Sizing help - check these figures please?

Scrumple
Scrumple Posts: 2,665
edited March 2010 in Road buying advice
I have been fitted to a 54cm Top Tube Sabbath:

Small : 5’6-5’10 / (167-177cm)
actual seat tube (CT) 54
Top tube (equiv) 54
seat angle 73.5
head angle 73
head tube length 13

I'm looking at a bike:


seat tube (c-c) 47
top tube (effective) 55.5
head tube 15.9
seat angle 73.5
head angle 73

These are my measurements as given by the fitting v new bike

top of saddle to centre BB = 72 - can match this by stem reduction

tip of saddle (arione) to bars = 52.5 - 53cm to centre of stem, 56.5 to end of bars

top of saddle to floor = 95cm - can match the height with stem reduction

top of bar to floor = 91 (seems more like 89 on my bike!) - 93cm lowest possible

saddle set back (tip to centre bb) = 5.5 - I think its 5cm

The saddle height reduction will bring the tip 1cm closer to the bars, making this difference manageable with a shorter stem? Bit worried the from end will go no lower than 93 to put a 2cm drop between saddle and bar compared to my 4 - 6cm current.

Simple question, is the new frame I'm looking at too big, or fine. Ideally, I'd get the size down but this isn't an option.
It is a carbon bike for best / sunny days when the titanium one can have a rest. It is also expensive so I need to get it right.

cheers

Comments

  • Scrumple
    Scrumple Posts: 2,665
    Anyone - is the drop too small to make this a sensible option?
  • it looks as if the new bike isl compact geometry - if I read it right.

    So you'd be looking at a shorter stem - whats on the Sabbath ?

    If its a bike for your sunny and fast days - you might want the drop ? - you could get a stem with a steeper angle ? (eg upside down on the steerer)

    I'd think carefully about the extra top tube you'd be getting. though. If you are closer to the 5,6' end I would say its too big and you would regret it.
  • Scrumple
    Scrumple Posts: 2,665
    I'm a smidge over 5'10.
    think it is 11 on the sabbath... but in reality it is more the hight head tube and the small saddle to bar drop.
  • weeve
    weeve Posts: 393
    looking at you picture of your current bike I notice couple of things ...one is you have spacers under your bar...so if the efffective increased head tube height is less than these spacers on your new bike you can re-create the drop (by not having spacers) just like that

    however ...to me it looks like the drop you have isnt that much on this bike. Im same height with apparently longer legs (looking at set up up) and wouldnt by more than a 54.5 effective TT - my drop is more. Im not especially supple (40 next week) although Ive ridden a while but I can enjoy long fast rides okay and the loss wind resistance of a lower position is big ...if you intend to have some carbon bling you'll be riding pretty quickly so for the record I would NOT buy the next size up myslef ...it would feel too shallow. Sure you can recreate the position but I would think youve got room to drop further as you do more cycling and staying with the smaller size (which is also lighter) allows this option in the future
    cheerio