[bizutch]

Next up....yaw.

 

[cesar_rojo]

Got it! Tomorrow first day riding it, we'll see

 

[cableguy]

Got it! Tomorrow first day riding it, we'll see

Wow, that looks awesome! Look forward to your review. Could change how people size bikes!

 

[cesar_rojo]

first day on it and feels awesome! Longer bike shorter stem, same position on the bike. We are on a race this weekend, track is quite fast on the bottom section and bike feels so stable.

Direction now feels awesome direct, didn't expect to be such a nice thing, I feel with more confidence on the bike... We'll se how the race on sunday works out...

Gonna try to get a gopro from someone tomorrow a film a run

 

[Pelle]

Nice!
Very moto

 

[cesar_rojo]

Some video of the weekend race, just could do one run with the camera and was pointing a bit too low and got some mud on it, but is fine I guess... Hope to make it into the dirt Tv video resume from the race, haha!

Gouveia 2011 on Vimeo

 

[Tomasis]

nice video, it looks like you could press this at hard way

what is your height and length of TT on the frame?

 

[Deano]

balls, Now i have to exchange my M sized summum for a large ..

 

[cesar_rojo]

nice video, it looks like you could press this at hard way

what is your height and length of TT on the frame?

You mean the reach and stack?

balls, Now i have to exchange my M sized summum for a large ..

Longer bikes is going to be the future, I'm 100% sure of it. Defenetly we are going to see some pro's using it soon... Hart loved, Mulally tried for a bit and liked also... Fabien in going to try in this week probably...

It made big difference to me

 

[Pslide]

Very interesting Cesar, thank you for sharing your ideas and the results!

Anyone buying a new bike could try the same thing by going with a larger frameset with adjustable head angle and short stem. I guess I am still old school with my 64 deg HA, so no need for me to change, but I love reading about the experimentation.

 

[Tomasis]

You mean the reach and stack?

it'd good to know about it too. I see that mondraker Large has 600mm for ETT. What is your height?

 

[cesar_rojo]

it'd good to know about it too. I see that mondraker Large has 600mm for ETT. What is your height?

I am 178cm so not that tall and probably riding longer bike than peat, Minnaar and those really tall guys, but bike just feels great!

Some more info thanks to the Dirt guys!
http://dirt.mpora.com/news/cero-design-10mm-offset-stem.html

 

[I.van]

Great thread!

I am 174cm tall, which would normally see me fit onto a small or medium frame, but I have always felt more comfortable and stable on the large DH frames, simply because of the longer TT and Wheelbase.

 

[richgardiner]

I understand that you have the short stem to reduce reach on the larger frame so you can keep your same riding position on a bike that has a longer wheelbase without feeling stretched over the front, but how come you steepen the headangle?
Really interesting read, I'm building my medium sunday back up with a 28mm straitline instead of a 50mm funn, I felt pretty stretched out and felt like my weight was always too far forwards so hopefully this will help me be more balanced towards the center of the bike.

 

[Mo(n)arch]

but how come you steepen the headangle?

I think with this setup he's trying to get a more lively feel in the longer bike. I think you just don't need a 61° headangle and wheelbase long as hell. Otherwise you would get a chopper feeling and wash out in every single turn.

Really interesting thread. Thanks Cesar for sharing your ideas

 

[Slater]

Longer bikes is going to be the future, I'm 100% sure of it.

I agree, and have been saying the same for a few years now. Everyone (until this thread apparently) has been talking about "oh the wheelbase on that bike is too long" for all the new DH bikes with long stays and slack HA's. However, not only are long bikes more stable, but each of the component geometry figures that end up determining how long a bike is are much more important than the resulting wheelbase figure. Chainstays have to be long enough, cockpit (reach) needs to be long enough, and HA needs to be slack enough. If any of these are made shorter/steeper HA, the bike will certainly ride worse than otherwise despite the shorter wheelbase. Not only that, if you know what you're doing, turning a bike with a longer wheelbase is no more challenging than a shorter one, it just feels different.

Glad people are realizing this now.

 

[cableguy]

Longer bikes is going to be the future, I'm 100% sure of it.

Cesar, what about stand-over and stack heights on larger bikes? Wouldn't it be an issue for guys with shorter legs? Wouldn't using larger bikes with shorter stems work better for riders with shorter torso/longer legs?

 

[miuan]

The DH track looked very well suited for the geometry Cesar created. Nice video, nice idea.

 

[Sam B]

Say you like the weight balance and wheelbase of a head angle like 62 with a 50mm stem. I wonder how a bike with the same wheelbase and weight balance might ride with modifed fork offset, head angle and stem length. For example... keep the wheelbase but steepen the head angle to 63 degrees, reduced fork offset (to get the same trail) and use a shorter stem to keep the handlebar position the same.



