Which 27.5" Frame size

[Izak]

I am about 1.8m tall and normally take a large frame (20").

Would I need to take a slightly smaller frame on a 27.5er or can I work on the same size as 26er?

[hayleyearth]

Short story.........

 

You like chocolate cake.

 

I say: "I am going to bake you a chocolate cake and you are going to love it".

 

Would you say:

1. "mmmmmmm...thats going to be nice"

or

2. "I will have to taste 1st"

[MrJacques]

I'd say same size as 26er, but each manufacturer's frame geometry is different so you have to get a fitment on the actual bike.

[Iwan Kemp]

Short story.........

 

You like chocolate cake.

 

I say: "I am going to bake you a chocolate cake and you are going to love it".

 

Would you say:

1. "mmmmmmm...thats going to be nice"

or

2. "I will have to taste 1st"

 

3. I'll have me some of that!

[Captain Fastbastard Mayhem]

All boils down to geometry, mate. If the effective top tube and reach are the same in both bikes, then you have your answer.

 

Me - I'm a large at 1.82m. Large Giant Reign X. Large Ibis Mojo (borrowed from a mate) and a Large Mojo HDR 650 (mate's bike) - all around the same geometry & numbers.

[Izak]

All boils down to geometry, mate. If the effective top tube and reach are the same in both bikes, then you have your answer.

 

Me - I'm a large at 1.82m. Large Giant Reign X. Large Ibis Mojo (borrowed from a mate) and a Large Mojo HDR 650 (mate's bike) - all around the same geometry & numbers.

 

Cool that's the answer

It's a squint .... frame so only have the geometry schematics to work off.

 

Will use that.

 

Thanks man!!

[Capricorn]

Short story.........

 

You like chocolate cake.

 

I say: "I am going to bake you a chocolate cake and you are going to love it".

 

Would you say:

1. "mmmmmmm...thats going to be nice"

or

2. "I will have to taste 1st"

 

LOL..so.. how you feeling today?

[hayleyearth]

LOL..so.. how you feeling today?

 

hehehe...

I feel like cooking, baking isnt my thing....

 

Some of these questions asked about bike sizes and what size wheel one should ride is like internet dating........one just never really know untill you can touch/feel, smell, hear, etc in person..... or am I wrong?

[Izak]

hehehe...

I feel like cooking, baking isnt my thing....

 

Some of these questions asked about bike sizes and what size wheel one should ride is like internet dating........one just never really know untill you can touch/feel, smell, hear, etc in person..... or am I wrong?

Suppose you're right. But at least I will have some idea before I order. If it's then not 100% I will have an awesome bike to sell ....

[gummibear]

One companies medium is another's large.

 

You'll have to sit and compare the geometry of your 26er to the 27.5

[Izak]

One companies medium is another's large.

 

You'll have to sit and compare the geometry of your 26er to the 27.5

 

I've got the schematics so will do some proper measuring tonight

[beanz]

If you want to get scientific about it, there's two main geometry numbers that you need to look at - reach and stack, the horizontal and vertical distance from the center of the BB to the middle of the top of the head tub respectively. Especially for a trail bike. It basically gives the best indication of how the fit will be out of the saddle.

It's more important than the seat tub length or effective top tube length. For example if two bikes have the same reach but bike A has a longer top tube than bike B, it means in that the seat tube angle is slacker on bike A than bike B. You will probably need to move the saddle forward in bike A or back on bike B to get the right seated pedalling position.

The problem is not all manufacturers publish reach and stack, but most do. Reach and stack gives you the best frame of reference (excuse the pun) for comparing bike sizes without sitting on the bike. Especially if you can can compare with what you currently ride.

Then going for a fit might not be such a bad idea if you're not sure, because there's quite a few factors other than your height that determine the ideal frame size.

Another thing to consider is stem length. You don't really want to be forced to make stem length adjustments to get the right fit - you'd rather get the right size frame for the stem length of your choice that will give you the desired handling characteristics. The current trend is towards shorter stems, for more direct steering and more downhill stability, which would mean a slightly longer frame, but the downside is a slightly longer wheelbase, which may reduce maneuverability. So you have to work out what type of ride you want and then work from there. Unless you're right in the middle, there's probably more than one size that will fit you. I'm 1.8m as well and also find myself generally in between medium and large.

Edited November 6, 2013 by beanz

[Izak]

If you want to get scientific about it,........... I'm 1.8m as well and also find myself generally in between medium and large.

 

Great reply, Thanks.

 

I seem to also find myself between the two. I have a 19" and 20" bike and even between the two of them there is quite a difference in setup (stem, seat post, saddle position etc.) that makes them both work at their different sizes. However I feel the 20" is just simply more comfortable for longer rides and races. The 19" is my "play" bike and I have done multi-stage events and fairly long rides and races on it but it was never as comfortable.

However when I take it playing and stuff gets technical etc. then it just really is a pleasure.