Help Sizing and Geometry (Giant or Trek)
#1
Thread Starter
Senior Member
Joined: Aug 2007
Posts: 280
Likes: 0
From: Puerto Rico
Bikes: Look 566 Medium, Giant TCR C1 Small
Help Sizing and Geometry (Giant or Trek)
Hi. I'm relatively new to road bikes, but have own a GT LTS-3 for a few years (Didn't use it too much). I have been practicing spinning at work for almost a year by now and there is quite a lot of friends that run recreationally during the week and weekends on road bikes and would like to join them. I'm currently 40 year old, 5'7" and weight around 188 lbs. (Used to weight around 205 pounds before joining the gym around 1 year ago, slowly going down !!!). Since my bike is full suspension, it is pretty heavy (around 26 pounds I think) so don't beleive it will be a good choice, so am looking for a not that expensive (less than $1200) bicycle (can be used, doesn't matter to me as long is in good conditions).
I went to a local Trek store and my inseam is 76cm = almost 30 inches and was told could ride either a 50 or 52 cm; also went to a Giant store and was told could be either a small or a medium. The questios are as follows:
1- Do you believe that a 50 cm (or small on Giant) would be a better choice than a 52 cm (medium)? based on my height, weight and inseam measurement? Seems like 50cm and smalls are usually labelled for height of up to 5-6") The crutch clearance seems to be enough in both cases (small celarance on medium, though), but understand the small size is also shorter lenght overall.
2. I have been reading a lot about "relaxed" geometries (Pilot and OCR lines for Trek and Giant, respectively) and beleive they might be a better choice for what I intent to do with the bike (don't beleive will actually race, but maybe in the future could try, recreationally, to do some races or biathons). What do you think of relaxed configurations? What is the compromise?
3- Most of the bikes have seen for my budget are either used or new at deep discount prices / 2006 or earlier years (Giant TCR Composite 3, OCR composite 3, OCR Alliance 1, Trek Pilot 1.2 or 2.1). Does buying a 2005 or 2006 year bicycle a good idea? Seems like most changes from one year to another are colors, most bikes at this level has Shimano 105 components)
4- Good place or resources for used bikes from Giant or Trek online?
Well, guess those are too many questions already.... Thanks for your input.
Regards,
Francisco
Puerto Rico
I went to a local Trek store and my inseam is 76cm = almost 30 inches and was told could ride either a 50 or 52 cm; also went to a Giant store and was told could be either a small or a medium. The questios are as follows:
1- Do you believe that a 50 cm (or small on Giant) would be a better choice than a 52 cm (medium)? based on my height, weight and inseam measurement? Seems like 50cm and smalls are usually labelled for height of up to 5-6") The crutch clearance seems to be enough in both cases (small celarance on medium, though), but understand the small size is also shorter lenght overall.
2. I have been reading a lot about "relaxed" geometries (Pilot and OCR lines for Trek and Giant, respectively) and beleive they might be a better choice for what I intent to do with the bike (don't beleive will actually race, but maybe in the future could try, recreationally, to do some races or biathons). What do you think of relaxed configurations? What is the compromise?
3- Most of the bikes have seen for my budget are either used or new at deep discount prices / 2006 or earlier years (Giant TCR Composite 3, OCR composite 3, OCR Alliance 1, Trek Pilot 1.2 or 2.1). Does buying a 2005 or 2006 year bicycle a good idea? Seems like most changes from one year to another are colors, most bikes at this level has Shimano 105 components)
4- Good place or resources for used bikes from Giant or Trek online?
Well, guess those are too many questions already.... Thanks for your input.
Regards,
Francisco
Puerto Rico
#2
Senior Member
Joined: Sep 2006
Posts: 424
Likes: 0
From: Southern Ca
#3
Time for a change.

Joined: Jan 2004
Posts: 19,913
Likes: 7
From: 6 miles inland from the coast of Sussex, in the South East of England
Bikes: Dale MT2000. Bianchi FS920 Kona Explosif. Giant TCR C. Boreas Ignis. Pinarello Fp Uno.
Have a 31" inseam and ride a 51 conventional size and an XS in Giant Compact (equates to 42).
Standover height does not matter- Unless it is too tight on the vital parts. What does matter is seat position and reach to the bars.
Standover height does not matter- Unless it is too tight on the vital parts. What does matter is seat position and reach to the bars.
__________________
How long was I in the army? Five foot seven.
Spike Milligan
How long was I in the army? Five foot seven.
Spike Milligan
#4
Senior Member
Joined: Mar 2007
Posts: 5,737
Likes: 10
You could go right up to a 56 as long as you have an inch between you and your tender parts. If you can straddle the bike safely, it fits. As for the saddle and bars, those can be adjusted by changing seatposts and selecting the right stem height.
#5
Senior Member
Joined: Oct 2004
Posts: 5,250
Likes: 8
If you are not planning to get a racing license, you will get a better fit by riding the tallest frame you can stand over without the top tube pressing painfully into your crotch. Just go to the bike shop, and stand over the bike with your feet two feet apart and your belt buckle up against the back of the stem.
The top tube should be lightly brushing against the crotch of your jeans. If the top tube is pressing into the flesh, you need to move down one size. With Trek road bikes, moving down one size would give you an extra inch or so of standover.
With a Giant, moving down one size can take you from a bike that is slightly too big to a bike that is a bit too small. Giant dealers tell customers that "too big" and "too small" bikes can be fixed by adjusting the seat post and swapping out stems. But, it is better to get a frame that fits well without "fix ups".
The top tube should be lightly brushing against the crotch of your jeans. If the top tube is pressing into the flesh, you need to move down one size. With Trek road bikes, moving down one size would give you an extra inch or so of standover.
With a Giant, moving down one size can take you from a bike that is slightly too big to a bike that is a bit too small. Giant dealers tell customers that "too big" and "too small" bikes can be fixed by adjusting the seat post and swapping out stems. But, it is better to get a frame that fits well without "fix ups".





