What size mountain bike frame do I need? Yes, that’s the big question.
Ordering bikes online is becoming more and more popular due to there not being any shopkeeping or warehouse costs, making the prices better.
And don’t worry about the old wisdom of trying a bike before getting it, that is quite definitely overrated. And very highly. Salesmen say this just as a means to get you to invest in a bike. It really doesn’t have to do that much with finding the right bike size for yourself.
You should try your bike first! FALSE
Another reason is that salesmen know that there are decent bikes on the online market and the option of getting to sit on one gives them an apparent edge over that market, but in actuality, it isn’t by any means necessary to choose a bike with the right size.
Related: Best Mountain Bikes Of 2023
There are many good methods to choose a good bike. I’m going to highlight SEVEN METHODS to help you measure a bike.
Feeling more confident? Good. There are actually three different ways to pick a size: you can calculate it or use the bike size charts below. Let´s start with the easiest. The bike size is measured from where the seat post starts down to the crank. You can also use the bike height chart.
#1 – Mountain Bike Size Chart
What mountain bike frame size do I need?
Your height / Bike Size
- 4’11” – 5’3″ = 13 – 15 inches
- 5’3″ – 5’7″ = 15 – 17 inches
- 5’7″ – 5’11” = 17 – 19 inches
- 6’0″ – 6’2″ = 19 – 21 inches
- 6’2″ – 6’4″ = 21 – 23 inches
- 6’4″ and taller = 23+ inches
Or you can use the mountain bike frame size chart below…
Need Professional Fitting Service? Order From Amazon!
Or you can use the…
#2 – Bike Size Calculator
- Take off your shoes and stand with your legs 6″ – 8″ (15-20 cm) apart. Measure the height from the ground up to where your legs come together.
- Be sure about the bicycle type you want to choose: Mountain bike, city bike, or road bike. You can read about the different bike types here.
- Now you can take your calculator and quickly find the right size:
Right mountain bike sizing– Leg inseam (cm) x 0,66 = Your frame size
For example: If your leg inseam is 76cm, then your right mountain bike size is 50 cm (20”)
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#3 – Chart
|Rider Height||Suggested Mountain Frame Size|
|Feet & Inches||Centimetres||Frame Size (inches)||Frame Size (cm)||Size|
|4’10” – 5’2″||148cm – 158cm||13″ – 14″||33 – 37||X-Small|
|5’2″ – 5’6″||158cm – 168cm||15″ – 16″||38 – 42||Small|
|5’6″ – 5′ 10″||168cm – 178cm||17″ – 18″||43 – 47||Medium|
|5’10” – 6’1″||178cm – 185cm||19″ – 20″||48 – 52||Large|
|6’1″ – 6’4″||185cm – 193cm||21″ – 22″||53 – 57||X-Large|
|6’4″ – 6’6″||193cm – 198cm||23″ – 24″||58 – 61||XX-Large|
Extra: Right Saddle Height
Right saddle height has a very important role. If it’s too low, you won’t have enough power in your feet. In mountain bike racing, I have experienced that when the saddle falls one inch down from its normal position, I lose about 25-50% of my force.
Stopping to fix it can cost me my position and about 15 seconds too, but then with the correct saddle height, it’s not that hard to catch up with the group and even get all the way to the next group ahead. So the right saddle height plays a huge role!
The easiest way to find that height for you is to
- Lean against the wall with your elbow sitting on the bike (or let someone help you as shown in the picture)
- Push your leg down to the lowest point keeping it parallel to the ground.
- Move your saddle up or down until you have a small bend behind your knee. It should be something around 30° but don’t worry too much about finding that exact angle.
Go out and ride. Does it feel good? If not, then adjust. Also, you can adjust the seat forward and backward.
Related: Check Out The Best Fat Tire Bikes
Bicycle Guiders’ TIP:
When you have found the right height for yourself, you can use a marker or a sharp object to mark the right position for your saddle as some of them can sink down a bit with time. Some bikes also come with height lines written on the post, that you can check and remember once you’ve found the right one for yourself.
