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Added a comment about news blog RESULTS: Mont-Sainte-Anne World Cup DH Race 2017 8/5/2017 11:07 PM
CG83

Confused why UCI is giving Dean Lucas 4th place points for the overall? They switched Dean and Jack's...

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Added a comment about news blog Justin Leov and Tracy Moseley with Trek Double at EWS Tweedlove 5/31/2015 7:10 AM
CG83

What's up with Rene's time? Penalty?

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Added a comment about photo Electronic Shifting Gboxx2 Prototype DH Bike 10/17/2014 1:55 PM
Electronic Shifting Gboxx2 Prototype DH Bike

No worries. Sounds like you found out I am from California and got the material from Fairing. The controls back then were a little rough, would definitely be a lot cleaner now!

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Added a comment about photo Electronic Shifting Gboxx2 Prototype DH Bike 10/16/2014 7:54 PM
Electronic Shifting Gboxx2 Prototype DH Bike

8. Never underestimate how much you can get done in a few months. I conceived of, designed, built and raced the bike at Sea Otter in 2008, all in a 4 month span. I did the electronic shifting and custom rear hub before the year (08) was up back then.

Some more info: The Genesis of the design and first proto
Ridemonkey part 2

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Added a comment about photo Electronic Shifting Gboxx2 Prototype DH Bike 10/16/2014 7:44 PM
Electronic Shifting Gboxx2 Prototype DH Bike

Lessons learned:
1. It was definitely ideal to build multiple frames at once to save on machining and materials costs. We were also able to build alpha and beta protos this way.
2. I underestimated how annoying the chain tensioning would be. I should have designed a really simple roller tensioner onto the swingarm and made a standard thru-hole drop out.
3. The reduced unsprung mass and centralized CG made the bike ride a lot lighter than it actually was at 41.5lbs.
4. The G-boxx II unit was awesome because it was available, nicely made and functioned well, but it is definitely not the right direction for the future. The gear spread was too wide for DH, it was a big hassle to build electronic shifting just for the sake of getting rid of the grip shift, and it was quite heavy with 7 chains inside.
5. I should have run with the momentum and actually tried to make something of the effort. There was some interest, but I could have done a better job of turning that into something actually marketable. I got sidetracked with other projects/promises
6. The pro-squat design of the concentric pivot was nice an active while pedaling, but it would have been nice to have at least a little bit of anti-squat designed in. Next time I will work around it using an idler or alternate output location/gearing setup.
7. 7005 material was tough to get in the shapes and quality that was desired. It was nice because it naturally air-hardened, but that also caused problems with "old" material.

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Added a comment about photo E-shifting System 10/16/2014 7:25 PM
E-shifting System

The shifting system was fully custom. Onboard li-po battery, shifting logic via arduino board and a high torque RC sailboat servo for the pull-pull shifting system. Shifted while coasting, brakes locked up, or pedaling...

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Added a comment about photo Ceramic bearings 10/16/2014 7:23 PM
Ceramic bearings

The rear wheel ended up lighter than the DT-Swiss 240 front. With the savings at the wheel, and removal of the derailleur, the suspension was working with a good 1.5lbs less mass, unsprung.

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Added a comment about photo Electronic Shifting Gboxx2 Prototype DH Bike 10/16/2014 10:34 AM
Electronic Shifting Gboxx2 Prototype DH Bike

It's still around, though in need of some fork and brake love. Definitely considering using my lessons learned for another gearbox project, but it hasn't happened yet! thanks for the mini-showcase!

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Added a comment about photo Scurra Hard Enduro Fork and Frame 9/20/2013 7:05 AM
Scurra Hard Enduro Fork and Frame

Don't forget that every bike, single pivot or linkage, has inherent anti-squat properties! This is why most single pivot bikes (at least the ones without an idler) have the pivot in generally the same location. That is a spot with a good balance of pedaling and wheel path properties. Linkage bikes just have a bit more flexibility in controlling how the anti-squat progresses through the travel.

