Mechanical DIY is the essence of bicycle history. From Michaux to Macmillan to the Wright Brothers to today. Try and learn about every clever device and mod from the past. Most inventions are tweaks to already existing designs. Examples from the past belong in your toolkit.
In the 1980's, climbing gears were rare. Riders who sought stiffness, integrity, and wide ratios were out of luck. Converting road cranks to carry a third, small chainring became popular. 74 BCD allowed sizes down to 24T from the otherwise minimums of 38T or 42T.
Conversion to low gears could be achieved two ways—redrilling crank arms (to hold smaller rings) and adapter rings (to replace a double's inner ring and offer inboard holes to mount a smaller third ring).
In the '80's, at least two locations on the US West Coast perfected redrilling:
Here is our Wheelsmith tool.
A 130 BCD crank (Shimano standard) mounts on one side. 144 (Campagnolo) fits the other. Holes with hardened bushings allow accurate drilling for 74 BCD. The new holes are tapped for threaded standoffs which were offered by Campagnolo and others.
Our tool did hundreds of cranks in the Palo Alto area. Maybe you still ride one?
Campagnolo itself offered such a product from 1973–1987, but for only one chainring option, 36T. Our drilling fixture also offered holes for Campagnolo's 100 BCD triple.
Here's a double-drilled crank—someone wanted a smaller ring than the stock Campagnolo triple.
Jim Merz created a triplizing rings in the '80's in Portland. It replaced the inner ring of a double crank and offered holes from which a smaller third ring could be mounted. Jon Vara resurrected this idea in 2014 at Red Clover (Vermont). Below is a similar product from Velo Orange. These enabled triplizing without crank drilling.
Another triplizing ring was made by Sims (Santa Ana, CA). Here's one that fits Campagnolo C-Record's unique 135 BCD. 53-42-30 and away we go.
These mods were born of necessity and subsequently became obsolete but, bravo to making what you need. "If I can dream it, I can make it," a tradition that still drives the industry.
Les commentaires sont approuvés avant leur publication.
Veuillez remplir le formulaire suivant pour soumettre votre demande de rétractation.
Earle Young
avril 23, 2026
I used triple cranks for a number of years, but once I had 8- and 10-speed cassettes, found that compact double cranks worked as well. A 46×12 or 50×13 high gear is plenty, and a 30×26 or 34×29 low gear work for me here in Wisconsin, where I don’t encounter long climbs.