Why not SLR01-56?

Gyswandir

Hi everyone,

So after a year on my BMC AlpenChallenge02, I decided I enjoy this enough to consider a Road bike. As part of their end of year clearance, I found an amazing deal on an SLR01-DuraAce Di2 in size 56 http://www.bmc-switzerland.com/int-en/b ... a_ace_di2/
My AlpenChallenge is a medium for reference. Based on competitiveCyclist:
Your Measurements cm
Inseam:85.5
Trunk: 58
Forearm: 40
Arm: 66.5
Thigh: 63.3
Lower Leg: 57
Sternal Notch: 146.3
Total Body Height: 177

The Eddy Fit (cm)
Seat Tube Range c–c: 56.6 - 57.1 cm
Seat Tube Range c–t: 58.3 - 58.8 cm
Top Tube Length: 55.2 - 55.6 cm
Stem Length: 10.4 - 11 cm
BB–Saddle Position: 72.4 - 74.4 cm
Saddle Handlebar: 55.6 - 56.2 cm
Saddle Setback: 7.1 - 7.5 cm

The Competitive Fit (cm)
Seat Tube Range c–c: 55.4 - 55.9 cm
Seat Tube Range c–t: 57.1 - 57.6 cm
Top Tube Length: 55.2 - 55.6 cm
Stem Length: 11.5 - 12.1 cm
BB–Saddle Position: 73.2 - 75.2 cm
Saddle Handlebar: 54.8 - 55.4 cm
Saddle Setback: 5.9 - 6.3 cm

My understanding is I'm between the SLR01 sizes 54 and 56. However, the shop assistant and 2 different fitters told me over the phone I should go for 54 with a longer stem simply based on my height. My question is, why can't I go for a 56 with a shorter stem?

Apologies if this is self evident, but I'm new to this.

Thanks

diamonddog

You can go for the 56 with a shorter stem but you may feel a bit too 'stretched' on it, also it is far easier to get a slightly smaller bike to be a comfortable fit.

Bobbinogs

Personally, I would always err on the side of a smaller bike as it is easier to make it feel right with the odd minor adjustment (such as a 110/120 stem) as opposed to trying to make a bigger bike feel smaller (a shorter stem sems obvious but then the angle will need to be different to offset the higher headtube, etc). My first decent road bike was a Spesh and a size too big at 56 and I spent 2 years constantly adjusting/tweaking/swapping various things. Had a brain wave and flogged it, bought a replacement Spesh for about the same money but a 54 and I have never adjusted it since. I am about 180 tall but height is only one factor.

A bike slightly big, IME, always felt like someone else's bike.

Matthewfalle

Always found that slightly small, as above, is easier to make fit me. It also feels tighter, snappier and lighter.

Looks cooler with more seat post showing as well.

MikeBrew

I've had a 53cm Race Machine, and a 55cm Team Machine. Race machine withh 140 17degree stem, and Team Machine with 120 6 degree stem.

Both great fit. Marginally taller than you at 180cm though. Fantastic bikes, you won't regret buying one.

SCR Pedro

For what it's worth, I'm a little taller than 177cm and ride a 54cm SLR03. I assume the geometry is the same for the SLR range, right?
I would definitely call it a pro-fit, and like that other dude said, looks cool with more seat post showing, and there's a good 6-7cm of post being unused. I could maybe use an extra 1cm worth of stem, but I get on fine with the set-up as it is.

Gyswandir

Thanks everyone for the replies. So, my understanding is that it is easier for me long term to adjust the 54 than the 56, which will always be somewhat not right

pan280

i actually found the opposite. in smaller bikes I need to raise the seatpost quite high giving me a big drop and a long reach.
and to compensate i need a shorter stem and more spacers.
so it all depends and without trying it out you can't really say for sure.

if you are uk based then testing out bmc's is quite easy since evans stock them.

darkhairedlord

diamonddog wrote:

You can go for the 56 with a shorter stem but you may feel a bit too 'stretched' on it, also it is far easier to get a slightly smaller bike to be a comfortable fit.

not sure how it can make you feel stretched if the bars are brought closer with a short stem.
go and try one.

diamonddog

darkhairedlord wrote:

diamonddog wrote:

You can go for the 56 with a shorter stem but you may feel a bit too 'stretched' on it, also it is far easier to get a slightly smaller bike to be a comfortable fit.

not sure how it can make you feel stretched if the bars are brought closer with a short stem.
go and try one.

If 2 fitters reckon a 54 then obviously they think the 56 would be some sort of compromise for the OP, shorter stems are not always the way to a better fit on a bike that is slightly too long on reach.

Gyswandir

Just wanted to provide an update in case others face the same situation. So, went to a local shop and had a simple size fitting, where they used a setup that simulates any bike geometry. The fitter's conclusion was I can do either a 54 or a 56. Ideally, I should get the stack of a 56, with the reach of a 54.
Upon my return to the shop for my hybrid's service, I found the bike was still there. When they agreed to replace the stem and handlebars, as per the fitter's recommendation, I decided to buy it. Went the next day and had the BMC specific fitting and, lo and behold, the SW recommended the 56!!!
Today, I rode it for the first time...AMAZING!!! The bike is soooo fast, pure bliss. I also didn't expect the difference that the Di2 shifting makes. So smooth and fast. Makes adjusting very easy.
I still need to get some real pedals and shoes, as I am just using the pedals from the hybrid

Happy new year everyone!

Secteur

I once read that "the pro's" always ride frames that are technically too small for them by conventional measurements, and adapt with slightly longer stems etc - the reason being that smaller frames are stiffer and therefore help reduce power loss etc.

The article exemplified Wiggins' bike, but to be honest at the time it was all a bit above my head so I couldn't really tell.