WT21

All the charts say I should ride a 56cm or M/L (I'm at the top of the range at 6' tall). I'm shopping a road bike, having a 56cm Domane now that I'm going to commit to the trainer in the basement, and there's a well priced Giant TCR, sized L (about 58cm) that frankly feels pretty comfortable to ride.

My bike fitter, who is selling this bike, suggests he should swap out the stem to reduce it down by 10cm. I am also concerned about the 175mm cranks, given everything I'm reading about shorter, not longer, cranks, and the 44cm handlebars - the 42cm bars on my current Domane already feel wide. He's selling this TCR $500 below retail, so I have some room to change stuff, but the difference would be eaten up by stem, crank, and handle bar adjustments. HOWEVER this could be an opportunity to get the cranks and handle bars I want, rather than just stock.

Anyone else ride one size up, or tried a bike one size up? Success? Failure? Crazy? Reasonable?

jon c. 

Fitting theory has changed over the years. 50 years ago people tended to ride larger frames with less seatpost exposed. If it's comfortable, go for it.

Bald Paul

I'm in that "in between" range as well - either a 54 or 56cm frame. I started out with a 56, changed to a shorter stem, changed the cranks, etc. The bike never really felt comfortable on a longer ride. I felt like I was too stretched out. Now I ride a 54, and it's a world of difference. I think it's easier to go with the smaller frame and fit it to your body than it is to try to 'shrink' a larger one.

Iride01 

When I was looking at new bikes a few years ago, the 58cm frame felt better for my 5'-11" height and 34.5" inseam than the 56cm of the same model. However that was just sitting on them in the shop and a ride around the parking lot. After riding each for 10 miles, the 56cm won out for quite a few reasons.

Wider bars on the 58cm bike braced me too much against side to side sway and my shoulders took all the brunt of the force.
The 175mm cranks were just way too big since I am use to 165mm cranks. I felt like I was thrashing at high cadences and it was uncomfortable for the more aero position I desired. I was felt worn out after those first 10 miles, but the second 10 miles on the 56cm bike and I recovered and felt ready to do 20 or 30 more miles.

While you can make a bike of most any size fit you well, you might have to change a lot of stuff to get it there. Cranks, bars and stems can start to add up. So if you can, try to ride the bikes as far as they'll let you. The bikes I rode weren't the bikes I was actually going to buy, but they were the same frames with lower tier group sets and wheels on them.

WT21

Thanks for the personal experience.

Yeah. I may be trying to convince myself on the Large/58 because of the price, but looking at geometry and other stuff this morning, probably stick with 56. Swap out the crank to a 52/36 and get better tires might be all I need out of the gate.

zandoval 

Had a nice 80s FUJI that was way to big for me. Called it my Horse cause I had to jump on and off of it. Still it was a very nice ride...

So how did I end up with a too big bike? Long story but its what I had to ride at the time.

Ya do what ya have to do, to ride...

boozergut

I have very short legs for my height. Bike fitters have always tried to put me on a 56 cm whereas a 54 cm fits me perfectly. I also enjoy more of a hunch backed riding position.

Juan Foote

I have ridden between 56 and 61 frames, according to the geometry and frankly, my ability to reach the ground due to my prosthesis. That was the specific reason I chose to go too small with my first "road bike back". I selected two after that which were both 58 and sat so completely different that I was amazed they could even BE categorized as the same size. I later purchased a 61 fixie from BD and it felt wonderful to me to ride so long as I didn't have to stop and get off the bike. That subsequently led me to purchase a "larger than 58" city style hybrid like bike. Given how little I ride now, if I were to select another bike it may be a combination of both a smaller frame again as well as taller geometry on the bars/stem area to sit a bit more upright.

downtube42

It think it depends how the rest of the bike fits.

I ride a larger bike because I want/need more stack height and more reach - more than I want to address with spacers and stem length.

oldbobcat

Think of it this way. You have a standing height, a sitting height, and an unfolded height. Often, they are not proportional. If you have long legs, your sitting height is shorter---that often means shorter top tube and taller seat/head tube. If you have long arms, your unfolded height is taller--that often means size up and/or a longer stem, and you might want to shrink that head tube. The bike brand will have something to do with it. For instance, for me a 56 cm Trek is just too small, where with Specialized, Cannondale, Scott, or Cervelo, that would be just right. A Felt would just be too long and low. My 58 cm Trek is pretty sweet. My ultimate fit was a M/L Giant TCR with 175 mm cranks, but that was a long time ago.

Kontact

The difference between two sizes usually comes down to 1cm of added reach and 2cm of stem height. If you aren't at the extremes of height or stem length, there is no real issue.

