Virtual seat post length vs. Actual seat post length

rriiicchh

I have a Bianchi 928 B4P with a 57cm frame.


I am looking at buying an older bike cheap bike from ebay as a commuter but am confused about the sizing.

My Bianchi is a 57cm frame but when I went to check it the seatpost length it is actually 54cm. Looking in to this I see that the 57cm is the virtual seat post length and the 54cm is the actual seatpost length.

If I am looking at getting a bike of similar size, as I like the fit, do I go for one around 57 or 54 :?

Keith1983

You get my virtuoso that I'm gonna be sellign which is between the two at 55, perfect!

alan_sherman

57

topdude

You go by the length of the "virtual" top tube measured horizontally centre to centre
The seat tube is fairly irrelevant as it depends on how the top tube slopes

rriiicchh

Not many ebay listings give the top tube length, most go for seat tube length.

Thanks for the advice though.

topdude

I find you have to ask, make the seller do a bit of work and give you the measurements. They should have put it all in the ad anyway :?