nice calculator

well done!!

Only thing it lacks though is Gear Inches.

oops! pretty major fuck up there! guess everyone will just keep using the less attractive, more effective Rabbit…

Love that it’s got skid patch.

Do you really need a calculator to find how many skid spots you need? Not all that difficult to do in your head.

Well sir, i’m sure many of us are ‘too busy’ to bother taking the time to work out the formula, or whatever.

Odd numbered rear sprocket = amount of skid patches.

Even numbered rear sprocket = reduce the fraction of the gear ratio.

44/17 = 17 skid patches.

44/16 > 11/4 = 4 skid patches.

Rocket science, right?

An unlearned assumption.

While that may often be true of prime numbers, it is far from the case for all odd numbers.

By way of example, the often favoured prime 17t wil result in only 1 skid patch when paired to a 51t ring as 17 represents a factor of 51.

Don’t shoot me, I was just Sheldon’s humble messenger.

I understand now that it may not be true for the entirety of odd numbered gear ratios, but for the fair majority of cases (within the range of the norm, say 40-52 on the chainwheel and 14-19 on the rear end of things [not including trick/freestyle gearing, etc]).

Still, the point still stands that a calculator for such a thing isn’t really all that useful when it’s quite simple to reduce it in your head.

AS Jams said, just use the Rabbit calculator- easy to use and has everything you need


This one is average- it looks pretty but offers less.

With 3 and 5 being factors of 50% of the ring sizes you note, this also excludes 15 from your abovementioned assumption leaving 2 remaining odd numbers in your range (fortunately they are both primes and come close to satisfying your initial representation).

That’s quite a backpedal from the initial quote of all odd numbers (punn completely intended)

Duly noted, apologies to all whose feelings were hurt due to aforementioned by gross over-generalisation.

(Oblig.) there’s an app for that.

short memories…

Great Link, I never really understood skid patches and that explained it perfectly. Thanks

Bullshit, don’t blame Sheldon, he’s correct, you’re not.

“45/15 simplifies to 3/1 so there would only be 1 skid patch.”

Definitely the messenger’s fault.

Good read about skid spots.