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How much difference is 2CM in sizing a frame?(8 posts)

How much difference is 2CM in sizing a frame?Nebuladds
Jan 13, 2004 4:54 PM
I have a size 50 frame, and it's somewhat cramped. How much difference will getting a size 52 frame make?

Note: both frames are from the same manufacturer.
depends on TT length...torquecal
Jan 13, 2004 5:07 PM
compare the top tube lengths, for me anyway the TT is probably the most important to overall bike fit.

In this case, imagine using the same handlebars you have now, how much longer would your stem have to be for you to feel 'uncramped'? This is how much longer the TT length should be (in ballpark figures anyway).

BTW: all this assumes either frame will give you enough standover height for your comfort/safety.
Jan 13, 2004 6:30 PM
go for a good professional fit evaluation before just coughing up the dough to upsize. It may be a variety of things related to your reach, or it may be the wrong frame for you entirely.
also depends on which 2 cm.dzrider
Jan 14, 2004 5:59 AM
Most riders can be made comfortable on a range of sizes by moving the saddle up,down, fore or aft, and changing stem lengths. If any dimension of the 50cm bike is close to the upper limit of the rider's size range, he/she may not fit well on a larger bike. If all the dimensions are at the lower end of the rider's size range he/she can almost certainly fit well on a 52cm.
re: How much difference is 2CM in sizing a frame?mapei boy
Jan 13, 2004 5:45 PM
Enough to matter. Enough to turn an oversized beast or a tiggly roller skate into a supple, comfortable thoroughbred.
re: How much difference is 2CM in sizing a frame?lyleseven
Jan 13, 2004 6:21 PM
It can be a big difference. I went from a 58 to a 60 on the TT and it made a world of difference.
Jan 14, 2004 5:40 AM
Read the geometry chart from the manufacturer. Typically, a 2cm larger frame will have a top tube that is about 1cm longer and more importantly, a head tube that is 2cm taller (to reduce steering tube spacers and/or stem rise).

You could duplicate the change by using a 10mm longer stem.
re: How much difference is 2CM in sizing a frame?woofers
Jan 14, 2004 8:24 AM
Check the geometry charts for your frame. I was choosing between 50 and 52cm for a Trek 1500. Both sizes had the same TT length.