Front Chainrings and The Theory of Relativity
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.
((GL2 x %Gr) 1/age) Bf x BPf x Df
Where:
GL = length of toughest grade encountered on Sunday ride.
Gr = Steepest sustained section of GL.
Bf = 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.
This is the week to mount up the 54/44. Crank length is 175. Me 6′ 3″
I have a compact crank. Is it okay with these two as part of my weekly ride: San Miguel and El Romeral?
Ah! Great Gianni, you know how stubborn I am about the bottle cage so you can imagine that I’m no less stiff about the gears. I’m on a 52/39 – 11/23 since ever (well almost).
Imagine the expressions of my friends when we face slopes that go beyond the 15%…
But since I can choose I chose this, and with this combo I rode all the pass on the Dolomites the Stelvio (both sides in one day) and all the other hill I was lucky to encounter on my wheels. Time is no more on my side and sooner or later I’ve to abandon my beloved 23 and go compact, but I’ll try to keep it as much as possible, that’s for sure.
Gianni, I’m not sure about this one. I can go faster and in a bigger gear sitting (the relative lack of claibre in my guns does mean that I don’t last long in the saddle once it gets steep). Standing always seems like giving in to me and it requires a downshift and any speed is soon lost.
This could be down to the sessions on rollers during the winter or when Mrs Chris is away, I’ve not mastered riding out of the saddle on the rollers yet.
@Pedale.Forchetta
Man, I was in the Dolomites with my compact and dinner plate sized cassette earlier this year. I hereby declare myself a pussy !
@Mike_P ahah! You are not, if it was the first time you were there. Those mountains full of history are frightening the first time…
@Pedale.Forchetta
Amen. Choose your weapon and adapt as you may.
@Pedale.Forchetta Have kept one cage on the down tube since January 2012. A second cage has left my reasoning altogether.
@Pedale.Forchetta I’ll be back again next year so need to put that fear out of my mind.
@Mike_P absolutely!
@unversio …evidence.
@Pedale.Forchetta Now I understand. No cage. Nice.
@Pedale.Forchetta Behind the lens or in front, your photos never disappoint.
My knees are aching just thinking about climbing that on my 53/39 x 12/23. It’s pretty flat round my neck of the woods so I’d go 12/21 to get rid of the gaps if there were other any alternatives to the extortionate dura-ace option.
I can swap the spider to a compact on my crankset. My knees are to far gone for big gears in the mountains. (i’ve dropped about 8kg this year and there’s a bit more to come so that might improve things)
Two bikes, one standard, one compact.
Horses for courses.
@Martin
Yes, I don’t even have to do the calculation. That is a proper weekly ride.
@Pedale.Forchetta
I would expect nothing less from you! Hold out for as long as possible, it will only slow you down.
I was just traveling to visit my mother. My older steel bike stays at her house but no bidons. So I said, who needs a bottle? I will be like Pedale and ride all week without. And I did and it was great.
Great article….you had me, right up until the introduced the maths!
@Gianni – Beautiful. Funnily enough I was having a similar thought to your opening a few days ago as I was putting together bits for my retro rebuild. The bike still has the original 5Sp 14 x 24. I don’t know what the Chainset was when the bike was new as it was only 5 Sp and I upgraded it to 10 Sp in the 70’s. However, I was musing that either I was a lot stronger in those days or simply had more V as I don’t remember failing to get up climbs and as my two patches in those days were Somerset and South Wales they were not devoid of hills.
So it was about as I got to the bottom of the posts above that I suddenly thought – Cripes I hope there was an age factor in the equation – Fortunately there is, so I’ll use that to make it an age thing and not that I had more V back then.
When I get the bike back on the road I have a vision of that moment when the guns give up and I fall sideways to the ground. Just leave me on the bike and bury me here please just as I landed..
@Chris
I can go slower in a smaller gear sitting. Who knows. Maybe I need another correction factor, something about roller optimized pedaling efficiency. ROPE for short.
@ChrisO
Damn, that is the easy solution to all this.
Compact here all the way. Plenty fast enough on the flat, but low enough to cope with steepest climbs the Gorge has to offer.
if I want to torture myself I get the Fixie out!
@Deakus
I’ll be busted as soon as a math person shows up.
@Teocalli I think the V was stronger in everyone back then. Everyone had a straight block and raced nearly everything with it.
me too. People can ride by and touch the brim of their cap. ta.
@Gianni
In fact that might be a great way to go. Can you imagine an archeologist finding the burial in a couple of thousand years time and deciding it must be a warrior of a long lost cycling tribe. However, the way we are treating the word it’s more likely we will just be part or an ants nest as the insects are probably going to be the only survivors.
@Gianni
Four – don’t forget you have to double up for winter bikes………..
Perhaps I’m crazy but I’ve never fussed with the chainrings that have come on my bikes and the only crankset I’ve purchased a la carte has been a 53/39. So I have a 50/34 on Bike #1, a 53/39 on Bike # 2, a 52/42 on Bike #3 (that currently lives on the indoor trainer), a 46/36 on the CX bike and then another 52/42 that’s on the town bike. I’m too fucking lazy to figure out the math as to which, if any of those, are appropriate.
@Pedale.Forchetta I’m a bit of a camel myself, but how the heck do you climb a whole mountain without a single bottle?
P.S. you look dead sexy on that bike
Bike #1 Compact 50/34. Bike #2 Standard 53/39.
Bike #1 for more adventurous rides in the middle of the year. Bike #2 for colder months. I confess, I need the 34 on Britain’s short but steep hills and the 50 let’s me run a better chain angle onto the rear sprockets when rolling along the flats.
