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.
At 64 years of age (but who is counting) and living in the Peoples Republic of Boulder (Colorado) I’ve been riding our mountains for 35+ years. My knees still remember the days of 17 mile climbs to Nederland in a 42/21 as do I, somewhat tearfully and with some reverence. But time being what it is I just tried a compact on my mountain bike (no not a “mountain bike” – but a bike built for riding in the mountains) and I have to say, it is a pleasure. 36/25 and a positive outlook makes anything look possible… given enough time. Still have a 52/39 at #1 son’s in Portland. With a 27t Germantown and Newbury are still in the cards. I say anything goes…. as long as it’s not a triple.
Nowadays you can kind of sneak by the velonazis with a wide cassette to accompany the insecure ego of large chainrings. Plus no annoying upshifts on the compact.
@Chris
It might also be that your glutes are stronger than your quads. Some quad exercises for a few months may help increase your standing pedalling power.
Another option is that you quads get tired much faster than your glutes, so you run out of standing power quickly. This could be a position problem, or a physiology problem.
I’m only chipping in because I was the other way round for years (standing = faster, sitting = much slower), until I got my glutes firing. My massage therapist mate @Josh figured out how to help my glutes work through the duration of a ride, rather than seizing up at the first sight of a hill.
It may be contrary to Velominati instincts, but I spend much more money on body maintenance than I do on bike parts these days.
@bugleboy21
Cowface? Cow face? I’m intrigued and confused, my usual state. Please explain.
@Weldertron ah good, another in the broad shouldered 80-odd kilo club. I’ve found 34×25 is my best chance of keeping up with my more grimpeurishly built mates (see comparison below).
@Nate
Yes, but that’s my point. We don’t have a big power band. Nor do racing motorbikes. They gear them to keep the revs spinning in the power at the top. Close ratio boxes are de rigeur on racing motorbikes. On a nig grunt machine like a fat twin, it does ont matter what gear you are in, but on a low torque high revving race engine, gering is crucial. A compact not only buys you a more Achebe gear, but closes the ratios on your cassette as well. That is elementary.
I ride a 50/34 compact with an 11 speed cassette for that exact reason, keeps the ratios close, let’s me spin like one who moves back and forth on a mother, and avoids big steps between gears. I currently have an 11-25 on the rear, but would consider something like a 12-27 or more. Being PRO is all about getting to the top in speed and style, not puking by the roadside while looking forlornly at your wrong gearing.
I learned years ago while windsurfing to rig the gear that the conditions demanded, rather than the gear I wanted to run. Can’t tlell you how much good sailing I had on a 5.5 while any number of guys sat on the beach with their 4.5 rigged waiting for the wind to come in.
If there were to be a specific rule about gearing, it should dictate that appropriate gearing shuld trump ego. Ming and grunting and hurling the bike around, let alone riding across the road to deal with teh gradient is not pro.
@scotjonscot
hehehee, you might suck. The semi-compact has much to recommend itself too. The 50, (I’m banned from calling it the ‘big ring’), is good for keeping the momentum off a descent and immediately climbing out of saddle in the 50 where the 53 might bog down, if you suck. Like me.
@Ken Ho I maybe should have kept my mouth shut because I know fuck-all about motos, but you more or less enunciated my philosophy, which is to minimize gaps on the rear cluster and avoid cogs the size of dinner plates at all costs.
Just checked out the grades for this weekend’s Il Lombardia (click right tab “Climb Details”). Sick. Methinks there may be some compacts in the mix, no?
@Gianni
Truth be told, I was limited by the capacity of my rear mech. I couldn’t run the 11-28 with a 39/53. It is a nice combo, but on a good descent I spin out at about 45-48mph.(125-135ish rpm?) But around these parts, your’e pretty much at the bottom of the hill by the time you reach those speeds.(small hills) But the 39 part of the equation worked fine for me. A lot of folks thought I was nuts, but they clearly don’t understand the Rules. I will rectify this on my next build. I’ll probably still suck though.
Putting the 39 to use.
@offroaded
I don’t know, our illustrious leader can make seated climbing look pretty good.
http://bigringriding.com/post/966445460/wasp-stomping
@EricW Try doing Sweet Water Springs rd. from east to west, Bull Frog rd., or Spring mtn. rd., and tell me that a 26 is adequate (sure a 26 is enough to keep moving, anything larger will enable more speed !).
@Chris You don’t even know me douchebag, let alone how copious my V account is. Having worked in Orthopaedics for in excess of 10 years, I can assure you that potential knee damage resulting from pushing larger gears is given much more blame for injury than it is due. Other factors are significantly more problematic & causative (weight, prior injury or trauma.) Besides, for me, I’m young (40) only weight around 150, even when I’m Too Fat To Climb, & don’t have many monster hills nearby, so 53/39 drills it, plus Pantani rode a 54/42 :-)
@freddy oh yes! I’ll check it for you on Sunday!
@FNG well if you’re on a similar training regime to il Pirata it’s no wonder you’re finding it easy to push a bigger gear, just be careful you don’t wear out your brakes when you have to slow down to get around the switchbacks.
