Confused: bike felt right, LBS says too small...

[mrmacmusic]

I went to see the 2013 Trek 3.1 today and the LBS also had an old model on display (thought it was 2012, but turns out to be 2011 spec). It was red, white and black and I loved the look (see my "aluminium or carbon" post!), and being a 56cm thought the size would be right, if in fact a touch too big.

I couldn't do a test ride, but sitting on it the size felt right to me - a bit longer than I'm used to on my Flight, but comfortable. However, the highly experienced assistant (who does the paid-for fitting sessions) said I was a bit upright on it and it was too small, although he admitted looking at me he'd never have said I needed a 58cm. I'm 5'10" and 32" inside leg. With the seat in the right position he measured a 5cm drop to the bars, and was indicating my back was at about a 45deg angle and too upright.

There was a Madone 4.5 in a 58cm which I tried too, and whilst it felt too long to me, the assistant said the angle of my back was much better. The measured drop to the bars was the same, but the reach was 3cm longer than the 3.1. Another customer commented that he thought the 3.1 looked too small, although he'd put a shorter stem on the 4.5 and maybe move the saddle forward a bit....

I'm not suggesting that the experienced assistant's advice was wrong, but it's really confused me. Should a road bike feel so long if you're not used to it? I don't want a full on aggressive race position, but I don't want so relaxed and upright that it looks like I'm "granny going for the shopping" (other customer's quote!). By the sounds of things, what I think feels right might be too upright.

I'm planning to go see the Giant Defy Composite in another shop tomorrow, but on a previous visit they already said the M is the right size for me in the Giant... that's a lot smaller than the 58cm Trek recommended today.

The final bike on my shortlist is the Cannondale Synapse Carbon 105, but I'm not going to be able to see that in the flesh, and would need to order it blind online. Edinburgh Bicycle said that 56cm was the right size when I tried the aluminium Synapse there last weekend.

I feel like I'm getting conflicting advice regarding size and it's really confusing me... help please

 

[DCLane]

58cm sounds big to me.

I'm 5' 9" with a 30.5" inside leg and I fit a 54cm.

 

[mrmacmusic]

58cm sounds big to me.

I'm 5' 9" with a 30.5" inside leg and I fit a 54cm.

That was what I felt, but the assistant really didn't want to sell me the 56cm despite it feeling spot on to me, and me clearly having been slightly smitten by it....

The conflicting advice from different shops is really confusing me, and I don't expect tomorrow's trip to my other LBS to make things any clearer

The Boss is ready to order on Monday, and I need to decide which bike and what size before then!

 

[Cyclist33]

Can't help except to say you should deffo not get the synapse if you can't get a go on it first.

 

[Norm]

Bike fit is not, IMO, something which comes from a text book. BUT, it does suggest a theoretical ideal ignoring muscle memory, so it might be the suggestion is right, but it doesn't feel like it.

That said, I'm 5' 11" with a 29' inside leg and ride a 54cm Secteur.

 

[cyberknight]

There are bike fits and bike fits , depending on what sort of riding you do and how aggressive you want the position to be .Sounds like the shop guy is used to fitting people who want the most aero position they can get .Ths site has some interesting points regarding torso angle......
http://bikedynamics.co.uk/guidelines.htm
To me the bike sounds about right , i am 5 foot 7" and the bikes i ride have a 54 cm top tube with 100 cm stems , seat setback of maybe 4.5 cm from BB ,about 5 cm drop from saddle to top of the handlebars .Not sure what size they are as the both have sloping top tubes but they are both on the top end of my range as i have been advised to look at 52 -54cm frames .

 

[mrmacmusic]

Can't help except to say you should deffo not get the synapse if you can't get a go on it first.

Sadly I don't think trying it out will be an option, but I have sized the aluminium Synapse... is the carbon version not the same geometry which would allow me to order online with some confidence? Until I saw the Trek earlier today, the 'Dale was top of my list on looks and spec.

 

[zizou]

58 cm sounds too big to me but it depends on your dimensions i suppose. However i dont quite understand why an experienced bike fitter would be saying go up a frame size so you can have a more racey position. There are pros around your height who ride 52 and 54 cm frames and they certainly dont have sit up and beg positions on the bike!

 

[Norm]

Can't help except to say you should deffo not get the synapse if you can't get a go on it first.

Definitely. If they don't give test rides, they don't deserve your money. You're investing a lot there and a big benefit of an LBS is that you can try first.

 

[MacB]

58 cm sounds to me to be too big but it depends on your dimensions i suppose. However i dont quite understand why an experienced bike fitter would be saying go up a frame size so you can have a more racey position. There are pros around your height who ride 52 and 54 cm frames and they certainly dont have sit up and beg positions on the bike!

that puzzled me as well, some of the bigger riders in the peleton have surprisingly small frames but use some very long stems and setback posts. Though some of them do have some prodigious amounts of saddle to bar drop.

