MTB, the revolution of the weird stem thing could change MTBing ?

[weeksy]

I know Hattie our mate has moved to this setup as well, on her gearbox DH bike.... Mostly as her team boss ex-world champ Reece Wilson went to it first and Hattie seems to love it...

I need more info/knowledge on reach and height really before unleashing this on the boy fully.... but it's an interesting start of a debate that's for sure.

[Mr Moofo]

Stick more spacer under the current stem, and turn the stem round 180 degrees and see what it feels like

[weeksy]

Stick more spacer under the current stem, and turn the stem round 180 degrees and see what it feels like

Not enough clearance/steerer on the current forks to do that, i could raise it maybe 10mm, but the bars are something like 60-70mm raised, which isn't viable without changing a lot more.

[Mr Moofo]

Stick more spacer under the current stem, and turn the stem round 180 degrees and see what it feels like

Not enough clearance/steerer on the current forks to do that, i could raise it maybe 10mm, but the bars are something like 60-70mm raised, which isn't viable without changing a lot more.

Need a new bike !
He doesn't really come up with a valid reason why it is better, other that "they do it like that in motorcross"

[mboy]

I know Chris Porter was messing around with zero extension stems a decade or so ago and Mondraker had the 10mm stem probably 12-13yrs ago… Neither stuck… And IMO there’s a good reason…

Everything is a compromise. On an MX bike you’ve got a LOT more weight over the front wheel at all times, purely just cos of the weight of the bike. With MTB, the rider is a much bigger percentage of the overall system weight (typically 75-85% of it compared to 35-50% on an MX bike) and thus has a lot more influence over the handling characteristics of the bike by shifting their weight around than they do on an MX bike… And obviously road motorcycles (many of which will have the bars mounted some way behind the steering axis!) even less so…

Anyway… When the bike handling is more reliant on rider input then you simply can’t have the front wheel too far out in front, thus making it too hard to weight… We have seen the Long Low Slack geometry of many brands actually become slightly more conservative because of this, and knowing Chris Porter as I do, his own setups are quite a bit more conservative than they were even only 5yrs ago (G1 head angle is now 1deg steeper on V2 model, shorter reaches too) and he typically runs a 35mm stem iirc.

If you put the front wheel out a long way in front of you, the bike will be inherently stable but the rearward weight bias will negatively affect the handling. So there seems to be a sweet spot for most Enduro MTB geometry these days, the Goldilocks porridge setup of long enough but not too long etc and around a 30-40mm stem (because if you take the length out of the stem and put it in the TT, the wheel is so much harder to weight dynamically)…

The other thing to consider is how an mtb handles vs how motorcycles handle. Motorcycles have much bigger tyre widths, and they’re much taller in the middle than they are on the sides… A motorcycle isn’t steered (once past walking pace) so much as leant over… Now obviously the same is true for a bicycle, but the speed at which you’re still steering it rather than leaning it is relatively higher (compared to its maximum speed you will travel on it) than it is with the motorcycle. Combined with tyres that don’t “fall” onto the sides when leant, and you have to actively steer a bicycle a bit more than you do a motorcycle, and as such, a bit of forward extension on the stem helps in this respect, at least in the slower tighter sections of the trail…

Now why the sudden resurgence in zero reach (or even negative reach) stems again…?

Fashion!

They run it in MX innit…

There are less downsides on a bike that is purely going downhill as opposed to one that’s being ridden uphill too, and in combination with taller bars it means the rider gets a more upright stance when descending and is still able to weight the front wheel appropriately (albeit the front wheel is now about 6-8” further from your hands than it was, so handling will feel vague)… Also for someone like Hattie Harnden, who is tall but she’s all leg, no torso, modern long reach bikes weren’t designed for her anyway so there’ll be a small matter of “what works for the individual” coming in to play here too…

For the rest of us…? Would I advise experimenting with bar height, stem lengths, number of spacers under the stem…? Yes, absolutely… I have many times over the years… But I have found what feels comfortable and works for me, and it’s not having the bars up under my chin on a bike that I need to ride up hill and down dale… Doesn't mean I won’t experiment more still going forward (about to chuck some 38mm rise bars on my eMTB to replace the 25’s in fact, but might also drop a few mm of spacers at the same time to counter the increase a little), but not too radically…

