Bike too small or too big?

February 3, 2007 9:22 PM

Bikefilter: wondering if a Kona Jake cyclocross bike is too small...or too big. My bike was stolen, and I'm thinking seriously about buying a Kona Jake cyclocross bike as a replacement. I like the 56, but the salesguy thinks the 54 is a better fit. Which should I buy?

The 54 *looks* like it's too small, but it rides nice enough. Problem is, my toes can touch the tires when turning.

The salesguy says "Oh, that'll never happen. Besides I have the same thing with my bike." An internet search shows that this is a common problem with this bike.

The Jake is a great buy for the price, and I don't think I want to go back to mountain bikes (I've had a Trek, four Konas and a Brodie since 1990). I like this bike.

I can't quite figure out why the salesguy thinks the bigger 56 is so bad. My elbows bend when my hands are placed on the top bars. It's a bit of a reach to move down below.

My cyclist friend says it's because bikies always think "smaller is better". The salesguy is being more neurotic than helpful.

Which one should I buy?

posted by KokuRyu to sports, hobbies, & recreation (17 answers total)

Think about your knees. I recently bought a new bike and I thought I was buying the right size in going bigger but now my knees are killing me. I think it is because I am over extending my the stretch of my legs. If I was you I would see if they would let you ride a loaner for about 12 miles and see how you feel the next day.
posted by bkeene12 at 9:33 PM on February 3, 2007

You should buy the one that fits you.

Toe strikes are no biggie. My toes hit on my 29er (a Medium Niner SIR9) but it's never actually an issue in real riding.

A frame which is too small for you is better than a frame that is too big for you but the best frame is the one that is just right. This depends on your own body geometry -- arm length, leg length, the way you ride, etc. It's impossible to judge this over the internet -- you need to sit on the bike and have a bike store you trust tell you if it fits.

(That said, I've bought my two latest bikes over the internet and they both fit just fine... however the key thing is to talk to the manufacturer since they know their sizing best. Don't necessarily believe what you read on a website -- lots of manufacturer websites are WRONG).

Lots of the rules of thumb ('my elbows bend') are quite wrong.

That said, my own rule of thumb is that you should buy the biggest frame size which gives you two inches of standover clearance, or an inch and half at a pinch.

So far that's worked for me.
posted by unSane at 9:33 PM on February 3, 2007

PS to measure standover clearance, you need two measurements:

1. The Standover of the bike frame (this should be on the manufacturer's website under geomtery). Basically it is the distance from the ground to the top of the top tube, measured halfway between seatpost and stem.

2. Your own inseam. Jam a book up into your crotch, quite snug, and measure the distance from floor to the top of the book's spine.

Subtract (2) from (1) to get the clearance. An inch for a road bike, at least 2 inches for a mtb.

Most of the other geometry issues can be fudged by using shorter or longer stems, setback seatposts etc, until the bike fits.
posted by unSane at 9:37 PM on February 3, 2007

Thanks for this.

Interestingly enough, neither bike offers much crotch clearance (half an inch)? These are not big bike, either.

One reason I've always ridden Kona is because the geometry suits my body. I'm six feet tall, but have a 30-inch inseam, and a long trunk. Kona mountain bikes typically have a longer top tube, and this has always suited me fine.

But I would like to commute by bike (one hour each way) and I find mtb's are hard on the wrists. So I'm going to buy a road bike.

Maybe the Jake just isn't the right bike.
posted by KokuRyu at 9:46 PM on February 3, 2007

Maybe.

Another option is to use bar ends.

I use these on my Niner mtb for a 10 mile each way commute and they are a godsend.

They look kind of funky on a riser bar but on a straight bar they are fine.

I use the traditional ones but the Ergon bar ends get a lot of love.

They do not give as much variation as a drop bar but enough for commuting IMO.

I have mine set almost straight ahead so there is a much more stretched out -- almost aero -- position available.
posted by unSane at 10:00 PM on February 3, 2007

Try a frame size calculator as a rough guide, and make sure the store you buy from will work with you on the fit and/or has a generous return policy. Also, depending on where you live, you may be able to find some really nice used cyclocross bikes on craigslist.
posted by chudder at 10:03 PM on February 3, 2007

I always heard you buy a 'cross bike a size smaller than you would a road bike. But that may be just if you're going to race it. If you're doing long rides on the road, it may cramp you. That said, my 'cross bike's a size smaller than my road bike, and I sort of like the difference in handling. Seems more lively. But I use it off-road or for a short commute.

