HELP: Bike Size Selection Advice

Equipment
1

I’m being tempted by a road bike by a local shop’s closeout pricing on Cannondale Synapse Carbon 2 models. Stock is low, so I’ll have to make a decision this weekend.

They have the Carbon 2 RLE and Carbon 2 LE models priced at $4,542CAD and $3,999.99CAD, respectively. The more expensive model has Varia radar and Ultegra Di2 vs. no radar and 105 Di2 on the lower priced model. Wheels are different, too.

My conundrum is sizing. The RLE is only avail in 51cm, which is aimed a folks starting at 5’5" and the LE is is avail in 48cm, where the size range tops out at 5’6". I’m just under 5’6" and relatively long-legged (30" inseam jeans).

Riding the 51, I feel as if I’m stretched out, but I’m not sure if that’s because I’m used to riding nothing other than my mid-travel MTB (2021 Pivot Switchblade in Size Small).

Comparing Geometry:

Bike | Size | Reach | Stack | HTT | Seat tube Angle
Synapse | 48 | 371 | 530 | 533 | 73
Synapse | 51 | 376 | 550 | 544 | 73
Switcblade | S | 430 | 614 | 592 | 75.5

Looking at just these numbers, my instinct is that the 51 could be workable whith a shorter stem. I don’t know the OE stem that comes with it, but it is not integrated with the bar and has a normal 4 bolt bar clamp, so swapping out should be eay. It looked to be longish, certainly a lot longer than the 45mm unit on my Switchblade.

But, is going with the 51 the right thing to do, or should I “suffer” 105 Di2 and a boring black paint job and get the 48?

I’ll be test riding the 48 tomorrow and should be able to back-to-back them. I’ll bring my pedals and shoes for this, but given the high probability that my sub-conscious will push me to the 51, is moving to a shorter stem just a band-aid, or viable idea?

Disclosure: this would be my first drop-bar bike EVAR and it would be used on road and on the TacX Neo2T. If you know of any challenges fitting the bike on that trainer, please let me know.

Links…

Geometry Geeks geo comparison: Compare: Cannondale Synapse Carbon 2 LE 2023: 48.0 -VS- Cannondale Synapse Carbon 2 LE 2023: 51.0 -VS- Pivot Switchblade 2021: S -VS-

…to bike on Cannondale Website if anyone want to see more of the geo or spec.

2

Buy sram it’s superior system

3

I ride a 56, which fits my legs, and then go with a shorter stem. It’s so common to do and so many bikes come with long(er) stems. My last bike (Ultegra Di2 BTW, NICE…) had a 100mm stem, and I swapped for a 60. It feels so much better, not like I’m on a rack (cheap Halloween reference) being stretched.

I’d do the 51 and maybe they will swap the stem and give you swap on the stem and save you some money off the swap.

1 Like
4

If you like SRAM, or want to change to SRAM.

1 Like
5

105 and Ultegra are going to function the same it’s just weight and a name in the end get the one that fit’s the best rather than worry about the spec. Test ride the 48 see how it feels it’s ultimately down to with one you feel more comfortable on the 48 will be 11mm short but the conundrum it’s also 21mm lower and both sizes effective top tubes being rather long for what considered an endurance bike.

1 Like
6

Don’t get it, the saddle height can be adjusted on even a small to fit most people done, it’s everything else that dictates the size frame you need.

7

Not sure I’m following when you say, “Don’t get it.”

8

A lot of the bike can be adjusted to fit the rider. It’s possible to get a bike that is just way to big, and not much can be done to fix it, but, like me, I got a bike that is what my lower half needs, and can get a shorter stem (brings the bars, the REACH, back towards the seat/saddle. You can also get shorter and smaller handlebars, shorter crank arms, different seat posts that move the clamp forward over the center of the seat post. If the bike is too small, then you can reverse the parts to make it bigger, but there again, it it’s way too small, it might be better to buy a new bike.

Others can address this probably better than I can, but you CAN tune a bike to fit a rider, and in my mind, EVERY rider should look at how their bikes fits them. Many aches and pains can be addressed by dialing in the bike, and pedals, cleats, shoes, etc. Don’t give up on a bike that doesn’t fit without looking at options.

And remember that pain is your bodies way of telling you something isn’t right.

