Which of these two frame sizings should I look into ?

Raffles

An experienced fitter told me last week that an optimum set up for me would have a 540mm top tube and 522mm seat tube, in other words a frame combination of a size 54 top tube and size 52 seat tube, or in other words , a custom sized frame. Im only 5 ft 9 inches tall and have a 30 inch inseam, Im 5 ft 9 and have the legs of somebody 5 ft 7 unfortunately.

There are two frames ive been reading about.


Size 52cm which has a 535mm top tube and 522mm seat tube, 110mm stem and fore aft adjustment could make this frame fit comfortably.

Size 53cm, which has a 530mm top tube and 530mm seat tube. again the use of a 110mm stem would sort out the handlebar reach , but the seat tube would be 8mm longer than recommended.

In my case , which would you say is going to be more effective ? Other questions Id like input into are , for both frames :

Would the saddle post showing be on the longer or shorter side ?

I like saddle to headset height to be around 2 inches and definitely comfort orientated, is there a risk of a mountain of spacers being required to achieve this ?

Please keep BOTH frame sizes in mind and id be very grateful for your insight on this.

Wirral_paul

Effective top tube length would be my number 1 priority as the saddle height is easy to adjust. You dont say if the top tube lengths are actual or effective top tube lengths however - makes a difference as frames vary in the geometry a fair bit. Also, you would need to consider the head tube length when looking at the fit - from the sounds of it, you want a slightly longer head tube than average to keep the number of spacers down.

Simply put, there's not enough info on the frame dimensions given, but anyway - you have an experienced fitter giving you advice already. My advice therefore would be to talk to him about your options and then budget in a full bike fit with him once you buy the bike of your choice. Having had a full pro bike fit (Pedal Precision in Manchester) - its money well spent.

Raffles

Paul

The two top tube lengths are actual lengths. Which frame size should I give more attention to ? Ideally Id like to keep the saddle to headset height around 2 inches and ive no qualms about sourcing a 110mm stem.My sticking point is that I just cant visualise in my head how both options will look and which will do the job better me, if only I wasnt born with my dad`s short legs, fitting would be so much easier.

The bike im currently riding has 543mm actual top tube length and I have to use an inline seatpost and 90mm stem to get a decent fit. I just know that either the 52 or 53 sized frames will yield a better fitting bike.......problem is which one given my height and inseam disparity.

Raffles

Experienced riders,id be most grateful for your input here.

Raffles

I hoped you guys would be able to give me some sound advice with this one.

ShutUpLegs

Can't you ask the experienced fitter you spoke to last week?
Without knowing the headtube length/ seattube angle how will anyone know the saddle to handlebar drop?

Swos

I'm having similar issues as I'm 5ft 9" but only have a 29" leg as got a longer torso been advised I need either a 51, 52 or 53cm bike

jonny_trousers

What are the two frames?

You'll easily be able to find a workable solution on all kinds of frames.

Raffles

Swos wrote:

I'm having similar issues as I'm 5ft 9" but only have a 29" leg as got a longer torso been advised I need either a 51, 52 or 53cm bike

So you are in a similar boat to me then, what size bike are you riding now and what specifically is the reason you are looking at other size frames ?

Raffles

To help decide whether I should look closer at the size 52 or 53 frame , I was able to get the following information

Size 52 frame
Top Tube 535mm
Seat Tube 520mm
Head Tube 140mm
Seat angle 73 degrees


Size 53 Frame
Top Tube 530mm
Seat Tube 530mm
Head Tube 135mm
Seat angle 74 degrees

Bearing in mind Im 5ft 9 with 30 inch inseam, which of the two frames with those tube specs do you think would be the better fit ? Want a saddle to headset drop around 5cm,dont want more than 2 x 10mm spacers nor do I want a little tiny amount of saddle post showing.

Pigtail

I'm about the same size. 5 ft 9.75" with an inside leg of 30" riding a 54 specialized allez.

