Jump to content

29er Dh Bikes????


Nikolais

Recommended Posts

Read the following article on a tour around Treks HQ in waterloo.

http://www.pinkbike.com/news/trek-tour-29er-proto-2011.html

 

One of the prototypes they had was a 29er DH rig!!!!

Now I always wondered if 29ers would stick, and it seems they have, but I have also wondered how soon it would trickle into DH?

 

The Trek had 29er specific Dorados so I am guessing that they are looking into it quite seriously?

 

What are your views?

Link to comment
Share on other sites

  • Replies 41
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

well... Trek isn't the first manufacturer to jump on the 29er DH bike wagon.

 

I dunno who was, but I know the Intense 951 is a 29er DH bike and frames can be bought form CR, and have been available for a while.

Here's some pics of the beast...

http://www.nsmb.com/assets/images/A-events2009/Intense951/image003.jpg

http://www.tamedearth.com/wp-content/gallery/misc/intense-951-white.jpg

http://dirt.mpora.com/old_images/news/951-BLACK-(2)intense.jpg

 

and judging from these pics, the following (amongst other things) are already available for 29er DH bikes...

 

Fox 40

RS Boxxer

Mavic Deemax Rims

Link to comment
Share on other sites

WOAH!!!! i did not know that? I am behind on this one.

The 951 is sweet....

 

I rode my Old Mans Gary Fisher HiFi 29er when I visited them in the UK, but feel any noticeable difference from any 26" trail bike?

Link to comment
Share on other sites

Guest Omega Man

Those pics are of the std 951 which is a std 26 inch bike. The 2951 has been tested by JD Swangen and is apparently going to be raced by him this year. I'm not so sure about 29 DH bikes. Most of the XC dudes I've seen on them look so high off the ground. I keep expecting them to whip out the bowling pins and start juggling.

 

That might be ok for xc where power transfer and all that stuff is more important but in DH agility and acceleration are more important. The 2951 MIGHT work on the wide open courses but I'm pretty certain they will be crap in the tight stuff.

 

DH and XC have very little in common actually so the fact that it works for XC (and that isn't even certain) doesn't mean it works for DH.

 

Personally I think the entire 29er thing is pure marketing bull**** to get us to buy even more stuff we don't really need. The same way most of the "standards" that the bike companies continually change are.

Edited by Omega Man
Link to comment
Share on other sites

hahah! my bad :blush:

 

Seems I heard via the grapevine that all 951s were 29ers and the big walled rims and huge tyres made it hard to see the difference...

 

I retract my previous statements, hahaha!

Link to comment
Share on other sites

No stress, I am keen to see what becomes of this......

I agree that the frame shape makes the wheel look WAAY huge on the 951

But how hectic are the wheels (in the above article) on the 2951?? And the 26 Rear/29 Front combo - a modern take on the 'Big Hit's of old.

Link to comment
Share on other sites

well... Trek isn't the first manufacturer to jump on the 29er DH bike wagon.

 

I dunno who was, but I know the Intense 951 is a 29er DH bike and frames can be bought form CR, and have been available for a while.

and judging from these pics, the following (amongst other things) are already available for 29er DH bikes...

 

Sorry Patches but Nic is correct. The 951's that are shown in your images are 26" bikes. Intense designed and tested a 29er DH bike called the 2951 ...

 

There is NO Production model out yet and wont be for a while

 

this is from Dirt Mags convo with Jeff Steber (owner of Intense)

 

“Something I have wanted to do for some time & topic of many debates.

With a little help from Manitou / Sun & WTB we have the “2951″

This first proto is in the medium range 23.5 effective tt.

G3 dropout & Head tube

14″ bb in middle, w 64.5 ha @ 0

CS 18.25″

WB 48″

Where do you start with this, so I went with tried & true and we have a bit of adjustability to play with.

Travel is at 7.5 or 8″ with adjustable link.

fork is reduced to 7″

So everyone who has thrown a leg over it is blown away in one aspect or another.

This is just a test project at this point & hope to get some team riders on real tracks in near future. Tires are the biggest issue at this point but if it pans out I am sure Intense Tires will step up for some racing rubber choices.

