canklecat

There should be a bolt that attaches the front derailleur to a fixed bracket with a vertical slot to enable sliding the FD up and down. Easier than the locking collars on most steel frame bikes.

I've swapped chainrings and cassettes/freewheels around to suit my fitness and terrain. My routes are roller coasters, no serious long climbs, mostly lots of short steep hillettes. Around 500 feet of elevation gain every 10 miles, so typically 1,000-3,000 feet on my usual rides. I can get by with an old school 52/42 double and 13-24 freewheel/cassette, but I'd rather have some bailout gears for days when I'm tired or the headwinds are usually stiff (pretty much all winter and spring).

By the time I hit age 60 I realized I'd need to swap gearing around occasionally to suit my current "feels-like" gauge. Or have at least two road bikes set up for either go-fast or go-long days. So the '93 Trek 5900 had 52/42 Biopace chainrings (which I liked on that bike, but didn't care for on another bike -- probably minor differences in geometry, crank length, etc.) and 13-28 freewheel; and the '89 Ironman was switched from the original 52/42 and 7-speed 13-24 to 50/38 chainrings and 13-28 freewheel.

With that gearing the Ironman has been a great bike for casual and tempo pace solo and group rides, but I'd spin out on some downhills. No big deal. But for the moment the Trek 5900 is out of commission (time to service the nearly 30 year old Chris King headset, which was badly neglected). So I've been redoing the Ironman gearing.

I tried the same Biopace 52/42 on the Ironman. Worked great on the Trek with 170 cranks. But I just could not get along with the same chainrings on the Ironman with 172.5 cranks. Can't put my finger on it, but it felt too surge-y and herky-jerky, rather than the smooth transition to the elongated lobes that gave me a bit of leverage and oomph on climbs with the Trek. After a couple of weeks my right knee was twinging a bit. I couldn't find a setup of saddle angle, fore/aft or height that suited me on the Ironman with the Biopace.

So last night I switched the Ironman back to the original Suntour 52 big ring and a Vuelta 39T small ring. A few tweaks to the front derailleur locking collar. Same 13-28 freewheel I've been using for about a year. Felt great today on a 36 mile ride, with lots of rollers. Not my fastest ride on a favorite 6-mile time trial route, and today a fast group working a paceline bumped me out of the top ten on Strava to 14th. Ah, well. A couple of years ago I had 2nd place, but I knew it wouldn't last with just little old me riding solo. I doubt any combo of gearing would have mattered. I need a younger engine and legs.

I have a 2011 Diamondback Podium frame on the workstand at the moment, waiting to be built up. It came with an Ultegra 53/39 crankset, so I'll use that for awhile. It's not original spec (I think Diamondback used SRAM and FSA for their Podium series), so I guess the previous owner switched to Ultegra. And I have a 10-speed 11-25 Dura Ace cassette, so we'll see if I can handle that combo. I suspect I'll need to change the Ultegra crankset to 53/38 or smaller little ring. But the lightweight frame might surprise me and make it possible for me to climb with that combo.