I'm looking at getting a road bike for a bit of training for the mtb, just to get some miles in my legs.

I've spent my life on a mtb though so road seems totally alien. I was wondering if anybody could offer some advice on sizing?

I'm 5' 11" with a 32" inside leg but I don't know what that should really equate to in frame sizes. I appreciate that trying in a shop would be best but I'm struggling for time atm..

Thanks in advance,

Will

Probably a 56/57

Impossible to say. Even within a brand, different geometries will demand different frame sizes.

Have a look on the manufacturers web sites. They all tend to measure frames differently but usully have a sizing chart to give you some idea of what might fit.

If you're struggling for time then wait until you have some. Fit's far more important on a road bike than on an MTB.

I'm 5'11" with a 32" inside leg and ride a 56cm Roubaix

On reciept of the words of command "What size bike do I need for…" Can of worms are to be…OPENED!

Anyway, joking asides, Bez has it. There are so many different things that affect the size of 'your' road bike that just asking for forum advice for your first one is really a bad idea. Get a notebook and keep a record of what bike you tried, in what sizes and how each one 'felt'. Don't be scared to go back and try the same bike again after you've tried a few more.

Stuff to think about: Compact frame (sloping Top Tube) or Traditional (horizontal top tube)? Head angle. Seat tube angle. Top tube length. Is the frame measured centre to centre or centre to top? What is the intended purpose of the frame? What do you want the bike to do? Would a CX bike be more suited to your requirements? Will you need mudguard mounts? (hint…if you're riding in the winter then yes you probably do…the more so if you ride with a club).

Anyway…any ideas on budget? Or anything at all beyond 'a road bike'?

Hope that all helps.

+1 for Bez and Roadie. Also some LBS do bike fits for about 50 quid which is refundable if you purchase a bike. You will notice when you start sitting on the "same" size of different brands how different they can feel.

I agree with all the above, the only real way to find out is to try a few different bikes.
but, if you really don't have time and want a ballpark figure, then you'll want something with a 56ish toptube

all the "i'm xxft xin and ride a xxcm" statements are next to useless unless they are from people with the exact same body proportions and flexibility as yourself.

my bikes are 55.5-56cm and i'm 6ft1 but somebody up there is 5ft 11 with the same size. plus nobody mentions the stem length.
effective top tube measurement is crucial (as is stem length).
in short get fitted properly in a decent shop.

fwiw – I'm 5'11" with longer than average 33" legs. I ride a 56cm Cervelo and that's as small as I can go. I also have a couple of custom built steel frames (Argos and Enigma) and both builders sized me up for equivelant of 58cm. (that's the effective measurement of the top tube, which if it's a sloping top tube is the horizontal measure, not the actual top tube length – if you get my drift) – the Argos being a traditional design is 58cm seat tube also, whilst the Enigma being a 9deg sloping top tube is actualy 52cm)

if you take the time to read up about sizing and "front centre" vs "traditional" sizing of frames then it might help you understand that most frame builders have a different view about how to size you a bike. have a look at cervelo geom & fit

btw – I use a 12cm stem on all the above bikes.

And to highlight the point of fit being different, I'm almost exactly the same dims as mister t and yet a 58 is way too big. My current focus is 56cm, which has a 55.5 horizontal top tube and I run a 110mm stem and 5mm layback seat post with the seat almost in the middle of the rails…

I think you need to be prepared to shell out on a fit, which may get you close, or do as I did, and be prepared to try different sizes. A 58 for me – 57 horiz top tube) was way too big.

5'11" – ride a Ribble in 56cm with 570mm effective top tube, layback seatpost & 100mm stem (althought I may try an in line post or 90mm stem)

Just borrowed a mates Planet X SL Pro Carbon in large (570mm eff top tube) & that left great although the 120mm would have been better at 100mm.
Low standover also gave impression of riding a smaller bike – check these out if your looking to buy new – great value for money.

Road frames come in normal, compact, semi compact designs with top tubes of varying length according ratio to seat tube from each mfr.

So decide your budget, a range of waht you fancy and take it from there. For info at 6ft I ride a 56 semi compact Van Nic with 55cm top tube, 11 cm stem

MrSmith and cp are spot on… showing that height and leg length alone is still not enough, we are all very different in ability (and desire) to get long low and aero on a bike, as well as having different length arms, and ability to rotate pelvis forward with ease. I've been a roadie since the age of 11 and have a clear view of what works for me. in fact I can get a good position on the 56 cervelo R3 (with saddle set far back on a 25mm setback post) on the 58cm Enigma and Argos and on my 60cm Kenesis Tk (forgot that one)…. using 3 dimensions. 1) centre pedal (at 5ocklock) to top of saddle (parallel with seat tube) 2) horiz setback of centre pedal (at 3oclock) to saddle sit bone point. 3) saddle sit bone point to handlebar hand hold positions.

the thing to start with is the measurement from top of saddle to middle of pedal spindle. this is pretty much the same (within 5mm) on my XC mtb's as on my road bikes. then take the measurement from the sit-bone position on the saddle to the centre of handlebars and use this as a start of the measurement of same saddle point to the center of the drop road bars where they intercept the stem. finaly work out the horiz setback the saddle sitpoints are behind the pedal spindle centres when the pedal is at 3oclcok. take these measurements, and go to bike shops to see what size you can get a bike to replicate those dimentions. then ride it, and see what it feels like.

adjust the height difference from saddle to bars to meet your flexibility levels and core muscle strength. I have my road bike bars between 8cm and 10cm below saddle (depending on their purpose)

if you are used to high front end situp DH style MTB then you will likely prefer a smaller frame and smaller taller stem. if you are a bit of a stiffback XC MTB style rider, then bigger and longer lower is more likely.