In Japan, I am 30 minute’s ride from the mountains. We have everything from short, 2k climbs at 8% to 20k at 6%. On every climb, though, there always seems to be a Wall (or “Cowface” we call it) that is 100 to 200m at a ridiculous 20%. I guess Japanese cars are great at going up hill. However, it’s not uncommon for seeing pros here on compacts with 28 or 32 large cog. I was riding standards with 11-28 for a couple of months before I decided to get a compact. Best decision I made.
@DeKerr Acually I’ve a bottle in the back of the jersey! You can tame it but you can not beat human physiology (especially in Summer).
Flemish compact with an 11-26 cassette works for everything here in norcal. Most climbs are 5-10% and 3+ km’s long. Anything over 15% takes a good grunt, but it’s not unrideable. I think about 20% is my limit with that gearing.
The cx bike has 42-39 on the front and 11-28 in the back. Grip starts to become the limiting factor here but Garmin tells me I’ve made it up 25% hills before.
@EricW Come up my way, I’ll take you on a couple climbs that will make you wish for some lower gears!
@Nate Sounds good, although I think Coleman Valley Road will be teaching us (me at least) a lesson or two about gearing this weekend.
@EricW Hey I am planning on doing Willow Creek.
@Nate Just as brutal, it seems.
Just have to look at people who race, especially motorcycle racers. They don’t care what gearing it takes to get the job done, they care about lap times and podium position.
@EricW But on gravel, for V-riety.
@Ken Ho I’d take that approach if I could generate the watts across a wide power band like a moto engine.
Semi-compact? 50/39 with 11-28 8spd worked very well for last years Wisconsin Triple Crown series. Then again, I might suck.
@scotjonscot
I mean this years.
@Gianni
A perfect way to reinforce the n+1
I will say that having a 54/39 with a 12-23 is a great lesson in Rule #5 with the Rocky mountains at my doorstep.
@Chris
You’re doing it wrong… I spin to win also, but the strong folks who stand and in the correct gear generally stretch out on me. If by ‘downshift’ when standing you mean shifting to a smaller/harder gear in the back, that is correct. If you mean you shift to an easier gear, that is why you are going slower standing.
In order to hammer it along faster, try pulling up at the back of the stroke then using your weight to push down the front, there is far more leverage in your body weight than you could ever generate sitting while hammering a gear that is one, two or more teeth easier.
But it is harder, I find exhaustion quicker standing than sitting. Usually I use it to switch up the muscle groups used, when tired in one position, I’ll switch. Also I find switching to standing when there is an abrupt change in rise helps to keep the pace smooth.
As for gearing, the Flemish Compact is well established as more manly in the previous article (prepare for the onslaught of compact apologists and standard crank evangelists, haven’t we all been through this before? Where’s the prozac), but what the hey.
Does it really matter what you have on your bike at that precise moment, as long as you are pushing the hardest you can handle? Non.
I run 53/39 x12-27. Which gives me a nice range (39×27 for tranquilo days @ 10%+, or over 16%). But I don’t race, which leaves me thinking that a 50/42 might be optimal for my day-to-day purposes…
@ChrisO
Four bikes, two standard, two compact. The standard cranksets are on aluminum bikes, the compacts are on a steel and a carbon bike. The aluminum bikes get the lion’s share of the kms. Just worked out that way.
@Beers
Whilst I think we should take that as given, it’s not part of the equation that I’d like to dwell on. It wouldn’t be good for the picture I like to paint in my mind that helps hold the thoughts of pain and self doubt at bay.
Pay it no mind @Chris, I was making a tongue in cheek reference to the ‘you’re doing it wrong’ meme, the witless trying to be witty etc.. give the other a try and see how you go, and rest in the knowledge it’s not my style to put others down, those in glass houses and all that..
Climbing while standing looks best. Gear accordingly.
Even mentioning riding a compact rule V violation, at least that’s how I read The Rules. As in everything else relating to setup of one’s steed(s), we should look to the Professional’s & Merckx for guidance. How many hatdmen of the peloton roll anything beyond a Flemish Compact? If you want it easier, first get a 12-28, or a Wi-Fli & roll 12-30 or some such nonsense. Actually if you can’t ride a in a 39-26, then you need to Rule V & train harder. Just sayin….
@Beers No offense taken. If people being wrong on the internet bothered me, this is the last place I’d come to.
I will give it a go, my climbing does need a bit of refinement. It’ll have to be hill reps though, it’s pretty flat round here.
@FNG
FFS! You might as well tell @ChrisO to wear a helmet. I think it’s widely recognized that tearing your knees apart just to look pro has little to do with Rule #5 and alot to do with the imperfect amount of dumb. If your knees and the terrain you ride allow a standard then fine but there’ll always be a bunch people out there on compacts that are far more acquainted with Rule #5 than you’ll ever be.
To quote Samuel Dumoulin “J’utilise souvent un chainset compact, je gagne souvent. Il n’importe pas si c’est une étape s’élevante ou une étape plate, je contestera pour la victoire. Il n’importe pas où vous courez ou ce que vous courez, il est comment vous courez. Je donnerai un coup de pied également votre âne, vous les pandits d’amateur.”*
*This quote comes from the internet so it’s authenticity is unquestionable.
I run a compact for a few reasons.
1, It came on the bike, 2, I’m 83kg (broad shouldered), 3, The city I live in is named after the mountain it’s built around, so hills are everywhere.
That being said, A compact should NEVER be paired to anything larger than a 23. 21 straight block is preferable.