Weird Reversed Stem Geo / Chat

[BeMoreBikes]

Comments do say maybe he had issues because he hadn't set the sag correctly/softened the fork and pumped the shock up...

In the instructions included with the stem, I suggest 10% softer fork and front tire pressure and/or 10% firmer shock and rear tire pressure to start with. I even had one customer where I had to reduce his fork pressure by 50%, and after that he loved how much more calm controlled traction he had over the front end relative to his old setup with a traditional stem. With the RR stem you ride with pretty much all your weight through your feet and hands light. If you don’t rebalance the suspension and tire pressures, trouble with the bike loading really rearward dynamically, poor front traction, harsh bottom outs on the rear, twitchy and unstable feelings from the front end especially in loose or chattery terrain, and feeling like you need to ride really aggressively over the front to keep control are all expected. Rebalance the bike for the new position and ride dynamic, and all those issues go away.

 

[BeMoreBikes]

Possibly, but I'd add caution and say that most products are not designed for this and could have very negative consequences.

That disclaimer out the way, yes, for sure, there will be a ton of options - but you'd need to explore and hack some stuff together. I think if this concept is widely proven that it could be quite a pivotal moment for bike design and geometry.

One massive thing for me (discounting the DH benefits) is just how darn comfortable it is for seated pedaling / climbing.

That being said, there's a lot of folks online who have tried it and cant get it to work for them. So it's not something that seems to be a magic wand that will work on every bike.

I prefer long chainstays, big travel bikes, and am tall, so perhaps my combo of needs / body shape just works very well with something like this.

If the folks online you’re referencing are reviews that have come out, I’d point out that for some reason unclear as of yet to me, most of the reviews that have come out refused to make the necessary setup changes that I told them to make for it to work best, and never communicated their issues so that I could help direct them to solutions like I do with my customers despite me reaching out to check in on if they were having any issues. All of the issues I’ve seen mentioned in reviews are fairly common issues I’ve heard from customers before they make the changes I suggest to fix them. After they make those changes, the issues go away. The main one is rebalancing the suspension and tire pressures, and very few of the reviews did that… Also adjusting your seat position for nose down more and adjusting on the rails for better climbing plus some technique adjustments. I’ll mark it down mostly as my lack of experience as I’m still learning this industry and how best to work with reviewers to get them to run a fair and full test, as I feel most of the reviews out are incomplete. We live and we learn.

 

[claudiobosticco]

I'm tempted to just reverse my existing 32mm stem and try that (running single crown 38s so non of the DH/dual crown stems are relevant to me). It's not like it's a big job and totally reversible if it's crap. I would be a bit concerned about the reduction in reach but it would be interesting to at least try it.

I had tried a 40 mm one (paired with a handlebar with 12° of sweep!), but it absolutely didn’t work on my bike. On top of that, the handlebar would drop quite a lot.

 

[BeMoreBikes]

But really, is all that new found speed and confidence worth going through life looking so ridiculous?

Most things that are now common place on modern mtbs were once new and thought to look ridiculous. Wide bars, 29ers, dropper posts, suspension, etc… The look grows on you once you have an associated positive ride feel connected to the aesthetic. Also, if you’re looking at your frame while riding, you’re not going fast enough…

 

[BeMoreBikes]

The question is, does it work because of the stack, or is it a steering axis vs hand position thing ?

I'm all about that high stack life, running 30mm of spacer, 10mm of stem lift, and 50mm bars on my dreadnought v2 (471mm reach). I'm 6'. It works mainly because of the f/r ratio of 1.8.
I've tried something similar on my crafty, and it didn't work as well. Perhaps because it has a f/r ratio of 1.84, or perhaps because it is large for me at a 495mm reach .

It’s both, but mostly the Reversed offset made to work by combining it with the Raised height. That’s why I call them Raised Reversed stems, these are the Raised up version of my tuned Reversed offset stem philosophy.

