Have I bought the right size frame?

MrWill

Hi,

I'm using a Ribble winter bike with a 56cm horizontal top tube and 11cm stem with 3cm spacers and 9cm saddle to bar top drop, at the moment, which is perfect.

I've ordered the 57cm Kinesis ( 56.8cm projected top tube) and to get the same reach I'll need to put on a 10cm stem and to get same saddle/bar drop I'll need 1cm or maybe no spacers.

The 54 Kinesis ( 55.6cm top tube) would fit I think with the same 11cm stem and 3cm spacers as my current bike. Although would have a lot of seat tube showing.

Do you think I have ordered the right size?

It's a weird one because both options end up with the same reach within 2mm.

Going off a few bike fit calculators the 57 is right. And Kinesis's guide.

I'm 179.5cms tall with 79cm inseam.

darkhairedlord

get a piece of paper and a ruler. draw out both frames on top of each other. Better still, just look up the geometry and compare the stack and the reach. These are the only numbers you need to compare. It is up to you if the frame is the correct size as it is only you that is going to sit on it.

MrWill

I've done that and can get the same fit with both but,

With the 54 there will be 3cm min of spacers, with more (15cm) seat post, and a 11cm stem.
With the 57 there will be 1cm max of spacers, with less (12cm) seat post, and a 10cm stem.

Only diff seems to be 60g in weight and .5cm longer wheelbase and 1cm stem length.

neeb

Yup, get frame stack and reach figures if you can. You can't just look at tt length for reach, seat tube angle will influence effective reach. Similarly, things such as bb drop and fork length can affect stack (and thus the amount of spacers you will need) as well as head tube length. Head tube length can even influence the relationship between tt length and reach a little, as a frame with a shorter head tube will have a slightly longer tt length for the same effective reach (if you think about it).

MrWill

Sorry should of mention the seat tube angles are the same at 73. And same forks on both bikes.

ic.

As you can get the same reach on both frames and all the other measurements look good I'd say go for the smaller frame and longer stem

I've just moved from a 56 to a 54 and done this. Gives me more seatpost out of the frame and a longer stem but I think I'd do the same again given the choice.

drlodge

IC. wrote:

As you can get the same reach on both frames and all the other measurements look good I'd say go for the smaller frame and longer stem

This.

BUT, I wonder if you can get 3cm of spacers under the stem...normal limit is 25mm and you should also have a 5mm spacer on top so is the steerer long enough? Worst case is that the bars are a bit lower.