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Added a comment about feature First Look: Radical New 2015 Specialized S-Works Demo Carbon 7/30/2014 12:54 AM
C50

I used a modified version of the publicly available Status linkage geometry in the library of bikes that comes with the Linkage program. So the speculation in my comments is well informed speculation.

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This feature has 31 comments.

Added a comment about feature First Look: Radical New 2015 Specialized S-Works Demo Carbon 7/29/2014 11:42 PM
C50

Had I done that then someone could respond "doesn't look flexy to me". I prefer to make people who disagree with me work much harder than that.

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This feature has 31 comments.

Added a comment about feature First Look: Radical New 2015 Specialized S-Works Demo Carbon 7/29/2014 7:43 PM
C50

Besides the carbon artistry what is new is the linkage. With any linkage what you are concerned with are its structural and functional - wheel path and kinematics primarily - characteristics. So how does this new bike rate on that scorecard.

Wheel path and pedal feedback - not too dissimilar to the old bike (probably)
Anti-squat - the new bike is greatly improved (i.e. more pedaling neutral)
Anti-rise - braking will be different on the new bike but AR will continue to be low which is generally considered to be good for traction when braking
Leverage rate - that was alright on the old bike, the new one won't radically deviate

There is nothing wrong with or especially notable about these functional changes. The same result was readily achievable with relatively small changes to linkage pivot positions on the existing bike. Where the new bike is let down is in the structural characteristics of the rear end. The rear axle is mounted on two separate linkage pieces on each side of the wheel - the single rear end structure that the wheel mounts to, common to all Horst-link bikes, is gone. These separate pieces on either side of the wheel join to the other linkage bars via a couple of pivots within the circumference of the wheel (looked at in side view). In general full width pivot axles are better than aligned pivots on either side of the wheel and if aligned pivots are used it is important that they are near a structural member bracing drive and non-drive sides together.

I am not impressed by the new design - it appears to be prone to flex. To what extent that concern will manifest itself, is hard to say. Just how noticeable flex becomes will depend on the quality of the pivots, bearings and carbon structures used.

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This feature has 31 comments.

Added a comment about feature Vital Power Rankings - Fort William, Scotland World Cup - The 15 Fastest Racers Going In 6/5/2014 8:07 AM
C50

I completely agree. Mulally has been oustanding. Mulally, Bryceland and Bruni, all relatively young guys look to be showing vast improvement this year. Without doubt, they are contenders.

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This feature has 17 comments.

Added a comment about news blog Judge Rules Trek's ABP Design Does Not Infringe on DW's Split Pivot Patent 12/17/2013 7:44 PM
C50

Oh, by the way, I recommend reading @Varaxis comments on the particular patents below. Its as good an effort as I have seen to survey this tricky (and sometimes nearly impenetrable) territory.

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This news blog has 12 comments.

Added a comment about news blog Judge Rules Trek's ABP Design Does Not Infringe on DW's Split Pivot Patent 12/17/2013 7:32 PM
C50

I agree with some of the sentiments expressed by @prestondh. Concentric pivots (not a new idea) at the rear axle dropouts of a bike (also not a new idea) should not be patentable. However, the known history of DW's dealings with Trek prior to the APB patent being filed is really much more in line with DW's presentation of the facts. It is very unlikely that the inspiration to the creation of APB came from anywhere else than DW's presentation of the concept and the design to Trek when he tried to sell his design services to them, well before APB existed.

There are some aspects of the judge's findings that are troubling. The emphasis on shocks and leverage rates makes it clear that the judge is not ruling against the existence of some kind of notion of special usage rights that attach to concentric drop out pivots at the rear axle. So, for example, to build a bike with a split pivot that has a similar LR curve to DW's own bike designs would be infringing. A better result, in my view, would have been a restriction of the patent to very particular mechanical features of the dropouts. That would mean that design approaches could be freed up and people could stop losing sleep over who is going to sue them next.

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This news blog has 12 comments.

Added a comment about video Introducing the 2014 BMC Trailfox TF01 29 10/14/2013 12:45 AM
C138x104

There is a lot to like about this bike, but some bright types who have put it through a suspension physics simulator have concluded it is 140mm not 150mm as claimed. It doesn't bother me, except insofar as it is false advertising, because long travel 29ers are not an especially good idea.

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This video has 5 comments.

Added a comment about slideshow PAIN OR PLEASURE? Trans Provence Finale 10/7/2013 12:09 AM
C138_tpfinalsthumb

1 second separating first and second over 24 stages. Amazing. Jérôme Clementz is at once a very tough and gracious competitor.

This slideshow has 7 comments.

