Frame Sizing question (newbie)

jamiemilbourn Posts: 62
edited May 2013 in Road buying advice
Afternoon all,

I currently own a 54cm Jamis Xenith Comp (sizes below) and have been sniffing around a 52cm S-Works Venge (sizes below) - been to the concept store and they recomended the 52cm OR the 54cm frame and I sat on both - only difference i could notice was that on the 52 there was more seat post than on the 54.

So i thought i would compare my current 54cm Jamis geometry to the S works 52cm and its below...

Size 54 52
Seat-Tube Length, B-B Center to Top 486mm 487mm
Top-Tube Length, Horizontal 544mm 537mm
Chain-Stay Length 405mm 405mm
Seat-Tube Angle 73° 74°
Head-Tube Angle 73° 73°
Wheelbase 967mm 970mm
Stand-Over Height 766mm 766mm
Head-Tube Length 140mm 120mm
Reach 378mm 385mm
Stack 542mm 528mm

To my untrained eye there appears to be no difference apart from reach (which can be adjusted with stem length? and i have short arms anyway) and Stack which I have no idea about.

Standover is identical and the rest is marginal difference - however is there anything i seem to have missed?

I have sat on both and as above it seems fine to me, just want to address all avenues before shelling out a lot of money..

i am test riding a 54 tarmac (its the only demo bike they have in that size) this weekend so this might reveal more...

Any advice greatly recieved!


  • drlodge
    drlodge Posts: 4,826
    I would focus on the effective top tube length - the 52cm S Works is nearly 1cm shorter ETT (537 vs 544) so you might want to look at the 54 cm frame, or use a 10mm longer stem if your current fit is perfect.
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  • thanks drlodge - well i had a bike fit on my bike and apart from changing the handlebars (smaller width) the stem stayed standard - so adding a 100mm Stem is a good option.