Flexibility in Sizing

I have just about settled on purchasing a new bike. I have narrowed it down to either a Cervelo Aspero or a Cervelo Caledonia. I’m leaning Aspero based on the benefit of a more cushioned ride on the wider tires. I’m around 5’9” without shoes. The 54cm is the recommended size. Unfortunately, my preferred color and equipment package may not be available. I’ve read it is not uncommon to ride a size smaller than the manufacturer’s recommendation. I was wondering if anyone has gone down this path and would share their thoughts and/or recommendations. I’m not sure the 51cm will be available, but was wondering about the viability as an option.


Hate to give the diaper answer but it depends. Where are the differences in the geometry between the two sizes? I am long waisted (short legs for my height) so when I got my Orbea Orca I tried both my recommended size and one size smaller. The top tube was just too short on the smaller size.

If it’s possible, try the smaller one equipped as you want and the recommended size equipped any way they have. The size won’t change based on the equipment.


I would suggest getting a professional bike fit if you could.
A good fitter could simulate both geometries, and you could see which one is better.


Find a bike fitter and let them set you up on your current bike where you’re comfortable and have them recommend the size and what changes need to be made. I picked my first bike off the height chart and had issues that they fixed with a fit but then had him refit me before buying my new bike, night and day difference. Had it set up before I rode it, haven’t had an issue yet.


I would describe my body type the same. Unfortunately, they don’t have the smaller size in stock. Perhaps I could try a different brand in the smaller size to get a feel. In either case, I will likely have to order the bike. I was hoping it might give me potentially another option to get everything I wanted.

@Heretic @Sir_Alan

Unfortunately, there are no professional fitting services locally. The best advice I can get is from one of the sales people at the shop. I’ve found it to be hit or miss on their expertise. When I do get the bike, I am planning to go to a shop about 5 hours away to get a proper fitting.

The one thing a bike fit cannot fix is bicycle geometry.

When I got my bicycle fit, the fitter told me a story of someone who got a good deal on a good bicycle. When they got their fit, it was very clear that there was no possibility of making it work for him, the geometry was all wrong. He had to buy another bicycle.

If you are truly worried about the sizing, and are going to travel five hours anyway, it would seem better to do it before you buy the bicycle. You are spending the same amount of time in any case.

The bicycle fit will give you measurements that can then be used in your search for a bicycle.

If you want more information about bike fitting, I suggest Phil Burt’s Bike Fit: Optimise Your Bike Position for High Performance and Injury Avoidance.


A bike fitter is the best advice to give

Height doesn’t say much, inseam leg length and arm length helps

Change the seat post and/or stem can help but you might end up with something which is not too stable on the road

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I’m a little torn. I want to support the local bike shop, but I imagine the fitting store would expect the bike purchase. I’m going to call the fitting store tomorrow and lay my cards on the table and ask them about possibly doing an evaluation as opposed to an actual fitting. My hope is they could give me bike geometry specs I can use for my local purchase. They may not be interested, but I’m going to ask.


I understand that you are torn.

The fitting store should be charging an appropriate price for the fit, whether or not they expect you buy there is their problem, not yours. You can always look at some bicycles, and tell them you need to think about it - which could easily be true. That is not being dishonest - it is being an educated consumer.

You can go to the LBS shop, and see if they have what you need. After all, it is your money and comfort that has to be satisfied in the end.


Phil is great. So is Neil (RCA Cycling). Both have a lot of tips snd tricks on getting a good bicycle fit. Both recommend getting what I call a bicycle sizing BEFORE buying/ordering.


There surely must be HEAPS of independent fitters? I’m in little ol’ NZ and there are at least 5 I know of in Auckland. They don’t sell bikes, they just do fits. Best $ I spent was getting a pre purchase fit.


The bike fitter I work with is associated with the local Trek store. While it’s true he does recommend Trek bikes as part of his list, he also recommended me something from Giant, Canyon, Specialized, Look and Felt. When I asked about the possibility of a Cervelo or Bianchi, he gave me those models as well even though they required more tweaking to fit me. In the end I went with a Trek because it had the least amount of parts swapping that needed to be done to fit me and more importantly, I was able to find one. So long story short, the fitter may not care if you buy from that store or not and should recommend what’s best for you. If in the off chance you find one not associated with a store then it’s game on because they have nothing to gain/lose because they don’t sell bikes.