Also, during breaking, it is "Anti-Dive" as opposed to "Anti-Squat". Glad some people are thinking a bit more critically about the design instead of completely blowing it off!

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Added a comment about photo Scurra Hard Enduro Fork and Frame 9/20/2013 7:01 AM
Scurra Hard Enduro Fork and Frame

Correct, but since your steering axis and wheel path are independent, you can maintain the trail value, which depending on what you are looking for, is potentially more important than steering axis angle during large compressions

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Liked a comment on the item Scurra Hard Enduro Fork and Frame 9/18/2013 11:23 PM

something similar has been done before..supposed to work really well

Added a comment about photo Scurra Hard Enduro Fork and Frame 9/18/2013 11:22 PM
Scurra Hard Enduro Fork and Frame

Its actually not really about wheel path at all. There are a few reasons to explore a linkage on the front of a bike, but the primary one is to be able to tune the anti-dive dynamics in the front end. If you get anti-dive values correct, you have the potential to keep the front suspension completely active under braking, without diving, no matter how deep the braking bumps. The one main problem with this is rider feel, and the sensations that all riders are used to feeling while hitting the brakes into the corner.

In addition, with a design like this, you could easily make a lighter, more stiff front end, due to the limitations of telescoping bearing and sealing systems. Also, some interesting things like the steering axis being independent of the wheel path, keeping consistent geometry/trail during compression and trail values that don't effect steering feel keep these designs interesting.

Whether or not riders accept them is another story, but I certainly believe that the design is much more sophisticated than the average reader of the standard MTB message board would understand. Because of this, spectating the armchair engineering is rather entertaining, in a "I feel sorry for civilization" sort of way.

EDIT - Its also pretty cool how they are utilizing the front and rear shock mounting to centralize and minimize the frame loads due to large bottom out type scenarios.

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Added a comment about photo GT World Champs Bike Build Up 8/27/2013 11:55 AM
GT World Champs Bike Build Up

20" rear on the upside down bike in the middle for excellent acceleration out of the corners

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Added a comment about feature Race Report: 2013 VP EnduroFest 5/2/2013 10:16 AM
CG83

Unfortunately upon seeing the mess that was being created when the faulty results were being posted, and the fact that I wouldn't be attending the podium, my wife and I headed out. Sounds like we missed out on some good TMZ drama. A bummer because after the snafu was resolved, I ended up in 4th (instead of the original 8th that was posted), so I missed out on a chance to podium and get some free stuff. Oh well, the racing was fun, beautiful day out there and I certainly got a good work out from all of the sprinting.

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Added a comment about feature Race Report: 2013 VP EnduroFest 5/1/2013 10:59 AM
CG83

Have been in touch with the organizers and they spotted the timing issues. Results will be updates soon, hopefully!

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Added a comment about news blog 2011 Mont Sainte Anne Downhill Qualifications 7/1/2011 2:28 PM
CG83

Yeah Affy! Dan out-qualifying an impressive group. Way to recover strong!

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Added a comment about feature 2010 UCI World Cup, Fort William Downhill Results 6/4/2011 11:02 AM
CG83

Gwin: 4:34.56, Rach Atherton: 5:10.27

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Added reply in a thread offset shock bushings for slacker head angle 3/16/2011 10:51 AM

Who needs engineers for suspension and frame design anyways? There are quite a few variables that these bushings effect in the geometry and handling department. In my opinion, it is a little too broad stroked of a design to be implemented for all bikes. ... more »

Added a comment about photo M9 Bike Check. 1/29/2011 5:50 PM
M9 Bike Check.

Jealous dude! Wish I could be out there racing with you guys...

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Added a comment about video Red Bull Moments 2010: Gee Atherton 1/15/2011 10:47 AM

Take a look at the beating the wheel takes on landing. Wow!

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