What size frame should I be looking for?

Jackal79

I've seen a few various manufacturers tables that suggest that I should be looking for a 47cm frame. I'm 5'8" with a 29" inside leg measurement, is this right?
Just looking for general experience as I know your going to say "bike fit" to me.

merak

I'm not going to say "bike fit". 47cm seems small but, as you might have seen in other threads, some manufacturers' 47cm is others' 51cm. If you are looking at nominal 51/52cm with actual 47cm on a sloping top tube then I'd say you're about right. Nominal 47cm seems small.

ollyridesfirst

47cm does seem small for someone who is 5'8"

As stated above though, each manufacturer is different. Probably best to measure yourself up and then have a look on the websites of the bikes you like to see the build up of them and sizes.

Have a look at these for assistance:

http://www.road-bike.co.uk/equipment/bike-size.php

http://www.ebicycles.com/bicycle-tools/ ... /road-bike

nferrar

Firstly you need to be aware of whether the frame size being given by the manufacturer is the seat tube length, top tube length or a virtual equivalent of either. Top tube length is actually more important if anything than seat tube but a lot of manufacturers model sizes are based on seat tube. If it is seat tube then you need to know whether it's a compact geometry/sloping top tube and if the model size takes that into account (some do some don't). So a 47cm model size from one manufacturer could be the same as a 50cm from another and a 52cm from another etc.

Jackal79

I think one of the problems I have is some tables are listed in rider height and some in leg length.

@merak - So how does this relate to a Giant Defy 4 for instance? Sorry if I'm starting to sound thick.

topdude

same height as you, normally i would buy a 54 medium frame.
Giant sizing is a bit different, you could get a M or M/L depending how they feel to you, ie how stretched out you feel comfortable with.

merak

Jackal79 wrote:

@merak - So how does this relate to a Giant Defy 4 for instance? Sorry if I'm starting to sound thick.

Well, just looked at Giant website and 47cm (actually 46.5) seems to be the actual length of the seat tube. Given the length of the top tube which is 53cm (I'm assuming they are measuring the horizontal TT length rather than the actual length) then the nominal size will be around 52cm, which seems a little small for you. Maybe the M is the right way to go as others have suggested.

colsoop

Some manafacturers quote seat tube length as their size guide some the top tube length.

You could probably get the small or i would move more towards the medium for the Giant, assuming thats what you are looking at.

It's going to come down to how comfrotable you feel with the differing top tube lengths although that can be altered to some extent via differing stem lengths.

Sit on a few bikes and see what feels best for you.

geoff93

Same dimensions as yourself and I'm on a 54cm frame, its a Trek madone, so here are the geometries for that frame, and then find one with very similar sizing and should fit you. Or, buy a trek 54cm frame .
Seat Tube Length = 50.6cm
Effective top tube length = 54.3 cm
Standover = 74.2cm

phiadad

Hi,i dont know if this will help the OP but I am 5'8 with a defy as a training bike and I ride a M which is just fine for me

Ezy Rider

this is interesting to me

at the end of the month im going to be buying a carbon frame from carbonzone in china, im 5 ft 9 inches and have a 29 cm inside leg. my 56 cm trek is too big for me and thats my reason for sourcing a new frame. id been strongly considering buying a 52cm frame and im reading posts from guys here who are 5 ft 9 also, who are saying go for the 54 cm one. :?

would the original poster and myself not be better off going for a 52cm rather than a 54cm which could turn out too big ?

Dalton

In my (limited) experience, try before you buy!

I have two bikes, one is a Trek 1.2T which is a 52cm the other is a Langster which is a 54cm.

They both fit me perfectly. The extra length in the Langster makes it more comfortable for my daily commute, whereas the slightly smaller Trek feels more aggressive.

I am 5ft 6ins with a 29inch inside leg. So would definitely reckon a 47cm bike would be too small for you.

merak

Dalton wrote:

I am 5ft 6ins with a 29inch inside leg. So would definitely reckon a 47cm bike would be too small for you.

If you read the thread you'll see that Giant 47cm is the measurement of the actual seat tube length which, becuase of the sloping top tube, equates to a 52cm frame.

merak

Ezy Rider wrote:

this is interesting to me

at the end of the month im going to be buying a carbon frame from carbonzone in china, im 5 ft 9 inches and have a 29 cm inside leg. my 56 cm trek is too big for me and thats my reason for sourcing a new frame. id been strongly considering buying a 52cm frame and im reading posts from guys here who are 5 ft 9 also, who are saying go for the 54 cm one. :?

You have to look at the geometry and how each manufaturer specifies their quoted size. Nevertheless,56cm is big for 29 inch inside leg. You have short legs for your height, and presumably a longer torso, so you could be cramped for reach on a 52cm with a standard stem.

would the original poster and myself not be better off going for a 52cm rather than a 54cm which could turn out too big ?

Possibly - I always prefer to err on the side of small because a longer seat post and stem can fix that, but if the frame's too big, you're stuffed. Having said that, the solution for relatively short legs and relatively long torso and arms might be a 54cm with 170 cranks. It's a risky business buying off the internet, unless you know exactly what you need and what you're going to get.

obi wan dandobi

Had the same issue when I got my bike. When I got fitted the guy even said 'I see you're a bit stubby'. Nice! :roll: My inside leg is 30in and I'm 5' 8''.

Picked up my new 53cm Cube and it fits sweetly!

Jackal79

Thanks everyone. I've got the week off work next week so I think I'm going to spend a day going round different bike shops, try a few on for size.

Big DS

Looks like from the comments posted, it will be best to go to a bike shop and try them out.

cyberknight

I think you have to be aware that soem bikes are measured to where to top tube meets the seat tube and others are measured to where it would meet if the top tube were level.

The real measurement maybe a 47 -48 and the virtual would be a 52 cm ish.

I am 5 foot 7" with a 30.5 inside leg so i tend to ride a 54 cm ( the max i can ride ) so a 52 sounds about right.Remember that assuming you can get your leg over it comfortably you then need to consider reach as many bikes have different length top tubes depending on the role they are designed for.

My 2 bikes are both a 54 cm virtual frame and both have (luckily) the same reach but if you look at the seat tube you can see a difference in the amount of seat post showing as one is a "compact" and the other is a semi compact design.