A good fitter isn’t going to care where you buy your bike, just that you get one that will work for you!

Locally here in Western NC, a proper fit is probably $250-300. With today’s component prices (like say an integrated stem and handlebar) it ends up being peanuts in comparison. The fitter I would use here would probably spend 3-4 hours with a client for that price, and make adjustments to an existing bike (but he also has ADHD and is a talker, but you feel like you are getting a great value!)

Finding the fitter could be your challenge, you may need to ask around for good recommendations. I wouldn’t go with someone that just uses Retul fit numbers as a bible for example, it’s a starting place but doesn’t work for all.

On your bike choices, those are probably both stellar options based on all I have ever read about them. I also would invite you to check out Lauf bikes, they recently opened a US assembly operation in Virginia and compared to the Cervelo prices… wow! :heart_eyes: My buddy just got one and I was very impressed with the build he chose for the price.


Get a bike fit. Buy a cheap bike. Set the bike to the fitting. Then and only then buy an expensive bike. Anything else is a waste of money. The industry is hood winking you into thinking the bike makes the difference. It does not. The fit makes the difference. The issue is stack and reach. My daughter is about 10cm shorter than me but very long arms and legs. We ride the same size frame. Hers has a short reach and short stem, mine has a long reach and long stem. Ask round to find a good bike fitter, preferably one that is a physio. I pay about £400 for a fit, but I would be prepared to pay more. If I was still racing I would pay £2500+ if I new it was a good fitter. I good fit will make you much faster, way faster than an aero frame, wheels, skin suit, aero handlebars, concealed cables combined. Don’t choose you bike based on the colour or marketing talk. You buy a frame based on your relative size. Italian frames typically have short reach. American frames have longer reach. Womens frames have shorter reach than mens frames. Work out what your relative size is and then choose the bike. Otherwise you are fitting you to the bike. You should be fitting the bike to you. It is like shoes, some are narrow and if you have wide feet the shoe will never be comfortable.


A size 51 will be lighter and have more responsive handling. But for tight, slow turns the front tire will likely hit your shoes unless you stop pedaling and hold your feet at 12 and 6 o’clock.

I am 5 ft, 9 in, and ride a 54 cm Caledonia-5. My wife has the same in size 51. Surprisingly, the seat hight adjusts to fit me on her 51. However I would need a MUCH longer handlebar stem (120?).

We put 700x34 tires on her bike and the ride is plush. I weight 155 lbs and could ride her bike wit 50 psi.

I just received, but have not yet mounted a 700x35c gravel tires for mine and expect they will fit with no issues. Her 34’s have plenty of clearance.

Also, I had my first professional fit at Cyclologic in Phoenix, AZ, plus purchased my C-5 there. It was an 8 hour drive each way and worth it!

I love the Caledonia-5 and will road race with it 2-4 times per year in addition to riding it everywhere.

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After a test ride on the 54, I pulled the trigger on the Aspero. I didn’t get the color I wanted, but I think I can live with Black. Anxious for it to get here.


Congrats. Pix will be required.


Great place for a fit, but EIGHT hours, each way? Im about three hourscout, but there’s four good fitters here, if not more. Enjoy the bikes and tires.
Lastly, be prepared to go lower on pressures. I was on 38s and 50PSI on a 75kg person was like riding on rocks when on gravel. 40 or lower was recommended by the local gravel gurus. Went to 43s and they recommended 5 PSI above burp pressures or 30 PSI on the roads around Patagonia.

Hadn’t heard of Lauf bikes before, but I’m in Virginia so I checked it out for gravel possibilities. But they only spec with SRAM drivetrains, sad to say. For me, that’s the end of the discussion, unless I want to buy a stripped frame. Too bad. I’d like to go see their facility and products firsthand.
Thanks for passing that on anyway. Maybe things will change with their drivetrain options.

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