Follow the science… NOT the marketing hype…

[weeksy]

I know Chris Porter was messing around with zero extension stems a decade or so ago and Mondraker had the 10mm stem probably 12-13yrs ago… Neither stuck… And IMO there’s a good reason…

Everything is a compromise. On an MX bike you’ve got a LOT more weight over the front wheel at all times, purely just cos of the weight of the bike. With MTB, the rider is a much bigger percentage of the overall system weight (typically 75-85% of it compared to 35-50% on an MX bike) and thus has a lot more influence over the handling characteristics of the bike by shifting their weight around than they do on an MX bike… And obviously road motorcycles (many of which will have the bars mounted some way behind the steering axis!) even less so…

Anyway… When the bike handling is more reliant on rider input then you simply can’t have the front wheel too far out in front, thus making it too hard to weight… We have seen the Long Low Slack geometry of many brands actually become slightly more conservative because of this, and knowing Chris Porter as I do, his own setups are quite a bit more conservative than they were even only 5yrs ago (G1 head angle is now 1deg steeper on V2 model, shorter reaches too) and he typically runs a 35mm stem iirc.

If you put the front wheel out a long way in front of you, the bike will be inherently stable but the rearward weight bias will negatively affect the handling. So there seems to be a sweet spot for most Enduro MTB geometry these days, the Goldilocks porridge setup of long enough but not too long etc and around a 30-40mm stem (because if you take the length out of the stem and put it in the TT, the wheel is so much harder to weight dynamically)…

The other thing to consider is how an mtb handles vs how motorcycles handle. Motorcycles have much bigger tyre widths, and they’re much taller in the middle than they are on the sides… A motorcycle isn’t steered (once past walking pace) so much as leant over… Now obviously the same is true for a bicycle, but the speed at which you’re still steering it rather than leaning it is relatively higher (compared to its maximum speed you will travel on it) than it is with the motorcycle. Combined with tyres that don’t “fall” onto the sides when leant, and you have to actively steer a bicycle a bit more than you do a motorcycle, and as such, a bit of forward extension on the stem helps in this respect, at least in the slower tighter sections of the trail…

Now why the sudden resurgence in zero reach (or even negative reach) stems again…?

Fashion!

They run it in MX innit…

There are less downsides on a bike that is purely going downhill as opposed to one that’s being ridden uphill too, and in combination with taller bars it means the rider gets a more upright stance when descending and is still able to weight the front wheel appropriately (albeit the front wheel is now about 6-8” further from your hands than it was, so handling will feel vague)… Also for someone like Hattie Harnden, who is tall but she’s all leg, no torso, modern long reach bikes weren’t designed for her anyway so there’ll be a small matter of “what works for the individual” coming in to play here too…

For the rest of us…? Would I advise experimenting with bar height, stem lengths, number of spacers under the stem…? Yes, absolutely… I have many times over the years… But I have found what feels comfortable and works for me, and it’s not having the bars up under my chin on a bike that I need to ride up hill and down dale… Doesn't mean I won’t experiment more still going forward (about to chuck some 38mm rise bars on my eMTB to replace the 25’s in fact, but might also drop a few mm of spacers at the same time to counter the increase a little), but not too radically…

Follow the science… NOT the marketing hype…

Not sure about some of that mate, there's enough people i know and trust as riders who are now running them to make me think "maybe" at the very least. I don't think the AON guys would run this setup purely for fashion or sponsorship with so much on the line in terms of WC qualification and results.
I do know though of some riders at a high level who've tried this and not exactly gelled with it, but some have. So it is of course as with everything, completely subjective.

I'm certainly not against the idea of throwing a set on the Atherton should some come up for testing.

We are waiting for a set of DMR 65mm rise at the moment which will be going on for some timed runs and testing to see if the boy prefers that...