I was starting cycling, went to try an allez and the lbs suggested a 52. Partly because it was what they had in stock. I decided to go out on a limb and ignore their advice, so I bought a 54 elsewhere. I really like it and have never regretted the purchase. Main issue is standover height. There really isn't any! Apart from that reach seems fine, and it has served me well over several 1000 miles.

Raffles

From looking at the specs I listed above , my gut feeling is saying go for the size 52. The headtube is 140mm whereas the size 53cm has 135mm and this would give a slight height gain. The recommended seat tube length of 522mm is absolutely bang on the money for the size 52 frame also. This just leaves a recommended toptube length of 543mm from the fitter and the 52 frame has 535mm.If I fitted and 110mm stem and slid the seat back a bit then surely this would correct that and give a bit of setback.

Now the only worries concern no pillar of spacers and no tiny saddle post. Would the size 52 frame come up trumps here too given the spec details Ive listed ?

Wirral_paul

Raffles wrote:

Paul

The two top tube lengths are actual lengths. Which frame size should I give more attention to ? Ideally Id like to keep the saddle to headset height around 2 inches and ive no qualms about sourcing a 110mm stem.My sticking point is that I just cant visualise in my head how both options will look and which will do the job better me, if only I wasnt born with my dad`s short legs, fitting would be so much easier.

The bike im currently riding has 543mm actual top tube length and I have to use an inline seatpost and 90mm stem to get a decent fit. I just know that either the 52 or 53 sized frames will yield a better fitting bike.......problem is which one given my height and inseam disparity.

As per previously then really - with the two frames that you have mentioned being actual top tube lengths then the figures are pretty much meaningless when it comes to discussing the best fit. There are so many variables on a frame with all of the various angles / lengths of each tube etc that two bikes with identical "actual top tube lengths" could be very different when it comes to the more important "effective top tube length"

Have a look at the following link..
http://www.bikecad.ca/effective_top_tube_length
Now if you kept the rear triangle of the bike exactly the same and then at the front, the only change you make is to fit a shorter head tube (which lowers the bars), the actual top tube length would become longer (judging by the angles) whilst the effective top tube length could remain identical (if the head tube and seat tube angles were identical).

What i'm getting at is that you will need a frame of a certain effective top tube length with a stem to suit you, but that there are so many other variables in both frames and your own body that its nigh on impossible to tell you what is the best size to go for.

Wirral_paul

The 52cm frame looks a bit more relaxed (shallower seat tube angle and taller head tube). Sounds more suitable to "comfort orientated"

Raffles

Wirral_Paul wrote:

The 52cm frame looks a bit more relaxed (shallower seat tube angle and taller head tube). Sounds more suitable to "comfort orientated"

Paul, Ive given you wrong infomation, the top tube lengths are EFFECTIVE, I thought they were actual but I misread the data. Given we now know the effective TT lengths, what would you say now ?

Wirral_paul

Raffles wrote:

Wirral_Paul wrote:

The 52cm frame looks a bit more relaxed (shallower seat tube angle and taller head tube). Sounds more suitable to "comfort orientated"

Paul, Ive given you wrong infomation, the top tube lengths are EFFECTIVE, I thought they were actual but I misread the data. Given we now know the effective TT lengths, what would you say now ?

If your guy who measured you for fitment is correct then the 52cm frame is looking a very good option. He will have meant Effective Top Tube Length himself and seeing as the 52cm frame you mention is only 5mm short then its pretty damn close. Combined with the longer head tube then it sounds closer to what you are looking for with your comfort fit - as you'll need less spacers to get the saddle to bar drop where you want it.

Can you try one out??

Raffles

What about saddle post showing, take it the saddle wouldnt be just plonked on top of the seat tube if i chose the size 52 frame ?

Wirral_paul

Shouldnt think so. I'm 5ft 10 with a 31" inside leg, and there's loads of space between the saddle and frame