Frame size?

if you can stand over the bike comfortably with just 2-3 cm's of clearance, it fits. basically.

What if you had really long legs but short arms/torso. You could get the 2cm of clearance above top tube on a very large frame but then wouldn't be able to reach the bars as the top tube would be too long.

Standover is the least important factor to me when looking for bike fit. The most important is top tube length.

Hi there,

I am 193cm tall (6'3') and i want to build a fixed gear bike and i am interested in

The Tonic Fab Supernaut frameset

My worries are the frame sizes.

The Tonic Supernaut Size Ape has a 60cm seat tube (c-t) and a 61cm (C-C) Top tube and the Size XL has a 58cm Seat tube (c-t) and 59cm (C-C) Top tube.

Which one would be more suitable to my height.?

My inseam is around 90 - 91 cm

Quark.

Its difficult to pick one based on inseam as the frame has compact geometry (slopping top tube). So the seat tube length is misleading.

On a traditional geometry frame, I'd guess at a 62cm (seat tube C-T).

(91 x 0.883) = saddle top to BB center length needed
minus saddle height (5cm), and minus 13cm of seat tube.
Gives a seat tube length (c-t) of 62.

A 62 would usually have around a 60cm top tube (C-C). Bang in the middle of the two sizes.

But given that the frame you are looking at has a steep seat tube angle, you are likely to have to use a bit more saddle set-back, to put you in the correct position over the BB. This increases the distance from saddle to bars. So I'd round down to the 59 top tube of the XL.

This is merly an educated guess though. The absolute best thing would be to work out your reach (saddle to bars), by trying a few bikes out for comfort. Then use this to find your idea top tube length (using say a 110/120mm stem).

If you can test ride to bike in question. Make every effort to do that IMHO.

Hope that helps.

Quark.

Its difficult to pick one based on inseam as the frame has compact geometry (slopping top tube). So the seat tube length is misleading.

On a traditional geometry frame, I'd guess at a 62cm (seat tube C-T).

(91 x 0.883) = saddle top to BB center length needed
minus saddle height (5cm), and minus 13cm of seat tube.
Gives a seat tube length (c-t) of 62.

A 62 would usually have around a 60cm top tube (C-C). Bang in the middle of the two sizes.

But given that the frame you are looking at has a steep seat tube angle, you are likely to have to use a bit more saddle set-back, to put you in the correct position over the BB. This increases the distance from saddle to bars. So I'd round down to the 59 top tube of the XL.

This is merly an educated guess though. The absolute best thing would be to work out your reach (saddle to bars), by trying a few bikes out for comfort. Then use this to find your idea top tube length (using say a 110/120mm stem).

If you can test ride to bike in question. Make every effort to do that IMHO.

Hope that helps.

Basically i am after the level top tube version so the sizes are not into the compact geometry category and i am going to use it with a bmx stem at 53mm reach so thats the reason i think the XL size (59cm) will be small for me. Any suggestions on this? I would not be able to try the bike because i don t know anyone to own it here.

Basically i am after the level top tube version so the sizes are not into the compact geometry category and i am going to use it with a bmx stem at 53mm reach.

At your height compact geometry doesnt make much sense anyway IMHO. Does mean my chioce of the smaller size due to seat tube angle, is unfounded though.

If you are thinking of running a stem of less than 100mm then Ape would be my guess.

Bare in mind that big frames often have steep angles, so short stems can give twitchy handling.

Bare in mind that big frames often have steep angles, so short stems can give twitchy handling.

True. The thing is. For example say that my reccomended reach for my height and torso measurement is 70 cm. SO that 70 cm must be Top tube + Stem Reach.

Now you can have 2 bicycles with the same seat tube but bike A has 58cm top tube + 120 Stem and BIke B has 60cm Top tube + 100 Stem which both have 70cm reach. But is that the same regarding bike fit?

Now you can have 2 bicycles with the same seat tube but bike A has 58cm top tube + 120 Stem and BIke B has 60cm Top tube + 100 Stem which both have 70cm reach. But is that the same regarding bike fit?

Roughly speaking yes.

But....

The position of your saddle relative to a vertical line going through the centre of the BB is constant for a given rider. A plum line hanging from your knee, should meet the pedal axle, when the crank is in the forward horizontal position.