@FNG
Coming from the person who said “Actually if you can’t ride a in a 39-26, then you need to Rule V & train harder. Just sayin….” I don’t think you should be taking offence based on lack of knowledge.
You have no idea how hard I or anybody else trains and what we can do but those years in orthopaedics might come in handy when someone comes along and rips your legs off.
@FNG
Michele Ferrari was a doctor and look where that got us. And Pantani wasn’t exactly playing it by the book medically.
You don’t know me so you’ve no idea how deep my douchebag account is. I’m sure you’ve got so much V it’s oozing out of you but in my experience there always someone out there with more.
Your little rant doesn’t stack up. You tell us that it’s deeply anti v to ride compacts but go on to say that you ride a standard because you’re a skinny little fucker with no hills nearby. That suggests that you’d switch to a compact if you were somewhere hilly.
I’d suggest you are probably spot on when you highlight “significantly more problematic & causative” issues (weight, prior injury or trauma) as a contributor to knee injury but it would seem me that if you’re suffering from those a compact would be a good way to go towards minimizing the risk of future injury or long term damage.
So, what shall we cover next. How wimpy it would be not to slam your stem if you’ve got back problems?
I was pretty happy about my compact crank and 11-28 cassette when doing Sega di Ala. 14km with long sections of 20%, almost never flatter than 15% (except towards the very end), and a distinct lack of switchbacks. I positively looked like shit (at times) riding up that hill with a cadence of about 2 rpms, swerving all over the road like a complete beginner. I don’t think I would’ve gotten up that bastard otherwise.
@DCR
Does that mean the rule just became n+2 if you have to double up every time? Nice. Heather I need to…..SMACK!
@Chris
He he. I have a friend out a bit further east from you in Suffolk. He talks of peaking his local Cols at 50 feet and needing Oxygen at the top. He suffers somewhat when he comes over to the Surrey Hills.
Ha… nice one, Gianni. Your math is impeccable, as far as I can tell: (I suck at maths, so my rule of thumb in such matters is easy: if I don’t understand it, it has to be proper and correct mathematics…)
My 88-year-old dad has decided that his days as a cyclist are over, so he has given me his 30-year-old steel *Moser’ to play with. (It’s presently my #3 bike). In fact, with regard to frame geometry, it looks similar to that beautiful Masi that @Haldy has put on display in post #66 (but not nearly as pretty and well-groomed, at the moment.) It even has the same lovely saddle (a white Rolls San Marco)
Anyway: the Moser has a 42-52 chain ring combo, and a ‘straight-6’ at the back (13-18). Perfect for the pancake-flat Dutch ‘polder’ landscape it was made for, then. Here in Denmark – and more specifically, Eastern Jutland with its relatively short but steep climbs, it’s a different story. Until now, I’ve been riding it with that same, original gearing, because I think it looks so fucking cool. But, as my knees keep reminding me every time the road points up, I am an idiot.
And to be honest: the bike may look cool, but the way I have to wrestle it up the nastier inclines, out of the saddle and weaving from side to side, most probably doesn’t.
By means of compromise, I’m seriously considering fitting a slightly more merciful freewheel on the steel steed (I have a couple of 14-24 blocks lying around, one of which just might fit). That would make quite a difference, I suppose. But the 42 stays for now…
For the record: my #1 is fitted with a compact – works beautifully around these parts.
@Teocalli
Ahhahhah… Thanks mate – that provided a very welcome good laugh this morning. (Wiping coffee off the keyboard here…)
@Teocalli
That’s quickly becoming n^2. Every time a new bike is acquired, it requires the purchase of a winter version, a matching mountain bike, cross rig, and classic steel restoration.
On the subject of big gears and legs/knees, I’ve always been a spinner – I would regard a 95 rpm average for a ride as normal, and anything below 75 as grinding and only to be endured for the shortest time possible.
Recently however my coach has been setting sessions building up long periods of low cadence. I’m up to 30 minutes tempo at around 65 rpm. Also sessions with big gear acceleration bursts
I was expecting it to be leg-shattering but although the first few sessions felt like I’d been doing squats it has been relatively OK since then and I think it is quite helpful in building leg strength.
Gianni is becoming the rogue compact-riding, EPMS-toting Keeper here. I like it.
Judging by his math, my terrain requires a compact. I live at 800m altitude, and from home it’s a 600m descent into a valley from which you can only go up. Average grades are between 6-7% on the mild ascents to 15% on the steeper sections. A round trip of roughly half the local climbs (as in, each done only one way) ends with 3200m of climbing, verified. No, it’s not the alps, but if you want to keep a solid cadence you could use a compact. hen my group went together up our country’s only HC climb, I thought I was fine until the final kilometres. Having had to grind my way up at 30RPM when others spun their compacts, and when the fuse was lit in the final kilometres, I was already spent.
Sadly, I don’t have one nor the budget for a compact these days. In the works: A compact for both my TT and road rig. Why? This is why. If he can go sub-50min for a 40k TT on a 50-39, why should my weakling 61-minute legs need something bigger? For pan-flat road races and TTs, you could always sub in a 52 chainring in case of backwinds.