- Fourth Sizing method: Amazon Fit Guide
- Fifth Sizing Calculator: Competitive Cyclist Fit Calculator.
- Sixth – Jenson USA Bike Fit Calculator (Beta)
- Extra – Professional Bike Fitting Service – Order From Amazon!
What If I Got My Bike Size Wrong?
Then tell the merchant, who can easily exchange your bike for the right one. If you don’t want to do that, then you can try the following things:
- move your saddle forward or backward
- buy a longer or a shorter stem. It will change your body position
- buy a longer seat post
Give it time to get the feeling right. I remember when I got my first 29er mountain bike. It felt like a ship and seemed difficult to ride it in narrow trails or the forest. But I’ve become so familiar with it and can ride with full ease and skill, that when I sit on a 26″ mountain bike it seems so completely ridiculous how tiny it is.
If you don’t know, what to buy, then read those reviews below
Mountain Bike Reviews
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- Top 11 Best Full Suspension Mountain Bikes
- Best Mountain Bikes Under $500
- Under $1,000
- Under $2000
- Best MTBs
Hello, I am 165cm in height.. so can i ride on a 17-inch frame bike? Is it suitable for my height?
Hey Am, you should be better off with a 15″-16″ bike, but depending on the model, a 17″ bike could fit you as well. It’s best to give it a try if you can.
I’m 5.7 – right in the middle of a MED and a SM… so hard to decide what size I should go with.. is it really much of a difference? I’m looking into a Fusion 30 2022… I ride both pathways/roads to basic mountain trails… Is the only difference the more responsiveness in a small rather a med?
Hey Christa, it’s usually better to go for the smaller size when you’re right in the middle. It’s a lot easier to lengthen a smaller size bike than shorten a larger size. So I would say go for a SM and enjoy it.
Great article!! It definitely clears out some of my struggle. But still, I have this main concern that is the right range of reach and stack for my height. I am 5″11, 180 cm. I have longer limbs than most people, but super lean, about 68 kg 150 lbs. I am currently riding a L hardtail with 470 reach and 620 stack, I always feel it is too big for me, but every single size chart suggest that the L is perfect size for me. I ended up used mullet wheelset and use the shortest stem that fit- 32mm. Now it feels about right. I am going to purchase my first full sus bike next year, and the 29er enduro bike I am looking at has M(450 reach and 442 chainstay and 630 stack) while L(475 reach, 435 chainstay and 640 stack). I know that the 475 is definately too big for me, but the 450 seem too short too. My most riding condition is XC trails 50%(lot of climb but not too techy), dirt jump park15%, urban freeride 15%(mainly just up and down stairs and bunny hop some curbs) and downhill park 20%. I like doing bunny hops, manual and wheelie, pop some small bump here and there, not a speed seeker but I will use this bike on Whistler bike park so it can’t just be a big full-sus BMX. Since neither size is spot on, and based on my goal, do you think I should go M with a longer stem 50mm+, or gain 15 lbs muscle and get the Large.
Looking forward to hearing your thoughts,
Sorry, Correction :Chainstay length is M 435mm, L 442mm. The specific bike I am looking at is the Cannodale jekyll. It is an DH oriented enduro, but I am not going to use it for dh only, so this is another reason why it is tempting to size down.
That is why we always emphasize here the need for a proper bike fit. Sure, the standard size should fit people under that category, but making adjustments with the length of the stem, saddle fore and aft, and sometimes crank length is crucial for general comfort during long rides. And talking about sizing down, the smaller the frame, the more responsive the bike is, but here we still rely on what’s conventional, especially since we cater to the general cycling public and not pro racers. So, in conclusion, you need to follow what you feel is comfortable to you.
I am 6’3 (75 in), inseam is 93 cm. What size mountain bike would you recommend? I’ve been told that my inseam is longer than average person of my height.
I suggest you get the XL just to be on the safe side and do minor tweaks after, for your comfort. Getting a proper bike fit is the safest bet especially when you suspect that your body geometry is unique.
My mistake, my inside leg to floor measurement is 34in