Road Bike

Good Morning All

I’m looking for advice. I’m wanting to try a road bike. I can’t afford a new one so will be starting with A second hand.

The big question is size. I’m 5ft 6 with a 28” ish inside leg. Looking at most manufacturers size guide I’m a small.  Is this a good starting point as in go by what they say then get a bike fit done to perfect it ?

if I was buying new I’d go to my lbs and get it sorted from the word go but since I’m buying second hand I feel cheeky asking. Also I believe every frame differs slightly with size.

Any help would be much appreciated

Tom

Yes, when you find something you like take a look at the manufacturer sizing info. There is no defined standard on measuring bike sizes. It used to be seat tube but modern aero designs make that a bit useless.

You’ll be able to sit on a second hand bike so should get an idea of if it is broadly ok. It will feel different though.

It works a lot like mountain bikes.

Get the frame size about right. Reach, Stack and (effective) top tube length. Make sure there is scope to adjust the seat post and relative saddle position (it is not at an extreme). Look at spacers by the stem can you raise/lower as required? You can change the stem but you should be looking at about 100mm on a road bike. Much shorter ca make the handling a bit twitchy. It is common to go longer, loads out there with 120mm stems but beyond that becomes a bit niche and you might consider a size up.

You can probably do a lot of the bike fit yourself. The pro ones can be good but also expensive.

The larger manufacturers (at least in my limited experience) seem to have size charts that match reasonably well with reality. I’ve had one frame from a smaller wannabe-boutique brand that was all over the place but the likes of Giant/Spesh/Trek seem pretty consistent.

You can adjust the fit of a bike – seatpost height, stem length, bars, even the cranks if you have to. So even if it’s not right immediately, if you’re in the right ball park you can get it where you want it.

One thing to think about is toe overlap. As you make the frame smaller, the front wheel comes closer. Maybe think about a bike with shorter cranks (170 or less) ?

There’s nothing to stop you window shopping and sitting on a few different new bikes to get a feel for size and fit, then using that to inform your second hand search.

See if any mates  or mates of mates have bikes you can try for size. Someone on here may be local.

Hi

thanks for the advice. You say I can do some

of the bike fit my self ? Any tips on this or good tutorials? I’ve priced up a few near where I live and yeah they are expensive but I’d like to have ago my self 1st.

I would say that the manufacture’s sizing recommendations are pretty much spot on these days. If you’re in the middle-ish of a size then I’d have no qualms about just buying what they suggest. If it’s second hand you can always move it on for a minimal loss if it doesn’t work out. I’m on the cusp between a 54/56 (at 5’10”) so I can ride either with a bit of bar/stem fiddling, but I would usually size down.

A lot of road bike fit is just a question of how aggressive a position you want. My summer bike as a different fit to my winter bike because in summer I tend to ride harder/be racing and therefore putting out more power and so I’m able to tolerate a longer/lower front end. In winter, I’m going slower and it’s nice to have a shorter/higher front end so there’s less weight on the hands. E.g. my summer bike is 381 reach/552 stack with a 110mm stem, my winter bike is 378 reach/580 stack with a 100mm stem.

As for bike fits, I think they’re a bit of a con to be honest. Set the saddle by pedalling with your heels, then bar position is just personal preference really. I could ride anything from a 90cm to a 120cm stem on my bikes, same for stem spacers – all of them or none at all. You’re looking for around 90 degrees at the shoulder, but you can go shorter or longer if you want. A touring bike might be shorter, a racing bike might be longer, an ‘endurance’ bike would be somewhere in the middle, saddle position will be pretty similar for all of them. Over time you will get to know what you prefer and what suits your riding.

Agree with most of what Jonba says apart from stem length. I’m a bit taller than you (175cm) and loads of bikes sized for me will have a 90mm stem as stock from the manufacturer and I wouldn’t be surprised if there’s plenty of bikes being sold with a shorter stem. It will only make the handling twitchy if the frame is too small for you.

Be aware that sizing is not consistent between brands – I ride a small canyon but I’d be a medium on a trek. If you can find a bike that fits you then you should be able to find it on the geometry geeks website. They have a tool that lets you compare several bikes – the stack and reach figures are the most important to get right.

