42T Front Chain Ring
#1
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42T Front Chain Ring
I was feeling nostalgic recently and wanted to remember what it was like to ride the gearing of my first "real" road bike in 1988, which was 52/42 up front and a 6-speed 13-23 in back.
I got a brand new, still-in-packaging Biopace 42T ring on eBay for $10 (I was also curious how Biopace used to feel after being away from it since 1990).
I put it on an old 80s Bianchi I built up, with 12-23 8-speed in back. I have to say that I really like it. The Biopace feel isn't as pronounced as I remembered, but I am enjoying the extra gear inches available while in the small ring. Coming somewhat from the old days, I ride trying to keep the chain running as straight as possible and with a 53/39 I find myself jumping between the front rings a lot. Not so with the 42T.
I like this retro arrangement enough that I picked up a couple more Biopace 42T rings for my other two bikes. There are some tough climbs in my area (Las Vegas) and the extra 3 teeth don't make anything unclimbable.
Anyone else using a 42 up front?
I got a brand new, still-in-packaging Biopace 42T ring on eBay for $10 (I was also curious how Biopace used to feel after being away from it since 1990).
I put it on an old 80s Bianchi I built up, with 12-23 8-speed in back. I have to say that I really like it. The Biopace feel isn't as pronounced as I remembered, but I am enjoying the extra gear inches available while in the small ring. Coming somewhat from the old days, I ride trying to keep the chain running as straight as possible and with a 53/39 I find myself jumping between the front rings a lot. Not so with the 42T.
I like this retro arrangement enough that I picked up a couple more Biopace 42T rings for my other two bikes. There are some tough climbs in my area (Las Vegas) and the extra 3 teeth don't make anything unclimbable.
Anyone else using a 42 up front?
#3
" 42t, round one, is the middle on my triple.. " Same here. I used to have the same setup, except 13 - 21 Regina. It helped to be young and stronger! Then I didn't find the 39 too bad and liked the lower gears... then the 12 - 26...... then the 30 - 42 - 53 triple. Best of both worlds, with the 42 and fewer double shifts and the bailout gears. If I win the lottery maybe a Chorus 12 - 29 & 36 -52
#6
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49/42 and 49/44 are wonderful. With a 12 x 29 cassette I still have a very good climbing gear, even with the 44.
49 x 12 is 110 inches. I just don't need to go 50mph down a hill, it doesn't really matter for the type of riding I do.
But I love the big(ger) inner rings!!
49 x 12 is 110 inches. I just don't need to go 50mph down a hill, it doesn't really matter for the type of riding I do.
But I love the big(ger) inner rings!!
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The reason I started thinking about old school gearing was when I watched this YouTube video of the 1974 Giro awhile back. At about 3:45 you get a glimpse of the drivetrain of a rider. I'm no authority on the history of gearing used by pros, but back then I'm guessing 42T was standard and that rear freewheel looks like it is 23T, maybe 25T max.
https://www.youtube.com/watch?v=8km8B7A0L9Y
42x23 never kept me from riding anywhere on my '88 Sirrus, so I figured I'd give it a shot again. 42x23 is the lowest gear on the Bianchi Nouva Racing frame I built up last year; I have 42x26 on my LeMond Buenos Aires and 42x25 on my De Rosa.
https://www.youtube.com/watch?v=8km8B7A0L9Y
42x23 never kept me from riding anywhere on my '88 Sirrus, so I figured I'd give it a shot again. 42x23 is the lowest gear on the Bianchi Nouva Racing frame I built up last year; I have 42x26 on my LeMond Buenos Aires and 42x25 on my De Rosa.
#8
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Back in the day a normal low gear was a 42x21. If you ran a 42x18 that was a "high low gear", so sort of like running a 39x21 nowadays. A quick and easy way to relate to a 42T is to subtract one tooth if you're using a 39T, so a 42x21 is like a 39x20. A 42x18 is like a 39x17.
I only used a 23T for hilly road races, like most people, and I would build the freewheel just for the race, then remove the unwanted 23T after. For climbs under a mile or so I usually had a 42x21 or 42x20, for climbs that required standing or that didn't, respectively.
Keep in mind that before ramped cogs most riders would customize their freewheels and, later, cassettes, so you could really build a super custom setup out back. No worries about lining up ramps etc - there were none. Remember also that riders only had downtube shifters. Some racers would use a right side bar end, but mainly they were crit racers thinking about the sprint. Usually if you were standing on a climb you committed to a particular gear and went for it. Sitting, shifting, and standing again would really kill your momentum. Bar ends didn't help much because you usually don't do long out-of-saddle climbs in the drops.
