Road Bike Fit Question.

[Marcel]

I am between 5' 9" and 5' 10" and transitioning from a mountain
to a road bike for the very first time.
I am looking at a couple of bike's at the Trek superstore and
have the choice between a 56" and a 58" frame. On the 56", it's
a tad crowded in the leg area when riding--but not much. But
the reach is perfect for the handlebars. It's spot on perfect.

On the 58" the reach is a tad long, just so it's noticeable. There's
more room because of the larger frame.

The sales guy says I'm a 'tweener' and if there were such a thing as a 57"
frame, that would be for me. My wife thinks the 56" looks a little small
beneath me as I ride, and that the 58" appears more natural--but admits
that like me she knows nothing about how a road bike should look or fit.

If anyone has a suggestion, feedback or input it would be wonderful to
hear your views.

[roper]

Bike fit can also vary depending of the geometry of the bike so it might be worth looking at a few other brands and types of bike.
If I had to choose from the info you have posted, I might be tempted to go for the smaller. If you have to over stretch you could give yourself some back or neck trouble.
Could you give them a test ride?

[xrodolfox]

You can always switch out a stem to help with the tweaking of a fit.

Your sizes don't really help. It all depends on how YOU ride. I am nearly 5' 11", and I ride a 54cm or a 53cm. It's all about how long your legs torso, arms are, and with your flexibility what you find comfortable. I find that riding as low as possible is ideal for me. for some reason, I get less stress on my back and hands that way. Most folks would hate my riding position. But that's what works or me, and thus, small frames are just more comfy than large frames.

If you feel that the smaller frame doesn't work, but the larger frame does, but you overreach, switching out the stem (the bike part between the steerer tube and the handlebars) to a smaller stem would definitely help. Also, the angle you ride at can make the bike less huge. If you put the seat really high, then the smaller frame might be better. If you ride your seat low, or far back, then a bigger frame might work. That's all in the fitting. The bike store should definitely be helping with that.

When you buy a bike, don't just *buy* the bike. You should also be looking to get it from a bike shop that you trust. Ones that have good mechanics, and good customer service because you'll likely be brining the bike back once in a while for new parts, tuning, or advice. If the folks are just selling you a bike without offering to switch out the stem, then that places might not be the place to buy a bike.

Try a local bike store instead of a superstore. A bike store run by non-pretentious cyclists (a tall order, but places like that do exist). You might pay $50 more, and they might have a worse selection, but it'll be worth it three years down the line.

[Marcel]

Here's the deal with the bike shop: it's a Trek Superstore.
I'd ordered a 56 2011 Trek 1.5 Compact, which they'd promised was there and being built.
When I got down there (after driving a long way), they said they didn't have it and it wasn't
in stock anywhere.

So, as compensation, they offered the two bikes I'm talking about: the 58 2011 Trek 1.5 Triple
(I'd originally requested a Triple) or the 56 2012 Trek 1.5 Compact. The 58 Triple is obviously
less expensive than the 2011 Compact, but they'd be losing a couple hundred dollars on the
2012 Compact if I took it.

I snagged the 58 after a fitting as the manager was quite sure it fit better after measuring, but
the 2012 56 handled better for the size, so it's haunting me: I feel the manager was motivated to
unload the 58 on me--and it's my first road bike. I can return the 58 anytime.

I plan to go back and re-test the 2012 Compact.

Thanks so much for the comments.

[Gastroplodder]

I'm also just under 5'10 and am happy on a 56cm frame though can ride a 54cm no problem.

I think 58 is a bit big and you'd be better with the smaller one.

[vCLaW]

Different brands measure frame sizes in different ways, so they can't really be compared.
58 cm would usually be a large frame, but checking the Trek website, I see they go up to 64cm, so maybe it is only a medium. Maybe it is because they have low stems without any spacers.

2cm difference in frame sizes isn't really that much, you can make more difference by adjusting the position of the bars and the saddle anyway.
If you have been fitted by a good bike shop, I would probably agree with that. If you have never ridden a road bike before, then the handling might feel a bit weird at first, but should be OK once you get used to it.

[Marcel]

Thanks so much for all the comments.

I am going to another bike store to get a second opinion on my proper fit.
If it looks like a 56 cm. frame is obviously more suitable, I'll make a new appointment
with Trek to test ride the 56 they originally offered for the reduced price.

