Frame size?

Going to get a new frame, have seen a nice one but it's 56cm. I'm 5'9" ish do you think it's too big? What's the general rule with frame sizes?

you'll be better getting a size smaller a 54cm would be better for you

It is down to the individual really there is no general rule. I am 6 foot dead and ride a 55 centre to centre in absolute comfort, where as a friend of the same height swears by his 58cm machine measured the same way. Just take a few out for test rides..

i'm 6ft and ride 58 - 60

Exactly

im 6'2" and usually ride a 56"

i'm 183 cm and ride on 58

6ft1 ride a 55

3inchs, ride one of those little finger bikes

It might be worth your while checking an online fit calculator (I think competitive cyclist have one) and plugging some numbers. Remember that these only give a rule of thumb and that you should compare with what you currently ride and how it feels.

Your overall height is irrelevant to your frame size, because it includes your head. The size of the head is not a factor in sizing a frame.

Inside leg determines max standover, and seat-height (a formula that works for me is inside leg X .885)

Another factor is thigh to calf ratio as this determines saddle set-back (the distance at which you sit behind the bb).

Finally, your reach determines how long the frame should be. Most people I see riding bikes in London have their hands far too long, and far too low. You should be able to sit with your lower back concave, and still be able to reach the bars without rounding your shoulders.

Anyway, there are many resources that will help you DIY a bike fit (I used Claud Genzeling's book) but the best way is to get professionally fitted. It is waste of money to buy a new frame without getting professionally fitted.

Cheers guys. Off shopping today!

it must be very easy to buy the wrong size bike.

i couldn't believe the difference 1cm extra stem length made to the fit of my bike. it took somebody else to spot i needed a longer stem (londons 2nd most famous ex-courier) i would have carried on riding it without realising i was bending my lower back and the reason for getting backache.

6ft1 and i ride a 59/60. gives me the fist full of seatpost needed.

Finally, your reach determines how long the frame should be. Most people I see riding bikes in London have their hands far too long, and far too low. You should be able to sit with your lower back concave, and still be able to reach the bars without rounding your shoulders

Is that riding like Miss Marples Bill...?

I take it then with drops, on the bar tops your back should be concave and in the drops convex...?

I used this to fit up a EAI bareknuckle
http://www.coloradocyclist.com/bikefit/
and this confirmed it when I found someone to come and measure me
http://www.competitivecyclist.com/za/CCY?PAGE=FIT_CALCULATOR_INTRO
Monday I am off to Mercian to be fitted for a custom frame
I'll let you know if how this compares but I don't have a funny shaped head

So I guess I'll be alright...;)

this should sort the problem out

[cite] the-smiling-buddha:

I take it then with drops, on the bar tops your back should be concave and in the drops convex...?

No, even in the drops your lower back should be convex. If your lower back starts to lose its natural curve (a gentle 's' shape) then you are stopping your glutes from firing properly. Long-term this can lead to sciatica.

Stef this should sort the problem out

There are some pretty good rules of thumb apart from:

"When sitting comfortably on the bicycle it should be possible to see the front hub behind the handlebars. Otherwise the cycle is too short."

The only problem with this is that this will include the length of neck and head in a measurement where only the arms, back and thigh are relevant.

I used to ride a 57c frame with 14c stem set around 12 c below the height of my saddle, and sitting around 24c behind the bb. It looked 'right' but actually I should be riding around 60c 9c stem set around 6c below the saddle height, 22.5 behind bb.

I only got it right after a 3 hour fitting at Mosquito. One of the best £60 I have ever spent on bike related stuff. Previously, I used to get very sore shoulders and lower back on long rides. Now I only get a sore arse!

It's really important to remember that the bicycle is a piece of bio-machinery, not just machinery. It has to fit you! Not some average person postulated by mass-production

Even these guys are different shapes. Lemond's legs are really short relative to his body, compared to Roche.

Speaking of Lemond, he was fitted for his bikes using Claud Genzeling system when he was first at Renault.

well my problem is the sore arse too but i think i got the right saddle height, it might be icm off or so but...

Sore arse. Nothing to be done about that apart from rubbing more cream into your chammy. I remember after a long day in the saddle on a tour my companion (a tough Polish messenger) saying to me:

my arse feels like I have been fucking with a thousand monkeys!

And while we're talking of Roche, anyone wanna hear my Roche story?

i was thinking of padding maybe...chafing's not a problem for me, i mean it would be if it happened

Try assos. Their short inserts are the best. I have the F15.mille, I think it is. Really thick. Well worth the money, IMO.

ill bite whats the story

Buffalo Bill Try assos. Their short inserts are the best. I have the F15.mille, I think it is. Really thick. Well worth the money, IMO.

Didn't you say Assos was the choice of fakengers ;)

I totally agree though. Most of the time the saying "You get what you pay for" is quite true, and definitely with cycle shorts. You can skip specialised shirts and other stuff, but a great pair of shorts (bib shorts are my preference) are really worth the money. The comfort level really does shoot up.

Sorry to clarify, do you guys mean concave/convex relative to the ground? I think you need a point of reference to describe something as concave/convex. my back sometimes feels concave sometimes convex. Buffalo Bill described a "natural S shape", does that mean one part of the back concave and one part convex? If so which part is which. Thankx, I'm trying to sort out bike fit and posture too.