Eddy Merckx was interviewed at what appears to be the Campy 80th anniversary shindig. They asked him about compacts. "I wouldn't need a compact". Not only would he not use a 42, sometimes they were fitting a 46 or 48 INNER ring for the climbs.
Thierry Claveyrolat won the polka dot jersey in the Tour using a 45T or 46T inner ring, this in 1990. He helped Lemond in the Tour du Pont using similarly huge gears.
Right now I'm running a 53/44, left over from last year when I ran a 55/44. Normally I run 53/39 but my two sets of rings wore out so I borrowed the set off the tandem - when I got the 53x39 I kept the 44 for whatever reason. For about 10 years I ran a 54x42, 12-21, going to an 11-21 when 11T cogs became available.
53x42, 12-21 in this picture:

54x42, 12-21, a couple bikes later. Note the bar end shifter (just the right side), the Aerolite pedals (other than Looks the only clipless pedal really available for about a year or two).
I only used a 23T for hilly road races, like most people, and I would build the freewheel just for the race, then remove the unwanted 23T after. For climbs under a mile or so I usually had a 42x21 or 42x20, for climbs that required standing or that didn't, respectively.
Keep in mind that before ramped cogs most riders would customize their freewheels and, later, cassettes, so you could really build a super custom setup out back. No worries about lining up ramps etc - there were none. Remember also that riders only had downtube shifters. Some racers would use a right side bar end, but mainly they were crit racers thinking about the sprint. Usually if you were standing on a climb you committed to a particular gear and went for it. Sitting, shifting, and standing again would really kill your momentum. Bar ends didn't help much because you usually don't do long out-of-saddle climbs in the drops.
Eddy Merckx was interviewed at what appears to be the Campy 80th anniversary shindig. They asked him about compacts. "I wouldn't need a compact". Not only would he not use a 42, sometimes they were fitting a 46 or 48 INNER ring for the climbs.
Thierry Claveyrolat won the polka dot jersey in the Tour using a 45T or 46T inner ring, this in 1990. He helped Lemond in the Tour du Pont using similarly huge gears.
Right now I'm running a 53/44, left over from last year when I ran a 55/44. Normally I run 53/39 but my two sets of rings wore out so I borrowed the set off the tandem - when I got the 53x39 I kept the 44 for whatever reason. For about 10 years I ran a 54x42, 12-21, going to an 11-21 when 11T cogs became available.
53x42, 12-21 in this picture:

54x42, 12-21, a couple bikes later. Note the bar end shifter (just the right side), the Aerolite pedals (other than Looks the only clipless pedal really available for about a year or two).
#9
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#10
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Thanks for your response, carpediemracing. In the Summer of 1990 I put a 13-18 6-speed straight block on the aforementioned '88 Sirrus. This was after I'd switched to a 53/39 Dura Ace crankset. Didn't get out of the small ring much that summer, but that small cassette sure looked cool!
I like seeing the old footage of pro riders gear mashing up climbs. The kids these days spin up these mountains in gears that used to be only available on mountain or touring bikes.
This video isn't too clear, but Bauer and Grewal look like they only have 21T or 23T on the climb about 1/2 way in.
https://www.youtube.com/watch?v=6tWg_CR43rg
I like seeing the old footage of pro riders gear mashing up climbs. The kids these days spin up these mountains in gears that used to be only available on mountain or touring bikes.
This video isn't too clear, but Bauer and Grewal look like they only have 21T or 23T on the climb about 1/2 way in.
https://www.youtube.com/watch?v=6tWg_CR43rg
Last edited by Eric S.; 10-09-13 at 08:21 PM. Reason: Forgot link
#13
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Thanks for your response, carpediemracing. In the Summer of 1990 I put a 13-18 6-speed straight block on the aforementioned '88 Sirrus. This was after I'd switched to a 53/39 Dura Ace crankset. Didn't get out of the small ring much that summer, but that small cassette sure looked cool!
I like seeing the old footage of pro riders gear mashing up climbs. The kids these days spin up these mountains in gears that used to be only available on mountain or touring bikes.
This video isn't too clear, but Bauer and Grewal look like they only have 21T or 23T on the climb about 1/2 way in.
https://www.youtube.com/watch?v=6tWg_CR43rg
I like seeing the old footage of pro riders gear mashing up climbs. The kids these days spin up these mountains in gears that used to be only available on mountain or touring bikes.
