Mountain Bike Anatomy – 50 parts in 5 minutes

Mountain Bike Anatomy – 50 parts in 5 minutes

This is a mountain bike, and at the heart of any bike is its frame. Let’s start with the parts of the frame. This here is the top tube, the down tube, the seat tube, the seat stay, and the chain stay. This area down here is called the bottom bracket shell. At the very front of your bike is the head tube, which houses the steerer tube. This moves smoothly thanks to a set of cups and bearings collectively known as the headset. Above that are headset spacers and the stem. The stem, which clamps on to your handlebars, is fastened to the steerer tube with a top cap and pinch bolts. On your handlebars you’ll find brake levers, shifters, grips, and end plugs. All this stuff up here is collectively known as the cockpit.

Moving down is your fork, which in this case is a suspension fork. This top piece is called a crown. Some bikes are fitted with dual crown forks for added strength. The crown is what holds your stanchions, which you should try as hard as possible not to scratch. Don’t hang your bike by the stanchions.

Down here is your brake caliper, which camps down on your rotor when you squeeze your brake lever. Some calipers are mechanical, while others are hydraulic. Hydraulic brakes push fluid through a hose, while mechanical brakes pull the caliper using a cable.

This big round thing is a wheel. If you buy a front and back wheel together, it’s called a wheelset. All the parts of your wheels are held together using spokes, which connect to your rim with these little guys. They’re called nipples. Also on the rim is a valve stem which is used for pumping air into your tires. At the center of the wheel is the hub, and inside the hub are bearings. The hub rotates around an axle. On a lot of mountain bikes this takes the form of a thru axle, which can be removed or installed by hand.

On the rear wheel a cassette hub. This has a ratcheting mechanism built into it which is made to accept a cassette. The cassette is a set of cogs which can actually be changed to your liking. The size of each cog is measured by the number of teeth it has, and these teeth are specially designed to work with a chain. Your chain is made up of individual links, with one link in particular being possible to unfasten easily. This is called a master link.

The chain can be shifted up and down the cassette with a derailleur, which is attached to the bike via a small breakable part called a derailleur hanger. If your derailleur hanger snaps or bends, you can just get a new one. On the derailleur itself is a long spring loaded piece called the cage, which keeps tension on the chain. The chain passes through the upper pulley and lower pulley, also known as the jockey and idler respectively.

Moving down to the bottom bracket shell, you’ll find your crankset, with the most visible parts being the crank arms. The crank arms are attached to the spindle, which runs through a set of bearings which are inside the bottom bracket shell. The spindle and bearings collectively are known as the bottom bracket.

The part with all the teeth is called the chainring. Some bikes have up to 3 of these. At the end of the crank arms are pedals, which can be found in many different forms. The crankset, chain, derailleur and cassette are collectively known as your drivetrain.

On a full suspension mountain bike you’ll find a variety of stuff connecting the front and rear of the bike together, known as the suspension linkage. At the heart of all this is your shock. This is usually fastened to the linkage on one side, and to your top tube or down tube on the other.

Moving up, we have the seat, or saddle. The two words are interchangeable, but some people think it’s pretentious to call it a saddle. Personally I don’t care what you call it as long as you don’t correct other people. In any case this is most definitely not a saddle post, it’s a seat post, and it’s held on to your bike with a seat post clamp, or collar. These days a lot of seat posts can be adjusted on the fly. Those are called dropper posts.

So I just named well over 50 parts of a mountain bike, but all of these parts can be broken down into hundreds more. So, put those terms down in the comments, and if you’re really bored see if you can come up with an exact count of the terms I used in this video. Also, tell me how you pronounce derailleur. Are you one of those people who say “derailleeyur?”. In any case thanks for riding with me today, I’ll see you next time.


  1. Bustin Brown on June 25, 2019 at 6:57 pm

    Anybody else look in the chat just to see who made a nipple joke?

  2. Lincoln Barbagallo on June 25, 2019 at 6:58 pm

    1:22 No god please no no noooooooooo

  3. Ramón García on June 25, 2019 at 6:59 pm

    I say desviador and i keep being "corrected" by other spanish speakers who call it derraileur because of reasons (?)

  4. Humongous Chungus on June 25, 2019 at 7:02 pm

    Thanks for your vids you taught me how to mtb! Keep up with the great work

  5. Jack Vinje on June 25, 2019 at 7:03 pm

    And all these parts are collectively known as the “mountain bike”

  6. peter MacKenzie on June 25, 2019 at 7:04 pm

    1:46 I just died…

  7. bannanas lego technic workshop on June 25, 2019 at 7:05 pm

    I say derailiur (say it phonetically)

  8. MILLS T.V on June 25, 2019 at 7:07 pm

    Can you say the use?

  9. Finn Overton on June 25, 2019 at 7:08 pm

    thanks seth!

  10. Blinky on June 25, 2019 at 7:08 pm

    I want to make my drivetrain 1×8 what derailiur should i use and what chain ring

  11. Marshall David WahlstromHelgren on June 25, 2019 at 7:09 pm

    I pronounce it De-raill-eur it’s French actually and I Use The “u” letter spelling. I always make sure I pronounce the u letter with a French accent.

  12. LIVE to RIDE on June 25, 2019 at 7:11 pm

    Thank you Seth I needed this video.

  13. Basty Mahipus on June 25, 2019 at 7:11 pm

    I keep pronouncing derailleur wrong I keep saying derairrur

  14. Kyle Araullo on June 25, 2019 at 7:12 pm

    24 years of my life and I only knew now what that big round thing was called. Much thanks, Seth.