[mboy]

Not sure about some of that mate, there's enough people i know and trust as riders who are now running them to make me think "maybe" at the very least. I don't think the AON guys would run this setup purely for fashion or sponsorship with so much on the line in terms of WC qualification and results.
I do know though of some riders at a high level who've tried this and not exactly gelled with it, but some have. So it is of course as with everything, completely subjective.

I'm certainly not against the idea of throwing a set on the Atherton should some come up for testing.

We are waiting for a set of DMR 65mm rise at the moment which will be going on for some timed runs and testing to see if the boy prefers that...

In a world full of racers all looking for an edge, but many of them not been racing long enough to have either seen the full moto setup last time it was on the scene or to have tried it themselves... Of course they're going to try it! And no doubt some will prefer it... Hattie Harnden does well on it, but like I said, she's like 5ft9 or so but has crazy long legs, almost no torso... So modern long reach bikes don't suit her anyway...

Everything has to go too far, before it can come back to the "goldilocks" just right setup... The moto setup rears its head again every 7-10yrs, a couple of people go quicker on it, most don't... It dies away again...

Trust me... If CP abandoned it then it ain't sticking... Cos if ANYONE is pro adopting lessons from MX and making it stick in the MTB world, it's him...

There's more about why super short stems don't work for most people for the most part in here... (well worth watching the whole thing if you have the time)...



Anyway... Like I said... The MORE you go downhill, and the more naturally stable the bike is, the more a zero reach bar setup and high rise bars make sense... For the average person riding up and down, just makes no sense at all, especially given the extra steering twitchiness it brings...

[weeksy]

In fairness, i have certainly never considered it on anything less than a DH setup, from a pedal perspective I don't really have a slight clue whether it'd work or not. But it's not a consideration for me, so out of the discussion.

We'll see how well Hattie is going on it in just under 2 weeks at BPW

[mboy]

Doddy just posted about it on Insta funnily enough…

I know CP well and have spoken at length with him about the work he was doing with Fabian Barel & Cesar Rojo developing the geometry on those Mondrakers back in the day… If it was going to have stuck, then it would have stuck by now… And like I say, even Chris has reverted to a 35mm stem these days iirc.

[weeksy]

If it was going to have stuck, then it would have stuck by now… And like I say, even Chris has reverted to a 35mm stem these days iirc.

Time will tell about that, some things don't take straight away potentially and frame geometry has possibly changed enough that bikes are now more suited to this than previously ? Might be that tracks suit it better than they used to now.

I know of some Pros who've tested it and some have got on OK on steep tracks and some less so on flatter tracks... maybe it's something that riders won't run everywhere.. ?

Don't forget, Bemore are not the only company working on this setup style, there's a few out there.

I'm not sure we'll ever get to try one in anger... but that doesn't mean i'm not curious about it.

[Couchy]

It’s interesting to me as my background is motorbikes, but in mx the riders seat allows them to get almost sat on top of the forks which at times they need front end feel and weight enables them to offset this setup. How does a mtb rider get that much of their weight forward. I guess for the steepest downhill it could have a benefit but that’s probably for the quickest riders in the world but once not pointing downhill I guess it’s not as good. I fully expect to see it locally on what is basically xc courses soon

[mboy]

Time will tell about that, some things don't take straight away potentially and frame geometry has possibly changed enough that bikes are now more suited to this than previously ? Might be that tracks suit it better than they used to now.

Wanna put your money where your mouth is...?

I'll bet you a 4 bed house in the Forest of Dean!

There are and always will be rare, individual cases, particularly on super steep tracks, where zero extension or super short stem and high rise bars will be mildly beneficial... But those situations will be so few and far between, to effectively render it irrelevant.

The only possible caveat here would be if eMTB racing gets the go ahead again, with new rules around motors and batteries, and bike power outputs, battery capacity and overall weights of the things sky rocket upwards, bringing them much closer to electric MX bikes...

[weeksy]

Wanna put your money where your mouth is...?

I'll bet you a 4 bed house in the Forest of Dean!

NEither of us own a 4 bed house in FoD

I've got no skin in this game, i'm just a curious outsider looking in and guessing. It makes sod all difference either way to me though