roll as fast if not faster than the 23mm and much smoother. Actually it felt like the difference of going from 20mm to 23mm which I changed to years ago, smoother & faster.