I am looking to buy a hardtail for the winter and i’ve been trying to work out the crucial dimensions for a suitable bike. I’m 6’4″ and weigh a svelte 100kgs, more if i wear clothes and i have a 36in inside leg.

I know everyone will say you have to try each bike and that would be the ideal solution only i can’t seem to be able to hire any bike of the right size for a morning to take up and down the hills to try it out. So this leaves me with having to make a judgement about what i’m really looking for.

I’ve owned a Scott scale 26 hardtail, a Trek fuel 26 full sus and now a Commencal v4, all in XL. The EFT lengths are very similar 640-650 as are the reaches 466 but the commie rides way better than the other two and i think it has to do with the long wheelbase 1225 and longer chain stays 437. The slacker head angle explains why it descends better but it’s way better climbing because the front doesn’t keep popping up so it is much more stable.

So my question is what does the panel think about the pursuit of the shortest possible chainstays which every review seems to laud as massively important? Am I right to think that as a tall rider with a very long seat post it is more important to see where your Centre of Gravity is in relation to the back axle and a longer wheelbase brings the CoG forward as well. It seem obvious but why is it never mentioned? Bike geometry never seem sot consider the height of the rider and that taller riders have a higher CoG which changes how the bike responds at extreme angles ie when climbing. Unless of course i’m wrong but I’m hoping someone out there who really understands bike geometry can advise so I can make a better desk study of what i should buy. Then i can try and demo my shortlist.

thanks

John

So my question is what does the panel think about the pursuit of the shortest possible chainstays which every review seems to laud as massively important?

I think discussions about how great they are either miss about 50% of the point or are focussed on a certain area of ride characteristics.

Am I right to think that as a tall rider with a very long seat post it is more important to see where your Centre of Gravity is in relation to the back axle and a longer wheelbase brings the CoG forward as well.

Yes, it’s C of G in relation to both axles really, the balance between them. A steeper seat angle helps for climbing and may be a better-handling way to go than a long chainstay if most of your riding is either up or down, but a balance of the right chainstay length and a middling seat angle can help for ‘riding along’ – steeper seat angles can pitch your weight forward and can lead to seated discomfort for longer-distance pedally stuff. What works for you is more about what you ride and your build / proportions than any ‘right numbers’.

Your commencal at 437mm isn’t what I’d call a long chainstay, I’m 6ft and would be happy with that for a lot of bike types or uses.
It’s no one dimension that counts most and all about pros and cons, just my opinion that the focus on CS length alone can get out of perspective. Brant’s done some good work on seat angles and how it affects big guys on MTBs, worth taking note if he posts up.

jameso has it all covered off there.

Riding behind Ton, on the climb from Hebden up to the New Delight taught me lots about seat angle and big tall riders.

The unfortunate side effect of that is that vision stays with me and his large arse is clear in my mind right now when I’m thinking about it.

Hmm