Dodici Special - size 53 or 55?!

Hello all at LFGSS,

I just ordered a Dodici Special, size 55. However I am not sure that this is the right size for me. Dodici Cicli shop recommended the Special 53. My height is (184cm) and inseam (33inch). I heard that the Dodici Special frame can run big so it may be good to size down…?

I am planning to use the bike for short/long distance as well as the Velodrome. I am not getting the frame + build purely for track racing.

What do you guys think? Any advice and comments would be much appreciated!
Cheers,

Kacper

Dodici Special - Geometry:

Special 53:

• seat tube center/top: 57
  
• top tube center/center: 55,5
  
• vertical tube angle: 74,3 degrees
  
• head tube: 120 mm
  
• head tube angle: 73,3 degrees
  
• bb height: 285 mm
  
  

Special 55:

• seat tube center/top: 59
  
• top tube center/center: 56
  
• head tube: 140
  
• vertical tube angle: 74
  
• head tube angle: 73,3
  
• bb height: 285
  

That's really surprising that there's a .5cm difference in top tube length which is the main measurement, i had to double check and he's right, charts below. That .5cm can be sorted by a slightly different stem and/or seatpost so it mainly comes down to whether you have long or short legs, if long, get the 55, if short, 53. Given you're height though 33inch inseam seems quite small?

Thanks sirbikealot. It is a good point, the difference is only .5cm in top tube so in that respect they are very similar. So it all comes down to seat tube. My current Leader steel track frame has a seat tube of 58cm with a bb height of 25cm. This feels fine in terms of standing over frame with inseam. The top type is 57cm, which sometimes feels too long, so top tube of Special being 55.5 or 56 would fit well.

So according to these calculations, would the Special 53 still be the right size?

Does anyone have the Special 53 or 55. How do they feel the frame fits according to their height/inseam?

There is also a big difference in head tube (20mm), how much of a difference would this make when riding? Would the 55 frame perhaps be more comfortable then the 53?

Frankly, from reading the geo, both have almost identical reach, the only difference is seatpost height.

Go for the 55cm if the chart that sirbikealot is anything to go by.

it basically comes down too whether you want 1cm more or less seatpost showing than what you've got on your leader, don't worry about the 2cm difference in headtube because different stems and spacers can sort that out, eg: if you're worried the 55 is going to be too high on the headtube, slam the stem and use a stem with a big angle like a deda pista newton, posting a pic of you're current leader should be the easiest way to work it out aesthetically, functionally there's next to nothing between them

Thanks for edscoble & sirbikealot for your comments. They are really similar so it makes the choice even more difficult. I am just worried that because of the seat post and smaller head tube, the Special 53 bike may feel small, although I know I can adjust this with seat post height, stem etc…

Do you think it is better for the frame to run slightly big or slightly small for such a frame? I think I am somewhere in the middle of these two frames to be honest. More inclined towards the 55 for some reason... I need to make a final decision today as Dodici is waiting.

Cheers.

As a rule of thumb, best to be slightly small, but if you fit a 58cm Leader, then the 55cm Dodici will fit you.

Plus if you're keen on making it look good, you can able to have less spacer on the steerer.

I made some extra measurements of my Leader:

Leader:

• seat tube centre/top: 58
  
• top tube centre/centre: 57
  
• head tube: 155
  
• bb height: 250
  
  

The stand over feels good on the Leader frame, although the top tube feels a little too far...

For the Dodici Special, I agree with edscoble, I would rather not use spacers and raise the steerer. I think that with the 53 I may need to use spacers as well as raise the seat post higher then usual.

Would the BB height make much of a difference for sizing? The Leader is 25cm and the Dodici Special is 28.5cm.

. .

I spoke to Dodici today and they said they calculated frame size using this formula:

Inseam (mine is 84cm) x 0.65 = 54.6
54.6 - 1cm (to allow difference for track style frame) = 53.6

53.6 - closest matching frame is Special 53.

Dodici said they feel that the Special 55 may feel a little too big for me…

p.s. previously I tried a Cinelli Mash Bolt size M (53), and that felt too small. The closest equivalent to the Cinelli Mash size L (55), would therefore be the Special 55.

I would ignore the BB height, but I don't think the Leader's BB height is correct as 250 is incredibly low, lower than touring bicycles even!

285mm is standard for a fixed wheel/track bike to prevent pedal strike.

edscoble, you are right indeed! I checked again and the Leader's BB height is 285mm, same as Dodici Special.

I decided to go with the Special 55, as it seems to be the most similar geo and measurements to my current frame. Thanks for you help!

I finally received my Dodici Special. She is a real beauty!

It took 5 months to arrive because of various delays. BUT that being said, it really was worth waiting every minute for. I have now ridden it at Herne Hill Velodrome and the Olympic Lee Valley Velodrome. It also rides real nice on the street, always fast, stiff and very responsive.

I am also happy that I went with the 55, feels just right.

So if anyone is thinking about ordering from Dodici, I say do it! Just keep in mind that the delivery may take longer then 2 months, but it is worth waiting for, trust me.