You mention bike fitting – if you’re planning on getting it done professionally then see if the fitter has a jig or test bike. They might be able to give you the right sizing without needing to buy a bike first.

Just go into halfords and ask to sit on one. But at 5.6 I’d say defo small

If your only options are small or medium then yes small but a lot of road bike are still sized a bit more accurately than that, i.e.50cm, 52cm. That is the seat tube size which is irrelevant so look at top tube length which combined with head tube length should do it. No need to worry so much about geometry being all over the place as it is with MTBs as road bikes are still typically 73/73.

Much as I sing the praises of bike fitting: for now, just focus on getting something that basically fits right. Like, fits are about fine tuning, and you’ll only discover what you need there after a bunch of riding. Also, I only started noticing the need for a fit once I was regularly riding 50+ miles on a ride, I rode for a couple of years fine without them. If it’s your first road bike, the priority is getting the right size frame, and just discovering what you like.

Also, beyond a few really broad things, it is very, very hard to fit yourself.

You sound like a 52 or 54 in road sizing, might vary per manufacturer. Go and sit on some, even if you’re not looking at buying those particular ones. Have you ridden drop bar bikes before? That might affect how you feel on them.

Firstly apologies if I’m mansplaining, just thought that if your new to road some of the words being used may not mean a great deal.  Road fit is actually fairly nuanced, and while your probably going to be fine on a small, its worth a quick read of the below.

Small would probably be about right, some minor differences between bike types and manufacturers. I’m just a smidegen taller than you at 173cm. I ride a 52 or a small, Cannondale SuperSix was a 51, I did test ride a size 53 Supersix and SytemSix but preferred the smaller size (51). My Canyon Aeroad was a small, but that may be too big for you, I could have comfortably rode an XS in the Aeroad.

My Trek Emonda and Madone was a race fit, so they were a small (52) with a longer stem (110mm). My winter bike a Trek Domane is a medium (54).  Trek have different type fits, the H1.5 or H2 is more racey. If this isn’t mentioned then it will be a normal fit.

The numbers represent the effective top tube length. Have a look on bikecad.ca, use the search on the right hand side of the page, enter effective top tube and it will show you what this means. Do the same for Stack and this will give you the diagram representing what Stack and Reach mean.

A lot of manufacturers refer to the effective top tube as the size, not necessarily small medium large etc. 52 is generally considered a small. I think for Canyon a 54 is a small, but I found that I could have comfortably gone to an extra small on their bike. There’s a website called Geometry geeks, if you enter the details for the bikes your interested in it will bring up the measurements and you can compare differences. If you’re having trouble understanding the data, let the chaps on here know and they will be able to help you with explaining what it means.

Whilst size charts are a good starter don’t take them as a given to be right for you.  I’m 5’10, with Specialized that put me right in the middle of a 56 frame (bought secondhand), I was never 100% comfortable on it despite changing stem, saddle position etc.  A proper sizing for the replacement out me on a 54 (another brand, but I also sized up on a 54 Specialized) as I have short legs, I also moved down a bar width. My new bike is a lot more comfortable.

Another thing to consider is that geometry of road bikes could be loosely grouped into ‘race’ and ‘endurance’ fits, with the former being slightly longer and lower than the latter. What suits you will depend on the type of riding you want to do and your flexibility. If you have tight hamstrings or back/neck problems then you probably want to go for more of an endurance bike like a Cannondale Synapse, Giant Defy, Trek Domane, Spesh Roubaix type bike which will position you a bit more upright – usually these have a longer head tube and slightly shorter top tube than their race equivalent.

Similar size to the Op, usually ride a small or 48cm- 52cm frame on the road.

Thanks for the advice everyone. I do have back problems I have a curved spine which doesn’t help. So maybe something abit more upright would definitely suit.

after doing some research online I’m realising I’m very close to been in between two sizes in a few brands I’ve checked out. In this instance what’s the best thing to do ?