 

[claudiobosticco]

I’ve had many of my customers get a PR first ride without even trying, and then continue to beat those PRs as they get used to it and their bike dialed in for it. With the RR stem, everything tends to feel calmer, so you go faster without really realizing. That calm feeling doesn’t always feel as fast even though it is faster, so if you want to reach the point of feeling fast with it, you’ll just go even faster.

I should add that, because of my age and not only that, I don’t always feel like pushing myself to my limits, but at the same speed I feel much more confident.

 

[Suns_PSD]

It’s both, but mostly the Reversed offset made to work by combining it with the Raised height. That’s why I call them Raised Reversed stems, these are the Raised up version of my tuned Reversed offset stem philosophy.

Do you feel that the entire bike frame needs to be set up around your stem?

What I mean is do you need to buy a larger sized bike with a longer than typical CS or the like?

I've tried very short stems and high-rise bars, and both killed front wheel traction. How to you counteract this? With the lower front tire and fork pressures or do you and others not experience this?

 

[BeMoreBikes]

View attachment 178738
It’s taking notes from the moto world. Bars over/slightly behind fork.

I think it could be made to look ok if it wasn’t so tall then get the rise more out of the bars if needed. I’d be interested in trying one out

Funnily enough, no connection to moto. I don’t ride and have never ridden a dirtbike. That said, on dirtbikes your hands are behind the steering axis typically about 45-55mm with the bar sweeps they use, and a straight line drawn from the foot pegs to the center of the grips is about 65-66 degrees. With the RR stem on a size L mtb from many brands, your hands are 45mm - 55mm behind the steering axis, you have a 65-66 degree angle, and the actual stack and reach is within mm of on a dirtbike. I came to this geo over 3 years experimenting with 70mm forward to -70mm Reversed offsets from below traditional heights to about 80mm taller than the Gen 1 150mm RR stem across 9 different bikes of various frames sizes, wheel sizes, and geos. I often jokingly say that I could have saved myself 3 years of development if I just copied a dirtbike. My driving philosophy though is you never learn if you don’t experiment, and I’ve certainly learned a lot.

 

[Canyon Shawn]

I’ve been talking about this on MTBR for years and everyone thinks I’m crazy. And now it’s slowly happening. But, and this is very important: To get the full benefit from this, the frame has to be designed for it. Otherwise, you’re going to have significant compromises. And, I don’t care what anyone says, even in a frame that’s not designed for this stem, it does not take weight off the front wheel.

 

[pinoymamba]

I'm tempted to just reverse my existing 32mm stem and try that (running single crown 38s so non of the DH/dual crown stems are relevant to me). It's not like it's a big job and totally reversible if it's crap. I would be a bit concerned about the reduction in reach but it would be interesting to at least try it.

When I first started riding two years I saw this older gentleman who had a setup like this. I wasn’t confident back then to ask why he did that. But fast forward a couple years and I guess he was on to something.

 

[BeMoreBikes]

Rob's comment about different shaped people liking vs not got me wondering if shorter stem would be worth a try. I'm more on the long torso short legs form factor. I've been good on 470-475 reach bikes (eeb & DH), but the seated position on my K2 Voima MX didn't feel great out of the box and got numb hands on climbs. Played around with stem height a bunch, went from a zero rise 40mm stem to a Hope 50mm 20 degree rise and then kept stacking spacers under it until I ran out of steerer tube, probably somewhere around 5-6cm.

Higher up did help the hands but didn't solve it. I noticed on climbs that the eeb was much more prone to lifting the front wheel. I could lean forward, but it got to the point it felt awkward, especially on switchback climbing corners when you had the bars cranked sideways. On steep descents it felt great, being more stood up makes the trail feel less steep, but when I got into sections with banked turns, I noticed the higher the bars the more I started feeling the front tire lose grip and even dumped myself off the bike a couple times.

Fast forward to this fall, after riding my DH bike all summer, the Voima just felt off. So went to the local jump park and started lowering the stem again and when I hit about 20mm of spacers removed, the confidence came back in the corners and on jumps.

