You are hereForums / By Discipline / Mountain (off road) / MTB Gear / Choosing correct frame size
Choosing correct frame size
NB: Originally posted elsewhere on the Global Riders Network and appears via syndication.
Hey everyone, I'm looking at getting a mountain bike. I don't know much at all about them. I'm most likely going to buy a second hand one with front suspension to begin with. I just want to know how I decide on the correct frame size? I'm 183cm tall, but I don't have long legs as I'm taller in my upper body. If theres any advice you can give me in purchasing a second hand bike that would be appreciated too.
Cheers
- Login to post comments
- Bookmark & share
Tags
Hmmm... perhaps you're on the border between Medium/Large for most manufacturers? Have a look in the classifieds and see if there's anything suitable - I'm sure any local rider would let you have a little test spin first? There's usually bargains to be had on flea-bay too.
I'm 186cm and ride a large Yeti and Cannondale. Let's say I'm normal (yeah - right!
) and your legs are the same length but your body is 3cm shorter - you might get away with the same and just put on a shorter stem.
Check for chain/ring/cassette wear, make sure everything is running smoothly, etc, etc. There's probably other threads on looking for second hand gear, eg:
http://nobmob.com/node/13816
http://nobmob.com/node/10341
http://nobmob.com/node/1359
More:
http://nobmob.com/search/node/%22second%20hand%22
I'm 182, and used to ride a lge Specialized Enduro. I thought it was the right size for me. I was constantly going OTB on the thing, like every ride at least once. I ran a 40mm stem. I sold that frame and got a Medium '08 Norco 6 and swapped all my parts over to it. So same stem, bars seatpost, saddle etc. There was an immediate difference. So much more comfortable, and I've only been OTB maybe 4 or five times in the last 8-10 months, and that is due to doing something either stupid or being too blazzae (spelling???) and not concentrating.
I'd be going for a medium.
I just helped a mate get into a dually. He had a lge hardtail that he bought brand new from a shop on the beaches, they sold him a lge when he's lucky to be 178 or 179cm tall. He liked it, but found it really hard around the dam (at the time he just thought it was him). I got him onto a sml dually and he said the difference is amazing. He felt it was a million times easier doing the steps and drop downs on the smaller frame as he could get right back over his seat, compared to his HT that he could barely get back at all on and felt he was always going to go OTB.
It's very much a personal thing.
... if you're on the border between the two.
I'm 185cm but long in the legs. Both my 'dales are Large, both the HT and the dually. A Large Cannondale is about the same length as a medium Giant.
Today I've been faffing about on a hardtail I'm reviewing that would have the same horizontal top tube length as a Medium 'dale. This was on a couple of fire roads and some singletrack I discovered .
Once I got the seat position dialled and got used to the narrow flat bars I had a really good time.
The descents were great fun, and at no time did I feel like I was at risk of going over the front of the bike. Where it caught up with me was on the climbs. Trying to stop the front wheel from wandering on steep rough climbs was a bit harder, due to less weight on the front wheel. However, a wandery front wheel on a slow climb isn't going to send you to hospital like an OTB on a descent can.
Thanks guys...so if sizing is different from brand to brand then maybe I should look at sizing in terms of inches rather than in terms of small, medium etc...would 17 to 18 inches be about right? Also is there a way that I can tell if the bike is the right size when standing over it...should there be a certain distance between ones crotch and the top bar...I don't know where I heard that but it rings a bell...and how do I determine if I need a shorter or longer handle bar stem...flying over the top of the bars sounds like a painful way to figure that haha! Do you guys insure yourselves, income wise, incase of serious accidents on the bike?
No, they're all over the place as well. And with bike frames being varing degrees of "compact" these days - that is, variations on a sloping top tube, depending on brand, and model within brand - standover height is no guide either. Naturally you don't want to crush the family jewels, but mountain bikes are designed with pretty generous standover clearances these days.
The only measurement you can trust as a comparator between brands is Horizontal Top Tube Length. It's how long the top tube would be, measured centre to centre, if it was an old-school road bike with a top tube that was parallel to the ground. It's the only measurement that follows the same standard on every brand and model.
And it's the measurement that's most fiddly to adjust for on bike fit, as it means swapping stems and possibly bars in and out so as to get your reach to the handlebars right. Stem length affects steering responsiveness and descending ability as well. So I suppose it's just as well that it's directly comparable.
Yes, I've had income insurance ever since we took out our first home loan. It's tax deductible, and prudent for anyone who has dependants and commitments.
Ah ok, I think I may have more of an idea now...and I think I may have found a bargain too: merida XC TFS 900 2009 model. Its selling for $1300 (i'll offer $1100) and the RRP new is $2400. Anyone familar with this type of bike? Does it compare well with giant xtc 1 or 2?
the drive train , brakes & forks these are the things I look out for when buying a bike for myself .
Check top tube length as your guide to compare sizes.
Sit on some bikes in a shop, test ride, get their sizing advice and take the horizontal top tube lengths of the ones that seem to fit.
- I am 182cm and typically ride a 590 to 610mm horizontal top tube. with a 80- 90mm stem. Regardless on the sizing assigned to the frame, medium or large if it is in this range, or you should find a fit. via stems - and spacers adjustments.
I must admit I usually run about 30mm of spacers under those stems for a more upright but centred position so may be runnig a longer top tube than some. Standover height is rarely an issue with most frames these days and for most trail riders.
Hey Ben, if you don't know anything about bikes, don't know how to size them and are new to the sport, do yourself a favour-go into a reputable bike shop and try a few out, getting them to size you up and letting you swap parts around. If after that experience you think you're going to enjoy mountain biking, spend your $1300 on a brand new hardtail from the store, that fits you, that doesn't have a crack in the frame you missed because you didn't know how to look for it, worn parts you're gunna have to replace in a month because you didn't know what to look for, isn't possibly stolen, and does have a warranty.
Then if you've been riding for a while and you get to love the sport, use the knowledge you've gained in the 12 months, or however long that 'while' is, from talking to others and trying out your mates' bikes and parts, and then go look at and buy a better bike, possibly second hand (and you've already got a "one owner only" bike to sell & put the $ towards it).
The alternative is to spend time trying to work out what might be best for you from a load of people that have big hearts and the best intentions, but at the end of the day have their own style of riding, different perceptions of risk, different body geometry and differing levels of flexibility in their back and hammies, and then end up spending $1300 on something that gives you backache on your first 1 hour ride and puts you off mountain biking for life.
OK Gen Y sermon over. I'm off to quackdoctors.com to find out what that lump is on top of my neck.
Good luck whatever you do and maybe see you riding in Canberra, God's MTB park, soon!