# SLR01 sizing - not sure "size down" is valid advice



## 9W9W

There's been a lot of talk about BMC's "running large" and accounts of people ignoring BMC's explicit suggested sizing chart and buying frames one size smaller. These aren't the rumors on some deeply dug in crit racer website, but advice given out on this and other forums. 

I've recently had the chance to get on a second hand SLR01 at a great price. The bike is a 58 size, which is 402mm reach and 584mm stack. I am 183cm or right in the middle of the suggested 180cm to 188cm sizing for a BMC SLR01.

















All the SLR01 sizing threads I've research would have me on a 56 frame, and I've ridden my bike trying to imagine a smaller frame. I'm perfectly happy on the 58 as a six footer. I'm running a 110 stem with not a lot of spacers and have 1.5cm should I ever need it...which is a huge amount. If I need more I swap the -6 for a -10 stem. 

The seat is about 77cm and the rubber Fizik ring which the light clamps to make this look a bit shorter than it is.

Yes, most people can fit on more than one frame size, but I think the general advice to "size down" isn't doing beginners or casual riders any favors. I have 7.5cm seat to bar drop. If I had a 56 frame, I would have had the 2cm spacers I do now, and another 1.5cm for almost a stem height stack of spacers, before the stem...just to run a 7.5cm bar drop. :crazy:

Get the stack and reach calcs for your current bike, as that comparison never lies and go off of that. Think hard before "sizing down".


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## GOTA

For most brands I ride a 54 or a 55. I was fitted for both a BMC GranFondo and a ALR and ended up with a 51. I wasn't trying to size down. All that mattered was that the bike fit. I was actually skeptical when I was told that the 54 was too big. Once I tried the 51 I understood exactly why I was pushed that way and they were right.


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## 9W9W

GOTA said:


> For most brands I ride a 54 or a 55. I was fitted for both a BMC GranFondo and a ALR and ended up with a 51. I wasn't trying to size down. All that mattered was that the bike fit. I was actually skeptical when I was told that the 54 was too big. Once I tried the 51 I understood exactly why I was pushed that way and they were right.


The SLR02, ALR, and GF are different geometries than the SLR01 (yes, the SLR01 and SLR02 are different on paper, check stack height)

With that said, were the stack and reach numbrs of the 51 comparable to the 54? Can you elaborate on what you mean when you say "understood exactly". I see a lot of SLR01's ut there with a ton of spacers under the stem. which makes me think they could have benefitted from a larger frame and 1cm shorter stem.


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## campyjoe

I don't know about BMC sizing compared to other manufacturers, but I've always been told to size down if you are between frame sizes. That rational is due to a lighter and stiffer frame, generally speaking. Some manufacturers do however, change frame dynamics to create the same characteristics across every size.


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## GOTA

9W9W said:


> The SLR02, ALR, and GF are different geometries than the SLR01 (yes, the SLR01 and SLR02 are different on paper, check stack height)
> 
> With that said, were the stack and reach numbrs of the 51 comparable to the 54? Can you elaborate on what you mean when you say "understood exactly". I see a lot of SLR01's ut there with a ton of spacers under the stem. which makes me think they could have benefitted from a larger frame and 1cm shorter stem.


Your initial statement was about BMC running large. I don't race and wasn't looking to buy a SLR01 but I did buy a Granfondo and an ALR01. I also considered the SLR02 but since I'm not racing the Granfondo made more sense.

When I was fitted the stack and reach of all 3 bikes felt better on the 51. That's with the spacers as they came on the bikes. The 54 Granfondo and SLR02 felt a little long. I was not measuring and the fitter was making the adjustments. He suggested the 51 for both and it was more comfortable. Later when I purchased the ALR01 we started at 51 and I felt no need to move up to the 54. I've since removed all but 1 spacer on each bike and am very comfortable. 

I think the BMC frames do run large as do Orbea and the Giant TCR. Other bikes that I have owned from Trek, Felt, Jamis and Salsa have been larger sized frames. I always go with the shop fit and am not doing on my own as you are with a used bike. I am also not looking to slam the stem and win any races. Reading your post you are analyzing it a lot more than I am.


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## 9W9W

My initial statement was that my research into the frame uncovered tens and tens of post that had people talking about how the SLR01 was large and they need to take a size down then all their other bikes. I found this to be untrue, or at least not as pronounced as reading multiple forums would have me believe.

On a used bike I am simply replicating the fit from my old bike, which was fitted. Transferring stack and reach numbers is relatively easy if you understand basic math and angles. There's no need to pay someone to think for you. Stand, laser level, beer, job done. 

I'm not sure why you mention not racing and slamming stems, the SLR01 is a very comfy bike with a neutral handling disposition.

Here's to riding great bikes! I'm thinking about picking up a grand fondo frame and building it up as a winter/spring ride.


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## Peter P.

9W9W, your BMC looks perfect for sizing i.e., seat height vs. seat tube length, and saddle to bar drop. You know what you're talking about. Good on you for not following the crowd, or BMC's recommendations.


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## 9W9W

Peter P. said:


> 9W9W, your BMC looks perfect for sizing i.e., seat height vs. seat tube length, and saddle to bar drop. You know what you're talking about. Good on you for not following the crowd, or BMC's recommendations.


That's the thing, I bucked the trend and bought it exactly as per BMC's sizing recommendations. Everyone is different and your personal fit will ultimately decide. I'm hoping that someone in the future will be doing the same research I was and stumbles upon this thread. BMC's sizing recommendation PDF is not incorrect.

Cheers!


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## looigi

Go by stack and reach, which makes the traditional and ambiguous "size" immaterial.


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