Any sizing gurus ?

[Bear]

I just need abit of confirmation really ... After trying alot of road bikes, i now know what i want.

I'm 6' with a 32" inside leg, and feel very comfortable on a Trek 1.9 58cm ... I have tried many 56 / 57 / 58 in all brands, but unfortuntaley, the majority of local shops have no idea on sizing.

I certainly dont want a bike that is too big for me (why do pro racers all look on the smaller size ?)

Being comfortable is the key now, any thoughts appreciated

Thanks

 

[Wigsie]

Well I am 6ft 4 and ride a 61cm Road bike. My boss is 6ft and has a 58cm Trek 1.7 so that is the right sort of size for you.

But IMO it is important that you try and find somewhere that can tinker with the seat, seat post, bars/stem etc to make the subtle amends as these can make all the difference with comfort and performance.

 

[mickle]

I'm 6' 1" with a 32" inseam and ride a 58 Colnago.

 

[Landslide]

By way of comparison, I'm 6', with a 32" inseam. I ride a 57cm Bob Jackson, with a horizontal toptube (also 57cm). The Trek looks to be of a similar size and shape.

As a lot of bikes these days have sloping toptubes (which may be one of the reasons that the pros' bikes look so small), frame size as measured in terms of seattube length is becoming less relevant, and of more importance is the reach from saddle (at the correct height) and bars.

As you say, being comfortable is the key. Look for a good degree of adjustment in any potential bike - saddle and handlebar height, stem reach, saddle fore and aft etc.

 

[zacklaws]

I'm 6' 1, also with 32 inch leg and I have a Trek 1.2, 58cm frame and find it very comfortable. In fact best bike I have ever had for comfort.

There are many web sites with sizing guides, heres a couple :-

http://www.evanscycles.com/help/#road

http://www.edinburghbicycle.com/com...izecharts-brands.htm&f_cardinal=3#bike_sizing

 

[punkypossum]

I'm 6 foot but with longer legs than you and I ride the 1.7 in a 56 - therefore, with your longer body, 58 sounds about right!

 

[Randochap]

This bike fit primer might help.

The trend toward smaller frames is baffling, though I have no choice.

 

[peanut]

I just need abit of confirmation really ... After trying alot of road bikes, i now know what i want.

I'm 6' with a 32" inside leg, and feel very comfortable on a Trek 1.9 58cm ... I have tried many 56 / 57 / 58 in all brands, but unfortuntaley, the majority of local shops have no idea on sizing.

I certainly dont want a bike that is too big for me (why do pro racers all look on the smaller size ?)

Being comfortable is the key now, any thoughts appreciated

Thanks

sounds like you are doing exactly the right thing and trying lots of bike sizes.

I shouldn't worry too much about what the pros are riding .They generally do not choose their bikes and they certainly do not choose a bike based on confort criteria first.

Race frame sizing and geometry will tend to make the bike be more rigid and responsive and feel more 'alive' which is perfect for racing but at the cost of comfort and stability.

A larger non race frame will generally be a little more flexible perhaps with more relaxed frame angles and soak up the bumps and vibration better and because your bodyweight is not so far forward will feel a lot more stable and comfortable.

The bike fit primer posted by Randochap is an excellent aid and dispels the myth that there is some magic formula for sizing a bike frame.

 

[accountantpete]

TBH it's all down to personal choice. I'm 5' 9" and ride a 56 as I prefer a lower seat profile.

As the others have said - get a mid range size for your height (56-58) and then fine tune with the seat/stem arrangements.

 

[jimboalee]

The Hardback book method of measuring 'Inseam' as suggested by no other than Ribble cycles amongst others, is a very subjective method. It depends on your foot width when you stand and the pressure you apply.

When I measure myself using this method, I get 31". +/- 0.5 for the inherent inacuracy.

When I measure myself using the SHR ( Seated Height Ratio ) method, as in the medical profession, I get 33". ( 68.5" - 35.5". 51.8% SHR ).

In the 'Old days', Off The Peg bikes were sized as 2/3 inside leg, so in my case it was a 22" frame.
Pug didn't have a 22" exactly, so Tom Crowther ( take the time to google him ) sold me a 22.5" ( 57 cm ); and suggested I might grow another 1/2" as I was only fourteen.

There is another method of sizing a frame for a person that involves measuring the Thigh Length and Lower leg Length, working a 'frig factor' with a bit of trig' to get the Seat Tube Angle; and from the person's 'Stand over height', do more trig' to calc the seat tube length.
This works fine too but gives me a frame size of 54 cm.

My Pug is 57cm and my SWorks is 54cm.

Reach can be calculated from Torso length and Arm length and the stem sized to suit.

Both bikes are 'dead comfy' and I have no problems riding either 200km in a day.

Now, are you confused?

 

[Bear]

Thanks everyone for the replys.

Interesting you say that Randochap, "The trend toward smaller frames is baffling" ... thats why i was questioning myself, and trying bikes that were too small for me.

I have no interest in racing really or looking cool ... its all about the fit. I've bought bikes before which are far too big, and recently, too small ! so this time it has to be spot on.

From new, it would need nothing i reckon, very comfortable.

Watch this space

 

[Randochap]

The thing with bike sizing is it shouldn't be (or lead to) a medical procedure.

The method I recommend is entirely precise enough to ascertain standover height for a frame. .5 doesn't amount to squat, if you get my meaning.

But I do specify that the subject "snug the spine of the book into your perineum with about the same pressure you might expect sitting on a saddle" and stand with feet six inches apart.

This is the DIY home method of inseam measurement used on shop measuring devices.

Precision to the millimetre comes with fitting, especially when one comes to deal with cleats and such.

 

[jimboalee]

The thing with bike sizing is it shouldn't be (or lead to) a medical procedure.

The method I recommend is entirely precise enough to ascertain standover height for a frame. .5 doesn't amount to squat, if you get my meaning.

But I do specify that the subject "snug the spine of the book into your perineum with about the same pressure you might expect sitting on a saddle" and stand with feet six inches apart.

This is the DIY home method of inseam measurement used on shop measuring devices.

Precision to the millimetre comes with fitting, especially when one comes to deal with cleats and such.

The only response I can offer is:-

The SHR method of determining Leg length does not require the previous experience of riding a bicycle. Perfect for the beginner. No perception of 'sitting on a saddle' comparison needed.

BTW, my gym has a stadiometer. I did both methods this afternoon while the rain fell on Warwickshire, and got a 0.25" difference - 'squat' :?:

 

[Will1985]

I'm 6' with a 32" inside leg, and feel very comfortable on a Trek 1.9 58cm ...

You've answered your own question there, although an extended test period would confirm your feeling.
I reckon the technical methods can be both confusing and offputting for beginners, and trial and error through testing at an LBS is the best way forward followed by tweaking of position at home.

 

[jimboalee]

I can remember being at a bike shop in Solihull.

A wealthy couple came in with their eight year old daughter.
She wanted to ride in the U9.

Her father was willing to shell out a few quid on a really small custom frame.

What would be the LBS man's approach?

Answer - measuring tape, door frame and pile of old magazines.

Now you work out where the pile of old magazines came in?