Hard tail sizing

aidso

I am contemplating building a hardtail over the winter to use for racing and am stuck between sizes - this is an On-one frame. I don't know whether to purchase a 16" or an 18". I have a 30Short inside leg but that seems to cover both sizes:

Rider Height Inside Leg Frame Stem
5′6″ to 5′10″ 28”-31 16” 60-80mm
5′9″ to 6′1″ 30”-34” 18” 60-80mm

My current hardtail is a 17" and my full sus is a 17.5". Both have the seat quite high in an XC riding position. Would there be a noticeable difference in going for the bigger size(18)? Both have the same stem length...

Thanks,
Adrian

vmgscot

Hard to say without knowing your 'style' of riding or preference for position.
I would have gone for the 16 myself as I like a compact bike for flicking the frame around the tight techie stuff I ride in winter (mainly the likes of Drumlanrig, etc).

I'm a lanky 6ft2 and just replaced my broken 18inch 456 with a 20inch thinking i needed the larger frame cuz I ran on the max seatport extension (420 thomson) but it's taking me ages to get confident on this larger frame..... just feels like me clangers are gonna take a beating at some point.

Maybe just getting used to new frame perhaps

cooldad

Personally if I have to choose between (slightly) too small or too large, I go for small.
But can't help with your specific question, sorry.

supersonic

Look at the top tube length and reach too.

aidso

well if the stem is the same length on both frames, the reach would be the same, non?

nicklouse

aidso wrote:

well if the stem is the same length on both frames, the reach would be the same, non?

why? How? bigger frame tend to be? bigger.

cooldad

Stem is not actually part of the frame.

ThePriory1978

This probably wont help but a mates got a 18" carbon 456 and the stand over height and reach are virtually identical to my 26" wheeled 18" Kona Hardtail.

What i'm trying to say is if you can get a leg over a 18" Kona in a store somewhere you will basically know what you are getting for frame fit on a 18" 456 On One.

Cant help in the slightest about the 16" tho

davewalsh

With a 30" inside leg you would be ok on both sizes of frame, you just will need a 400mm seatpost on the 16".

As you're using it for racing, I'd go for the 18" version as there is a little more stretch in the top tube, unless you're less than 5'10" where you may struggle for reach. The 18" frame is longer in the top tube than the 16".

I'm 6' with a 30" inside leg and both my Inbreds are 18" and fit perfectly, with a 70mm stem on number 1 and a 75mm on number 2.