I think it might feel less floppy in tight sections with similar stability at speed. Hard to say without getting it on a trail; and unfortunately crowns with different offset wouldn't be as easy to try out. Just something else to think about.

 

[Leganetti]

I am not pretty sure that this stem will work good. In the past I had similar idea... use a big frame (stab size L) with a short stem (straitline 25mm)... that was the worst this I could do, the bike became unstable.

Anyway, congratulations for your idea. Which brand is gona produce this stem??

 

[cesar_rojo]

I am not pretty sure that this stem will work good. In the past I had similar idea... use a big frame (stab size L) with a short stem (straitline 25mm)... that was the worst this I could do, the bike became unstable.

Anyway, congratulations for your idea. Which brand is gona produce this stem??

It works really good for me. I did this to be able to ride a L size and still be able to be confortable, not for making it into production. (you can read the first post "This is a personal thing, so it's not related to any component brand, just wanted to make it clear")

Its really weird to me that if your two wheels are in same position (stem doesn't modify that) the bike became unstable, reaaaaaaly strange, but who knows...

Un saludo

 

[Tomasis]

it might has to do with how you move bars. If one gets used to move bars a lot with longer stem then he feels he is not able to hold bar more still with shorter one *hard to break habit thing*

 

[LMC]

It works really good for me. I did this to be able to ride a L size and still be able to be confortable, not for making it into production. (you can read the first post "This is a personal thing, so it's not related to any component brand, just wanted to make it clear")

Its really weird to me that if your two wheels are in same position (stem doesn't modify that) the bike became unstable, reaaaaaaly strange, but who knows...

Un saludo

Would you produce it if there was enough interest from prospective buyers?

 

[cesar_rojo]

Would you produce it if there was enough interest from prospective buyers?

I don't think so, if I produce it will be to do more components and for now I'm really focused on getting my design studio working...

This stem just came as a way to be able to ride a L size bike, feeling like I'm on a M bike. Just wanted to share my thoughts. Also is difficult to market it I think. Good for pro riders, I'm sure the not very tall ones will like to use it. But for the other people, is or feels to me a bit to much to buy a longer frame to fit this stem.

 

[cesar_rojo]

Fab is testing the stem after getting him a special longer and steper (63º and he must be around 62º, not sure what he ended after the tests))

http://www.zapiks.fr/wc4-mont-st-anne-bike-check.html

We'll see how it works for him.

 

[Pslide]

Crikey!

Courtesy Zapiks and 26-in.

Very interesting! Thanks for the update Cesar. Fabien is always ready to experiment, although I think that guy could ride just about anything down a hill fast. Cesar, maybe you could give us an update when you talk to him after the weekend and let us know what he thinks of it?

 

[Chaz-man]

Stem offset does not change steering geometry or dynamics of steering of a motorcycle or bicycle. It only changes the location of the rider's hands and by default the weight distribution of the bike. Leverage on the bars changes by less than 1%, the lateral distance that the hands move when steering does not change appreciably. Motocross bikes still run forward offset. Why? To tune rider fit and weight distribution. Stem offset does not change steering geometry or dynamics of steering of a motorcycle or bicycle.

Why not move the bars behind the steering axis? That way the bars can be as far as possible back. That should really unbalance the bike, even better, right! That would be so innovative!

 

[heavy metal]

 

[Mo(n)arch]

It will be avalaible!

centre-stem


Exclusive: Mondraker unveil radical new ‘centre stem’




Mondraker are planning on making some radical changes to key bikes in their line-up for 2013. We managed to get the full exclusive on this new development during a trip to Alicante, Spain to test ride key current models.

Evolution or revolution?

Over the past few years, trail bikes have evolved. Frames have become slacker and longer, and 700mm+ handlebars and stubby 60-70mm stems are now commonplace. These changes have enhanced stability, control and descending prowess, with the extra length in the top tube still allowing riders to get that all-important stretch when climbing.

For 2013, Mondraker look set to take things to the next level with a seemingly radical yet actually extremely logical change. It’s the brainchild of Cesar Rojo, the man behind the Zero Suspension platform, and brand manager Miguel Pina.

The pair set out to deliver a design that offers “more stability, more reactivity and more confidence” and combines the best features of all-mountain, gravity enduro and downhill bikes. So how were they going to achieve this? Cesar took things right back to basics, looking at motocross, BMX and downhill bikes and knew he needed to change the way in which the bike was piloted.



Big changes are afoot for Mondraker’s 2013 range; this is a prototype Foxy XR

Short, sharp shock

Motorbikes use the shortest stems available to enhance control. In recent years downhill race bikes have followed suit, with minimal-length, zero-rise stems now the norm. So why not apply this idea to other categories of mountain bike, and alter the frame to suit? Well that’s exactly what Mondraker have done with the advent of their ‘centre stem’.