Curious if you guys think keeping similar rise but using one of these short or reverse stems would be a worthwhile thing to try? I've got 46 & 54 offset crowns for the DH38 fork, so could get the 58 offset set if that would help? Or does getting on a larger frame make more sense? I'm getting a new DH frame soon, so part of me is wondering if maybe on that one I consider changing from a 475 reach L to an XL at 505?

I’d recommend the shorter fork offset with this stem concept. As for frame size, you can often keep the same size you already find fits you well when combined with the Raised height, or go bigger.

 

[BeMoreBikes]

I bought a Norco Vlt for a very good price but it’s XL and I normally rode a large. It's totally rideable but very long and not as comfortable or optimal as I'd like. This seems like it would be a decent solution to reach though,yes? I allready have high rise bars as I have a pretty bang3d up neck from years of snowboarding, MX mountain bike crashes etc so I like to be somewhat upright.

It’s great on a bike that would otherwise be too big and feel cumbersome. The Raised height combined with the closer bar position from the Reversed offset gives much more leverage over the frame to make it much easier to maneuver, and the Reversed offsets steering geometry helps the bike lean more to carve turns tighter with better sideknob engagement and a more predictable drift response.

 

[BeMoreBikes]

Very excited by this discussion! I've recently tried the ONOFF 10mm stem mounted backwards with positive results. Jumping felt a bit strange but in the steeps it was way better with noticeably less hand vibration. More experimentation needed in terms of rise, got some 100mm high tensile bolts on the way (if anyone has any cheap spacer options please let me know)! I'm interested in what the optimal negative reach would be too, BMBM is -15mm and Reece/Hattie seem to be running -25mm. For anyone interested in trying, I got the stem for 14,90 € here: POTENCIA ONOFF DH10mm INTEGRADA | Componentes Oferta | Oiartzun Bike

View attachment 178746

I’ve found -15mm to be a really good sweet spot for modern mtb frame, fork, and bar geo. Reece and Hattie are working with me on their setups, and due to the offset in the bolt pattern, a 25mm stem Reversed is -15mm. A direct mount version of the RR stem is coming soon.

 

[BeMoreBikes]

Hmm, was going to ask @Rob Rides EMTB , do you think the improvement comes from the higher bars or from having the bars effectively behind the fork crown? I was wondering the same thing when I was watching Reece's social media stuff. I think he's inferring that it's mostly having the bars behind the crown but all those spacers hint that the height gain is desired as well.

It’s both! The Reversed offset is the key feature and it’s best utilized when combined with the Raised height. This is why I call them Raised Reversed stems as these are the Raised version of my tuned Reversed offset geo philosophy.

 

[CJG]

I’ve found -15mm to be a really good sweet spot for modern mtb frame, fork, and bar geo. Reece and Hattie are working with me on their setups, and due to the offset in the bolt pattern, a 25mm stem Reversed is -15mm. A direct mount version of the RR stem is coming soon.

Thanks very much, so what would the effective reach number be if I'm using my 10mm direct mount stem mounted backwards?

 

[BeMoreBikes]

This is bit of a TL / DR question but I did try and read everything, and have watched Reece's video with great interest...

Can you climb with it? Even with long CS, that looks a lot like wheelie city on any kind of rise, let alone the kind of steep technical climbs that are possible on an eeb.

Interested in thoughts on that in addition to the along/down performance.

Climbing with the right technique and setup adjustments is not really an issue. There are no climbs I could do before than I can’t do now with the RR stem, yet there are climbs I used to struggle to make that I have made with the RR stem. The key parts are to adjust the nose of your saddle down so that you are nicely situated in the saddle with minimal arm input to keep you forward on steep climbs. You may also want to adjust your seat on its rails. The second part is keeping your elbows and shoulders low pulling back and down against the bars when you need to get forward instead of trying to get up and over the bars with your arms pulling up inline with the bars. When you are in the position, the front pulls straight with the Reversed offset to wander less, and tends not to better resist lifting. Generally climbing is really comfortable with minimal back neck and arm fatigue, and an open chest for easy breathing.

