I rode my namesake today fixed up to the ridge line of the Chehelem :mountains"s southwest of Portland (1500' staring at around 200.) My old Peter Mooney is now set up fix gear with 3 separate chainlines. This was a challenge. I needed the gearing range to match the custom fix gear I mentioned in my post last page since I am nine years older than I was when i got that bike and the hills haven't gotten any lower. Now the big challenge with the Mooney is that the dropout is a fairly short standard Campagnolo horizontal dropout of the 1970s. Sliding the wheel to change cogs allows for fine gear tuning only.
So 3 chainlines. 3 completely separate gear systems except: all run with the same chain and each combo adds up to close to the same number of teeth so the hub stays in nearly the same place.
I left the house on the 44-17. (70") Got to the climb. Stopped and moved the chain inboard front and rear to 38-21 (49") Stopped at the top, turned the wheel around and moved the chain to the outside chainring. 46-13 (96") Rode down a 9% 2 mile small country road using plenty of brake (alternating front and rear) and backpedalins some for a nice easy descent in light that is tough on my eyes. Got to the bottom, went back to the original 42-17, added a couple of extra miles and rolled home.
Now, let me explain the "triple chainline". It is a combination of a double sided track hub (fix-fix), a triple crankset and a 'dingle" double cog on one side of the hub. (All cogs 1/8") So, starting in back - I run that "dingle, 17-21 on one side of the hub. I run my small cog (today the 13) on the other, I also dish the hub slightly so the dingle moves in about 2mm and the small cog out 2mm. The dingle was made with two separate cogs that I bought new. The 21 was flipped so the cog is right next to the spokes. (Chain goes exactly the speed of the spokes so minor contact doesn't matter.) A framebuilder cut out the center of the 17 so it slid nicely over the "inboard" (now outboard) portion of the 21. He made a steel "washer" as a spacer between the cogs and brazed the three parts together.
In front, I run an old Sugino 110 BCD crankset on a short Phil Wood bottom bracket. Three 1/8" chainrings. The two small ones are set like a normal double, 38 inside and 42 outside, Then the big difference. I run the third cog outside the normal outside, using custom long bolts and spacers. The bolts are 8mm flat heads with the heads on the inside, nice big stainless steel nuts on the outside. That 46 tooth large chainring is close to the crank but there is no front derailleur so it is not a big deal.
So, each chainring lines up (almost perfectly - certainly within the variations of crank locations on a tapered spindle) with its respective cog. This is NOT a 3 X 3 = 9 possible combinations, This a bike with three different velodrome worthy chainlines but none of them on the track standard line. My lowest gear is inside the track standard and the flat ground gear is outside that line. High gear another step outside that.
This was not an easy project. I designed it on a CAD program (with many trips to the shop with calipers). Had a framebuilder with real machining skills (Dave Levey at TiCycles) made the dingle and the chainring bolts. The bolts took two tries. A place where there could be no play but I still had to be able to assemble it!) And yes, the crankset assembly is time and patience consuming. But the end result? A classic English fix gear road bike that handles like a dream (thank you, Peter Money) AND I can take it into real hills as a 67 yo, Going up, I get to keep my knees and have then have a blast coming down. (The road limits my speed, NOT my ability to spin and the crotch damage I am willing to accept.) Best of all, every inch of the ride is fixed.
The Mooney has finally found its true calling. It was conceived as a bike that could be ridden in the lower 48 states 12 months of the year, do fast club rides, climb (I'm a born mountain goat), tour, and do a little off road. It's done all that. And its first calling - be the place I could go anytime to keep my sanity after a major TBI that made for years of recovery. I had no idea where I would be living. So when I ordered that bike (with a sole job of being my sanity link) I had no idea exactly what it was going to do or need, So it's a real all-arounder. Doesn't do anything really well. Not until 3 years ago when I took advantage to the long chainstays and big tire clearances and horizontal dropouts (just in case I ever wanted to go fix gear) and set it up to ride Cycle Oregon's ride to Crater Lake with miles of gravel. Did this crazy conversion so I could enjoy the gravel fixed on big tires. Yes, it worked! Really well. But I had to try fast tires also, of course. And wow! This is what this bike was made to do! So at year 38 it found it's niche.
Oh, the Mooney' s name is Pete. (Not Peter like its builder or my brother and uncle. Just Pete.) Pete will be painted on the top tube when he gets the deserved paint job in the coming year.
Ride fix gears for 35 years as much as I have and you will start thing about a custom to do what you really want. At 40 years, you might do something crazy. Just warning ...
Ben