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Kulharin

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Discussion starter · #1 ·
I'm 5'10, 170 lbs... been riding a large anthem sx advance 2015 for 2 full seasons and enjoy the ride but decided to swap the 70mm stem for a 40mm... I thought it was a 60mm and I was looking to shave 20mm... my bad so I'm hoping I didn't go too far with the 30mm change.

With the 70mm stock stem I just didn't have a lot of confidence with steeper/technical descents, and uphill it was great so long as the ascents weren't too technical... during technical ascents I always felt when the dropper seat was raised I was putting my posture too far forward to reach forward and down for the bars, to the point where I felt I lacked control and at times I'd catch my front tire on rocks and roots during climbs... for road biking the forward/downward lean to reach even with a centered positioned seat was always a bit uncomfortable.

I do a mix of rural roads, classic xc and technical trail riding... never shuttled downhill riding. hoping this was a good move, but I'll get to find out soon enough.
 
Discussion starter · #4 ·
I tested it today on road and varying trails... Overall I'm very happy. I was pretty much in between an M and L size so went with the Large and this short stem has improved the bike for me. I feel more confident on dh sections, more comfortable on road sections and even the technical,uphill I find I can now leverage my body weight easier to get over or around obstacles, easier for me to keep the back wheel from skidding out and I'm not having to reach so far forward with the dropper post raised.
 
OK. Call me confused, but I don't get how shaving that 30mm off the stem length would make a lick of difference. Then I read more and got baffled why you ar riding down a steep technical decent with the dropper post raised? Why do you have a dropper post if you are not going to drop it to get it out of the way so when going down a steep technical decent you have un-obstructed ability to shift your ass end of your body a bit further backwards to put the required weight over the back wheel?

But if you find that it feels more comfortable for you, then bob is your uncle.
 
Discussion starter · #6 ·
OK. Call me confused, but I don't get how shaving that 30mm off the stem length would make a lick of difference. Then I read more and got baffled why you ar riding down a steep technical decent with the dropper post raised? Why do you have a dropper post if you are not going to drop it to get it out of the way so when going down a steep technical decent you have un-obstructed ability to shift your ass end of your body a bit further backwards to put the required weight over the back wheel?

But if you find that it feels more comfortable for you, then bob is your uncle.
Because I'm not having to reach forward 3 additional cm to grip the handle bars... and I stated it was technical ascents with the dropper post raised... as in going uphill.
 
going shorter than 60mm is not recommended on a bike with a rather steep 68.5° headangle
Why is that? I put a 50mm on my old 98 Kona Explosif with a rigid fork and don't see the downside.

If you like the 40 then ride it.
 
IMO, The point of stem length, bar width, and stack height is to find the most balanced position on your bike, for you personally.
It isn't about trends in stem length - it's about you and your specific bike, and finding that sweet spot for optimal control, balance, and comfort.

You want to be on the balancing point, where it is easy to shift enough weight onto the front for climbing and carving turns, and just as easy to shift weight far enough off the back for lifting the front wheel, etc. ... the sweet spot.

OP - those bikes came with 70mm stems, because they also came with narrower bars. If you're still using the stock bars, and you feel front wheel flop or twitchiness, then you may want to try some wider bars to accompany your shorter stem. The wider bar gives you more leverage, as the shorter stem quickens the steering.
 
Bike geometry 1.01:

A shorter stem makes steering faster as does a steeper headangle.

Coupling a slack headangle with a shorter stem makes a lot of sense on an Enduro or DH bike because while it help preventing going over the bars on steep descents the shorter stem equally quickens steering, it's a win win situation.

However the situation is a lot different on XC or Trailbikes which have a steeper headangle that already gives a quick steering response. The shorter stem will make the bike unnecessarily nervous and doesn't help on descents either as the steep headangle and thus twitchy handling is the main culprit here which only worsens with a shorter stem. A longer handlebar cannot compensate for that either, again people are confusing cockpit length (rider position) with steering response.
 
Discussion starter · #11 ·
here is the official 2018 stem length recommendation

35 DH
50mm Enduro
60mm AM
70mm XC

going shorter than 60mm is not recommended on a bike with a rather steep 68.5° headangle
No recommendation for Trail so obviously fake news.

And all I can tell you is, the bike for me now feels better with the 40mm then it did at 70mm. More comfortable and confident position for me where it was previously scary for downhill descents, uncomfortable for long road/path rides and awkwardly having to lean/reach too far forward during technical steep uphill that was causing my front tire to get caught up on obstacles while the rear tire would spin on occasionally.

Say what you will, but for ME the shorter stem is a noticeable improvement. As I said I'm an in between size between M & L; I went with a large and the only way I could comfortably reach the handle bars with the dropper post raised was to move the seat too far forward; otherwise I had to fully extend my arms and/or lean too far forward... and with the dropper post down on descents and my ass far back I couldn't grip the handles properly and was more so pressing my palms. So overall saving me 3cm of needless reach/lean gives me a more confident and comfortable ride overall.
 