It’s generally easier to make a smaller bike bigger than a bigger bike smaller. The thing to be aware of if you’re buying second hand is if the previous owner has removed spacers from under the stem and cut the steerer then you can’t increase stack.

I’m 5’ 9”, with a 30.5” inside leg.
I’m a medium in most stuff so I reckon your thinking re: sizing is correct.
But there’s nothing to stop you going into a halfords/lbs to check em out.

The thing to be aware of if you’re buying second hand is if the previous owner has removed spacers from under the stem and cut the steerer then you can’t increase stack.

Agree with this, although I’ve fixed similar situations by either flipping the stem up (heresy I know but you quickly forget about it) and/or fitting ‘riser’ drop bars such as Specialized Hover or similar. You can easily achieve up to 4cm additional height this way

I’m the same as @jwt, 5ft 6in and a bit, and usually go for a 50cm or 52cm, but some brands are different to others so familiarise with geo charts rather than just taking ‘small’ as a given.

For a really basic guide. There are loads out there if you search.

You need to be comfortable first. It takes a bit of time as the position is very different from mountain bike so it’s always going to feel weird at first. My position has changed over time. It got more aggressive for a time.

This talks you what a pro bike fit might do. The advantage being that you get a measured position and so only buy things once.

Cheers everyone.

You’re a small. What matters is handlebar position. We have hyper adjustable bikes now, and most people can adjust to a bike one size bigger or smaller. What matters for a first bike is stack – how long is the head tube? You want a head tube if at least 12cm. Sure you can adjust with an inverted stem, but you want it to look like a road bike 🙂

Small, 50-52 cm and a 90-110 mm stem. Look for a head angle of 72.5 to 73 degrees.

Sure you can adjust with an inverted stem, but you want it to look like a road bike 🙂

Haha! But seriously, I think I now prefer the look of an inverted stem with fewer spacers (or even a token one or two 5mm on top) to a non-inverted stem with a tonne of spacers underneath. Clearly slamming it always looks best but those days are long gone : (

If you get the right frame you don’t need an inverted stem or loads of spacers, that is the point being made on head tube length. If you get an endurance road bike the head tube is likely to be longer and top tube slightly shorter meaning you are higher at front and less stretched so can use ‘normal’ stem of around 100mm.

There are challenges with everyone being different dimensions though. I have relatively long legs and short arms so I need a smaller frame for reach (shorter arms) but a larger frame for head tube as sitting higher up (longer legs). Because I know that via experience I can choose the frame accordingly and look for 53cm top tube with 140-150 head tube.

I’m 5’8″ with a 29″ inside leg and always been comfy on 54cm road bikes, I’ve had a few Specialized and a Cannondale and they’ve all fit nicely, though I think on the Cannondale I did end up fitting a slightly shorter stem. It sounds like a 52cm would work for you.

A lot of manufacturers refer to the effective top tube as the size, not necessarily small medium large etc. 52 is generally considered a small.

No they don’t. I’ve not seem a single manufacturer refer to the effective top tube as the size, it’s the effective seat tube length they refer to.

I would say that the manufacture’s sizing recommendations are pretty much spot on these days. If you’re in the middle-ish of a size then I’d have no qualms about just buying what they suggest. If it’s second hand you can always move it on for a minimal loss if it doesn’t work out. I’m on the cusp between a 54/56 (at 5’10”) so I can ride either with a bit of bar/stem fiddling, but I would usually size down.

Same here but I seem to prefer sizing up.

IME/IMO The thing you notice looking across geometry charts is Reach figures, a ’54’ or ’56’ is an almost meaningless measurement, they can vary wildly for reach, the sweet spot for me seems to be about 390mm (+5/-10ish). From there I can adjust stem lengths and seat position but the reach has to be in the right ball park for me.

I’d try whatever/whoever’s bikes you can OP, but then look up the geometry for each one to see what the actual numbers are like, you can at least start to build up a picture of what fits (or is at least in the ballpark) and what doesn’t.

It’s also worth budgeting for for a change of stem and saddle, and possibly a new set of bars and/or seat post as these all allow you to tweak the fit and comfort of a bike (much like an MTB)…