Why the Front Derailleur is Still Better (for MTB)

welcome back to Berm Peak i'm Seth and today we're  going to be doing something a little different   but kind of the same we're going to be talking  about the benefits of the three-by drivetrain   now to those of you who watch the channel a lot  that's going to seem weird because oftentimes i'm   ripping these off of bikes because they're heavy  and difficult to use and difficult to maintain   and noisy and in a crash they become ninja stars  but we're gonna forget about all that stuff today   because actually I don't hate three buys they  have their place on certain bicycles oftentimes   they're more economical and there are certain  advantages that the one buy just cannot provide   now for those of you who don't really know what  i'm talking about let's clear it up real quick   this is a derailleur and this is a cassette  this cassette has seven gears on it as you shift   through those gears the bike either becomes easier  to pedal uphill or faster with each pedal stroke   this bike actually has a front derailleur and  three chain rings between those three chain rings   and this seven speed rear cassette the bike has  21 possible gears it's a 3x7 a 21 speed bike   now each of the cogs on this  seven speed cassette have teeth   on the smaller end we have 12 teeth  and on the larger end we have 28 teeth   this is a modern mountain bike cassette and it has  12 gears on the smallest end it's 10 teeth and on   the largest it's 50. this cassette has so much  range that we only need one gear up front this   is a one-by 12. so for the range of gears that  we use in mountain biking the one-by drivetrain   has become all but ubiquitous it's simpler it's  lighter it's more user friendly it doesn't become   a ninja star in a crash and it tends to run a  lot quieter but there are still mountain bikes   that come with three-by drivetrains and if you  have one you actually have some advantages over   people with a one-by and in the interest of  fairness we're going to discuss those today let's start with longevity if you have a  one-by drivetrain that ring up front is   always making contact with the chain on a three-by  you have three rings sharing the load of the chain   and so technically speaking they last longer but  it doesn't end there often times on a three-by you   have a smaller cassette with bigger gaps between  the gears and oftentimes those gears are bigger   and thicker so there are certain situations  where the cassette lasts longer and the chain   definitely lasts longer because it's a wider  heavier chain if you have a friend who races   enduro or xc often times you'll see them wearing  through drivetrain parts in one year even a season   whereas you'll find an old bike with a three-by  and all the original parts it was born with   are still on the bike let's also talk about cost  there's a reason why inexpensive bikes oftentimes   come with a three-by drivetrain they've been  making them for years and they can just poop   them out of a machine for next to nothing these  same drivetrains have been made for decades   and so through economies of scale companies can  get them for a few bucks a piece also the wider   cassettes on one-by drivetrains take more advanced  tooling to produce the gears are narrower and   closer together and any error in the manufacturing  process is going to have a bigger effect on how it   works so it actually is more expensive to make you  also need a narrower chain on a one-by drivetrain   and so it needs to be made from stronger material  in order to have a thin light chain that's   gonna be able to deal with those stresses it's  actually more expensive to make where let's say a   three-by eight or a three-by nine can just have a  big heavy chain that stands up to whatever abuse   you throw at it so for the range you get there  is a cost advantage to a three-by drivetrain another arguable sometimes advantage of  a three-by drivetrain is chain retention   I spoke to an engineer from a bike company  that was explaining to me why they put these   on inexpensive bikes and I was surprised to  find out it's for chain retention when you're   dealing with an inexpensive drivetrain  where the chain is flopping everywhere   there is an advantage to have the chain  going through a derailleur in the front   because that chain is now unable to pop completely  off the bike and so for a beginner that doesn't   necessarily know how to maintain their drivetrain  this ensures that the chain stays at least sort of   on the bike at all times so for companies trying  to make an inexpensive bike as safely as possible   the front derailleur has a dual  purpose range and chain retention the next advantage to a three-by drivetrain is my  personal favorite and what I think is objectively   the biggest thing you're losing by going one-by  and that is the ability to drop to a lower gear   by going to a smaller cog let me explain  why this is important i've mentioned in   past videos the terrible sounds your bike  makes when you try to shift gears under load this happens most often when you encounter a  punchy climb and you have to downshift in a   hurry on a one-by mountain bike your only option  is to shift to a bigger chainring in the back   to do this you have