And 2nd unSane about toe strikes. Never happens to me when I'm moving at any sort of speed.
posted by mfriesen at 10:16 PM on February 3, 2007

honestly in my experience the difference between a 56 and 54 is splitting hairs. what's far more important is stuff like crank length, saddle height, stem height, bar angle and other "adjustable" parameters. with otherwise equivalent bikes, i don't think you'd notice much of a difference.

what's important is that you tune the stuff you can to get your geometry correct; unless the sizing is way off you're probably fine either way. i've been in basically the same boat (having to pick between 54 and 56 a lot) - i've ridden both and both were fine.

i find this comment the most telling:
Maybe the Jake just isn't the right bike.

if you're saying that; then probably not. the right bike should feel right and not leave lingering doubts like this. it could just be a setup problem, but you ought to try some other bikes out.

at any rate you should buy from a store with a liberal return or tryout-period policy - most good shops will let you take a bike home and try it for a day. and yes, the only time i had any issue with toe strikes is when trying to do trackstands, but during normal riding it's never a problem.

of course, as always, ymmv (literally!)
posted by sergeant sandwich at 10:28 PM on February 3, 2007

Bikeforums.net
posted by Blazecock Pileon at 10:37 PM on February 3, 2007

I sized my On One Il Pomoino to the M instead of the L as I was in between and as above, I tend to size my mountain/cross bikes down if anything. But yeah - every single frame is going to fit differently, from the head tube angle to the bottom bracket clearance, so try to get your hands on one. Not an easy question to answer here.

I ride a 53cm Langster on the track, a 55cm Look on the road, a M (51cm compact == 54cm effective), and a 16.5" Trek mountain bike. It varies.

By the way, I'd recommend a full-on road bike, since any longer (10+ miles) distance will benefit from an aero position as opposed to a mountain bike with bar ends. If you still want more exercise from it, just go fixed gear. :)
posted by kcm at 10:51 PM on February 3, 2007

(two typos - a M/51cm Il Pompino, and I typoed 17.5" .. I'm not riding a Barbie cruiser)
posted by kcm at 10:54 PM on February 3, 2007

Also, more random options:

Soma Double Cross
Surly Cross Check, Steamroller
IRO Rob Roy (SS/fixed)
Bianchi Volpe
The Pake
Craigslist
posted by kcm at 11:14 PM on February 3, 2007

Smaller is better, because you can always raise up the seat post high. You can control a smaller bike better because the center of gravity is lower. I love a small bike with the seat jacked.
posted by Ironmouth at 12:29 AM on February 4, 2007

I bought a Surly Cross Check about a year ago and thought I really needed a 50cm (I'm 5'10"). The guy at the shop didn't think so and pushed me a size smaller. That was the right choice, for me. Also, I really recommend the Cross Check. It's a sweet ride.

Good luck.
posted by catfishjohn at 1:56 AM on February 4, 2007

FWIW it's also worth considering a 29er MTB like one of the Niners since you can set it up as a rigid bike with 700c slicks, or a front suspension bike with big fat Panaracer Rampages or Kenda Nevegals on it. I have two sets of wheels... one with slicks (summer) or studs (winter) on, and the other with fatties.

It's bloody fast -- not as fast as a road or cross bike, obviously, but still fast. The advantage is that on any given day I can choose whether I want to commute along the roads and paved paths, or along the roughest of trails.

Good choices in 29ers are the Niner SIR9, AIR9, EMD and the Surly Karate Monkey, among many many others.
posted by unSane at 6:50 AM on February 4, 2007

Konas have weird geometry. I've had my Kona for two years now, and love it. I dithered about the size, because my natural size, in terms of standover, felt too short. I went for one size up from that, and although in strict terms the standover height leaves slightly too little room for the family jewels, I still have to have the seat as far back as possible to feel comfortable.
posted by veedubya at 7:32 AM on February 4, 2007

mfriesen: I always heard you buy a 'cross bike a size smaller than you would a road bike. But that may be just if you're going to race it.

Yes. If you're doing cyclocross mounts and carrying the bike over barriers, you'll be glad for the smaller frame and greater clearance. If you're just commuting, this isn't so important.

But here's the thing: if the bike's too small, there are about 100 things you can do the adjust the fit -- different stem, saddle position, more spacers on the steerer tube, etc. -- but if the bike's too big, well, then it's just too big.
posted by dseaton at 8:17 PM on February 4, 2007