tudorowen1

How tall do you need to be to ride an old F frame Moulton bike..?

repechage

There are actually a number of Moulton frames. There are some specific Moulton discussion groups and forums.
I identify what you have by referencing those sites and the info you want should filter out.
"standover" height should be easy, it is a matter of seat tube length or seatpost length.

bOsscO

Depending how old a bike yer talkin' here, I'd wager one would need to be at least 16 hands tall to ride a Moulton F frame.

oneclick 

There are really only two F-frame Moultons if you are just considering frame size, the Series1/2 versions (bigger) and the Mini. They both take a long seatpost so you'd have to be shorter than about 5foot4 to feel stretched on the big one (the mini is 7/8 size). I'm a bit taller and prefer the Mini, but that's because of weight and portability (and it's been more modified with better equipment); the standard F-frame has a more comfortable ride.

gilesa

Three sizes IIRC: standard, midi, mini. Also a Triang-branded child's version. Midi was the 7/8th size with 14" wheels. Mini was smaller and lacked front suspension. The 5' 4" lower limit sounds about right to me. The stem and seat post have a lot of adjustment, but the reach might start to become excessive.

oneclick 

Moulton net wisdom says only two sizes, Mini was 7/8 with 14inch wheels - I know, still have (somewhere) the steel pair I took off my Mini - and it has front suspension:

clubman 

Moulton Midi, no front suspension and a Raleigh product. Pretty rare I think.

oneclick 

Rarity increased due to them breaking at the front main frame joint - a consequence of the lack of suspension.

rhenning

This is my 1965 Huffy sold 4 Speed Moulton that I ride and I am a bit under 6 feet tall. Roger

clubman 

Raleigh was starting to lose it around that time I figure.