Mountain Bike Set Up Explained: Handlebars, Stems And Seatposts
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Mountain Bike Set Up Explained: Handlebars, Stems And Seatposts

October 21, 2019


– Whilst there are many
different types of mountain bikes designed for different types of riding, the components you choose
to put on your bike actually make a big difference
to how that bike rides. So, in this video we’ll take a look at tailoring your bike to you, the type of riding you do, by choosing the correct
bar, stem, and seat post. (electronic music) So, first let’s start with handlebars. Here we’ve got a cross country 29er, carbon fibre, super lightweight bike. And here we’ve got a
long travel trail bike, or an enduro bike. So, on the more aggressive
style of riding, bar’s definitely wider. With downhill, for years
people went wider and wider in search of more control,
up to about 800 millimetres. The PRO Tharsis trail bars actually do come in at 800 mils. Personally, I like to ride
on a slightly narrower bar, so down to about 760 for downhill, and 750 for trail riding. It does come down to
my personal preference, also sort of shoulder width
will make a big difference to how comfortable you
feel with wider bars. You’ll also see that on these trail bars do have some rise to these bar, so that’s 20 millimetres, compared to the cross country bars with a much more flat, there’s
a five mil rise on those. That’s all about bringing the weight further back on the bike. And I’ll talk a bit more
about bar height in a minute. Something else you don’t actually see is inside these bars is more carbon layout to make them a stronger bar. Moving back to the cross country bike, this has actually got a
five mil rise on this bar, and this is the PRO
Tharsis cross country bar. This is 720 millimetres wide, but they are available in 740 and 700. So, for cross country, sort of the ride characteristics
matter a little bit less. There’s less technical riding, and the weight saving
is much more important. So, these are a lighter bar. So, both of these handlebars are 31.8 millimetres diameter, which I think it’s fair to say that’s the most common standard
you’ll find now on bars compared to the older 25.4 and the newer 35 millimetre bars. That’s all about trying
to get the correct balance between strength and flex in those bars. It’s fair to say that the thinner walled larger diameter bars are stronger, from an engineering standpoint. So, picking the right rise bars and setting your bar
height is really important to the ride characteristics of your bike. You see on the cross country bike, it’s much lower, slightly accentuated because the ground’s not level. But you can just compare the two there. That really brings the weight further forward on a cross country bike, where you spend much more time climbing and you need to keep that
weight on the front wheel. So, picking the right rise
bar makes a big difference if you’ve got five mil
compared to 20 mil here. But that’s not the be all and end all, you can still play around with spacers underneath the stem. On my trail bike here I’ve probably got 25 mils worth of spacers
underneath that stem to bring the bars up. On the cross country bike I
guess that’s more like 10. I’ve also got one on the top so I can play around
moving them up and down, trying to really find
that correct bar height. Something like the trail bike, if I’m going and riding
a lot of downhill on it, maybe going to the Alps for a week, again, I could put even more
spacers underneath that stem just to bring that weight that little bit further back on the bike. Okay, so stem length works with your bar height and width to set your hand position on the bike, and as a general rule the longer stems are gonna suit cross country better to bring that weight further forward so it’s balanced more
neutrally on the bike for going up and down hills. This is a PRO Tharsis 90 mil stem with a minus six degree angle, so again that brings the bar down. That’s available in 10 millimetre jumps from 80 up to 120. That’s all about perfecting the reach. That also, obviously, works
with your frame size as well. Bigger frames, you
might actually wanna run a shorter stem to get that
bar positioned correctly. Moving on to the trail bike. The average, I would say,
is probably 50 millimetres for downhill and enduro,
long travel trail bikes. This is actually a 45 mil stem, and that’s available in 35 and 55. Really, those shorter stems make it a much more direct,
quicker steering bike. You just sort of turn your hands and the bars really move. With a cross country stem it does feel like your bars
swing round that bit more. So, in conclusion on the stem lengths, the longer stem gives you a
much roomier bike, generally, which makes it more comfortable to pedal for long periods of time, and also keeps that weight on
that front tyre for climbing, whereas the shorter stem gives you a much more responsive ride, and also brings that weight
back further on the bike. Great for going downhill. So, you can see on the cross country bike with the long stem and the low bars, the centre of gravity is really in the middle of the bike. That can be moved forward or rear depending on the trail. Whilst on the enduro bike
with the 45 millimetre stem, while seated, again, the centre of gravity is pretty central to
the middle of the bike. But when you start riding
into the downhills, it’s much easier to get
to the back of the bike, and all that is doing
is really maintaining that centre of gravity in
the middle of the bike. As the front wheel drops you
need to move your hips back just to compensate. Now, the final piece of the puzzle when it comes to rider
position on the bike is the saddle position, and that is determined by the seat post. Now, for the most part, most cross country riders
still use fixed seat posts like this PRO Tharsis carbon post here. And the saddle height is set for the greatest pedalling efficiency. It does affect comfort, though, and does make it much harder
to move around on the bike, especially over the rear for descending. You can move that saddle front or rear, sliding the rails along
in that post for comfort. So, less reach or more reach. Whilst fixed seat posts are light, very light in the case
of this carbon fibre one coming in at 199 grammes, the disadvantages are, of course, when you move around on the bike. But for many cross country riders where downhill speed isn’t
the be all and end all, they will take that compromise. But, for many trail riders
they love the option of dropper seat post like this
PRO Koryak dropper seat post. 120 millimetres of infinite adjust travel. The maximum height is
obviously set the same, so for pedalling efficiency, then you’ve got the option to drop all the way into that post. Quite often it’s nice
just to drop a little bit so you can pedal still pretty efficiently and you can get up and
move around on the bike when you need to, and then drop the full 120
for a downhill section. It’s got internally
rooted as most frames now are set up to do, so it
keeps it nice and neat. But the payoff is this seat post weighs about 300 grammes more. Okay, so whilst there are obvious trends for, say, cross country versus enduro, long stems, short stems, it’s definitely always
worth thinking about trying to tailor that bike perfectly. So, like we said there are stem options and bar options, in all sorts of different varieties, and you try and get that bike
set up perfectly for you. If you wanna see more videos
click on the GMBN logo to subscribe if you haven’t done already. And for a couple of really similar videos click up there for how to
adjust your bar height, and down there for stem length explained. Give us thumbs up if you liked this video.

