Topic: Lenzsport Leviathan 3"FS 29er

[RiskEverything]

As much as I like Cannondale, this frame looks like it would make a very sweet XC racer. 3" rear travel, 29" tires. Toss a Lefty up front just to be Also, it's still hand-made in the USA

[FACTORe]

how much does that weigh?

[RiskEverything]

Click the picture and read the description 

[BeerCan]

Lenz makes a nice frame for sure.  They have a little shorter CS which some people really like.  Also BB height is not so little that it will be pedal striking all the time like a racerX 29er might.  Personally I am waiting to see what the Jet9 turns out like.  Not that I need a new bike but a racer type bike in the quill would be cool.

[EllsRider]

Good looking bike. What category suspension does that fall into? Four bar? ?

[BeerCan]

Faux bar = seat stay pivots
four bar (horst) = chain stay pivots

So the lenz is a faux bar which is really a glorified single pivot.  Not that it really matters, there is so much more to suspension performance than ss/cs pivot location.

[EllsRider]

So looking at the picture, which is the pivot point on the seat stay? I see three bearings  on the shock bracket. Is the pivot point on the gusset? Seems like they all pivot.

[BeerCan]

The SS pivots are the ones down near the dropouts.  The ones by the shock are just part of the linkage

[EllsRider]

There is  much to understand on these suspension designs. Looking  at the Leviathon, it looks like you can lose a lot of energy during active suspension times, when going through rough terrain. Not that I know, I'm learnin' all this stuff.  But it looks like that you can lose chain tension when active. Is this an accurate observation? Or am I off on understanding how it works.

[RiskEverything]

By keeping the chain-stay pivot point so close to the BB, there would be minimal, if any, change in change tension. The distance from the rear cassette to the chainring would remain fairly constant, and the derailer could handle any tiny bit of slack that may develop.

[EllsRider]

http://www.ellsworthbikes.com/home_flash/ict_demo/main.html#

check out this tutorial by Tony Ellsworth. I know it favors Ellsworth but it seems to be sound science and engineering. Found this last night and have been  studying it.
 You can go through the whole thing or go to "Take the ICT  Challenge" at the top.


Also, if interested  check out  the new bike called The Ride. It  has a very interesting rear hub and transmission. Looks like it has great potential. i don't lnow how it would work  for trail riding tough, Too much slippage and twisting the grip.


 

[BillT]

The design will still have some pedal feedback, probably in the granny gear and suffer a little bit from stiffening/extending under braking (which is not a big deal in Florida).  Looks like a nice bike.  I'm a bit partial to Intense bikes so I'll counter the Lenz with this:

[EllsRider]

Is that a VPP Bill T?

[FACTORe]

i love the VPP on the ole santa cruz

[BillT]

Is that a VPP Bill T?

Yeah...Intense is only using the VPP design for the their FS bikes now.  They decided to license the design from Santa Cruz rather than continue to pay Specialized for the horst design. 

I wonder when Giant will come up with a Maestro 29'r?

[EllsRider]

Wheres the pivot points on this design?  The rear chain stays, how are they attached to the frame? Looks like the same as as the Lenzsport which looks like the same as my bike.

[EllsRider]

I went to the Intense home page and looked at suspension tech page. Looks like they have  little pieces for the top  and bottom pivot points on the chainstays.  Since the pivot point is going to be varying between the two connections at the top and bottom, it is not at a fixed pivot point,  is this where they get the term Virtual Pivot Point? Or is it referring to something else?

[BillT]

I went to the Intense home page and looked at suspension tech page. Looks like they have  little pieces for the top  and bottom pivot points on the chainstays.  Since the pivot point is going to be varying between the two connections at the top and bottom, it is not at a fixed pivot point,  is this where they get the term Virtual Pivot Point? Or is it referring to something else?

They call it a virtual pivot because the effective pivot point changes/moves as the suspension cycles through the travel.  This results in a suspension path that is kinda shaped like a reverse letter 's'.  The wheel travels up and back initially before starting to arc forward.  VPP bikes require a bit more sag that other suspension designs as they have a sweet spot in the travel (about 25 - 30% of the total travel) where chain torque eliminates bobbing, yet is easily overcome by bump forces so that the suspension stays pretty active.  Having said all that, I think that VPP designs are ideal for longer travel applications where you want to maintain good pedal efficiencies, but may be overkill for shorter travel designs especially with today's shock technology.  I love my Blur, but I feel that the Ellsworth that my Blur replaced was a better bike for xc purposes; however, my Intense VPX is light-years ahead of my old Bullit in every conceivable way even after I had the Bullit's shock custom tuned by Push (which greatly improved everything about the Bullit).

Here's a picture of the VPP frame so you can better see the linkage:

[CrazyWhiteGuy]

Ventana please