Friday, August 29, 2008

Energy Return Bicycle

Mark Groendal provided this frame for me to evaluate. The first year 2007 I ran a rigid fork. As this year ends I will be writing up my experiences and compare with a 100 mm fork.

Year One: Kenesis Maxlight Aluminum fork. This set up allowed me to focus on the frame ride. Although the fork is not "suspension corrected" the bike handled very well. Total weight 26.4 lbs.

This frame is significantly stiffer side to side than the original flat board SlingShot. The hit angle for obstacles is different with the lower mid-seat tube location of the flex rods. On occasion a direct hit with the front wheel would cause the spring and flex rods to emit a loud bang. This only happened twice while running the rigid fork.

The original SlingShot design did this as well. If the obstacle was higher than the angle of attack in relation to the front wheel axle, the frame would momentarily flex back. This would slightly slacken the cable. As it snapped back it would make the bang sound.

Year two: After installing the 100mm Noleen Fork the angle of attack has changed and the fork absorbs most frontal impacts. I have not heard the bang with this fork set up.

Cornering- This bike has the unique ability to carve a turn while the flex rods and spring load up. This stored energy is released after the apex of the turn. A boost of acceleration is felt exiting a turn.

Suspension-The typical suspension feel experienced in 4 bar, single pivot and the like designs is mostly absent. Friends of mine have asked if there was a way to feel more suspension. The bike rides like a rigid bike- or more accurately a "soft tail". Like the no pivot Moots YBB and similar brands that used this design in steel and titanium. A curved stay titanium has a similar feel. It gives and flexes a bit under load. This gives the bike a distinctive feel. Not the typical cush and squash of a bike with a shock and pivot.

Differences-The SlingShot flex point on the top tube meant that while seated without feet on the pedals the suspension could not work under rider weight. The rider weight had to be on the pedals forcing the load to pull the fame wheel base apart.

The ERB flex point is in the middle of the interrupted seat tube. While seated the rider weight pushes down on the frame spreading the wheels apart.

The effective difference is that the rider can weight both the pedals and the seat to activate the suspension. There was s distinct difference in the old SlingShot design that required the majority of the rider weight to be on the pedals to activate the suspension.

This subtle difference makes for a better handling bike in the rough stuff with the new design Energy Return Bicycle.

Friday, August 22, 2008

50 and still going

Last week I turned 50. Here is a little slide show of the last 20 years or so...

Monday, July 21, 2008

Scotland MTB Tour

I have been out and about on vacation, just returning from a tour of Scotland where I hired a Guide and rode the Highlands. Phil, of Scottish mountain bike guides was a great host.

Here is Phil leading us up the 4th highest peak in Scotland.

Wednesday, April 23, 2008

Willow Lane Dirt Jump Park

Moving dirt to facilitate broader use of the Boise City Parks Department sport facility at Willow Lane this week.

Equipment work will conclude Friday.
The weekend we shape and pack.

Friday, March 28, 2008

World IMBA Summit

We are going to Park City Utah for the International Mountain Bicycling Association World Summit. Check it out:

2008 IMBA World Summit.

Mountain biking enthusiasts from around the globe will gather in Park City, Utah, June 18-21, for the 2008 IMBA World Summit.

IMBA Summits bring mountain biking advocates, land managers, ski resort professionals, trailbuilders, park and urban planners, tourism officials and the bike industry together for collaboration, planning and celebration.

The gathering will be based at the Park City Marriott. We have lots of opportunities for outdoor workshops, guided networking rides, and other field sessions so you can embrace all that Park City has to offer.

Apply online For a World Summit Scholarship

The deadline for scholarship applications for the 2008 IMBA World Summit has been extended to Tuesday, April 8. Those interested in reducing or eliminating the cost of registration to the summit can apply online. IMBA has a limited number of scholarships available and applicants will be notified of a decision in time to register for early bird pricing or canvas their local bike shops, organizations and other businesses for funding. We want to see all of you in Park City!

Friday, January 25, 2008

2008 - In with the New

New job; Computer Systems Analyst technical support for HP.
New Snow, shoveling almost daily.
New VeloPark construction progress.
Focus on contributing to the greater good.

Hope your year brings new focus as well.