Wait....WHAT ? Did I Just Hear That Right????
 

On today's Stage 9 of the 2020 Tour de France
Christian Vande Velde discussing climbing gearing, said it was conceivable for a rider to run a 32 tooth chainring and a 32 tooth rear cog.
"That would be a zero (0) inch gear.........!!!???

WHAT ******************************

Does he mean the rider running that gear can pedal and go NOWHERE ???

It's a 26.4 gear inches. Much like trials bikes, which often have a 1:1 ratio. And yes, you pedal and basically go nowhere. :)

I rented a bike in SF that had a 34 front and 34 rear. You need it there.

'gear inches' are gear ratio X wheel diameter in inches.. 1:1 x 28" is a 28" gear, dude.

Perhaps athletic ability and math acumen are not related, or he misspoke.

Yup....I know how to calculate gear inches................Christion may need a bir of an education....

W
 

Well, division is sort of like subtraction, right?

Subtraction with two more dots. (They can be had to see.) If you simply pull out the calculator (app or whatever) and do 32 - 32 X 27 you get 0. Every time. (You mean to tell me I had to put on my readers to find those silly little things?)

I find the loss of math skills and awareness a bit sad. I took math for 14 1/2 years. Don't regret it at all. Sadly, I lost a lot of it with my head injury 3 years later but when I went back to school, I got a tutor who suggested a math book with self-study chapters on many of its branches. I"m far, far from a math whiz but I do know math well enough to see quickly numbers that aren't in the ball park. (And time on the bike has meant I've figured out some tricks to getting "close enough" answers in my head while riding. Done gear inches hundreds of times!

Ben

Yeah, I heard him and also caught the error. As noted, math isn't everyone's field of expertise.

Maybe not,
But.............he WAS a pro rider for many years. He certainly should understand gear inches.....

He might have been trying to express a 0 overdrive ratio. Like in some cars when the transmission ratio is 1:1. The 6 speed automatic in my cuv is direct drive in 4'th for example, An overdrive of 0.

On a bicycle we typically call it a 1:1 ratio. Which is direct drive like a penny farthing bike. A 0 overdrive might come to mind in a pinch.

Why? Gear inches aren't widely used outside of some bike mechanics and junior racing limits. Racing wheel sizes are completely standard so looking at gear ratios tells you everything. Gear inches is not used in the mountain bike community at all.
Beyond that, it's very common for high-level athletes to have other people maintain their equipment. First parents, then team mechanics. Heck, look at the number of casual riders who take their bike to the shop to get flats fixed.

OK To all the above.

But.....
He used the term "inches." He should at least know what it means...........a 34X34 would be a 1:1 ratio....NOTHING zero about it...............
Basically 27 inches.
Gear inches does not represent anything accurate as far as travel per crank revolution.; it is off by a factor of Pi at the least.It is only used as a relatively
quick numeric comparison of the various gear ratios in a given drive train.
"Zero" is not even valid as a ratio, as a number can not be divided by zero, nor zero divided by a number.

Good for you Ben. I have always been math challenged. About 8 years ago I decided to take an algebra class at my local community college. Took the class, then another and another plus Gen biology, gen chem, O-chem and next thing I have a Biology AS degree that I don't need or will ever use. I'm starting to lose my maths for lack of use so have started just doing practice exercises.

I don't bother with inches..........an additional unnecessary step.....
A simple approximation of ratio is all I need.......

All I know, ist hat I occasionally need a bigger gear on the back!

How much bigger?

Bigger than the one on there!

Nope. My calculator app in Windows returns -832. Every time. I get the same result on my phone's calculator app. What app are you using that it gets PEMDAS wrong?

Wasn't that Bobkie's mistake?

Going fast on a bicycle doesn't have anything to do with understanding it technically. I'm sure he'd give you pass for being slow (compared to him); why not pass on the same grace?

I suppose....as long as he is to be regarded as a "color" commentator, as opposed to an "expert" commentator.

'gear inch' is the same concept... like a bunch of elementary boys comparing johnnies in the bushes.

Cadence at what speed vs at what work load... f math comparisons which are nonsense. What tooth counts are only really
references to physical ability.

And, the conversation takes another left hand turn...............

Perhaps you should go on a ride with him and explain it while climbing a local hill.

Ok,I will bite and help you keep this thread alive. Tell me how your ratios work out when comparing a 349mm Brompton and a 700x 42 Gravel tire.

If we circle back to the original post and topic, the answer is quite simple:
Based on Christian's statement, BOTH instances would produce ZERO inches if being driven by a 34X34 drivetrain.
And, it really doesn't matter if it is a blue bike or has Look Keo pedals.....
However, I realize how difficult it is to stay on topic...........