How many teeth?

[DooBlood]

Hi forum folk,

Am new to fixed/ss cycling, but have recently gotten my first fixed bike and it's awesome. I have 42 teeth on the front chainring and 16 on the rear. What is the teething of choice? How do other combinations compare?

Cheers, Doo

 

[Smurfy]

What is the teething of choice?

Farleys Rusks and Bonjela are the best choice for teething. Failing that, I find 42/17 doesn't cause too much teething pain.

 

[jim55]

more teeth on the front (with the back staying the same )=harder to start moving,i.e longer gear inches
more teeth on rear(with the front staying the same )easier ,less g.i
i run 44*16 which is more (not much(gear inches than yrs)
gen 16 on the front is a good middle ground ,it all depends on the terrain /leg strength /your preference ,but as a ballpark id say about 44 is ave ,some guys have a really big gear but thats them ,theres times id like to increase mine (46-48 or something )but i think id struggle up hill,
use sheldons site,but as a guide
less gear inches=spinny and high cadence

more gear inches =less cadence and higher top speed (but obv harder to spin )

 

[Dayvo]

It depends on where you live and what kind of terrain you'll be cycling in.

Have a look at this for an indicator.

http://www.flickr.com/groups/singlespeed/discuss/72157594527434280/

 

[Pottsy]

I run 42/16 too. It's pretty standard, as is perhaps 48/18 just due to availability of chainrings and sprockets in certain sizes.
Stick with it and see what you think. If you feel the urge to gear up or down, just get a 15 or a 17 for the back and try that.
As is said above, the terrain you ride will make a big difference to what is suitable (and fitness of course).

 

[Smurfy]

It's also worth mentioning that you'll get better wear from your tyres with some combinations than with others.

http://www.bikecalc.com/skid_patch_calculator

 

[jim55]

It's also worth mentioning that you'll get better wear from your tyres with some combinations than with others.

http://www.bikecalc.com/skid_patch_calculator[/quoteyeah ,if u skid like a hipster !!
normal riding using normal brakes (i.e)not skidding about like a div ,gearing makes no diff to tyre wear than a geared bike

 

[Smurfy]

It's also worth mentioning that you'll get better wear from your tyres with some combinations than with others.

http://www.bikecalc.com/skid_patch_calculator[/quoteyeah ,if u skid like a hipster !!
normal riding using normal brakes (i.e)not skidding about like a div ,gearing makes no diff to tyre wear than a geared bike

If you climb a lot of steep hills then the power is highly concentrated around the same crank positions as used by a 'skidder' (i.e. cranks approximately horizontal). Therefore, I believe the number of wear patches from climbing steep hills will be the same as that for an ambidextrous 'skidder'. Obviously the wear will be more diffuse than for a 'skidder', but it will still peak at the same locations (unless you regularly remove the wheel and rotate it slightly relative to the cranks). I'll bet if I changed to a teeth combination of say 45/15, which gives just two wear patches, the uneven wear would become quite apparent after 1000 miles. A good combination would be any chainring used with a 17T or 19T sprocket, or any sprocket used with a 37T, 41T, 43T or 47T chainring. Note the abundance of prime numbers here!

Chainring teeth suffer from the same type of uneven wear. Hence, many cyclists rotate their chainrings relative to the cranks to extend life.

 

[jim55]

i would argue that any extra wear on rubber (due to gearing (and in turn "extra power spots )from a fixed gear is negligible ,ur talking about splitting hairs here ,obv if u were applying that much pressure to exert wheel spin then its diff(much the same as skidding eh)but for every day riding id say it wouldnt matter

 

[Deleted member 1258]

I've tried a number of different sprocket/chainring combinations and my favourite is 44/18, about a 65 inch gear.

 

[Smurfy]

i would argue that any extra wear on rubber (due to gearing (and in turn "extra power spots )from a fixed gear is negligible ,ur talking about splitting hairs here ,obv if u were applying that much pressure to exert wheel spin then its diff(much the same as skidding eh)but for every day riding id say it wouldnt matter

If the basic assumption is applied that the rider applies almost zero power at the 12 o'clock and 6 o'clock crank positions, then I would expect the difference in wear around the rear tyre circumference to be similar* to that commonly seen between the front and rear tyres on a 'normal' bike with a freewheel. In my experience, the front/rear difference on a pair of 700x23 tyres at approximately 5000-6000 miles is somewhere around 2mm, which means the front tyre still has lots of life left when the rear tyre is ready for the bin. If you can't believe that it would happen or be significant, then you probably also have to deny that uneven chainring wear can happen or is significant.

* It won't be exactly the same because people use front and rear brakes differently, the rear tyre carries more weight

 

[jim55]

your obv right but i dont think it would b an issue is all im saying ,re the chainring its easier to see hooked teeth and gen wear on a chainring than a rubber tyre ,im not gona lose sleep over a tyres wear lol

 

[RedRider]

I'm new to ss too and I'm on 44x16. It seems a good ratio for London...gets away from lights faster and up the city's undramatic hills quicker than my geared bike.
It's a flip flop hub so I'm wondering what to attach to the other side. Should I go fixed with more or less teeth or have another freewheel with more or less teeth??? Decisions, decisions. I suppose a bit of trial and error is in order.

 

[Pottsy]

I'm new to ss too and I'm on 44x16. It seems a good ratio for London...gets away from lights faster and up the city's undramatic hills quicker than my geared bike.
It's a flip flop hub so I'm wondering what to attach to the other side. Should I go fixed with more or less teeth or have another freewheel with more or less teeth??? Decisions, decisions. I suppose a bit of trial and error is in order.

Normally people tend to go for a slightly higher gear on the fixed side, say 44/15 in your case. A fixed gear is easier to keep rolling and to get up hills than SS due to the bike's momentum helping you through the dead spot of your pedal stroke. It also means your legs won't be going round quite so madly on the subsequent descent.

 

[RedRider]

Normally people tend to go for a slightly higher gear on the fixed side, say 44/15 in your case. A fixed gear is easier to keep rolling and to get up hills than SS due to the bike's momentum helping you through the dead spot of your pedal stroke. It also means your legs won't be going round quite so madly on the subsequent descent.

That makes good sense and I'll keep it at the front of my mind. Would you say it still holds when it comes to longer/steeper climbs and descents outside of London or would being able to freewheel down be an advantage?

First rainy weekend I need to get comfortable flipping my wheel, but I like the idea of eye-ing up a hill and getting my spanner out!

(Hope this diversion is useful for the OP too.)