 

[BeMoreBikes]

I pinged you on PB actually. If you fancy a fast young DHer other than Stan to give it a try (Atherton A200) feel free to shout mate.

To start it’ll just be the AON Team, but keep an eye out for the upcoming direct mount.

 

[BeMoreBikes]

I'm tempted to just reverse my existing 32mm stem and try that (running single crown 38s so non of the DH/dual crown stems are relevant to me). It's not like it's a big job and totally reversible if it's crap. I would be a bit concerned about the reduction in reach but it would be interesting to at least try it.

You are welcome to try it, but you won’t get much idea what the RR stem is like from that. When you go back perpendicular to the angle of the fork, you also go down a bit. As such, your bars will be notably lower than when the stem was forward. Also, the RR stem uses a tuned -15mm Reversed offset for best performance with modern mtb geo, and works best paired with the notable Raised height.

 

[Walkea]

I have been thinking about this recently, but it seems as if the bars would be back way too far. I like to run the rise of my bars, inline with the angle of my forks. I dont think I could do so with this stem. I would have to roll them forward significantly. I normally run 50mm rise, but maybe a shorter rise would be better. Idk, I guess it takes a bit of experimenting.

 

[Jurassic]

You are welcome to try it, but you won’t get much idea what the RR stem is like from that. When you go back perpendicular to the angle of the fork, you also go down a bit. As such, your bars will be notably lower than when the stem was forward. Also, the RR stem uses a tuned -15mm Reversed offset for best performance with modern mtb geo, and works best paired with the notable Raised height.

Yeah, I know it'll probably be sub optimal but it'd be interesting to at least try it. I am already running a 60mm rise bar so I'm not too worried about the height, I reckon the reverse offset will be too much though (which is borne out by you settling on -15mm).
On a separate but connected note I've started riding my fork with 5psi less pressure in it than previously since going up to the 60mm rise bars and it's been really good so I can appreciate what you're saying about suspension set up needing to change in conjunction with your stem.

 

[BeMoreBikes]

Do you feel that the entire bike frame needs to be set up around your stem?

What I mean is do you need to buy a larger sized bike with a longer than typical CS or the like?

I've tried very short stems and high-rise bars, and both killed front wheel traction. How to you counteract this? With the lower front tire and fork pressures or do you and others not experience this?

Yes and no. No bike currently is designed for the RR stem, but the RR stem is designed for current bikes. Pretty much all if not actually all of my happy customers are on the same bike they were on before the RR stem. They have setup their entire bike around the stem. That said, I am working on developing a mtb around this concept through my various Mule prototype frames, and I would for sure say that the RR stem opens up the ability to run a much longer chainstay ie 500mm - 525mm like on my Mule prototypes. The main counter to issues with front wheel grip are the softer fork and front tire pressure. The Reversed offset and Raised height also helps with this but only really when combined with good setup. With good setup though, I’d say front grip is notably improved compared to a traditional stem on a bike that’s setup traditional. Cornering is probably the biggest benefit to me of the RR stem. The Reversed offset helps the bike lean in more and carve tighter with better sideknob engament, and a more predictable drift response.

 

[BeMoreBikes]

Thanks very much, so what would the effective reach number be if I'm using my 10mm direct mount stem mounted backwards?

That would now be zero, but when you account for the back sweep of the bars, you are likely around 15-20mm behind the steering axis.

 

[Walkea]

Liking the idea of this stem but at $400 + import duty into UK it could be an expensive experiment.
Found this website with a bike geometry calculator which if you input geometry of current bike then under bike number 2 should allow you to change bar and stem dimensions to get an idea of how reach, RAD AND SHO will be affected.
Bike Geometry Calculator - MAD SCIENTIST MTB

 

[lh270519]

Yes and no. No bike currently is designed for the RR stem, but the RR stem is designed for current bikes. Pretty much all if not actually all of my happy customers are on the same bike they were on before the RR stem. They have setup their entire bike around the stem. That said, I am working on developing a mtb around this concept through my various Mule prototype frames, and I would for sure say that the RR stem opens up the ability to run a much longer chainstay ie 500mm - 525mm like on my Mule prototypes. The main counter to issues with front wheel grip are the softer fork and front tire pressure. The Reversed offset and Raised height also helps with this but only really when combined with good setup. With good setup though, I’d say front grip is notably improved compared to a traditional stem on a bike that’s setup traditional. Cornering is probably the biggest benefit to me of the RR stem. The Reversed offset helps the bike lean in more and carve tighter with better sideknob engament, and a more predictable drift response.

