Moving from an "endurance" bike to a race bike, i can get the same fit on a size up (larger) with 10mm shorter stem (100mm)
On my endurance bike i went with the smaller size (between sizes) - but am an little nervous about a "bigger bike".
The only geo differences that matter AFAIK are 1 degree steeper headtube, and slightly shorter chainstays.
Should i be concerned?
Minor but sometimes important detail, if you like to use big water bottles especially insulated ones, you'll have an easier time getting them in and out of cages with a larger frame.
Sent from my iPhone using Tapatalk
Caveat: those are some VERY general comments I just made and the bottom line is that nothing is carved in stone and at some point it becomes a very individual preference.
Are you limited by flexibility? Going from enduro>race, same size will generally have shorter stack. Smaller size may see your stack drop 50mm. Quite significant.
Of the brands I have analysed, I have noticed a pattern. Sizing follows a bell curve. If you are average size, you have more options for stack. or the middle sizes reach increments are smaller than changes in stack.
How comfortable are you with your current drop to bars? Do you want to increase or decrease the drop to the bars?
To me, if you are sizing up and getting down to a 100mm stem then I'd probably size down if it means a longer stem. Bikes have always felt better to me with around a 12cm stem. I had an old Litespeed that I bought one size too large. On top of that Litespeed's had longish top tubes back in the day. I ended up with a 10cm stem. I just didn't like it.
Note that the pros are running 1 or 2 sizes too small these days with lots of drop and long stems.
To, the OP - what really helped me was putting all the frame data for both sizes in a geometry calculator. It ended up telling me exactly the reach and stack I'd have and how many spacers under the stem.
Just looking at front to center and chainstay length, they seem to be very close, but 54s has a stack 17mm higher.
Reach seems to be within 1-2mm between sizes.
I am also almost always between sizes. Either reach is fine, but bike is too low, or reach is longer and stack is better.
I am always fitted to the larger frame due to my overall length.
But i prefer a less stretched position due to bad back/ scoliosis and low core strength.
Out of pure curiosity i usually ask what a custom size would have costed, i hear from two brands i own, like a luxury car.
Not many brands carry such a wide platform of sizes as Colnago.
Ax Lightness Vial EVO D
Paduano Racing Fidia
https://opencycle.com/showcase/the-xplo ... eelsonfire
I went from a 56cm Scott Foil to a 54cm BMC TMR.
Granted they are both aero bikes, so not moving from endurance to race.
I got them both to fit with the help an excellent bike fitting.
However, I never seemed to have the same speed going up hills.
I've gone back to a 56cm frame, Focus Izalco and am much happier.
Before I bought the Izalco the vendor did a bike fitting to make sure I bought the best size.
Is a fitting a possibility before you buy?
If front wheel/toe clipping is not an issue then I prefer smaller.
Smaller gives me :- Slightly lighter weight frameset (assuming it's the same model)
Better weight bias as I prefer more weight on the front wheel.
Better power delivery - my body mechanics just work better with a slightly longer stem and an rear offset seat post - I fatigue/tire less on this set up.
I was riding a frame one size smaller the other day, longer stem to put my bars in the same position as my normal bike.
Whacked my knee on the stem out of the saddle a few times. Last time was hard enough for something on it to scrap and draw blood. Maybe just shitty technique.
Doesn't happen on my normal bike. Odd considering that the difference between the two is maybe 8mm of reach.
Scott Spark 720plus
- Similar Topics
- Last post
- 5 Replies
- 1489 Views
Last post by KCookie
Sun Jul 23, 2017 5:06 am
- 3 Replies
- 447 Views
Last post by cyclenutnz
Sun Oct 22, 2017 2:20 am
- 6 Replies
- 1192 Views
Last post by addictR1
Fri Jul 14, 2017 5:32 pm
- 63 Replies
- 9762 Views
Last post by survivor
Mon Apr 16, 2018 6:21 am
- 12 Replies
- 546 Views
Last post by TonyM
Thu May 03, 2018 6:58 pm