I just haven't quicker steering to be an issue, and the old explosive has had stems from 135 down to 50mm.
 
Say what you will, but for ME the shorter stem is a noticeable improvement. As I said I'm an in between size between M & L; I went with a large and the only way I could comfortably reach the handle bars with the dropper post raised was to move the seat too far forward; otherwise I had to fully extend my arms and/or lean too far forward... and with the dropper post down on descents and my ass far back I couldn't grip the handles properly and was more so pressing my palms. So overall saving me 3cm of needless reach/lean gives me a more confident and comfortable ride overall.
Your issue wasn't the stem length, is the top tube length due to picking the large frame. Your description of your seat position in order to "reach" the bars tells the whole story, you're trying to make the bike fit you and that almost always end bad. Know very well what you describe because have done it, went from a 90 to a 70 on a large frame and everything just clicked (didn't had the saddle all the way in), looking back I was better off with the medium frame and the 90 stem, felt more connected on the medium, could handle it better and my jewels weren't in harms way.

Happy to hear that you like how it rides and feel capable riding it, that's what matters.
 
I went with a large and the only way I could comfortably reach the handle bars with the dropper post raised was to move the seat too far forward; otherwise I had to fully extend my arms and/or lean too far forward... and with the dropper post down on descents and my ass far back I couldn't grip the handles properly.
you obviously bought the wrong framesize. A shorter stem may shorten cockpit length and correct seating position but your wheel weight distribution will still be way off for everything but descents and that's the last thing you wanna go fast with a short stem + steep headangle combo as pointed out before.

Bottom line, you cannot make a frame smaller by just swapping out the stem, it's the whole package that counts especially as you'll need a wider handlebar to regain some lost steering stability which will once again offset most of the effective cockpit reach shortening.
 
Discussion starter · #15 ·
you obviously bought the wrong framesize. A shorter stem may shorten cockpit length and correct seating position but your wheel weight distribution will still be way off for everything but descents and that's the last thing you wanna go fast with a short stem + steep headangle combo as pointed out before.

Bottom line, you cannot make a frame smaller by just swapping out the stem, it's the whole package that counts especially as you'll need a wider handlebar which will once again offset most of the effective cockpit reach shortening.
Well the option was to either go too small, or too big... As I said I was in between the medium and large according to the sizing chart. Everyone I asked said to opt toward a something slightly too big over something too small.
 
Well the option was to either go too small, or too big... As I said I was in between the medium and large according to the sizing chart.
You're assuming you were in between sizes because of the sizing chart but your own description contradicts that.

Think about it, if it takes you a full 30mm shortening just to have a comfortable cockpit reach the Medium size would clearly be the better fit from the start. A 50-60mm stem with a slightly wider 760mm handlebar would be a great combo for a bike like the Anthem SX.
 
Multiple people recommended the Large over the Medium in a previous discussion when I explained the situation.

http://forums.mtbr.com/giant/where-can-i-find-advanced-anthem-sx-m-l-2015-a-992589.html
Did you test rode or at least sat on both sizes? When buying a bike at least sitting on them is crucial regardless of what the internet tells you, that way you know/feel which is right.

Do you have long legs and short torso? That may steer you towards a larger size causing the reach issue but again nothing we can do now 'cause you already have the bike.
 
Discussion starter · #19 ·
It's good to know for the future though as eventually I would like to buy a Trance. I still have a lot of fun on the Anthem SX even if it's been a tad on the large size for me. I've ridden on it 2 full years and have made it work for me... It's a just a matter of how I can make it work better.
 
I see some pretty out dated info here.

If you shorten stem and leave "narrow" bars steering gets more responsive. Same if you leave the stem and shorten the bars.

Shorten the stem and widen the bars, steering can remain the same.

These matters of telling this guy he's doing it wrong means YOUR doing it wrong. No 2 trails are ever the same. He made the change and likes it. If it works for him on his trails and style of riding then hes good to go.

Im between sizes amd I size up as well because shorter stem and wider bars works well for me. 60mm stem with stock 68.5deg hta (about 68 now as I went from a 120 to 130mm travel fork), but my bars are 780mm wide.

Stem length is one part of an entire picture. What fits is whats comfortable for the rider and that it handles as the prefer. Stem and bars does nothing but decide how far the wheel turns in relation to how far you move your arms.

PS: just more perspective. Rigid Fat bike with 71deg HTA. Also 60mm stem and 780 bars. Steering is plenty stable and no OTB concerns. Also quite comfortable for long rides.

Sent from my SM-G950U using Tapatalk
 
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