I was offered a great deal (to me anyway) on a 2010 P3 and I bit on it.
Long story that I’ll shorten, if this bike was now made in a 55 cm it would be perfect. However, it’s either a 54 or 56. The gentleman that was doing the fitting told me that he’d suggest going shorter, as I could always lengthen the stem if I felt a little too cramped, but there weren’t as many options by going larger.
I ended up taking a 54 cm home rather than the 56. Since I’m new to the TT world, I ‘think’ I made the right decision; just would like someone to justify this for me. (For what it’s worth, I’ve always been in between as I’m just a little over 5’9, but I currently ride a 56 cm Cervelo Soloist. It too could have been justified as a little large for me at the time I reckon.)
Please be gentle. (Yes, I did mention I worked on getting it correctly fitted, so don’t slam me if you disagree.)
in my opinion the key thing to get right is the stack. if you end up needing spacers to get high enough, or end up UNABLE to get low enough, you are sacrificing aerodynamics and safety or are just plain screwed.
reach is pretty easy to adjust with stem length with not much penalty over a pretty big range.
at your height the 54 is great … 56 would be huuuuuuuge. There are a lot of folks your height who ride a 51.
I can’t imagine that the Soloist fits properly.
You’d be surprised…the Soloists have a relatively low stack height. I’m 5’ 10"-"11 -ish and I’m on a 56 Soloist. Judging by the amount of spacers and the length of the stem I run, I could *easily *ride a 58 and be just fine…in fact, it probably be the better fit for me.
To answer the OP’s question: If in-between sizes, I’d always go larger as long as you can get your bars in the right height using a reasonable length stem. In general, aerodynamically shaped frame tubes are more aero than round stem spacers Plus, the front-center dimension of the bike will be longer, thus making the larger bike slightly more stable.
You made the right decision. Don’t second-guess yourself. I did the same thing (between 56 and 54) and after I got used to the 54 I couldn’t have imagined going with the bigger size. And I’m 5’11".
Besides, smaller = more aero! You won’t even have to train!
FYI I’m 5’9" and ride a 54 … 90mm stem. It fits perfectly … I rode a 51 aluminum P3 with a 120mm stem and it was a little small, though comfy enough for 60+ miles.
in my opinion the key thing to get right is the stack. if you end up needing spacers to get high enough, or end up UNABLE to get low enough, you are sacrificing aerodynamics and safety or are just plain screwed.
reach is pretty easy to adjust with stem length with not much penalty over a pretty big range.
I realize this discussion (stack) has occurred in the past, but if you would please be so kind to give me a quick guide so I could tell whether this is correct or not? I don’t need the stem raised in my opinion. Although I haven’t gotten the opportunity to ride this bike long yet, I’m well aware that the positioning alone is going to be significant when compared to the road bike. However, how will I know if I need to lower?
The dealer told me to get some miles in it (not to exceed 200) and then they would see what I thought and then input a long term (cemented/glued) piece that goes into the head tube. (Apparently what’s in there now is only temporary. Never heard of this before) He did state that he thinks that I’ll ask that they remove a spacer or two once this is done. (There’s only 2 larger spacers in there now)
Besides, smaller = more aero! You won’t even have to train!
That does not seem to be the current consensus of the board. See Jackmott’s post above.
I agree with jack. And it appears that he agrees with me. I think you’re missing something?
Yeah, I would think if you are in between sizes you would want to go smaller if you like an “agressive position”. I’m 5’8 and ride a 51cm soloist with a 120mm stem and no spacers under the stem. If I went a size larger, I wouldn’t be able to get my bars low enough.
Besides, smaller = more aero! You won’t even have to train!
That does not seem to be the current consensus of the board. See Jackmott’s post above.
I agree with jack. And it appears that he agrees with me. I think you’re missing something?
Yeah, I would think if you are in between sizes you would want to go smaller if you like an “agressive position”. I’m 5’8 and ride a 51cm soloist with a 120mm stem and no spacers under the stem. If I went a size larger, I wouldn’t be able to get my bars low enough.
It seems to me that for most, smaller would only work for those looking for an extremely aggressive or a pure TT position. I sized up on my new TT bike so that I could make sure that I dropped all the spacers out. I then got a shorter, more angled stem and flipped it down so I could get even lower on top of that. The result was a 17° back angle which my fitter was hesitant to let me try (he usually likes to see triathletes between 19 and 21 apparently). However, it’s worked out fine so far, though I haven’t tested it at the half-ironman distance yet. If I was a cyclist looking for a time trial only position, I might have gone with the smaller bike to try to get down closer to a 10 or 11 degree back angle, but for long distance triathlon, this will be plenty low for me, and the longer wheelbase and shorter stem definitely helps out tremendously when trying to keep the bike upright with 30+mph winds and a disc in the back with an 80mm up front.
if you currently have two large spacers, and you don’t plan to get lower, you would probably want to size up, if the reach allows, this would be slightly better (stiffer/safer front end) and faster (head tube more aero than spacers)
if you do plan to go lower, what you have is probably right on.
A persons height has absolutely NOTHING to do with the size of the bike that they ride. The size is dependent on how steep they ride and their x and y coordinates of their pads. I’m the same height as the OP, and ride a 54 P4 and could easily ride a 56 and I was fit by JT, 1 of 3 FIST instructors.
in my opinion the key thing to get right is the stack.
Yes! And a tall head tube is more aero than a steerer with spacers sticking up. The ideal size is where a horizontal stem and no spacers puts the bars in the right place. If you are unsure of where to put your bars, then you will want to allow for more adjustment.
It is always best to size down especially with Triathlon bikes. The reason being that you can always lengthen the stem, increase the stack height, and raise the seat post, but if your frame is too large you will be limited in your ability to reduce (shorten) any of the above. If you went with the 54 you made the right choice, because the geometry is different with Tri specific frames and the goal is to put you in a lower and more forward position for aerodynamic reasons most triathletes will size down the frame anyway. I am just over 6’ and ride a 58 road bike but my Tri bike is a 54.
I ride a 51 Cervelo P3c. I could fit on a 54, but I could never use the 76 degree seat tube angle at all… too far back. The 78 seat tube angle just fits on the 51 and I can use the 76 sat tube angle too. I question if I should have gotten the 54…
This was before everyone went to the stack/ reach fit style of “fit”. I do have spacers, so I dunno. The 51 has a short head tube, so I don’t have a choice. To the shops defense, I had the setup prety agressive when I bought it and keep going higher with the front end by adding spacers.
I am 5’10" btw
The thing to take away from this is, if I am on a 51, I think 56 is way big.
Plus, the front-center dimension of the bike will be longer, thus making the larger bike slightly more stable.