Merckx Frame Size? Too Big? Help

A bike that fits properly is far preferable to making due on a bike that is too big or too small at least for me. I had the opposite problem my old schwinn is too small. Makes my butt and back hurt on even short (5 mile) rides, now the trek i ride now fits properly and i can ride 15 or 20 with no pain.

Main thing is if it's comfortable and safe, while sitting on the seat can you put one foot on the ground? and can you straddle the top bar without whacking... things?

Has it shipped? If so then hey,try it out and see. May need to return and rethink sizing. I tried to figure the sizing and it is a bit weird.

Merckx AMX size number looks like it's based off of the length of the seat tube, which on a compact frame with sloping top tube is actually quite small compared to the traditional size. A size "51" AMX has an effective top tube of about 57 cm from the geometry I looked up online, so it's more like a traditional size 56 or 57 cm bike. There's no way it'll fit a 5'6" rider, it's way too big.

If the top tube is 57, the reach will be probably too far unless your fingertips touch your knees when you are standing up. Or you switch to upright handlebars that are sweptback. Which on a racing bike you wouldn't do.

What are your proportions? Short torso? Short arms? Long arms?

richfootfastfate said:

i seem to have made a mistake in that i bought a merckx 51cm amx 1 assuming it would fit, little old 5ft 6" me thought it woulod fit but apparently its far too big, I have not received it yet but do you reckon i will manage to use it if the saddle is right down?

Dear richfoot, you haven't specified what the 51 cm refers to, so all may not be lost. If it refers to the actual seat tube length, then yes, it will be too big. If it does indeed have a 57 cm virtual (horizontal) top tube, it is for someone more like 6' tall.

But no brand with the savvy of Merckx and their dealers would be naive enough to list a bike by the actual seat tube length. I'm going to bet that 51 is the nominal size, with a virtual top tube around 52-53.5 cm (Merckxs run a little long), which should be right in your pocket. You could call the people you ordered the bike from, and ask them about the virtual size and actual measurements of the frame.