Added a comment about feature SPY SHOT! Prototype Specialized DH Bike 8/22/2013 3:17 PM
C50

Wait a minute, Ive got it. This is just a mule providing a bit of data for the real thing that is still under wraps. The next bike won't have a long intermediate link from the main frame to the chainstay pivot, but rather a short link with the pivot linked to the wheel carrying member slightly behind the bottom bracket. This pivot will join via a full width pivot axle to a slightly flexy carbon rear triangle that will also be braced at the reaward pivots of that upper intermediate link. The short lower link will be further braced Equilink style to the upper link keeping the motion of the whole linkage precise and true. If the rearward linkage points of the lower and upper intermediate links come together slightly over the course of travel (rather than move apart in the manner of the Equilink) then there would be further opportunities for additional triangulation to stiffen up the rear triangle.

Okay, I just made all that up, but Specialized would do well to follow my advice.

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This feature has 29 comments.

Added a comment about feature SPY SHOT! Prototype Specialized DH Bike 8/22/2013 2:07 PM
C50

More and more information is coming out about this bike (see http://www.ridemonkey.com/forums/f19/prototype-specialized-dh-bike-261009/). Specialized seems to be doing a remarkably good job in parading it in front of hundreds of riders every day - yeah that's what I call a secret. I would not expect to see anything too much like this ever make it to production - it defies too many basic principles of structural (and perhaps kinematic) design. If it ever was to make it to production Specialized's new patent portfolio would be safe. Who in their right mind would want to emulate this?

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This feature has 29 comments.

Added a comment about video Sea of Rock 8/5/2013 11:04 AM
C138x104

Incredible! Not to detract from the achievement of the riders, it is hard not to be interested in what bike(s) it is that they riding. A close look confirms that it is the Liteville 301.

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Added a comment about news blog Dave Weagle Sues Giant for Patent Infringement 8/5/2013 7:14 AM
C50

My sympathies are with Giant. If you read the DW-link patents you will notice that they convey the sense that any dual short link suspension linkage can be seen as a DW-link if the anti-squat curve is similarly DW-link like. I would say they are written with an eye to litigation. It don't think it is fair use of a patent that it should cover implementations that the patent holder does not use and will never use.

There is very little about Giant's linkage that is similar to the canonical DW-link. DW should be happy just having a better suspension design and stop playing litigious games.

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This news blog has 42 comments.

Added a comment about photo Winning Bike: Curtis Keene's Specialized Stumpjumper EVO 29 7/21/2013 3:16 PM
C138_baletd_b5a4155

In order to get a win Curtis has to abandon the "enduro ready" Enduro 29er and ride the stumpy instead. Hilarious!

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This photo has 15 comments.

Added a comment about product review First Ride: Öhlins TTX Shock - Yellow Gold 7/15/2013 6:51 PM
C50

Why do mountain bike pundits so systematically overestimate the contribution of mountain bikes to the technological knowledge of mankind? This is a case of Ohlins bringing its existing suspension technologies - already thoroughly researched in MX motorcycling and elsewhere - to the mountain biking world. Specialized is little more than a show pony in all this. The partnership here is the common commercial one of using each other for the (i.e. their own) greater good. The partnership also appears to be a sweetheart deal, otherwise why would it we wrapped in this silly pretense that Specialized understands Ohlins technologies as well as Ohlins does. In the deal, Specialized, who must be counted the lucky one here, because it will be basking in Ohlins radiance, gets a chance to stress its difference and uniqueness to buyers, but what does Ohlins gain? I imagine Ohlins is interested in taking profits and not moving units so much. This kind of introduction of its products will allow Ohlins to tie up the high end of the market without any reduction in the stratospheric pricing of MTB components. Like I said, everybody (i.e. Specialized and Ohlins) wins.

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This product_review has 10 comments.

Added a comment about video When Roadies Do MTB... Meet the Pinarello Dogma XM 7/15/2013 6:06 PM
C138x104

Oh dear! The first lecture from Pinarello on mountain biking could be called "Everything mountain bikers got wrong because they drifted from the true faith". I expect they do have something to offer relative to other bikes using flexible carbon fiber stays in their designs but I really can't abide the elementary errors that parade themselves as unquestionable truths in their lecture. There are simply no points of weakness, having a special prevalence in a four bar system, that cannot similarly arise in other suspension geometries. The problem is the same in all cases, slapdash engineering and/or sloppy implementation not whether you have one fewer "centres of rotation" (i.e. pivots) or not. Without fully owning up to it Pinarello indicates that the ride of the bike will be fairly uncompliant below a certain threshold. This is not something subject to adjustment or tuning, because the stays are not tunable. On the contrary it is a directive from Pinarello to all mountain bikers instructing them on what they should like and should be grateful for. Not an especially good start in my view.

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This video has 32 comments.