compact frame sizes help?

lcowner

can someone claify this for me ,im looking to buy a used 56cm compact frame(trek alpha 1.5)
dimensions:
55.7cm virtual top tube.
Seat tube is 53.5 C-T (deceptive as it's a compact frame).
Frame stack is 57.6(what is this?)

i ride a 56cm standard ribble frame at present but its just the compact sizing seems to be very small to me :?:
my question is whether it will be ok for me??im 5'10 height,i cant try it for size as i will be getting it posted to me
thanks

imposter2.0

Frame stack is sometimes described as the vertical distance between the centre of BB to top of head tube - not a particularly useful measurement, imo.

The measurements you've given don't sound particularly compact.

lcowner

thanks for reply,well in comparison to my std frame,to me it measures up v small(maybe just me)..... :?

imposter2.0

lcowner wrote:

thanks for reply,well in comparison to my std frame,to me it measures up v small(maybe just me)..... :?

What's the top tube measurement of your Ribble? Look for a frame that matches that. The seat tube size is usually irrelevant, mainly because the seat pin can be adjusted to suit.

skyd0g

The most relevant dimension to check is the Virtual Top-Tube (a horizontal line from the centre of your seat tube to the centre of the stem) - see how this compares to your Ribble.

lcowner

with a tape it measures my ribble is approx 57.5,so i guess that answers my question then ........

skyd0g

Depending on your physique / the Treks geometry, the VTT may not totally rule the Trek out. Many of the pro's ride a smaller bike, but use a longer stem (ie. 120 or 130mm) to 'fit' the bike.

It's easier to get a bike that's 'too small' to fit you - longer stem, raised seatpost, set-back saddle etc. than to fit a bike that's too big for you. If the Treks a bargain & the rest of the geometry isn't too far off, it may still be worth a punt.

kentphil

I thought the Compact Trek frames referred to the compact chainset, as opposed to a triple chainset? Perhaps I'm wrong?

Grill

You'll need that Trek in a 54. You may be able to get away with a 56, but it won't be as comfortable or adaptable.