So on a bike with a steep seat tube, you will need to push your saddle back. This will increase reach, for a given tt length. Whereas on a bike with a slacker seat tube angle, you will need to push the saddle forward, to achieve the same fore/aft position relative to the BB.

It is not advisable to adjust your saddle fore/aft to fit your reach. Rather to adjust your reach to fit your saddle fore/aft.

It also worth bareing in mind that the manufacturer will be assuming a stem length of 100 to 120 depending on size. If you deviate from this too much, your weight will not be positioned in the manner the manfacturer designed the bike for.

Bike fit is a complex business, if done correctly. Which is why people dont mind paying for an expert to fdo it for them.

I need a (trad) frame that will allow the saddle to be set at 105cm and the bars at 103cm (approx). I've got a 58cm but I'd need loadsa stem exposed to get that sort of height so I'm thinking it needs to be 60cm+ Anyone help me out?

hi!
what would be the perfect framesize for my girlfriend who is 5.4 - 5.5?
cheers

do some research on bike or cyclefitting

her height is not enough to know the perfect size

probably a perfect size would involve a custom fit, so go on and treat her.

Your not going to get perfect, just asking over t'internet.

Especially with so little info.
What sort of bike?
What is her inside leg measurement, with shoes on?
What sort of handle bars would she like to run?
How flexible is she?

Also FYI, this question should be posted here.
http://www.lfgss.com/thread60484.html

That thread contains this useful link.
http://www.competitivecyclist.com/za/CCY?PAGE=FIT_CALCULATOR_INTRO

I'm about 5'5-5'6 and have an Extra Small Plug, which is about 52cm. It's probably a little too small for me if I'm honest, but my friends 54cm SE Lager is too big.

if She is 5'4'' then as a woman 'should' have slightly longer legs than a man, (as men tend to have a longer torso) though usually girls like smaller frames, so I would have thought a 52 or 53, she should be able to stand over something that is 75cms or so..that will be her inside leg with shoes on and still have about an inch to stand over the frame? hope that can be helpful.
As everyone said that is pie in the sky until you actually measure her inside leg measurement.

anecdotal sizing evidence is worthless.

just took delivery of a size 53 fuji. my other bike is a 56.5. both fit perfectly.
i'm 6ft 1 but my shorter (and fatter) flatmate needs 585mm top tubes as his arms are 4cm longer than mine.

go to a proper shop and ask somebody who know's what they are on about.
failing that take measurements and use an online calculator but these don't account for flexibility.

I'd have guessed more in the 49/50cm area. I'm 5'6" and ride a 53cm ETT, which in old money would likely be a 51/52.

failing that take measurements and use an online calculator but these don't account for flexibility.

The competitiv cyclist one does. Varies the ETT reults a fair bit too. Which is enough o convince most to test ride.
Just to underline test ride.

just needed a rough idea.
would love to treat her with a custom fit - unfortunately not possible... .
i was more thinking of buying an old street bike of ebay and changing it to single speed.
no fancy stuff. need just need a light/decent ride for her when she visits me.
i saw some nice tutorials on how to restore an old bike so that is what i want to do. wasn't sure about the measurements. i think i will go with the smaller recommendations (if i find a suitable bike).
thanks for the help!

just needed a rough idea.
would love to treat her with a custom fit - unfortunately not possible... .
i was more thinking of buying an old street bike of ebay and changing it to single speed.
no fancy stuff. need just need a light/decent ride for her when she visits me.
i saw some nice tutorials on how to restore an old bike so that is what i want to do. wasn't sure about the measurements. i think i will go with the smaller recommendations (if i find a suitable bike).
thanks for the help!

If you're thinking of getting a upright position, something like a shopper. Then start off with something like a traditional 49cm frame, and add an adjustable stem. Pretty ugly but you can replace it when she's found her fit.

Can anyone give me some guidance please...

My sister is looking at one of these monstrosities:

Its a 51cm.

What does 51cm seat tube mean on one of these things? She's 5'10ish.

I imagine if it was dimensioned like a road biek it would be bigger than a 51 or something? Do I have no idea what Im talking about?

you have no idea what you are talking about.
look at the position of the bars/grips, as long as the saddle goes low enough anyone could reach them even if to them flexibility means ordering from the lunch menu at breakfast

thats my sister you're talking about.

fucking lunch menu... she's just big boned.

thanks mr smyth.

balkster don't all these bikes come in one size anyway?