Bisexcycle

But lesss aero?? also I need a longer steerer tube plug ahaha

brian44

Playing around with fit...

Last match sprint session, my front end was super twitchy and completely unstable when out of the saddle for an effort. Honestly, the setup has always felt unstable, but I chalked it up to user error. I'm on an XL Planet X Koichi San ii frame (~58cm effective TT) with a 140mm stem (bar reach 104mm). After messing around on other people's bikes (Large Argon18 Electron Pro and 60cm Felt TK FRD...I believe both had 150mm stems), they felt much more stable. Anyway...long story short, I threw on a 160mm stem after taking some measurements, and the result is in the linked YouTube video below. I'm trying to avoid buying a new frame right now...I think it would end up in a divorce .

Relevant antropometrics: 1.83m tall; 75 kg

Since I do mass-start and sprint events, I am trying to create a do-it-all position. This probably means that all positions will be suboptimal, but it's what I have to work with right now.

As cringy as this is for me...below is a YouTube link to a few positions on the "new" setup:

You Tube

I tried to keep my hands and arms as relaxed as possible...any comments or suggestions on improvement are welcome.

Here is the "old" setup for reference (140mm stem; different bars...saddle height might be a little higher).

- Brian

Morelock

It looks ok, and with the context of your post, you're closing in on hitting hard limits.

Realistically, you could use some more reach, especially if sprints/off the front riding were priorities. Keeping that frame your options come down to longer stem (which at a 160 already is going to be expensive, limited to basically the velobike stem / custom, and is going to impact handling, albeit likely not tons more than a 160)
You could give a little more setback on the saddle a try (back & down equal amounts usually) to try to open yourself up some "fake reach" but of course you will quickly get to a point where that starts impinging the hip (among other possible issues) - shorter cranks *can* be a solution to that, but at this point you're plugging leaks in the boat as another one is springing up.
A little stack would be good for the "sphinx" position (getting the elbow bend 90°) - the ^^^ might also accomplish similar.

brian44

Thanks for taking the time to provide your feedback Morelock . It's funny because after I posted this, I messaged my coach (John Croom) to get his perspective, which is consistent with your response.

I've since moved the stem up 1 cm and the saddle rearward only about 5mm (it's already at the limit on the rails/seatpost). My concern is going up in the front will reduce the reach proportionally (72.5 degree HT angle). This is the largest frame that Planet X offers...it's aero enough, and I got it at a steal. Anyway, needing more reach at this point is clearly pointing towards needing a longer frame.

To add more context to the videos...I'm rolling at ~200 watts, so at an actual effort, I could imagine the reach becoming more of an issue while scooting forward.

Morelock

yeah, the closer to the rivet you are, the more it's going to suck up a lot of what space you've got.
Ideally yeah, going up you'd also want to go out. It goes back to the hole plugging though.

I rode (still ride occasionally) a TT bike about 2 sizes to small for me for ~5 years. (thanks LOOK Ergostem!) You absolutely *can* make a lot of things work (and too small easier than too big) but it's a lot easier to start on something close.

Not super familiar with that planet x, no way to flip the saddle mount hardware?

brian44

Morelock Yeah...my roadie background has always shifted my thinking towards the small end of frame sizes (generally ride a 56 w/ 130 -10 stem). The seat post is pictured below. Not much room left for me...

bicievino

I'll echo that feedback.
When you got into an aero position towards the end of the video, there was obvious overlap of your elbows and knees. That means you're going to have to flare your elbows to avoid hitting them, reducing how aero your position can be.

brian44

bicievino, thanks for taking the time to respond. I think my position is as good as it will be on this frame after incorporating the feedback everyone provided. Took 3rd in the Pro1/2 omnium yesterday with the new setup and felt pretty OK.