Giant Frame Size Question

thescouselander

Hi - New member here needing a bit of help with frame sizing

I am thinking of upgrading my road bike and quite like the look of the Giant Defy 2. Problem is I went to the Giant store yesterday and couldn't work out what size frame I needed.

The shop had a M/L example on display and it felt ok just siting on it except for the brakes were a little too far away. Unfortunately there were no medium sized Defys on display so I couldn't try one out.

My questions are:

1) If I was to sit on another Giant bike (say a TCR) in a medium size would that be representative of a medium Defy?

2) Would it be better to go with the M/L size but with a shorter handle bar stem?

3) Could anyone hazard a guess at what size is most likely to fit given I am 5'11" with a 31" inside leg.

For comparison I'm currently riding a Carrera Virtuoso in a Medium side and that fits ok.

supertwisted

Sitting on it isn't really any good, you need to ride it around to get even a vague idea of fit.

I'm 177cm and ride a medium SCR (precursor to the Defy) and find it a very good fit. I'd hazard a guess and say the ML with a shorter stem sounds right for your size, but in your position I wouldn't want to put any money down until I'd at least ridden both sizes.

kettrinboy

A lot of Giant road bikes use compact frame geometry, that might make them feel a bit different to other brands in the same frame size, my FCR2, also a predecessor of the Defy,with compact frame is medium size and i,m 5 ft 6 in and also 31 in inside leg,but it fits me fine, it has a 100mm stem,better to try different sizes first rather than try to make a bike fit by changing the stem.

thescouselander

Yeah, I agree I'm going to have to ride the bike to get a good idea. I was a bit disappointed the so called "Flagship" Giant shop in Bristol didn't have a good range of sizes to try.

They could only offer a go on a lower spec Defy in the M/L size and didn't have anything at all in the Defy range in the Medium size. If I cant find another Giant dealer in the area I might just have to look at something else.

topdude

3) Could anyone hazard a guess at what size is most likely to fit given I am 5'11" with a 31" inside leg.

I have a Defy3 M / L and i am 5'8" you will need at least a M / L

Why not take some measurements off your current bike and compare to the defy geometry here http://www.giant-bicycles.com/en-gb/bikes/model/defy.2/7842/45447/

Xommul

Get a bike fitting from a professional to find out what exat size bike you need then you can compare geometries to ensure you minimise the risk of injuries and unwanted pains.

SCR Pedro

topdude wrote:

3) Could anyone hazard a guess at what size is most likely to fit given I am 5'11" with a 31" inside leg.

I have a Defy3 M / L and i am 5'8" you will need at least a M / L

Why not take some measurements off your current bike and compare to the defy geometry here http://www.giant-bicycles.com/en-gb/bikes/model/defy.2/7842/45447/

I suppose it depends on your proportions. I am 180cm and ride a M TCR, and a L SCR. The TCR is a much better fit for me. I think the virtual top tube length is 54.5cm, and that suits me better than the 57.5 of the SCR.

Giants will usually have quite a lot of seatpost showing, so don't worry about the seat tube length, rather, concentrate on getting the reach right.


Pedro

night_porter

I have a Defy 1 in M/L and it fits me perfectly, I am only 5' 9".

If you look at the Giant website you will see that the virtual top tube length is 56cm with the M being 54.5cm.

Looking at the Virtuoso the Medium says it is also a compact frame with a virtual top tube length of 54cm so the Giant M would be equivalent.

However, the smaller the frame will give you the biggest height difference between saddle and bars and a slightly bigger frame will reduce that difference.

I think that you would be happy with either size but you would need to get used to the M/L purely because it is different to the Carrera.

As far as other Giant bikes in M or M/L yes they will be similar in that they are compact frames but they may have more aggressive geometry anyway so it could be misleading.

Tell the shop you are really considering buying the Defy in medium but you would not be happy buying without a test ride and ask them what they can do for you? Speak to the manager of the shop if you don't get the right answer from the salesperson.

They should get the model in for you to test ride. Without commitment!

I do think that you would be happy with the M/L though without changing the stem length. I have 3 road bikes and they all have 56cm top tubes and I am shorter than you.

thescouselander

@ night_porter, thanks - sounds like good advice. Once the weather dries up I think I'll go back and test ride the M/L at least and go from there. I do think the saddle / handle bar hight difference on my Carrera is slightly too much so perhaps a slightly larger frame would actually suite me better.