Purchasing the correct size road bike is a crucial decision to experience the safest and smoothest riding position. It’s common for people to see a cheap second-hand bike or something in the sale and buy it, but it might not be the precise bike for your height, so you could choose a bike that is too short or tall for your size. Hopefully, I can help you to avoid that problem with this post.
The average male should buy a road bike sized between 56cm – 58cm (large) and a female 54cm – 56cm (medium). The best way to tell the proper seat height is to sit on the road bike. Both of your feet should touch the ground, but both feet should only touch with the ball of your foot and toes with the heel of your foot in the air.
There’s far more to think about than just the hight of the bike from the floor to the saddle. However, there is some simple step to receive before you buy or hire a bike, and I will explain in detail in the post below. For now, a great place to start is your hight and using the chart below you can quickly identify the size of bike you need. Furthermore, before buying a bike, I would, where possible, test it. Each manufacturer’s bikes are slightly different in size.
| Cyclists Height | Frame Size |
| 148cm – 152cm (4ft 10″ – 5ft) | XX-Small (47cm-48cm) |
| 152cm – 160cm (5ft -5ft 2″) | X-Small (49cm-50cm) |
| 160cm – 168cm (5ft 2″ – 5ft 5″) | Small (51cm-53cm) |
| 168cm – 175cm (5ft 5″ – 5ft 7″) | Medium (54cm-55cm) |
| 175cm – 183cm (5ft 7″ – 6ft) | Large (56cm-58cm) |
| 183cm – 191cm (6ft – 6ft 2″) | X-Large (58cm-60cm) |
| 191cm – 198cm (6ft 2″ – 6f 4″) | XX-Large (61cm-63cm) |
Table of Contents
How To Measure A Road Bike
To determine the best size of road bike for your height, many manufacturers scale their bikes in either number 48 – 62 or small to extra large. The measurement is taken, in centimetres, from the bottom bracket to the top tube.
There are three main areas to measure on your bike to trust its the right fit for your height.
- Seat tube length – is the most common measurement and is from the crank bracket to the insert of the saddle of the top tube.
- Reach – is measured from the centre line of the bottom bracket to the centre of the top tube.
- Stack – the section of the bike where your handlebars insert into above the wheel
How To Set Your Saddle Height?
The fastest way to measure your saddle height is to hold your bike against your hip. Your feet must to planted on the ground and not sitting on the bike. Adjust the saddle in line with your hip or slightly below and then sit on the saddle. For the optimum riding position, there should be a small bend in your knee when your leg is extended on to the peddles.
Alternatively, for more accurate measurement, place your bike against a wall or somewhere you can mount the bike without falling off. From the seated position on the saddle extend your right leg until your heel is placed on the end of the peddle. For the correct height, your leg must be completely extended. Once you have this position clip or put your feet on the peddles like your going to ride. Your leg must have the same small bend in the bottom riding position.
Incorrect Seat Height Can Cause Knee Pain
One of the most common injuries and areas of discomfort for cyclists is knee pain. The saddle height and frame size being incorrect is a contributing factor associated with knee pain. If you overextend your knees during a ride, you could be doing more damage than you realise especially, if you’re an average cyclist with a cadence of between 70 and 90. That’s nearly 90 revolutions of the cog every minute.
How The Reach Could Impact Your Ride
The vast majority of riders, including myself, will find a bike frame that’s has a shorter top tube and a longer seat tube suitable. The reason, the riding position will keep your body more upright at a 45-degree angle which will put less strain on your lower back. If your more flexible and want a flatter riding position you might want to choose a longer top tube and shorter seat tube length or frame.
The deeper riding position is best from people with longer arms and a longer back that have the flexibility to stay low for longer durations on the saddle. For the average person (man 175cm and woman 162cm) might find the more upright position more comfortable and less strain on their lower backs and legs. Either way, you must try this out for your self by sitting on the bike before purchasing.
Some bikes, however, might have the ability to adjust the stack, enabling you to bring the handlebars higher, so your reach is not uncomfortable. The seat can move a couple of centimetres forwards and back to get you closer or further away from the handlebars, but if you find it’s not enough, you will need a shorter or longer frame. You should never feel uncomfortable whilst riding your bike, especially if your planning on cycling for hours.
Crank Length
The crank is the part of the bike that your peddles are attached to. The length of your crank can range depending on the manufacture or dimension of the bike. An easy way to decide what crank size you might need is;
| Size Of The Rider | Crank Size mm |
| Tall (183cm 6ft and over) | 175mm |
| Average (168cm 5ft 5″ – 183cm 6ft) | 172.5mm |
| Small (148cm 4ft 10″ – 168cm 5ft 5″) | 170.5mm |
The crank is something that wouldn’t make a massive difference in your overall riding experience. Although if you have fitted yourself accurately using the steps above and you find you notice knee pain or feel like your overextending, then crank could be the wrong size for your height. It’s something you must try before buying the bike and make sure you have a good ride before reaching your final decision.
Conclusion
This size guide will help you choose the correct bike for your height especially, if you follow all these tips and techniques. My advice is to always sit on the bike you want to buy or if you like something go to your local bike shop test the same model out and then purchase the right bike for your height online. It can take a couple of rides to settle into a new bike because every model can ride differently. If after a couple of weeks you feel the bike isn’t for you return it and try something different.