The 951 frame works well for this as there is alot of room for seatube tire clearance.”

Link to comment
Share on other sites

I do think that 29er DH bikes would have to have a lower COG to aid agility as Omega Man said.

But I do not see Pro's cutting their times down solely due to running 29" wheels.... I do think that other advances in technology will aid this, but wheel size... I am not sure.

 

That said... If pros ran 24" wheels I am sure this would hinder rolling momentum - So I am unsure....

 

As I said before I have ridden my Old Mans 29er when I was in the Uk and I did some single Track and trail - I didnt find the handling much different as I rode the same trails on a standard 26" bike as well.

And it was rather rooty and slightly tech in sections - but then again, I am a hacker!!!! HAHAHAHA

 

We will have to see what becomes of this.

Edited by Nikolais
Link to comment
Share on other sites

oh and you actually talk to the pros who have raced 29ers (even XC) and get their real opinions (not th eones they have for media - which all say its great) and a lot of them dont like the 29ers. They are however an amazing bike for big guys .... its like a 16 inch for a 5 year old - a 20 inch for a 10 year old - a 24 inch for a 13 year old - a 26 inch for a normal sized person - a 29er for someone whos 190cm and over ... its all relative to proportions.

Link to comment
Share on other sites

  • 2 weeks later...

Just on a side note, the std 26" downhill bike (large size) whatever it may be is already a long bike if made into a 29" the frame design would have to be major, owing to the extra wheel base and as such manouverability will be affected. The bike cannot possibly have the same wheel base as the bike would be very high off the ground and its balance point would be screwed up. I was just wondering how you think the problem could be solved?

Link to comment
Share on other sites

IIRC, it was one of the yeti factory riders who happened to be spinning around on the 2951 that said the 29'er is a bit harder to manipulate in the air, table topping/whipping etc. stands to reason with the higher gyroscopic forces generated by the larger rotating mass of the wheels.

Larger wheels will definitely gobble up what a 26" wheel would consider gnar.

Link to comment
Share on other sites

IIRC, it was one of the yeti factory riders who happened to be spinning around on the 2951 that said the 29'er is a bit harder to manipulate in the air, table topping/whipping etc. stands to reason with the higher gyroscopic forces generated by the larger rotating mass of the wheels.

Larger wheels will definitely gobble up what a 26" wheel would consider gnar.

 

I've thought about this... and wondered in it really makes that much of a difference?!

 

So I decided to doodle it out (mostly to test AutoCAD for mac, haha)

 

and here's the result:

post-10758-0-34817100-1299227872.jpg

 

Green = 29" wheel with 2.5" tyre

Magenta = 26" wheel with 2.5" tyre

Red Block (obstacle) is 150mm high.

 

Dashed lines were used to work out a percentage of the wheel radius that is "over the obstacle"...

 

26" = 23%

29" = 26%

 

What the drawing actually means and how to interpret it and the 3% difference... I don't know... just thought I'd draw a quick pikcha, hahaha!

Link to comment
Share on other sites

patches: shallower contact angles wrt edges of obstacles for the 29er vs the 26er, so 'easier' mounting/rolling of objects. As an exaggeration of the effect, go try to mount a pavement with skateboard wheels versus that of your DH sled. I recommend a full face lid for the skateboard experiment :P

Edited by Capricorn
Link to comment
Share on other sites

well... Trek isn't the first manufacturer to jump on the 29er DH bike wagon.

 

I dunno who was, but I know the Intense 951 is a 29er DH bike and frames can be bought form CR, and have been available for a while.

Here's some pics of the beast...

http://www.nsmb.com/assets/images/A-events2009/Intense951/image003.jpg

http://www.tamedearth.com/wp-content/gallery/misc/intense-951-white.jpg

http://dirt.mpora.com/old_images/news/951-BLACK-(2)intense.jpg

 

and judging from these pics, the following (amongst other things) are already available for 29er DH bikes...

 

Fox 40

RS Boxxer

Mavic Deemax Rims

 

 

 

wow!!!! thats what a bike should look like!!! gggggrrrrrr......

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Settings My Forum Content My Followed Content Forum Settings Ad Messages My Ads My Favourites My Saved Alerts My Pay Deals Help Logout