Categories: The Bikes

Front Chainrings and The Theory of Relativity

The old rings.

Disregarding my Schwinn Typhoon, I started keeping score with my 1976 Peugeot PX 10 LE. It came with a Stronglight 52 x 45 and a 14 x 21 five speed freewheel. I always thought this Peugeot was set up for the pavé of northern France with those gears and wire-wrapped and soldered 3x tubular wheels. Yet according to Peugeot’s advertising, this is what the boys rode in the Tour de France. Chapeau! Since this was my first real bike, the coolness of this Rule #5 rig was lost on me. The uncoolness of Mafac brakes and Simplex derailleurs was not lost on me and over time I swapped out many of the French components for Campagnolo ones but the Stronglight crankset was worthy and it stayed the longest. I found a drilled-out 42 inner ring. Surely Bernard Thévenet would approve of that. It was not such a taskmaster as the 45 and scored very high on the cool scale.

Eventually the 52s went to 53s and the 42s to 39s and there they stayed.

Post-Peugeot I lived on the sandy moraine called Cape Cod. It is rolling, easy-to-ride country; there were no steep, long climbs and the default 39 inner ring was too small for the Cape. Some switched back to 42s but our LBS had a handful of Campagnolo 44 tooth inner rings and a few of us installed them. It didn’t occur to me at the time but I was reverting to a more modern version of my original Peugeot gears. This was not a chainring for the early season but once summer arrived, it made perfect sense. The shifts between the front two chainrings were subtle and smooth. It was all good until we ventured over to a proper climb on the nearby island of Martha’s Vineyard. That climb, known to us as the hill-o-death, started off steep and never eased (this was pre-Garmin world, an estimated 15% grade). It actually was the kind of climb where if you were going to have a heart attack, it would be here. The 44 worked, it just meant most of it was done out of the saddle and the pain cave entrance was lower down. But, it may have been a faster way to get the job done. There was no in-the-saddle spinning going on; it was just more heaving of bike and body trying to turn over the shortest gear the 44 would give up.

I came to Maui armed with the 53 x 39. Earlier on Kauai, I once felt shame and horror as an older dude with stick legs passed me on the Waimea Canyon climb. Those sorry sticks were whizzing over a vile compact crankset. It gave me pause. But on Maui the 53 x 39 got the job done, until I did Maui’s version of the hill-o-death, The Wall. I got up it, but it wasn’t pretty or easy. Something was going to break doing that: knees, heart, chain, pedal, more likely part of me, rather than the bike. I was on Maui for the long haul and the Wall was not going anywhere so I opted for a compact crank.

My above prologue leads me to this, my theory of relativity. The terrain dictates the chainrings. You want a 52 x45 on your bike, stay away from the Pyrenees. If you have a compact crankset on there, there had better be some big ass climbs out your front door. But here at Velominati we like to quantify our suffering. My math is as weak as my VAM but I’m working on a calculation with correction factors which would determine what kind of crank one should have on their bike.

((GLx %Gr) 1/age) Bf x BPf x Df

Where:

GL = length of toughest grade encountered on Sunday ride.

Gr = Steepest sustained section of GL.

B = Belgian Factor, also known as Museeuw. The need to always ride in the large ring, always.

BPf = Big Pussy Factor, inverse of Bf. The inclination when a climb begins to sit when one might stand, to shift down rather than up.

Df = The Dutch factor, this is a terrain correction for sea level riding, as the Dutch do along the North Sea.

 

 

Gianni

Gianni has left the building.

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  • This pic is a few weeks ago...the LvdK and I rented a house in the Ardenne for a week and invited her parents to come along for a few days. Her father, 65, who I have nicknamed the OFH(Original Flemish Hardman) rides an old Diamant alloy whose lowest gear is a 39/25. I on the other hand am still riding my first "serious" roadbike, a budget Trek 1.5 with a triple so low that a mountain bike would blush(soon to be replaced, but funds accrue slowly). In the pic you see the OFH about 3km into the Col de Haussire doing what he did nearly the whole way....standing. I am pretty sure he put 300 meters into me over the whole climb. Leaving me only one burning question....is September to soon to start training for spring?

  • @Ken Ho

    @Teocalli

    @Nof Landrien

    If the smallest cog on your cassette has more than 26 teeth (gear inches with a 39 inner ring = 39.5) then I suggest you come out of the glasshouse before you start throwing stones at compact users.

    I guess this just restarts the discussion as to what is changing up or down a gear but a SMALLEST cog of MORE than 26 teeth. Jeez - a 26-38 on the rear or something?!?! Who makes that?

    I think he meant "smallest gear", meaning largest rear cog. I could be wrong though.

    Close ratio clusters are not new. When I was a lad, a mate got picked on a racking team, and his bike was re-jigged by a local shop. He came home with a very cylindrical cluster, and this was in the days when 10 speeds was flash, meaning 5 cogs on the back. I wonder what it was ?

    There is a "front" reference of the cassette (outer cog) and a "back" of the cassette (inner cog).

  • @Teocalli

    I think you missed the implied at the start of my post.........

    Weird the middle of that got stripped - should have included [ fx: wind up ] after "implied" - I must have used a special char that Chrome didn't like.....(hope it likes what I just put in this and I'm not back in the dunces closet!)

  • @johnthughes

    This pic is a few weeks ago...the LvdK and I rented a house in the Ardenne for a week and invited her parents to come along for a few days. Her father, 65, who I have nicknamed the OFH(Original Flemish Hardman) rides an old Diamant alloy whose lowest gear is a 39/25. I on the other hand am still riding my first "serious" roadbike, a budget Trek 1.5 with a triple so low that a mountain bike would blush(soon to be replaced, but funds accrue slowly). In the pic you see the OFH about 3km into the Col de Haussire doing what he did nearly the whole way....standing. I am pretty sure he put 300 meters into me over the whole climb. Leaving me only one burning question....is September to soon to start training for spring?

    Brilliant  - chapeau to him. I hope I'm doing that to my daughter's boyfriend when I'm 65.

    "So you want to marry my daughter... I don't give a shit about your prospects sonny, if you can't beat me up La Redoute."

  • @johnthughes

    Great Photo.  Am I the only one who is torn between stopping on a climb to take a photo and the urge to keep going as to stop would spoil the achievement?

  • @johnthughes

    This pic is a few weeks ago...the LvdK and I rented a house in the Ardenne for a week and invited her parents to come along for a few days. Her father, 65, who I have nicknamed the OFH(Original Flemish Hardman) rides an old Diamant alloy whose lowest gear is a 39/25. I on the other hand am still riding my first "serious" roadbike, a budget Trek 1.5 with a triple so low that a mountain bike would blush(soon to be replaced, but funds accrue slowly). In the pic you see the OFH about 3km into the Col de Haussire doing what he did nearly the whole way....standing. I am pretty sure he put 300 meters into me over the whole climb. Leaving me only one burning question....is September to soon to start training for spring?

    Beautiful...

    And no, September is not too soon to start training for spring; sounds like about the right time to me  (assuming you live in the northern hemisphere).

    By the way: LvdK? I haven't come across that particular acronym before. What does it stand for?.

  • @ErikdR My nickname for my girlfriend, Lady van de Kempen, I am an American and have been living in Belgium for about three years now. She is from Belgium, from a region east of Antwerp known as de Kempen(loosely translated, "the country").

  • @Teocalli I managed that while moving...though I may have set a record for slowest forward movement on a bike that isn't a track stand. =)

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