As in 65-85 instead of 35mm.
Would this encourage weight on front style riding and/or facilitate steep techy climby stuff?
Personal prefs and fit aside, is it just a bad idea?
Anyone dabbled?
It would slow down the steering for sure. Just added a XC bike with 70mm stem to the fleet and had forgotten how much difference a longer stem makes to the handling (in a good way for it's intended use). I imagine the rest of the geometry figures will have more of an effect over where you sit on the bike though?
Yes but on tech climbs and descents you will be mostly standing.
Wouldn’t it be a contradiction in terms?
Part of the point of longer, lower, slacker is to lengthen wheelbase to improve stability.
Shortening the stem compensates for that by speeding up steering.
Lengthening the stem would make it less manoeuvrable, and inevitably lead to a shorter wheelbase, so impacting stability and undoing some of the benefits.
Yes, I swapped to a 70mm stem on my Scandal which is currently rocking a 65.something head angle, the stock size was 45mm.
It's a big improvement IMO. The difference in steering feel is marginal, certainly within the range of making not enough difference to be a negative. At the same time it's just enough of a change that it's stopped the front end from feeling like it was permanently on a knife edge of washing out.
I originally changed it as I was finding the bike just didn't work with SPD's and suspected it might be something to do with the weight distribution being slightly different. It worked, and I've not bothered to swap back with the pedals.
IMO/IME bike geometry exists within an envelope, within a range everything seems to work and only makes minor differences to the overall. Beyond that things get bad quickly. E.g swapping a 110mm stem on an old-school XC bike for a 90mm makes a slight difference, swapping to a 60mm makes the bike almost unrideable. Same on my gravel/CX bike. I put some nice wide flared fashionable bars on it, and raised them a few spacers and it ruined the bike entirely, lowering the bars to a more normal/racey height restored it, lowering them again didn't make much difference other than my elbows started to get a bit too straight. So based on that I think that:
a) Modern LLS bikes are often right at the edge of a workable envelope. Maybe if you tweak one number you can tweak another in a way to push it even further (lower and/or slacker and/or longer). Which is why some bikes can be slacker than others and still function. But on the whole the designer has hit some sort of limit where he cant lengthen/slacken/lower (or shorten the stem) any further without it going bad. Which means the counter is true, you can fit a layback seatpost and a longer stem and still be well within the workable range.
b) Different people, different envelopes. Some short-arse people can ride the aforementioned loaned Large 26" XC bike with 60m stem to fit them, off 6ft drops first time they ride it. Personally I thought it was trying to kill me just riding round the car park! A bit like droppers, I was an early adopter, al my MTB's have one, but TBH I don't miss it on some bikes, 20 years of muscle memory learnt from shifting weight around above the saddle rather than above the back wheel.
I don't see how. The closer a contact point is to your centre of mass, the easier it is to apply a force to it.
Makes sense, but if you move your centre of mass an inch or 2 forwards it would be no different and your centre of mass relative to everything else will have shifted.
Perhaps, though I don't see how the stem being further forward forces your centre of mass to move forward in any significant way. With the bars closer, you can more easily go deeper into the 'attack' position. Moving the bars further away makes it harder, and is more likely to result in just having straighter arms.
As most weight goes through the pedals anyway, bikes really should have been increasing chainstay length to compensate for longer front centres, but it's taken a while for that to catch on. At least we've moved away from articles asking for longer reaches when front end grip is a problem.
Tried a 50mm stem on my Whyte that came with a 35mm. Immediately hated it a took it off after one lap. Thankfully I’d taken the 35 with me just in case. Steering felt horrible and front wanted to run wide on every corner. I felt I couldn’t weight the front wheel like before. This was uphill as well as down.
Seems to be some webtalk about stem length being matched to fork offset leading to best handling?
I have a 50 stem and a 46mm offset, probably just going to muck around in both directions and see what I like.
for me, anything slacker than 67deg with anything longer than 60mm started to feel floppy, like the wheel just wants to flop from side to side.
I had a 60mm on my XL hello Dave, because that's what I had in the spares box when I built it up.
Its better with the 35mm stem that's on it now.
Its the best climbing bike I've had. Compared to Cannondale scalpel, cove stiffee, orange segment on the past and the geometron g13 I have now. The hello Dave gets up a particular steep slippy short punchy climb I can't get up on anything else.
It wasn't any better uphill with the longer stem and it is (unsurprisingly) better with the 35mm stem going DH.
With a slack head angle and a long stem your bike will certainly look pleased to see you
Lengthening the stem would make it less manoeuvrable, and inevitably lead to a shorter wheelbase, so impacting stability and undoing some of the benefits.
i must be missing something
The wheel base gets shorter?
TBH, I thought it would look a bit rubbish, but it looks ok ^^^
So stuck on a 75 eventually and its been ace. I find it easier to hop and manual and it does not feel like a floppy shopping trolley surprisingly.? it felt like it used to understeer with the 50mm stem now it corners like on rails..tighten the line mid turn till the front starts to wander then the back starts to kick out, brraaaapp. 🙂 YMMV but it suits my outdated riding style it seems!
/ridingodmode.
From a neutral riding position seated the bars now appear just behind the front axle rather than over the crown.
I've swapped from a 35 to a 42.5mm and it is a lot better.
I run a 70mm on my stooge dirtbomb , which is fairly long & slack. Ie just prefer the slower steering and more weight on the front overall. Might give it a go with a shorter stem when the chunky 3" minion DHF goes on the front for muddy winter fun
Seems to be some webtalk about stem length being matched to fork offset leading to best handling?
the back sweep of the bars will place your hands behind the the centre of the stem’s bar clamp, so your hands are never in line with the fork offset.
peter verdone did some calculations and talked about the impact of stem length on various aspects of bike handling. they suggested that the impacts were/would be/should be minimal.
thats instagram obviously. it may be on his website
@paule Last time I rode minions in the mud ended riding what seemed to be a fatbike!, did not shed at all. minions in the dusty dry are great though.
the back sweep of the bars will place your hands behind the the centre of the stem’s bar clamp
Interesting, I tend to roll my bars forward quite far, thinking about it when I hold my arms out (with elbows slightly bent) and make a fist my knuckles seem to naturally line up with the index finger one closer than the pinky? Reverse sweep?
hmmm.
