I can’t remember the actual reason why this all started; I guess I just figured that I could tackle some steeper hills with confidence if I had some lower-ratio gears. So I considered the possibility of fitting a smaller granny ring to my Campag Veloce triple (52Tx42Tx30T) on my Giant TCR 3. I called my LBS for advice:
“Do you have a copy of Fly Fishing by J R Hartley?”
That’s not what I asked, but I might as well have done for all the help I got.
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- “Oh, that’s a really old bike” (10 years old)
- “No-one does triple cranksets any more – everything is 10-speed compact”
- “Campag are notorious for not supporting older stuff”
- “Campag are notorious for not being compatible with any other make”
- “I’ve looked in the Campag catalog and no, we can’t get one”
- “Your best bet is someone selling an old one on eBay”
I wasn’t going to take that for an answer. So, after searching the web to no avail, I posted the question on this really excellent forum, where I was immediately informed that I needed a chain-ring with 74 BCD bolt holes, and I was directed to a site where I could get one.
So it was possible to fit a smaller granny ring, some folks reporting having successfully gone as low as 24T. The caveat was that some combinations of front/rear would be no longer usable; I wouldn’t be able to use the smaller rear sprockets while on the small front ring – the dérailleur just wouldn’t be able to take up that much slack in the chain. I didn’t mind this inconvenience. After all, I would almost never use that combination of front/rear gears anyway. I bought a 26T TA 74mm PCD from here for £25 and fitted it to my bike without making any other adjustments.
I can use the new small 26T front with everything except the 2 smallest (14-15) rear sprockets. On the 2 smallest sprockets the chain touches the dérailleur as shown here:
On the next sprocket (16T) there is a couple of mm clearance:
On the front, the chain still clears the front mech:
What did I gain from this? I gained two lower gears. On my old 30T chain-ring my lowest gear was 28 gear-inches. As you can see from the chart, the new 26T ring gives me extra gears of 27 (hardly any different to my old 28 really) and 24.
How does it perform? This is what I wrote at the time:
“Went for a 25-mile ride today and tested my new 26T front ring. Worked perfectly. No problems whatsoever changing up or down. The only thing is the extreme difference between the 26T and the 42T at the front, so when approaching a hill and changing to the small front it plunges me into a really low gear, resulting in my legs spinning furiously; so I’m perfecting the art of simultaneously pushing down both thumb levers to move to a smaller sprocket at the rear and the smaller at the front at the same time!”
Somewhat ironically it was only about four weeks later that I got a new bike that had a lowest gear of 28 gear-inches, so I was back to square one! Since that time my fitness has improved and I have shed a few pounds so I no longer need the ultra-low gears, at least on any hill I have yet climbed.
So what have I learned from this? That my LBS is no longer the font of all knowledge. Those days are over. In fact it pales into insignificance next to the vast amount of information and informed opinion out there on the web.