to be pedaling and  the chain has to climb to a bigger gear   the springs in your derailleur cage take up the  load as your chain climbs up the cassette if   you do this with pressure on the pedals it makes  horrible noises and happens often when you have to   change gears in an emergency that doesn't happen  on a three-by on a three-by drivetrain you can   drop the chain to a smaller gear at the click of  a button you are in a dramatically lower gear that   you can climb hills with there's no clanging or  grinding or anything it just shifts gears reliably   even if the drivetrain is under load now of  course you already have to be in the largest   or middle gear in order for this to work but  oftentimes if you were pedaling fast you are   and when one-by drivetrains first became popular  the curmudgeons in the comments section were   having a ball over this and there's really  nothing you can say because they're right so   riding a one-by drivetrain forces you to  change your habits a little bit because a   lot of people were relying on the fact that they  could drop into a low gear in one click of a   button on their three-by and a lot of people  don't want to let go of it because of that when any drivetrain is operating you have  your drive gear up front and then you have   your gear in the back ideally these gears are  completely in line with each other so that   the chain has an easier time making its way onto  the gear but on any system with a derailleur your   chain line is not always going to be straight  but this is more so on the more modern one-by   systems because you only have one gear up front  the chain has to move its way across the cassette   and be kind of torqued in one direction on a  three-by you can get your chain line straighter   now having a straighter chain line has a few  advantages it does oftentimes feel smoother it   technically puts less wear on the chain and  the teeth and in certain situations if you   use a three-by properly it is a reason why it  may last longer now the fact that chain lines   aren't always going to be straight has been  engineered into modern one-by systems but it's   still an objective reality that you can have a  straighter chain line on the older three-by system   so I have no proof of this but I suspect that some  people use the three buy as a marketing tool if   you're marketing a bike to a less experienced  buyer well more gears must be better to explain   to somebody why less gears might be better takes  a little bit of explaining you have to explain to   them about the reduction in clutter the ease  of use but to explain why 29 gears are better   or 24 gears or better well that's simple more is  better now let's forget about the fact that a lot   of these gears are practically unusable because of  cross chaining or that you're adding about a pound   of weight to the bike that doesn't matter when  you're trying to get the most features you can   for the smallest amount of money and so  especially in department stores you will see   marketing points on bikes and big letters 21 gears  24 gears they're trying to sell you on the fact   that the bike has more gears when more gears is  not necessarily what you want it's usable gears   it's not necessarily a bad thing since these  bikes would probably have those drivetrains in   the first place it just seems to be an unusual  marketing point that might actually work the final advantage to a three-by drivetrain  mainly applies to people who hate on anything new   back in the early 90s when suspension forks became  popular there were people who hated on them and   said they would never catch on same thing happened  with dropper posts and indeed it did happen   when one-by drivetrain started to become more  ubiquitous you're paying more for less gears chain   line where it is true that with the advantages  I gave you today you can be a more effective   curmudgeon as your riding buddies are crunching  their drivetrains before that punchy climb   you can scoot right past them drop a ring and tell  them they're stupid for having a one-by drivetrain   when i'm trying to ride as effectively as possible  I will definitely rely on my one-by it's just   better in so many different ways it's quieter it's  easier to use it's endless but sometimes I can   be a bit of a curmudgeon myself I like three-by  drivetrains the same way that people like stick   shifts in cars they're slower than new electronic  transmissions but they're fun when i'm riding my   vintage bike around that three-by drivetrain is a  novelty and I find it fun I use all the benefits   of it and enjoy them and embrace them I try to get  my chain line as straight as possible I use that   dropping into a smaller ring trick when a punchy  climb comes up and just like a stick shift on a   manual transmission car it makes me a little  bit nostalgic for when bikes were different   so if you still have a three-by drivetrain on  your bike remember that all the advantages I   listed today still hold true thanks for riding  with me today and I'll see you next time

Channel: Berm Peak Express

Views: 1,554,512

Keywords: do it yourself, diy, tools, home, backyard, mountain biking, cycling, outdoors

Id: v1MZkVJz90Q

Length: 10min 11sec (611 seconds)

Published: Sun Aug 29 2021