I used to be much more flexible and thus used to use 13cm stem on a traditional 58cm frame with 11cm saddle to bar drop (that was back in my road racing days). now some 15yrs later I'm happier with a 12cm stem with 9cm drop for the same frame.

if all that's to much to do.. then as cp says, go get a bike fit from a high class bike shop with the proper kit to measure you. don't trust a sales assistant to eye you up for size… since they can't see flexibility and core muscle strength.

end of story is that it's gotta feel right… and you can't measure "feel"

Don't do it, roadies are knobs..

I would try and ride a few. I'm a firm believer that a active fit is far better than a static fit. Then there are little things like a preference for a slightly smaller frame to over power or slightly larger to sit in.

The bikes that come in SM and L based on height can be a problematic fit. I am for example 3" shorter than you, but my inside leg is the same sadly we don't come in S,M and L.

MisterT – are there any shops that you might recommend that actually take into account core strength as well as flexibility?

stu_d – yes I 1st came across Core strength being taken into account with Arthur Needham at Argos Cycles back in the late 80's.. he got me to ride on his static jig without holding the bars to see a natural forward position.
most recently the best I've come across was a company in the states that used the Retul approach. – I think Bespoke Cycling in london uses that approach too. have a look on YouTube for some insight.

Get fitted, or at least get a book on riding road bikes and it will have a section on fitting. Bear in mind the stem/bars are replacable/adjustable so as long as the frame is the right size (probably 54-56 I'd guess) the rest is fixable at a later date. Even bars come in 3 differnt widths (normaly) and compact, normal, ergonomic bends, short drop etc, and every maufacturer has their own take on eachof those as well!

I bought my road bike from Condor in London. I chose a frame, they put me on the measury-thing and we picked the bits. when the bike arrived, I had to lower the saddle by 5mm because they'd assumed I'd be using road rather than mtb cleats. Apart from that it was utterly perfect and I've changed nothing about it in nearly 3 years.

Compared to mates who've bought sale bikes off the internet in a size that ought to be about right and then struggled with back pain and endless adjustments to stem length etc etc I feel like I got a very good deal. 🙂

BigDummy +1 bike fitting at condor is excellent.

Bike sizing is just mental! The first size given (and only size, often) is the seat-tube one, and no bike is made that the saddle doesn't go up and down on!

Anyhow, get a feel for the eff top tube length that you need and work from there. I'd have though 55.5cm ish with 100mm stem would be a good place to start.

Actually glenp…not to be a 'know it all' but many of the top-notch carbon frames have a built in seat pin/tower thing which is cut to the correct height and the saddle then bolts in place.

Oh…and as for a bike for our man will 1991, as he's 5"11 I'm thinking 56/58…

misterT talks sense.
some of the people posting on this thread are riding the wrong size frame 🙂
flexibility, knee over spindle and bar drop are all important steps in finding your fit. it's also worth having another fit after a few months of road riding as flexibility improves, and don't forget cleat and varus/valgus angle of your foot.

i have been fitted at condor and more recently at a specialized BG dealer.
i recommend the BG fit mainly for the insoles and shims that ensure a straight pedaling action.

I'm 5'10" with 31" leg. According to most manufacturers that should mean 54cm frame. However, i appear to have monkey arms that require the top tube from a 58cm frame. Compromise is a medium/long with a 120mm stem, none of which i would have known without a professional fitting.

2 minutes around the block on a 54cm trek confirms this as it felt like the bars were on my knees.

I'm your size and I ride a 53cm Kona Zing, which is only JUST big enough (long story but it's what I ended up with). I changed the stem to 120mm from 90mm and it fits pretty well, although on the drops I wish it were a big bigger. Some of the TdF pros seem to be in similar positions to me though. It is absolutely brill standing up and hammering, and also very comfy on the hoods.

I suspect that it's closer in fit to my mtbs though the small size might be advantageous. And small road bikes are apparently 'in' according to my roadie friend.

And small road bikes are apparently 'in' according to my roadie friend.

are they trendier than ones that fit?

maybe he forget to mention the 120/130/140 stems and bigger saddle to bar drop?not to mention no huge stack of spacers under the stem.

Road bike fit is crucial, it should be comfortable to ride, Don't worry about "what's in" or trendy, as unless you're a hobbit most small frames will be too small.

Get a bike fit from a good shop and then TEST ride that fit on a bike for at least an hour!

Have fun, road riding is ace 😀

I said that he said they were 'in', I didn't say that fashion was a sensible way to choose your bike size!

In fairness, there's a range of sizes that you can make fit. Mine is about as small as I could manage (but not deliberately… I needed a bike to replace my nicked one, and I ordered a 56 through a dealer mate at discount, but they only had 53 and they assured me it'd be fine.. :?) and it has advantages and disadvantages I reckon.

I can see the argument for going for the smaller size that might fit.

Probably just an off the cuff remark, but I kind of know what he means.
And here's another generalisation. When I see fit sports riders on the road their bikes look like they fit. When I go racing a lot of bikes look slightly undersize.
I've not been fitted since the old days of steel custom race frames, but I know my needs. I'm long legged with short reach, so I go small compact so I can still use a 110 stem to get over the front wheel. I raced a bike that was the 'right' fit for one year and it was dreadfull.

I also am quite flexible, so I can use the drops even though they're quite a bit below my saddle. Gives me a good flat-backed aero position that way. I do wish it was a smidge longer tho, I might experiment with a 130mm stem and see if it doens't mess up the handling or weight distribution out of the saddle.

I'm 5.11" with a 32" leg and my bike fit came up with 56 which carries over to most road bikes I ride.

i'm 6ft 4 and ride a 56cm.
HTH

http://www.competitivecyclist.com/za/CCY?PAGE=FIT_CALCULATOR_INTRO