Hi Paul,
I've covered a 5 tooth difference with Campy 1010 (road) dropouts, with a slot of 37mm end-end or 32mm center-center (of the axle).
With a different chainstay length, i might have had to use a half link.
So about every 1/4 inch of usable (center-center) slot will compensate 1 tooth difference in the most ideal case.
Another limiting factor is brake pad alignment, and with horizontal track ends (road dropouts are slightly angled) this will probably make it impossible to ride more than 1-2 teeth difference without readjusting the brake pads. (This depends on the width of the brake surface and shape of the brake pad too).
Flip-flopping(?) wheels on the road is no fun. The 42:17/22 fixed/free setup i used on an off-road bike, with the fixed gear as an on-road option. In spite of dropouts and a quickrelease axle (both of which make flip-flopping easier), i usually would just pedal faster on pavement, or take public transport.
For a road bicycle I'd opt for 2 closely spaced all purpose gears (e.g. 18/20, with the 48 chainwheel) and choose between the gears based on daily/weekly/seasonal form and preference rather than expect flipping the wheel on the road.
Tobit Linke,
too lazy to change gears in
Dortmund, Germany
> Message: 11
> Date: Sun, 25 Oct 2009 17:43:44 -0700
> From: "Dr. Paul J. Wilson" <>
> Subject: Re: [CR] "Path Racer" "Road-Path" NOW Legnano
> To: <edvintage63@aol.com>
> Cc: aldoross4@siscom.net, ritzmon@sbcglobal.net, CLASSIC RENDEZVOUS
> <classicrendezvous@bikelist.org>
> Message-ID: <2B9C88A4-52E0-4C25-A96D-09065BE6652C@yahoo.com>
> Content-Type: text/plain; charset="US-ASCII"; format=flowed; delsp=yes
>
> Hi All, and Ed,
>
> I don't have near enough knowledge to respond to Ed's question.
>
> And so, I have a related question.
> I live in a very very steep hilly area and want to ride to town (very
> flat) & back on my Legnano Pista.
> I have a "flip-flop" Campy rear wheel that I would like to set up with
> a freewheels 22 or hopefully 24 and on the opposite side of the hub a
> 15 or hopefully a 14.
> And the question is, how small of a Campy chainring can I put on the
> front. It now has a Campy Pista 48. Taking a 41 that I have lying
> around shows that it is a tiny bit too small. Will a 42 fit? And if it
> does, I would love to buy one from someone.
> Also, what differential range of gearing will the dropouts handle? Do
> I have to go 15/20, or can I get away with 15/22, or 14/20, or 14/22?
>
> Here is the description of what I bought on eBay 8-2008. Some of you
> may remember.
>
> I am going to call this a 1969 Italian Path Racer
>
> Late 1960's early 1970's original Legnano with track drop-outs and
> front and rear brake bosses. All seems very professionally done.
>
> Can you say Italian Path Racer? Wierd I know....
>
> The bike has sew-up rims which I replace with Rigida clincher rims
> laced with DT Swiss spokes to the original Campagnolo Pista hubs.
>
> The bike features front and rear Universal Super 68 brakes with NOS
> Campy cables which I added the rear as the frame feature a brake boss
> at the rear and I wanted a 'finished' look.
>
> I would guess this to be a custom Legnano as in my research I could
> not find a pista with brake bosses front and rear. Servicing the
> headset there were no numbers on the fork tube and it appears to be
> original and there is no sign of the fork ever having been painted.
> Under the bottom bracket is the numbers 6125R
>
> There is no touch-up done anywhere on the paint and other than an area
> of the head tube decal lifting the paint off (Chrome underneath) the
> paint is very good with normal chips and decal scrapes for age of bike.
>
> Specs: * Legnano Chrome Fork * Campagnolo Light Blue Frame (56
> cm) * Campagnolo Seat Post * Campagnolo Handlebar Post (Fully-
> Adjustable) * Campagnolo Pedal & Toe Clips with original
> harness * Cinelli (Milano) Handlebars * Weinman Brakes *
> Fiame Rims (Double-butted spokes) * Avocet Seat * Brooks
> (England) Saddle * Reynold 531 Tubing * Silca (Milano) Pump *
> Campagnolo Wrench (in saddle pouch)
>
> Thanks for any technical help out there.
>
> Dr. Paul J. Wilson
> paul@wilsondesigns.net
> Temecula, CA. 92590