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  1. This is the earliest I've ever been. I'm trying to get a few hits on my channel. I'm neither great or rubbish so I don't stand out . I'm hoping to get to a point to advertise to raise funds for Bikeness trips parts the running costs etc. It's something we all could do . Thanks bike comRADS 😀🇬🇧

  2. As much as I love you guys you seem to act like Scotty was never on GMBN, just mention him a few times with what he's done if u go to a place or add a clip of him in or something.

  3. I thought lower bars (no spacers) was better for downhill/more aggressive riding? Rather than having spacers and getting the bars higher

  4. I just realized that your bikes had their brake routing switched. Means you guys got left for rear, and right for front brakes.
    Almost all bikes I saw have left/front and right/back routing out of the box/shop.
    I changed my routing as well, but only because I'm left-handed and find it more convenient to use the rear brake while one handed riding.

  5. #AskGmbn Can you use ski goggles when racing Downhill and what's the difference between ski and mtb goggles?

  6. 300 g is .66 lbs heavier. I think the advantages of a dropper post far outweigh less than one pound. I'm surprised more XC riders don't use them. Especially since seeing the comparisons where it is faster anyway.

  7. I have a neck brace and it keeps sliding forward on steep parts on trails and the back of my helmet keeps on hitting my neck brace does anyone know how to stop the problem ?

  8. I would love a 50mm stem and 785mm bars but that would cost me around NZ$130 which as a student I simply can't afford. 🙁

  9. Nice video. Btw it seems that my xc Giant Yukon is absolute contraption. I have recently applied PRO Koryak 80 mm stem with Mortop 785 mm wide and 23 mm rise handlebars. But actually it seems ok to me, when compared to original setup – 620 mm bars with 110 mm stem. It climbs surprisingly well. Neither do I suffer rear wheel spin nor my front wheel looses contact with the ground. Confidence during descends is far better.

  10. I wish bikes were more adjustable without buying new parts! For example, a telescopic stem would be pretty sick if it could be made stiff enough

  11. I put SR Suntour Auron 160mm Enduro forks at the front on my Hardtail-XC Bike…. And just to add 203mm Dics Zee 4-Pot brakes, and 180mm rear 4-Pot aswell. 2.4" tires just to finish it off. Heheh pretty good setup I think.

  12. #askgmbn can i put higher seatpost, shorter or longer stem with more rise to compesate slightly smaller frame for my height

  13. #askgmbn wondering what you think about the pedaling innovations catalyst pedal?? the scientific studies, and reasons behind it. flat pedal game changer maybe, but someting i think your should review.

  14. Great explanation of the comparison between one and the other. Really helps grasp the dynamics when looking to upgrade components Handlebars, when there are so many options out there and how they'll affect a rider.

  15. I always thought that the saddle front-rear adjusting should be done to optimise the peddaling position, not for the reach adjustment. The change in reach is more of a side effect.

  16. How about a comparison of straight, upsweep and backsweep bars? Proper backsweep, that is 15+ degree? Compare for comfort / ergonomics and handling.

  17. Would using a shorter stem help me with my hands going numb? moving my center of gravity back over the seat more instead of over the bars?

  18. OMG! REALLY? Does a 5mm rise in the handlebar, or a 10mm rise on the stem really matter when the rider's body moves at a sloppy 200-300mm and more in all directions while riding? Let's leave precision to the robots and basic comfort to the cyclists, at which the only critical adjustment is the seat height & angle.
    Pro bikers crack me up as much as a salesman trying to sell me a $100 6-foot Monster brand HDMI cable to go with my $75 Sony bluray DVD player. The video quality doesn't even start to degrade until 15-feet out! Lol

  19. I have a hardtail with 130mm of travele a 30mm stem 780 by 35mm bars 3 stem spacers and a reallt short chainsaty and my god it flys of everything its the best bike ive ever rode absulute wepon up and down

  20. I have XL size bike frame and about 25 mm spacers under stem, stem is 60mm long with +35 degree angle and bars has 40 mm rise and still my seat is slightly higher than bars when on flat ground, that's what you get when you are 6'6" tall.

  21. So I'm 5'11 and have a 19.5 inch trek, I do mostly flat riding with some occasional climbing and downhill what would be a good set up for me

  22. So I’m 5”11 but I don’t have enough money for a large frame yet and I’ve found some sweet deals on medium frame dh bikes would it matter for me what size I get

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