 

[mrmacmusic]

Bike fit is not, IMO, something which comes from a text book. BUT, it does suggest a theoretical ideal ignoring muscle memory, so it might be the suggestion is right, but it doesn't feel like it.

So perhaps the 56cm Trek 3.1 felt right because it was actually putting my body in a similar position to what it is when I'm on my Flight... It's just that the 58cm 4.5 really did feel too long. Long enough that I'm convinced if I went for a 58cm Trek (wouldn't be the nice red, black and white one though) I'd always mentally feel it was too big for me.

 

[Norm]

So perhaps the 56cm Trek 3.1 felt right because it was actually putting my body in a similar position to what it is when I'm on my Flight...

I'm no bike fitter, but it wouldn't surprise me. Then again, I've six bikes I ride regularly (I steal borrow my son's as well) and each has different bar height, saddle-bar distance etc, because each bike has a different purpose so has a different position to feel 'ideal'.

Riding so many and varied also makes me a bit blasé about bike fitting, I think it's one of those things which only niggles if you think about it, until you get past a couple of hours in the saddle anyway.

 

[mrmacmusic]

There are bike fits and bike fits... Sounds like the shop guy is used to fitting people who want the most aero position they can get .Ths site has some interesting points regarding torso angle......
http://bikedynamics.co.uk/guidelines.htm
To me the bike sounds about right...

Thanks CK I think maybe that's it... I'm sure the shop sees many proper roadies through the door who will want aero tuning. I'm convinced I wasn't that upright and was around the 40deg mark which is where I want to be - comfortable enough for the miles, but not full on race mode. The 56cm 3.1 felt right, the 58cm 4.5 just felt wrong.

 

[cyberknight]

here is a copy and paste regarding pro bike sizing..

- Seat height should be based on knee angles during the pedal stroke regardless of whether you get there with a bigger frame with less seat post showing or a smaller and or compact geometry frame with a lot of seat post showing. So the absolute distance from the pedals to the top of the saddle is driven by knee working angles and the ability to generate and sustain power during racing as well as the long term need to avoid overuse injuries that can result from things like overly low or overly high saddles. You can be certain that most pro riders have been professionally fitted and are riding an appropriate seat height from the standpoint of power generation and injury avoidance, sure there could be some who have achieved high levels of success on poorly fitted bikes but the vast majority have sorted out any seat height issues.

- Your frame is too small if you cannot achieve a proper fit which includes not only seat height for the reasons above but also appropriate reach and drop to the handlebars and appropriate weight balance between the front and rear wheels of the bike. Again pro's tend to fit quite well on their bikes with a good balance between aerodynamic and comfort concerns again with a strong consideration to being able to sustain the power they need to race effectively.

- A couple of decades ago 'compact geometry' road bikes started to become popular. These bikes have sloping rather than horizontal top tubes and overall their frames are a bit smaller and require longer seat posts to achieve the proper fit. There are a lot of arguments for the compact geometries, but the big advantage is that manufacturers can build and stores can stock fewer sizes and still fit a wide variety of customers. Basically the compact frames along with extra long seat posts (that were originally introduced to support mountain bike frame geometries) and long and short rise or drop stems allows more flexibility in terms of achieving a good fit for a wide range of body sizes.

- There's been a trend in recent years for racers to race on smaller frames. They still need to achieve a good and efficient bike fit but they'll do so with compact geometries and appropriate seat posts and stems. Not every pro goes with this approach but it's been real common in recent years. Some argue that it's lighter (but pros are already bumping into the lower end of bike weight regulations set by the UCI) some argue it's more nimble or feels stiffer or a host of other reasons but the bottom line is that a lot of pros have been riding smaller frames lately.

So your bike is 'too' small if you can't achieve a comfortable and efficient fit with available stems and seat posts or your fore aft balance or overall handling is impaired by extreme component lengths. But if you can achieve a good fit and the bike handling and comfort is good then the bike itself can't really be 'too' small even if it's not as large as traditional geometry bikes. If OTOH you're cramped with not enough reach even with a really long stem or have to max out an ultra long seatpost past it's safety limits or ride without enough leg extension during your pedal stroke (which is both inefficient and can lead to overuse injuries of the knees) then yeah, your frame is probably too small.

 

[cyberknight]

And more regarding fit, from competitve cyclist....
http://www.competitivecyclist.com/html/fit/traditions_of_road_riding.html

My fit comes in close to what is called an "Eddy" fit