You say no current bikes are designed for the RR stem, but which currently available (or coming soon) e-bike (ideally Avinox powered) do you think would be most suitable for a 6'1 rider intending to try this stem and setup philosophy? I gave my height as chainstays tend not to grow proportionally with frame sizes.

 

[irie]

With good setup though, I’d say front grip is notably improved compared to a traditional stem on a bike that’s setup traditional. Cornering is probably the biggest benefit to me of the RR stem. The Reversed offset helps the bike lean in more and carve tighter with better sideknob engament, and a more predictable drift response.

Please explain what you mean by a bike that’s setup traditional.

 

[Suns_PSD]

You say no current bikes are designed for the RR stem, but which currently available (or coming soon) e-bike (ideally Avinox powered) do you think would be most suitable for a 6'1 rider intending to try this stem and setup philosophy? I gave my height as chainstays tend not to grow proportionally with frame sizes.

Speaking out of place here but no one has longer CS's for a given reach than Forbidden (that I know of) once the growth at sag is accounted for. But also, they already have a lot of stack as well which might be a negative in this case.

 

[lh270519]

Speaking out of place here but no one has longer CS's for a given reach than Forbidden (that I know of) once the growth at sag is accounted for. But also, they already have a lot of stack as well which might be a negative in this case.

As far as I can tell a lot of stack would be a good thing and one of the things this setup is trying to achieve. Crestline appears to have the option for a long rear end too?

 

[Deleted member 37410]

These stems in many ways do the same as slackening the head angle. The "effective head angle" (I just invented that), that is angle between your hands and your front axle, will change a lot, and I think that's the main factor behind it feeling more composed. Its not the same as reducing reach, reducing reach brings the axle closer as well

As for high stack, look at old and new snow mobiles. New have super tall bars and are built to ride standing fully straight, and old are built to sit down and are "unrideable" by modern standards

 

[Brawwp]

Also I don't think it's exactly comparable to an MX bike. First, MX bars are pretty low and nearly straight so they don't sweep way back. Secondly fork offset is typically about 22mm, not 44mm like on a MTB. Thirdly if set up correctly, even after bar sweep, the bar ends should not be behind the inline of the fork. I do agree that on a MTB the bar should be aligned with the fork angle, but not a dirt bike. Because when you huck big on an MX bike your weight comes nearly straight down over the front end so that's the angle you want the bars at for the most absorption. But importantly, MX bikes turn on the throttle with very light front ends and really don't depend on front wheel traction the same way a pedal bike (or e-bike) does.

I’m sorry dude I have to call you out on this info being completely false.

Eli tomac bar rise 54mm and bar sweep 54mm

Jason Anderson bar rise 52mm sweep 52mm

Chase sexton 56-58 on both

Bar ends are 100% not in line with the fork. That would be a terrible setup. You make the bar bend parallel to the fork which is in line with the steering axis and with the bar sweep your grips will be back end or behind the fork. Unless you’re calling ever professional racer ever wrong.

When your are turning you 1000% are depending on front end traction lol. You have to counteract the throttle by moving your weight forward. That’s why we sit way up near the gas tank and keep head over bars in turns with smooth throttle to weight the front end and get traction.

 

[Michaelll]

@Rob Rides EMTB I am guessing you have a direct line to Cesar Rojo (Unno). He designed a 10mm DH stem in 2011. I would be curious as to why he went away from exploring the short stem avenue.

https://www.pinkbike.com/news/Proto-DM-Stem-Cero-Design-2011.html