How much difference does a tooth make?

The History Man

Retrobike Rider
BoTM Winner
Gold Trader
rBotM Winner
Overbury's Fan
Feedback
View
This is not strictly and MTB or Road question but applies to both.

I have two interchangeable front cranks one 49T and one 48T given that the bike is a 5 speed 12-28 does the one less tooth make that much difference across the range or just on the climb or not? Anyway have fitted the 48.

can someone enlighten me?

Sticking this in the road section as well to see who is the most helpful and or articulate. :mrgreen:
 
Being as I'm primarily an off-road person (I do road bikes too but to a lesser degree), I'll reply here ;)

If you work the percentages the difference there is less than 2%... I would say it'd make very little difference unless you're a pro-level rider (in which case you might notice a difference in your cadence) you'd get 2 gear-inches of difference on the 12-tooth, less than one on the 28.

Dropping from 12 to 11 on the back would make more of a difference (as would moving from 28 to 29 on the other end of the cassette if 29's are available) as the percentage difference is much larger.
 
Congratulations. And thanks. That was the most useful answer and one that I could understand!
 
It really depends on weather it is a front tooth or a molar...


...but to the question: one tooth on a relatively large chain ring like a 49 will make little noticeable difference. If you look at a gear chart (for 27 inch wheels) it changes the ratio by only two gear inches where as if you change the rear cog from 12t to 11t it changes the gearing by 10 gear inches. (Attached is a gear chart for refernece, although it is a tad hard to read.
 

Attachments

  • gear chart.gif
    gear chart.gif
    30 KB · Views: 517
Dunno mate...
 

Attachments

  • 37.jpeg
    37.jpeg
    56 KB · Views: 475
  • Shane_Macgowan_With_Teeth.jpeg
    Shane_Macgowan_With_Teeth.jpeg
    38.2 KB · Views: 475
Yes been there. Sounds like it will make a little difference. Can you get twin ringed cottered sets?
 
Yes you can get double ring chainsets for cottered cranks. Stronglight and Magastroni were the two big names in the 50s but there were many others.
 
Back
Top