If it's comfortable, I'll snag it. If there are some issues, I'll keep the 58 cm. frame.

Awesome to get feedback--of course, further comments are welcomed!

[Gastroplodder]

I've found this Trek bike sizing guide which might be useful if you need to argue the toss with the bike shop management - not sure how official it is but it reflects what I'd expect.

http://www.trekbikes.com/faq/questions. ... stionid=63

[Alistar]

I'm 181cm or 5ft 11 and ride a 56.
I have very long arms and legs, and a short torso for my height.

Therefore in terms of my leg length a 58 frame would be fine in terms of the seat tube. However due to my short torso the top tube(measured horizontally) should ideally be around 55.5 to 56cm and they don't make bikes like that. My current frame is a 56cm, and has a 56.5cm toptube which is, if anything, slightly long. But the 54cm frame was way too small.
So my frame although not perfect is close enough, and handles really well.

Due to my longer than average arms for my height I need a 120mm stem as 110mm that came stock is too short. This also helps so my knees don't hit the handlebars when off the seat going up a hill!

Leg length relates to seat tube length and saddle height.
Torso length relates to horizontal toptube length
stem relates to arm length and reach

IMO the Top tube length is the most important in terms of fit. You can always put up your seatpost, or get a longer/shorter stem.

For your height, a 58cm frame would in most cases be too large. Generally a guy b/t 6ft to 6ft2 would fit a bike of that size.
I'd be going with the 56 if I was you.

[Herbsman]

I'd get the shorter one and look at getting a longer stem and a setback seatpost.

Also, If you can go to a professional bike fitter, don't dare to hesitate to book a fitting.

I rode for years with a setup that I'd done with trial and error. I thought my bike was comfortable but I kept getting back pain. After my first season of racing I went to Adrian Timmis (Kellog's race winner, ex-Halfords ANC pro, Tour de France rider) at Cadence Sport, who adjusted my bike. I felt stretched and thought I needed a shorter stem and to move my seat forward, so bought a stem 30mm shorter and moved my seat right the way forward.

After a couple of hours of watching me ride on a turbo trainer, making measurements and making adjustments he put a stem 40mm longer than the short stem (so 10mm longer than the original). He put my seat nearly all the way back and lowered it a couple of cm. He also rotated my bars downwards and moved the brake levers upwards.

The difference was shocking. I have never felt so comfortable on a bike. Every time I go out now when I ride my bike it feels like I am in a warm, cosy bed wrapped up in a duvet cuddling my beautiful wife, it's that comfortable. And I go faster!

Get your bike fitted to your body, not the other way around. It's worth it in the long run and you won't regret it.

[JohnBarleycorn]

I'd get the shorter one and look at getting a longer stem and a setback seatpost.

Also, If you can go to a professional bike fitter, don't dare to hesitate to book a fitting.

I rode for years with a setup that I'd done with trial and error. I thought my bike was comfortable but I kept getting back pain. After my first season of racing I went to Adrian Timmis (Kellog's race winner, ex-Halfords ANC pro, Tour de France rider) at Cadence Sport, who adjusted my bike. I felt stretched and thought I needed a shorter stem and to move my seat forward, so bought a stem 30mm shorter and moved my seat right the way forward.

After a couple of hours of watching me ride on a turbo trainer, making measurements and making adjustments he put a stem 40mm longer than the short stem (so 10mm longer than the original). He put my seat nearly all the way back and lowered it a couple of cm. He also rotated my bars downwards and moved the brake levers upwards.

The difference was shocking. I have never felt so comfortable on a bike. Every time I go out now when I ride my bike it feels like I am in a warm, cosy bed wrapped up in a duvet cuddling my beautiful wife, it's that comfortable. And I go faster!

Get your bike fitted to your body, not the other way around. It's worth it in the long run and you won't regret it.

Damn good advice !

Adrian was a great rider. Finished around 70th in his first and only Tour, with zero preparation. Class act and nice guy.

And there is nothing like a correctly set up bike.

Do you have a beautiful wife ?

[Herbsman]

Well she's not my wife yet, but she might as well be.

[JohnBarleycorn]

Well she's not my wife yet, but she might as well be.

Splendid !