Frame size confusion

pav_infidel

Hello,

I have been lurking around here for years, starting out with no bike knowledge I've found the expertise invaluable.

I've been riding a while and recently started looking to build a couple of bikes with my dad, part bonding, part learning, part it's always nice to have a new bike.

I have been looking at the ribble 7005 as it was well reviewed as a winter frame:

http://www.ribblecycles.co.uk/sp/road-t ... ibbfraw220

This is where the confusion started as I read their bike frames typically require you to go 2-4cm larger than usual. The label on my merida 880-16 says 54-56 bb to tt, which using ribble's maths equates to a 58cm frame on the 7005. However, my inside leg is 75cm, which equates to a 52cm on the 7005. To add more to my confusion, when i measured the Merida from BB to TT, it seems to actually be 50cm, and in fact the horizontal is 54cm.

I should add, I am aware that by normal size chart measurements the merida is too big for me, but i find it really comfortable.

Any help would be greatly appreciated

smidsy

Perhaps ring Ribble and chat through with them?

drlodge

I always go with the effective top tube length, together with seat tube angle is the best indication (steeper seat tube requires shorter top tube). Then you need to consider head tube length depending on the kind of position you're after. Look at the ribble frame geometries and compare these to your existing bike.

pav_infidel

Thanks for the replies gents.

I think I will have to give them a call, which I was trying to avoid because I am even worse at explaining myself verbally than I am on here . But I just don't seem to be able to get my head round it.

Better than wasting money on a frame that wont fit.

Cheers!

pav_infidel

Looks like they've all clocked off early for the pub. Job for next week then.

Thanks again