1 Like
9

First, you need to stop comparing the road bikes to your MTB. Different bikes require different positions and will feel different. And looking at the stem length on your MTB and then looking at those on the road bikes is the same issue. Just a different use case, so there is no comparison. A road will likely feel more stretched out than a MTB….completely normal. So don’t try and compare the two.

At almost 5’6”, it seems unlikely that the 48 is the right choice for you. Look at it this way….if a 48 was “right” for you, what are people who are shorter than you supposed to ride? It just doesn’t add up logically.

Does the shop you are working with do fittings? If so, take advantage of that….they can simulate both bikes and you can then decide. If not, check the stem length on the 51 and see if you can go shorter.

It would not surprise me that, if you get the 51, within a year, you find yourself putting the original, longer stem back on as you adjust to the differences in road vs MTB fit.

3 Likes
10

Will be interesting to hear which one they go for if there set on Cannondale, but the answer to the question above would be above is another brands bike a Trek Domane for instants in a 47cm & 50cm is pretty close on stack shorter in reach also effective top tube are considerably smaller sometimes rather than get stuck on a brand your forced to look for another that sizes better.

1 Like
11

True, but it’s ironic that I too was stuck with a holdover Cannondale that was a bit too large. I got a great deal on it, and the shop I worked at got rid of it too. Double win…

I changed the stem and it sure helped. I got used to it, and rode that thing quite a lot. I did a couple of centuries on that too. You CAN dial a bike in better. I still have the frame, and was going to try to rebuild it.

But I was a ‘starving student’ and hoped that I could buy that bike before someone else did. They sold Schwinn, and a Cannondale. I had thought of a Super Le Tour, but it was too expensive compared to that hold over. (We did not get any discounts, on anything)

1 Like
12

:joy::joy::joy:

13

Totally get it on the potential to adjust seat post set-back, stems, bars, etc. Thanks!

14

I hear you on the moutain bike fit vs road fit, but part of this change is combatting some shoulder and neck problems I have my old MTB on my trainer for something that will be more comfortable.

Regarding the “people smaller than me” observation, as @Jowen989 pointed out, the Cannondale is quite long in reach compared to some other bikes. The company’s size charts (yes, big grain of salt) undicates that 5’6" falls at the top of the 48cm fit range and the just inside that of the 51cm. Being mostly leg, I’ve found that in these situations, going to the smaller option has usually worked out better for me.

I don’t thiink the fitting is an option in my situation (close-out bike, low stock, etc.), but I will try both back to back.

Thanks for your input. Appreciated!

15

I’m not stuck on Cannondale, I’m stuck on the 40% off discount given I’m a mountain biker at heart and see this bike as:

  1. replacement for my 1992 StumpJumper on trainer over the winter
  2. giving me the option to ride from the front door for endurance and recovery rides
  3. option of doing rides with roadie friends and my wife

Yes, both trim levels are overkill and I could achieve those without electronic shifting, etc., but I’m a stupid sucker for a deal. Kinda like @robcow, but without the starving student dynamic. More like the confluence between “cheap”, DINK, and Road-Curious.

The discounted Treks aren’t avail in my size or even more $. Thanks for your input.

1 Like
16

Yeah, the only discount I got was on that bike, and the spokes to build wheels because the owner thought that more employees needed to know how to build and service wheels. (I built 2 sets! Thanks Denny!)

But seriously, get the Di2. No cables, no adjusting, smooth, can control bike computers, just awesomeness to me. I do not regret going Di2. :+1:

17

That was a comment to wooger…

18

Decision Made: Went with the 51cm.

Rode the 48cm first and it felt good. The 51cm felt OK, too. Definitely not a huge difference.

Settled on the 51 based on:

  • we discovered the 48 would need a longer seat post to work for me
  • the stem on the 51 was 10mm longer than the one one the 48.
  • switching out stems is cheaper and simpler than seatposts, particularly given the cables running thorugh it.
  • Ultegra Di2, nicer wheels, and radar for $500 more

Got it home and updated firware… weird thing to do on a bike. :slight_smile:

Thanks everyone for your input and assistance.

2 Likes
19

Congratulations!

1 Like
20

That’s a beautiful bike! Enjoy it! :mountain_biking_man:

1 Like