In order to make the super-short stem work without throwing a mid-travel bike’s handling characteristics out the window – unlike downhill bikes, they need to be pedalled uphill, after all – Rojo needed to make changes to the front triangle of the frame, in particular the relationship between the bottom bracket and front axle, or ‘front centre’ as it’s known.

The 140mm-travel (5.5in) Foxy normally comes with a 70mm stem. In Alicante, we were shown a prototype model with a 10mm stem sitting proudly in place. With the stem now effectively 60mm shorter, Mondraker have added 60mm to the front centre of the bike but the rest of the geometry remains the same. The stem is taller than usual to compensate for the rise of a standard stem; this may change as development continues.

This bike will sit alongside the standard models in the 2013 line-up – the Foxy, Foxy R and Foxy RR, all of which will still come with 70mm stems – and will be called the Foxy XR. Although the ‘centre stem’ looks like quite a radical move, it makes a lot of sense. Reactivity through the bars should be increased, as should stability thanks to the longer wheelbase.

The concept will be extended to one bike in each of Mondraker’s mid- to long-travel ranges – Foxy, Dune and Summum – for 2012. The Dune XR and Foxy XR will both be equipped with adjustable-travel Fox TALAS forks so the rider can lower the front end for improved control and grip on flat or uphill trails. It’s good to see a company thinking about bikes as a cohesive package rather than just a collection of parts.



Mondraker reason that if minimal-reach stems work for motocross and downhill bikes, they should give extra control on trail and all-mountain bikes too

So, how does it ride?

We were lucky enough to get hold of the prototype Foxy XR for a few hours and take it for a spin in La Fenasosa bike park, which is littered with some of the roughest trails we’ve ridden. Look down at the stem and you’ll certainly do a double take, but on the trail acclimatising to the new feel that the longer front centre and stumpy 10mm stem produces doesn’t take long at all.

Over some of the roughest rock sections the improved stability was clearly apparent, letting us hammer into sections with more confidence, and it was hard to believe we were only aboard a 140mm (5.5in) trail bike. It was hitting the turns where we were really impressed though. Initially we were concerned about how the bike would handle in the tighter corners, but the enhanced reactivity through the bars and improved riding position meant carving through the turns was a controlled affair.

On rougher climbs you can feel the extra twitch through the bars caused by the super-short stem but this should be remedied with use of the TALAS fork, which this prototype didn’t have. We’re keen to give different stem heights a go too, just to see how bar height affects the feel of the bike. Bear in mind that this machine is still in its prototype phase and we’re sure Cesar will be playing around with the concept extensively before release in 2013.

We can’t wait to see this design roll out across the Foxy, Dune and Summum line-ups and we’re impressed to see such an innovative and ballsy move by the small Spanish company. Roll on 2013!

http://www.nutsbike.com/tag/centre-stem

 

[frango]

One question, if you tighten bolts that hold the stem on the steerer, you make two top (rear) bolts come closer, right? Similar to Syncros FRIC stem, which have got split-type front plate... Mondraker stem has got regular plate... will it work, at all?

 

[nh dude]

i am considering trying this out with a straighline direct mount stumpy at 28mm. I'm 5 8 on a medium demo has anyone tried this? Can anyone comment with some real word experience for average joes?

 

[offtheedge]

I'm doing the same thing this year. Large frame, short stem(s) and flat bars. I have left the steerer uncut so I can raise and lower the bars to find optimal position without having to factor in rise and sweep.
Although stem length won't change the steering geometry, it will change the riders perception.
Your hands determine the center steer of the bike, not the head tube.

 

[EVIL JN]

Have been doing the short stem thing this season and i can safely say i wont be going back to 50mm+ stems any time soon. Just need to get my hands on a xl v10 and then its trucking time.

 

[trib]

I remember when I first read about the gary Fisher 'Genesis Geometry' of longer top tube/ shorter stem. That was when an 80mm stem was short though

 

[William42]

and then they went back to 100 and 120mm stems.

 

[Lelandjt]

KTMs have adjustable bars mounts and on both of mine (300xc, 105sx) I've settled in the farthest forward settings. My DH bike is a large V10 and I definitely like the long front end and kinda steep HA. Switching from the stock 888 stem (58mm?) to a 45mm felt great but I have no urge to go shorter.
*I'm a 6'2" regional pro.

 

[Lelandjt]

I remember when I first read about the gary Fisher 'Genesis Geometry' of longer top tube/ shorter stem. That was when an 80mm stem was short though

I got the guys at my shop (we were all XCers) to do that a couple years earlier. It was hard to find light 70mm stems. I came from BMX and always thought long stems felt weird.