This video isn't too clear, but Bauer and Grewal look like they only have 21T or 23T on the climb about 1/2 way in.
https://www.youtube.com/watch?v=6tWg_CR43rg
I watched that race on TV, it was spectacular. I felt sorry for the racers, virtually no spectators for long stretches of road, it looked like an industrial park crit. Today is the first time I saw the bucket of water that someone dumped/threw-on Grewal on the hill. He said that's what saved him, his core temp dropped immediately and he was okay again.
#14
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I didn't intend to speculate what gear they were riding in on that climb; just making a guess as to their lowest gears.
I didn't see that race "live" in '84, though I was a teenager working at bike shop enthralled with cycling at the time. Soon after, the shop got a promotional poster of Grewal on that Pinarello all sweaty from somewhere on the route.
I didn't see that race "live" in '84, though I was a teenager working at bike shop enthralled with cycling at the time. Soon after, the shop got a promotional poster of Grewal on that Pinarello all sweaty from somewhere on the route.
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I read a Graham Watson article from the 80s saying how they knew Pascal Simon was finally a contender when he was able to go up the Ventoux in a 42x18.
I'm riding a compact now for the first time and finding it frustrating not having those 42x15/17 gears that were my go-to cruising gears before the pace picks up. Without cross-chaining, that is.
I'm riding a compact now for the first time and finding it frustrating not having those 42x15/17 gears that were my go-to cruising gears before the pace picks up. Without cross-chaining, that is.
#17
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From: Tariffville, CT
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I didn't intend to speculate what gear they were riding in on that climb; just making a guess as to their lowest gears.
I didn't see that race "live" in '84, though I was a teenager working at bike shop enthralled with cycling at the time. Soon after, the shop got a promotional poster of Grewal on that Pinarello all sweaty from somewhere on the route.
I didn't see that race "live" in '84, though I was a teenager working at bike shop enthralled with cycling at the time. Soon after, the shop got a promotional poster of Grewal on that Pinarello all sweaty from somewhere on the route.
The Pinarello posters were kind of funny. Or were they Battaglin? I forget, but the name was obviously put on the picture after the fact. Now I'll need to dig one up. I think you couldn't open a bike racing magazine for a couple years and not see that ad.
#18
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For anyone contemplating a 52/42/30 triple on a modern (10 speed) bike, note that Ultegra FD-6603 (and presumably FD-6703) deraillers will not shift this combination of chainrings. Those deraillers are designed for a minimum 13 teeth difference (52/39) between middle and big rings and the 10 tooth difference of 52/42 creates an interference, unless you mount the derailler so high that it doesn't shift properly. The solution is to use a FD-5603 (or FD-4603) both of which are designed for 11 teeth difference (50/39). I'm using the former with a Stronglight Fission triple crank (52/42/30 10 speed chainrings) on my LOOK. 9 speed and older front deraillers don't have this issue as most of those were designed for 52/42 combinations.
#19
In 1991 I rode in an event in WVa called the Snowshoe Challenge. Lots of great climbs, with my favorite going up past Cass and over to Snowshoe. John Howard was riding, giving helpful tips and easily standing and climbing in huge gears.
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Us guys in the "23"/CXer's like to use a 42 up front on 1x8/9/10.
#23
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What's your average cadence? This front gear size blows my mind. I saw a few Shimano 7900 cranks with 55/44 sizing and such up on ebay the other day. The fact that people push that gearing blows my mind.
But then again I like to average a cadence around 100+. Considering going mid-compact (52/36) over my current compact (50/34). Even considering going 50/36. Lose a little of the low end I never use and have a more practical setup for my riding.
I also like climbing a bit, and I don't get to ride much since to much riding negatively impacts my running, so I haven't had much time to build strength.
But then again I like to average a cadence around 100+. Considering going mid-compact (52/36) over my current compact (50/34). Even considering going 50/36. Lose a little of the low end I never use and have a more practical setup for my riding.
I also like climbing a bit, and I don't get to ride much since to much riding negatively impacts my running, so I haven't had much time to build strength.
#24
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I used a 55T for most of my 2012 season and switched to the 53 I think in March or April this year (when I went to 170s). I'm now back on 175s, 53T. I started putting my data on Strava because of some of the skepticism I see related to my posts:
https://app.strava.com/athletes/143064
I should note that I've also used a 51T outer ring so I'm a half gear off from the riders around me, or at least different enough that they won't have the same gear as me.
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