Denis’ FRC Road/TT

Denis’ FRC Road/TT

Denis came to visit from Australia to discuss a custom bike build. He didn’t initially plan on having a travel bike built, but having dragged his full size bike case around six internal US flights (and been excessively charged a few times), he decided that a bike that fits in an airline checkable case would be a good choice. He was also torn between a TT bike and a road bike. So I suggested we do a fitting session for both and see if it might be possible to achieve both positions on the same frame with a change of cockpit. This is where the fully adjustable Calfee sizing jig is very helpful. With the measurements in hand, I set about designing and discovered that the goal was attainable – the road position uses a 120mm stem with a 6 degree angle (upwards) and a 25mm spacer underneath. The TT position uses an 80mm, 17 degree stem angled down, with the 25mm spacer above the stem. The use of Di2 simplifies the cockpit swap – just one wire to unplug to disconnect the shifting. Then there is a cable splitter for the rear brake, leaving just the front brake cable that must be unclamped from the caliper.

The frame then has the FRC system for folding the frame up to fit in the travel case. The blue/candy apple paint is an inverse of Denis’ other custom frame, applied by Colorworks.

5 Comments

  1. Nice idea and execution. What seat and head tube angles did you use? Also wondering if getting two positions from one frame is always going to be a compromise? If so, did you split the compromise 50:50 or did you aim to nail one position and function (TT or Road) more than the other. Great idea to make the cockpit change as simple as possible though.

    • Hi Dave,

      The frame ended up with a 74 degree seatangle and 72 degree headangle (45mm of rake for 62mm of trail). In this case we optimised for the road position as Denis will use it that way the most. He actually had not ridden a TT bike before, and only intends to race some local events – thus we did the best we could for his TT position without adjusting the saddle position (thus maintaining the BB-saddle relation that his body is most used to).

      thanks, Rob.

      • If you routed the front brake cable via a fixed point – a bridge on the head tube say – could you also split the front cable and make the swap even slicker?

        • Hi Dave – yes, though perhaps a fixed point on the bars or something would be better, as that would then turn with the fork/caliper. I think the neatest solution would be to modify the cable clamp on the caliper so that the cable can just be unhooked (something like a barrel nut in a hook), and add a slot to the barrel adjuster so it can then be cleanly removed. If something along those lines worked well then it could be used on the rear too.
          Rob.

  2. Above Rob suggested, “I think the neatest solution would be to modify the cable clamp on the caliper so that the cable can just be unhooked (something like a barrel nut in a hook), and add a slot to the barrel adjuster so it can then be cleanly removed.”
    And on a return visit en route to RAGBRAI, 2017, Rob did just that. It’s a great solution – much easier and simpler.

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