kaiserschmarrn

This evening I bought a New Trek Emonda ALR 5 Disc (that is what the receipt says). It is last year's model,a funky purple or blue. They sold it to me as a 56 cm frame. When I got home, I found a sticker on the front of the tube that holds the seat, but down low nearer the crank. The sticker says "TREK-054-RD" and "Frame" and "43256", and what looks like "UCI", but it is really stylized and I am not certain on that. To me, that is telling me that it is a 54 cm frame. I feel that may be too small, but that is another story. The other is that they made an error in what they sold me.

I am 5' 8-3/4" tall, but I have really short arms and legs. The pants inseam that I wear best is 30", but it could measure directly as 30"+

Is this size frame wrong for me? For years I was used to riding a 23" Peugeot. which I think is a 58 cm.

Thanks for any help,

Danny

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GeneO 

It sounds to me like a 54 might be about right from your description of yourself. A picture or video of you on it would help.

kaiserschmarrn

GeneO,
Thanks for the help. I looked at my old Peugeot manual for fitting and what they show for fitting seems to tell me that the fit is probably correct. The problem is that I thought I was 5'9"+, and I might have been once, before I aged, and got disc issues and Scoliosis. When I thought I was 5'9", it seemed like I should have been in a 56cm frame. I measured my height and inseam after getting the bike and got the numbers quoted. Trek's site for this model showed my frame size as an overlap between 54 and 56cm, BUT, that would assume normal inseam for my height, which I don't have. Back to my old Peugeot manual. They said that to find your correct frame size, subtract 9" from your inseam size; 30" -9" = 21". In cm, 21" is 53.34. Peugeot also said that you should be able to straddle the top tube comfortanly with both feet flat on the ground, which I just can with this new bike. On my 23" (58 cm) Peugeot, I measured the top tube height at 33" (it is stored, hanging). That is three inches higher than my inseam, so I could not straddle the top tube without standing on my toes. It seems debatable that a 56 cm would have been the best, or at least only fit. I guess that I am at an inbetween size. My getting the 54cm frame might have been a fortunate mistake.

Thanks,

Danny

Iride01 

Why would you look at a Peugeot manual for fitting a Trek? Though many can be similar, they might have some variance where the overlaps occur.

Bike geometries are different from model to model and between manufacturers. Also, the older bikes don't size quite the same as the newer bikes. I haven't gotten to the point of measuring yet, but I have put my very old and very new bikes next to each other and eyeballed the reach, and other body contact points are on the two bikes. There isn't a lot of difference when I put my 56 cm 2020 Tarmac against my 60 cm 1991 Paramount. Most surprising for me, reach is almost the same, but I did put a shorter stem on my Paramount than what would have been on the original spec.

Trek's website has the sizing recommendation for each of their models, use it.

philbob57

Your pants inseam is not the measurement that counts; rather, it's the height from the bottom of your pubic bone to the floor when you're not wearing shoes. If you hit the top tube on your 58 CM Pug, I'd consider it too big for you.

Did you ride the Emonda? How was it? With short arms and legs, longer torso, and a sloping top tube, the smaller frame may or may not be better for you than a bigger bike.

Very few of us can get a perfect fit off the rack. I've owned and ridden bikes with diamond frames of 50, 54, and 58 CM. I came down hard on the top tube on the 58, so that went. I felt cramped on the 50 - an over reaction to the accident on the 58. The 54 is best - but I, too am longer in the torso than average, and my particular 54 has a 56 CM TT, which is great with a 11 CM stem. But I've had my 54 since 1981. If I were buying a diamond frame today, a 52 or 53 would probably be best, still with a 56 CM TT. You don't see many of those coming of assembly lines. If you rode the Emonda, and it felt like a good fit, it may be a compromise that works, even though it may not be an exact fit as it is.

kaiserschmarrn

I found, and used Trek's sizing guide for the model. I found that I was in an overlap between. 54 and 56, but it seemed likeI might have been slightly closer to the center of the 54 than the 56. Then there is the fact that the chart expected normal leg and arm length, which I do not have, so I figured that realistically, that put me even more in the 54 realm. I looked up a bunch more fit charts, some of them based on height only, some on inseam, and some where you did a calculation based on inseam. All, save one, agreed on a 54 frame for me. The one that was off, was off by quite a bit.