  15. Eyes On the horizon on June 25, 2019 at 7:13 pm

    A lot of us say de rail e er here in England

  16. Riley Carter on June 25, 2019 at 7:14 pm

    Look this is how you say derailer de re le er of le movie chain thingy of of of casset to a new sprocket thing of migiger

  17. Nathan Zari on June 25, 2019 at 7:14 pm

    1:45 WOW I HAD NO IDEA!

  18. Angelica Maravilla on June 25, 2019 at 7:16 pm

    this big round thing is called a wheel

  19. Jakob Krellner on June 25, 2019 at 7:16 pm

    4:47 I say "Gangschaltung" 😂

  20. Mr.Chief Loafer on June 25, 2019 at 7:20 pm

    Breast nipples?

  21. Turtlecuber on June 25, 2019 at 7:21 pm

    De rail er

  22. Daniel Ignacio Cabrera Villarroel on June 25, 2019 at 7:22 pm

    Pata de cambios 🙂

  23. Ville Lahtinen on June 25, 2019 at 7:22 pm

    I love nipples, and dont mean my bike nipples 😊😂

  24. Reese K-S on June 25, 2019 at 7:26 pm

    I got 58

  25. gunnar j on June 25, 2019 at 7:27 pm

    I counted 78 I think

  26. Albon on June 25, 2019 at 7:28 pm

    great for learning some vocabulary in english for me as a non native speaker

  27. Haydnbrook 03 on June 25, 2019 at 7:29 pm


  28. Nathan Sharp on June 25, 2019 at 7:32 pm

    This is a really good video! My sister just got her first real mountain bike and asked me to teach her this stuff.

    One huge thing you didn’t spend enough time on was the wheel.

    Wheel: made of a rim, hub, spokes, nipples, and sometimes eyelets between the nipples and spokes; An inner tube (unless tubeless) is inside the tire that is attached to the wheel. Inside the tire there can be gooey stuff whether running a tube or not. Air is put into the tire using the valve stem. The wheel is held onto the bike with nuts, a skewer, or a through-axle. Some skewers and through-axles are quick release. The hub consists of an (actual) axle (in addition to a through-axle or quick release skewer) and bearings that allow the hub shell that – has holes in the flanges (to accommodate the spokes)- to spin freely upon. The rim may have a braking surface for the brake pads, or the hub body may have a way to attach a brake rotor (splined [like a cassette] or bolted). The wheel is attached to the bicycle via the dropouts on the frame and fork. And there’s also rim-strip that goes between the rim and tire that generally protects a tube from getting cut on the holes drilled into the rim to accommodate the spokes and nipples. An adhesive rim-strip is commonly used to seal similar holes for tubeless tire setups.

    Tire: The rubber part that attaches to the wheel and should be the only part of a bike that touches the ground. It has treads (lugs) on a flexible sidewall that use two beads to clinch onto the rim (on mountain bikes). A tube is commonly found inside the tire unless running tubeless.

    Bicycle tire sizes: JUST KIDDING!! and it’s spelled tyre, and pronounce ‘Derail-your!!’

    NOW DO FORKS – I need a refresher there!! …elastomers…🤣

  29. Keith Thorne on June 25, 2019 at 7:34 pm

    It’s clearly a stool

  30. Zild Benitez on June 25, 2019 at 7:34 pm

    What are those 2 black round stuff?

  31. Bite of the Bleeding Hollow on June 25, 2019 at 7:35 pm

    It’s not called a seat or saddle it’s called a butt stool

  32. trouble_shoot on June 25, 2019 at 7:37 pm

    USA= Inner Tube
    PHILIPPINES = Interyol

  33. Mason Howell on June 25, 2019 at 7:37 pm

    i think that was a little more than 50

  34. calum Tchakmakdjian on June 25, 2019 at 7:37 pm

    De rail er

  35. Murugan Sathya on June 25, 2019 at 7:40 pm

    bro i am your new subscriber please show me a video of how to clean the rust

  36. callum arden on June 25, 2019 at 7:41 pm

    Yes I say dur…rel…ee…ur

  37. Nathan Sharp on June 25, 2019 at 7:41 pm

    1:19 Rental Bikes: Sometimes a great purchase for a huge discount at the end of the season – sometimes not so much.

    …but why would a rental have wheel reflectors??? …town cruising and lawyers I guess.

  38. Rinyotsu on June 25, 2019 at 7:41 pm

    Um, the correct name for the seat is "butt holder".

  39. Cooper Williams on June 25, 2019 at 7:41 pm

    What was your first bike

  40. Wizdomtrek on June 25, 2019 at 7:42 pm

    Wish I had this at the very outset, very helpful!

  41. dec lunt on June 25, 2019 at 7:42 pm

    Reminded me off plane staff the exits are hear and hear

  42. Jaden Clemow on June 25, 2019 at 7:42 pm

    56 parts

  43. waquzy on June 25, 2019 at 7:43 pm

    Excellent video

  44. musicsuxnowadays on June 25, 2019 at 7:46 pm

    are you supposed to grease/oil the crank set at all? Mine has a loud POPPING noise when i pedal.

  45. Budgie Vlogs on June 25, 2019 at 7:49 pm

    Lol today my friends derailluer hanger broke and we were lazy and didnt want to spend 25 dollars so we fixed it up with lots of duct tape and zip ties. The wheel fits nicely and is secure. Is this safe?

  46. Frank The Rabbit on June 25, 2019 at 7:50 pm

    Mmmmmm nipples

  47. Osiris Virus on June 25, 2019 at 7:51 pm

    This thing,that thing what ever the fuck that’s called…i don’t know what that is but it does this…spot on!!!!!

  48. Richard Sleeve on June 25, 2019 at 7:52 pm

    I was shocked to learn I knew them all…

  49. Owen Wilcox on June 25, 2019 at 7:53 pm


  50. Xavi Neira on June 25, 2019 at 7:56 pm

    I’m enjoying these videos from you and others on bikes.