I am too short to be riding a 52, but there is nothing about that bike (except standover - level TT) that makes riding it weird.

Bob Ross

Well... not intentionally. But fwiw, when I first transitioned from Casual Utility Cyclist to full-on Obsessive Recreational Roadie, I bought a very nice swanky new Cannondale in a size 58, based on the recommendation of the sales dude at the LBS.

And I still have that bike, and lately (for a variety of circumstances unrelated to size/fit) I've actually been riding that bike more than any of my other bikes.

But in the years after getting that 58cm Cannondale I had one professional bike fit, and had two custom bikes built for me by framebuilders who have their own fitting methodologies, and all of them recommended a slightly-smaller-than-58cm top tube. One of the custom frames is closer to 57cm, the other is 56.5. Oh yeah, plus I bought an off-the-shelf cyclocross bike in a 56cm size and it seems to fit fine.

And yet, when I'm riding that 58cm bike I don't find myself thinking "oh, gosh, this feels so huge!" It feels fine. It's only when I get back to riding the custom bikes that I think "Ah, now this feels sublime!" ...which I never say to myself on the 58cm Cannondale.

phughes

Yep, which is why I chose the larger of two frame sizes when I got my touring bike. Since I wanted my bars higher than a regular road bike, the higher head tube was a benefit.

oldbobcat

Getting back to the OP, by all measures the large Giant is too big for a 6-footer unless you have a 91 cm inseam. Insist on a M/L It won't satisfy your bike-buying jones but you won't be doubting your decision a year from now. Life is too short to be riding ******-fitting bicycles.

Wildwood

"... about 58cm that, frankly, feels comfortable to ride"

IMO, there is your question answered.




FWIW = 186cm tall (6'1"), 87cm (34") cycling inseam - ride 60-62cm frames.
edit: 38cm bars seem my best width and newer bike builds are with 170 or 172.5mm cranks (175s on my older builds)

Kontact

I'm sorry, I missed this. The "normal" size for someone 6 feet tall is 58cm. I was just looking at the Trek fit tool and it said 58 for your height all the way down to a 32" inseam.

Which charts are you looking at?

Lombard

This was my thought. I'm 5' 9 1/2", 32 inseam and take a 56. A 56 is too small for someone 6 feet tall. I've tried 54's and they felt like clown bikes.

I think it's wrong to make a general statement like this. Whether it's easier or better to make a larger or smaller frame fit is a big.........it depends. Do you like a more upright riding position or a more aggressive race position. If you like to ride more upright, the shorter headtube of the smaller frame is difficult to compensate for. A more upright stem can only get you so far.

Bald Paul

Then I guess we're both wrong. I'm 5'10", had a 56cm and it was too big. After a professional bike fitting, I went to a 54 "clown bike" and instantly regretted getting the 56 (it was sold.) The 54 is super comfortable.
I guess the 'correct' answer (or opinion) would be to find a pro fitter and spend the money to get it done correctly, instead of asking "experts" on a forum that don't know you or your riding style.

RB1-luvr

At 5-10", 32 inseam, I raced 56s in the 80s-90s and still ride them. Any purchases made after that have been 54s, except for a vintage Bridgestone recently which is a 56 and fits fine just like back in the day. Top tube length has a lot to do with what works for me.

Kontact

Considering that the typical difference between a 54 and 56 is only 15mm of top tube length, what was the problem? And did you get the same model in a 54 or a completely different frame?

Lombard

Exactly. Like I said.......it depends.

Iride01 

It's really not good, IMO, to assume the same size bike in one model of bike is the proper size bike in other models of bicycles. Even from the same manufacturer. And sometimes you can clearly see that when you run the sizing guide for various models of their bikes.

Although I have seen a few bike manufacturers that don't have a wide variety of different geometries between their models use the same recommendation for every model of their bikes.

I was between a 58 and 56 cm size according to Specialized's sizing chart for the Tarmac. I went with the smaller and like it a lot, but I'm wondering if I might have liked the 54 cm even better. Though I'd probably have to keep the 30 mm of spacers under the stem.

Kontact

You shouldnt assume anything when spending thousands of dollars when geometry charts are universally available. However, most manufacturers have no reason to sew confusion and anger among their clients by severely screwing with sizing. It isn't like "58" is an actual seat tube measure anymore - it functions more like a dress size in suggesting an overall fit. That's why height is a closer guide than leg length.

The main thing that has happened since sloping top tubes is that there is a wild variation in head tube lengths between different models. This can be a real boon to people with long legs, but a pain for sportier riders or folks with long torsos. Geometry charts are available - be a smart consumer.

BFC

1 size larger should be fine, can 'fine-tune' with different stem and saddle position and maybe cranks