@Chris
I do look forward to these mornings where some new brave young thing pops up, citing their experience or relative riding abilities and preaches to the world before signing off again. We should come up with a Lexicon Entry for these people.
I mean calling yourself FNG (Fucking New Guy for those not familiar with the colloquialism) and then ranting is either cleverly ironic or a very poor Troll cover, I’m betting on the latter….
Still it has kept me chuckling for the first few minutes of the day.
What about calling them Velopandas….i.e. Eats Shoots and Leaves…
@tessar
Hmmm – I quote “There are a lot of variables, but a 50×11 is a bigger gear than Eddy Merckx ever had.”……Discuss, over to “the panel”……
@Teocalli
Factually probably correct – I don’t know every gear he ever had but his Hour 52×14 is 100 gear inches, which is significantly smaller than 50×12 (112) and 50×11 (122).
I have a bike with a compact and one with a standard chainset. They both have 11-25 casettes.
The standard is fine for around 95% of the roads local to me but I’d probably be better off with a slightly larger cassette on that bike. According to Campagnolo I can switch up to a maximum of a 29 cog without needing to swap my chain (chorus 11sp). Apparentely running 39 / 29 gives a slightly lower gear than 34 / 25. I wouldn’t to go that big anyway and I’m slightly dubious that it would work without a chain swap, any thoughts on this?
When the time comes to replace my standard bike casette and chain I think I’ll go to a 26 or 27. It seems like a sensible middle ground. My average cadence on longer rides including a fair amount of climbing is around 85rpm so I’m probably somewhere between grinder / spinner.
@ChrisO
Besides, this whole mashing thing will die out when Cadel hangs up his wheels. The pros of yore could have had a lower gearing if they wanted to, but they had to be all manly, following the same principles that led them to believe whiskey is a good sports drink and a smoke here and there will improve their breathing. In medieval ages when coffee was introduced to Europe, people thought it was good sleep-medication…
You’re a racer, Chris, and ride compacts. When was the last time you spun out, descents not included?
@Teocalli
50ft hills, lucky bastard. The Huntingdon branch of Waitrose (a super market chain for the non Brits and Northerners) has roof top car parking accessed by a nice straight ramp. That’s where I go for my hill reps. Only problem is all the learner drivers practicing their hill starts.
@Chris Fortunately I had just swallowed my tea otherwise I’d be cleaning my screen and keyboard now.
@Chris Having said that, it’s a quality hill, it could have been Tesco’s or even Lidl…..
@Deakus Vleopandas. Nice.
@FNG isn’t a one hit wonder, he has been around for a while.
@Chris
Just watch those white lines in the wet when descending….I mean you could pick up enough speed on that bad boy to drop your shadow!
@Teocalli
Nice bit of cake with that or is this a recovery day?
@Chris
In which case I remove the label I placed on him and credit him with the clever irony label….still it seemed quite some response from him crying out douchebag…40yrs old and that qualified I would have thought lucid well thought arguement would prevail.
O shit there I go again…apply judgements to others that I cannot hope to live up to myself!!!
@Chris
VMH is away this week so had to make do with bought Soreen (and making my own tea/coffee – shocking).
On the car park thing – I’m sure someone has probably already thought of this though – for evening winter training set up a series of “hill sprints” in a local multi-storey car park? Lit and out of the weather but in the fresh air, convenient local parking. We could even have a world series – Great Car Park Climbs of the World………
@Chris
I’ll be sure to hit you up with some Kudos when you take the KOM on that bad boy.
@Teocalli Or we could get the mountain bikes out and go for The World Urban Lift Assisted Gravity Series.
@norm Next time I do my hill reps session I won’t tag it as private on Strava, that would really fire up Frank’s pet peeve with inconsequential social media postings.
@tessar
Agreed – I can get up to 70km/h on a 50×12 before I really spin out. Certainly 60km/h is relatively comfortable.
That’s not just racing BTW, it’s drafting trucks – much more fun. Plus it annoys the Strava Queens no end when you take a segment… sic transit gloria mundi.
All compact (50×34), all the time since 2002. (Although I’ve stopped with the EPMS.) 50×34. Rule of thumb for the rear: >3,500 metres climbing in a day slap a 12-27 on; more than 2,500m climbing in a day put the 11-25 on; otherwise an 11-23 does pretty much everything.
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 climbed the Giant of Provence with a 53×39 11-23 in 2000. It wasn’t heroic, it was just stupid.
I feel like I imagine Luther felt at the Diet of Worms.
@Henrik Sega di Ala is a monster!
@Nof Landrien
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?
@Teocalli
We could even have a world series – Great Car Park Climbs of the World………
If they hadn’t knocked down the Trinity Square in Gateshead that would be on the list.
When you go to the top you’d have to say ‘You’re a big man, but you’re out of shape’. Then do it again.
@Teocalli
Miche makes some pretty odd cassettes – I’ve seen a 16-25 by them around. Surely there has to be something like this for Cadette racing?
@Teocalli
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 ?