I am looking to start XC racing in 2010, but i am coming from a background of Cyclo-Cross, so the type of bike and sizing is a little bit different.
So…. i have got my heart set on one of the Specialized S-Works M5 frames, but i'm not sure whether i would be a 17.5 or a 19.

I have heard people say in the past, that for XC you want a smaller frame, with a longer seatpost and longer stem.
But i have also heard people say you want a bigger frame with a lower seatpost to get the most from your pedalling.

I have had a sit on the specialized bikes in the 2 sizes and both feel fairly comfortable, just not sure which one to go for.

I am just about on the 5'11 mark so wondered what the STW people would recommend, or what they use?

Thanks in advance
Josh..

Go to a decent shop and get fitted!!

thevanman,

I have done, thats why i know both the 19 and the 17.5 feel fine.

I am just wanting some advice on which is better for racing, a smaller or larger frame.

Just my opinion, but the larger of the two.
For road racing and cross I'd always go a tad smaller and build it out with stem and post.
That didn't seem to work with mountainbikes, most manufacturers put me on a small, but I'd end up with layback posts just teetering on min insertion and mega long stems.
I know there's a general rule about going a bit smaller on mountainbikes but for racing xc I don't think that need apply.
Anyway just my opinion.

I'm the same height as you and I ride an 18' Stumpjumper. Based on the info you've supplied I would recommend the 17.5 frame.

it depends where your length comes from, your legs or your torso.
if its from your legs you want to run a shorter stem and run your saddle further forward. if your back is quite long, the opposite with a small frame.

im 5'11 and i ride a 19" XTC race bike. fits me well.

Hi Josh,
I'm just over 5'11" and ride an 18" s-works hard tail. Personnaly I would always go for the smaller frame if undecided between two sizes, and Specialized frames do have fairly long top tubes.
I think we live local so if any help you're welcome to take mine for a spin round the park. Will be at Thornbridge race next Saturday or could e-mail if interested.
Cheers
Ian

I think for racing you should be looking for a long toptube to get a racer stretch, but as above it depends if length is in your legs or torso.
I'm 5'11" & always go for a 600mm+ effective top tube. I've just sold a Giant Anthem in medium which I ran with a 100mm stem & layback post but I was always trying to push myself off the back of the saddle. These frames have an effective TT of 595mm but I find myself in between large & medium in Giant frames.
Its personal preference in the end but for me I think would be in between sizes on Spesh too.

This is the problem with fitting everyone into small/medium/large bikes.
Everything I read said small i.e 16" for my height 5'8" but they were always terrible even other racers would say they were too small.
I now run a medium XTC/18" with 110mm zero rise stem and zero stack, and approx 101/2" of visible post. I do need to fit bar ends to get even flatter for racing.
?

Coleman,
Whats you email please mate?
I think i cycled past you yesterday along the A6 in Allestree (on the bright orange specialized) so i think we must live fairly close.
My email is in my profile..

Also thanks to everyone who has replied, quite interesting to hear everyone's opinions.

Thanks
Josh..

I thought the Spesh HT frames came in 17, 18 and 19in frames anyway?

I also find it a bit worrying that you say you have been to a shop and came away with the view that either a 17.5in or 19in would be OK. I would be going to a different shop, especially seeing that you are 5'11" which IMO does seem tall for an 17.5 in race frame?

My reach front/rear of saddle to the centre of the bars measured along the top tube is the same across all my bikes, HT, FS, Road and CX. Don't have a big FS or LT hardtail so all my bikes are towards the racier end of the spectrum.

Looking at your CX bikes may give you a guide as to what total effective TT length you require, then taking into account an ideal stem length and seat post lay back you may get a better indication if one size is really a better fit than another.

GJP,
Cheers for that, kind of what i was thinking.
I will go round the shops this coming week and see what i find out.

Just on the frame sizes as well, the S-Works frames only come in 17.5 then 19 there isn't a middle one.

Cheers
Josh…

smaller frame will be lighter, might be a consideration if you are then going to replace everything on it with c-fibre.

At 5'11 sounds like the 19 would be best, but as others say depends where your height is, and how you like a bike to feel.

Remember the best solution might be something like the 19 with a shorter stem on. Shorter stems *generally* handle a bit better, so that might be preferable to the smaller bike with a long stem.

I'd go for the one that felt about the same stretch as the cross bike with your hands on the hoods – cos you'll know that's a comfy position for you (that's about how my MTB/cross bikes compare).

Josh – have sent e-mail.