Specialized Shiv, help me pick my size...Medium or Large

Triathlon Forum
1

I’m just putting this up to see what input the Slowtwitch community has to offer. I plan on buying a Specialized Shiv due to its very short reach and very tall stack. I was going to set it up with Tririg alpha bars. Please help me choose a frame size based on my stack and reach requirements. Am I large or medium???

I would like to add a couple of disclaimers

  1. My stack and reach numbers are from a bike fit. The fit was legit and I am comfortable with the data and do not feel they are abnormal numbers or an absurd fit. I’m not mentioning my height, etc. to avoid the tendency to “refit” me. Just going purely by stack and reach numbers.
  2. I will not refer to the bike fitter by name in order to keep he/she out of it. I’m in no way questioning the bike fit in terms of stack and reach numbers. He gave me his recommendations and i’m putting this up out of my personal interest. Any it’s always interesting to get input and opinions from ST.
  3. Although not my favorite frameset, I’m sort of stuck on it due to my fit coordinates.
  4. I’m always open to suggestions.

I used the Slowtwitch stem calculator to arrive at these numbers

My required stack to top of armrest pads is: 683
My required reach to the back of the armrests is: **393 **

Shiv large is 565, 425
Shiv medium is 540, 405

From my repetitive calculations of the Tririg bars, I get a max pad setback of 55mm and a min armrest stack of 37 max armrest stack of 71. I’m leaving pad thickness out the equations. (they look pretty thin)

Here are my thoughts.

Large frame with 60mm stem at 30 degrees with 10mm headset topcap and no steerer tube spacers. Lots of frame and no spacers and no crazy aerobar pad stack. The stem is so short and hidden in front of the " cable steerer tower thingy" on the shiv, and will be tucked behind the armrests that it might not look too funny. Actually you might not even see the 60mm stem with this setup. Not sure how much the stem with affect handling, as you still have the extensions acting as a lever and triathlons are primarily a straight line sort of thing.

Frame and stem stack of 638 + 45 from bars = 683
Frame and stem reach of 457 - 55 from bars = 402 (couldn’t really get any shorter with these bars)

**Large frame with 60mm stem at 30 degrees with 10mm headset topcap and 10mm steerer tube spacers. **Same funny looking stem but with 10mm of spacers. Keeps spacers and aerobar pad stack to a minimum.

Frame and stem stack of 647 + 37 from bars = 684 (couldn’t really get any lower with these bars)
Frame and stem reach of 454 - 55 from bars = 399

Medium frame with 70mm stem at 6 degrees with 10mm headset topcap and 25mm steerer tube spacers. More normal stem but more steerer spacers, more armrest pad stack and less frame.

Frame and stem stack of 620 + 63 from bars = 683 (getting towards upper limit of bar stack which would limit increased stack unless I went to 50mm of spacers)
Frame and stem reach of 453 - 55 from bars = 398

I’m clearly for once in my life trying to fully maximize frame underneath me and minimize spacers.

Any thoughts on these setups?

Thanks,
Jack

2

If it is close size down, I overlapped in the sizing charts and went the safe route with a large and now wish I had went with the medium.

3

For me, the large fits but it feels like a lot of bike. I could’ve probably went with a medium.

4

How tall are you? I’m 6ft and 180. Not sure how far behind the bb my saddle is. I’m on a large Shiv (not TT) with a 110 stem. It’s a -28 degree stem and I still need to get lower.

If there’s any chance of losing weight or increasing flexibility, then what the poster said about sizing down is the right way to go.

5

thanks. the large is a lot of bike. i’ll likely go with the medium.

-jack

6

I would go with the medium, to get a better steering geometry. Also take a look at the alpha’s pad risers. Plus in the future you could get a bit more agressive.