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James Bolduc [email protected]

Projects I worked on at Specialized Bicycle Components as lead engineer and supporting engineer respectively.


Designed and built a bamboo/carbon 29er while at Cal Poly!


Custom built 3-ring chain roller:

When the chain is on the small ring (shown right), the roller is barely engaged reducing friction as much as possible to allow maximum power transfer while climbing. Also there was never really a problem with the chain falling off during a climb anyway.

When descending, the roller works best when the chain is on the big ring. More speed generally meant more violent impacts causing chain to fall off so this is where I made sure the roller worked most efficiently.


Materials used for the chain roller:

The chain roller is made from two rollerblade bearings with a nylon spacer in between them with a slightly smaller OD to help keep the chain in the middle of the roller. The rubber around the roller is a section cut off a road bike tube and stretched over the bearings. A few washers helped to create the clearance required for the roller to spin. No side rubbing occurs in any gear.

New water bottle cage to prevent the rear shock from contacting the bottle.

The water bottle cage was slid up the down tube so that the upper mounting bolt is now center of the water bottle cage. The magnetic securing system allows for very minimal clearance above the water bottle since the bottle can be side loaded/unloaded. The rear shock no longer contacts the bottle.


Childhood bike made new.


My first century ride (one of several).

My wife’s first century ride.


Custom fire pit made from old shelves. Used plasma cutter and TIG welder. (Custom made fire poker not shown) Our initials

glow when the fire is burning.


Wedding ring I made for my wife on the manual lathe out of Al. Later I made matching

rings out of Ti, also on the manual lathe.


Piggy bank using oxy-acetylene welder.

Custom made kitchen cabinets.


Senior project: Designing and manufacturing a prosthetic hand for an active duty Navy SEAL.


The vast majority of the parts were machined by our 4-man team, on campus using the CNC mill,

manual mill, and various other power tools.


New design of the fingers incorporated a 4-bar linkage and one less spring, making the fingers easier to work on and actuate more smoothly. The new design was rapid prototyped on campus to

save time and test proof of concept.


Titanium cable end fittings, machined on campus by our team.

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Documents