Frame Size
Sol71
Posts: 3
Hi, I'm looking at buying a new road bike - Specialized Tarmac SL3 - and I'm really stuck between going for the 56 or the 58. I've ridden the 58 and to get it to fit correctly the stem was shortened from a 110 to 100 and the saddle was brought forward about two thirds of the way along the rail. Photo attached. As in making these adjustments I have effectively shortened the bike I'm wondering if I should be on a 56?
I don't really have a feel for how the bike should be as it's my first road bike. I started doing triathlons last year and have spent the last 12 months riding a tri bike so the roadie seems massive by comparison ..... but very comfortable!!
All advice would be most appreciated.
Many thanks.
I don't really have a feel for how the bike should be as it's my first road bike. I started doing triathlons last year and have spent the last 12 months riding a tri bike so the roadie seems massive by comparison ..... but very comfortable!!
All advice would be most appreciated.
Many thanks.
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Comments
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The only way to decide is to ride them both and see which is more comfortable. not everyone will fit standard geometry - thats why seats adjust and differnet stems are available. Don't be concerned you turned a 58 inot a 56 - you haven't - the frame is still the same size which is probably right for your legs and you just needed the "arm reach" adjusting a bit.Bianchi Infinito CV
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I'm not an expert on bike fitting, but I would have thought one of the most important things to get right is where your hips/knees are in relation to the pedals/cranks (this determines where your saddle should be and whether you need a layback post or not)
Reach should be adjusted after you've worked out the above.0 -
In an ideal world you shouldn't put a 100 mm stem on a 58 frame. Ideally a 120 mm stem on this size of frame, unless your a man with incredibly long legs and very short body and arms. So, if you need such a short stem and the saddle right forward the 58 is probably too big. How tall are you? How long is your inside leg from crotch to floor?
The positioning of the saddle is dependent on the length of your femurs not the reach to the handle bars.
One thing a 58 will give you is a longer headtube so the bars wont be so low. But you can use spacers under the stem on the 56. Your flexibility comes into play here. A good bike shop should help you with the fit. Go to the bike fit page at Competitive Cyclist.com for a rough guide.Pegoretti
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If you are shortening the stem and bringing the saddle forward, then that might suggest a 56 rather than a 58.... a 56 will be easier to fit if too small, than a 58 that is too big.
As already stated the drop from the saddle to the bars is the one measurement that increases when dropping to the 56, but that can be adjusted with spacers and/or an upward alligned stem.... matter of choice as to preference but there may also be a slighty more 'twitchy' ride on a smaller frame.0 -
As said above, it sounds like the 56 would be a better fit for you.Cycling weakly0
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Why don't you have a test ride on a 56 and just see what feels better? That's what "how the bike should feel" means.0
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the headset tube will be taller on the bigger bike so you will not be as low down in relation to your saddle height as you would be on a smaller bike. if you want to be in the 'pro-race' position go for the smaller size, if you want a more normal 'out for an afternoon, comfortable ride' go for the bigger bike. the bigger bike will be better for your back, shoulders and neck in the long run. hope this helps0
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mrwibble wrote:the headset tube will be taller on the bigger bike so you will not be as low down in relation to your saddle height as you would be on a smaller bike. if you want to be in the 'pro-race' position go for the smaller size, if you want a more normal 'out for an afternoon, comfortable ride' go for the bigger bike. the bigger bike will be better for your back, shoulders and neck in the long run. hope this helps
Agreed, but it might also feel like you are riding a carthorse.
No disrespect, but i would go for the 56. If you get out on the road for enough hrs a week then your body will adjust anyway.
100mm stem seems too short imho.
Just used to a smaller frame myself...0 -
That's all helpful information so thanks everyone. I'm going to measure myself as suggested on the Competitive Cyclist website and see what that tells me. From a physical point of view I'm pretty flexible, 6ft and quite skinny at 75kg (165 lbs). The idea of a slightly more extreme position is o.k. with me.
Thanks once again. First time I've used a forum and wasn't really expecting anyone to take any notice.0 -
At 6ft, I would expect to be on a 58.
It all depends on how the 6ft is split ie legs/body.
Some 6ft+ have very long legs and some have long body length.
From your posts, it sounds like you have long legs and short body, this is why you need a shorter stem.
I am the other way, long body and relatively shorter legs.
This is why you need to adjust the bike to fit or test ride lots of bikes.0 -
Personally i'd suggest finding a bike shop that actually knows what they are doing when it comes to fitting you.
For starters, getting the saddle in the right place is critical. Both saddle height and setback are really important to get you pedalling correctly - and the setback should NOT be used simply to shorten the bike enough for you to ride it.
Have a look at this anyway as it shows very simply how you should be positioned. http://bikedynamics.co.uk/guidelines.htm
Saddle position should always be set first, then get the bars in the right place afterwards.
Once the height and setback are correct then the right size from should put the bars in the correct place +/- a cm ideally using the standard stem supplied which should be matched to the frame size.0