It was at this point that I started to examine what my old Peugeot was in frame size, since I was just going by an ink pen handwritten not on the cover which said that it was a 23" Frame (58 cm?). I thought maybe that was wrong. I made a calculation and found it to be in fact a 23" frame. Since I was there near my Peugeot and the manual, I looked into it because it had some setup notes with pictures for setting up the new one. I also found a note on selecting the proper frame size, and that was based on inseam. I did the calculations just as they had them, and then I found that it too sized me for a 54 cm frame.

Danny

kaiserschmarrn

Thanks for the help. Initially, just for quick reference, I used my pants inseam, but did measure as you say, for the calculations. I do distinctly remember riding my Peugeot, stopping, and having to stand on my toes. I will know for sure tonight, as I just got tires and have gotten it down and inside. Due to Corona, no bike shop here is right now allowing test rides (that I am aware of). Maybe not the best situation, but I did it and it is done. I did get to sit on it. though, and it seemed to fit. I was just led astray by the fact that I thought I was taller and needed a bigger frame, then found that I got a 54cm. My judgement is also being manipulated by the fact that I have so many miles on that 23" frame, so that it seems that it is normal and that the 54cm seems small, when in fact it isn't. When I swung over it and stood, there was just a little clearance between my crotch and the top tube just ahead of the saddle, which was a nice feeling. All of the measurement charts and calculations that I have found point me to a 54cm.

My wife will be soon buying a bike. As an eample, she is 5'4" with a 29-1/2" inseam. I am 5'8-3/4", over 4" taller than her, but with an inseam only 1" longer than her at 30-1/2".

Danny
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AdkMtnMonster

The “Road 054” designation in the UCI sticker is the frame approval protocol for that model of bike. It has nothing to do with the frame size, other than insuring that the top/down/seat tubes, and seat/chain stays are of standardized dimensions, or some such rules compliance.

Iride01 

How old is that Peugeot? Even back in the 70's and 80's different mfr's used different conventions to come up with that number for their frame size. Most would start at the crank center, then measure to one of three places. The intersection of the center axis of the Top Tube with the Seat Tube, the intersection of the top of the Top Tube with the Seat Tube, or just all the way to the top of the Seat Tube. So even back then on to the other mfr bikes were off by 1 to 2 CM or more from each other and still in fact basically the same size frame.

Sizing today can be even more different because sloping top tubes and other things in the design have changed. Some mfrs are trying different ways to describe their sizes too. It just really implies to me that you should weight your choice heavily by the mfrs sizing recommendation. Especially if you don't have a trained fitter or other expert, or the results of a long test ride on different size frames of that model bike.

And if you aren't putting out 4000 miles a year, you can probably make a wide variety of sizes ride well for you, just like I am able to do.

kaiserschmarrn

YES! I found that out today when I had to have my shop do a rear derailleur adjustment. Mine is in fact a 56 frame. The confusion came in when I saw that "054", which does look coincidently like a frame size dimension. Internet searches did not help because it said that the frame size should be on a sticker, roughly where that one is. Trek, for that model, for my dimensions, put me in either a 54 or 56. A fictious "55cm" in that model, if it existed would probably be what would fit my height and short legs. It feels like a good fit.

Danny

kaiserschmarrn

Thanks for the help,
My Peugeot is a '76, '77 or '78. I watched a Youtube video on determining a bike frame size. They measured from the center of the crank to the top of the tube where the seat post fits in. When I did that, I got 23" exactly, and Peugeot called it a 23". I sat on it yesterday. It is too big, but not by much, but I rode it a lot of years. Trek, for that specific model, puts me into either a '56 or '54, and now I know it is a 56. The fit seems good.

Danny