I got my 26" cruiser the other day however it has a tricycle sprocket on it, I guess it's "hella sick" to have a tiny sprocket on your bike these days. I have no idea what size would be considered standard, back in the day we never bought different sized sprockets, just ones that looked cool and they came in a standard size.

I bought one over the internet, I picked the 47t because I thought that'd be the correct size, the thing is HUGE.. like the size of a manhole cover, lol

What would be a standard size for a BMX bike used to race? Just the gold standard in terms of size, I know I'd need one to fit me, but I want a good place to start, what came on all the popular BMX bikes in the 80's?

Thanks for any help.

I have no clue what would be considered standard on a 26", but when I think standard BMX gear, 44-16 comes to mind. Granted, that is a 20" gear, but still what came to mind when I read your thread topic.

Thanks, so 44 is the gold standard, right? Something you'd find on an old school Hutch or something?

I guess since the bike is bigger, the gears are gonna change... maybe I should find the stock specs on my bike, the way it came from the factory and then start there.

it also depends on the freewheel...count the teeth. I have several 26" set ups. My Prodyne has a 16-42 (on 175mm cranks) setup that works great for cruising and wheelies but if you want a bit more take off, my boy insists on the 18-42 for 26ers (yeah you Jason).

So, if you do the math:

42/16 gives you 2.625 rotations at the back wheel for one rotation of the crank and Jason's set up gives you 2.33 rotations for one crank revolution. So no matter what the combination, just divide the number of teeth on the chainwheel by the number of teeth of your freewheel and try to keep it around 2.5 - higher if you want more cruising ability and less if you want more take off. Also keep in mind that longer crank arms will assist with your take off regardless so if you run some 180s or larger you'll be taking off a bit easier just from that too.

my "standard" gears where 44/16 for my 20" but then I ran 42/16 on my cruiser.

just seemed to fit right. maybe because the bike was a bit bigger and it took a bit more effort to push it around.

the easier gear for ME was the way to go.

Now if my calculations are correct.... a 36/18 would give you the same approximate inch-gear as a 44/16 on a 20" bike (if the diameter of your wheel-tire is 26")

I tend to run a higher inch-gear on my 24" cruiser to get the same "feel" as the 20"

If you like the feel of a 44/16 on the 20", you might like a 36/18 on the 26" (or a little higher if you don't like spinning.)

The same aprrox. gears are:
36/18
34/17
32/16
30/15 etc.
Pretty easy with a 26" as the division of the ratio to tire size diameter equals between 2.07-2.01, so if your front gear is twice your rear gear(or a tooth or so higher) your about the same as a 44/16 on a 20"
These are all just estimates and how you like it to "feel" could be way different.

Thanks for the help everyone, ordered another sprocket, hopefully it works out better than the manhole cover I got before, lol.

The sprocket I have on my bike now is WAY too small, I can't ride it, a couple of pedals and I've maxed it out, I can't pedal standing up because my feet just fall. I hate waiting for parts... I wanna ride NOW!

20"- 42-16, 175 cranks
20"- 44-16, 180 cranks

24"- 40-17

26" 40-18

FRONT #TEETH DIVIDED BY REAR #TEETH MULTIPLIED BY WHEEL SIZE.

it's that easy.

44/16 X 20" = 55


55 is the magic number. .

although for cross-town rides and hauling [please review the site FAQs], you'll want to be in the 55-65 range. anything less than 55 is very spinny and you will top out real quick.


so 34/16 X 26" = 55.25


36/16 X 24" = 54. spin out pretty quick.
42/16 X 24" = 63 haul [please review the site FAQs].

the correct part about the above is "(or a tooth or so higher)". 2:1 gear ratio on a 26" only gives you "52." 2/1 X 26 = 52. that is spinnier than 44/16 on a 20".

you would want 34/16 on a 26" to get close to the classic gear of 44/16 on a 20".

What I really should have asked is what size rear sprocket/cog are you currently running? That way we could give you a better estimate of what you might want.
What size tires are you running also? 2.125 makes a gear taller than a 1.75.
What length cranks are you running? Longer cranks increase torque.

The only time I ran a 26" was in the early 80's and I beleive I ran a 40/18 with the 7 1/2" astubula cranks. Those long cranks made it easy to pedal.

I have a 41/17 on my 26in cruiser

In the eighties, my favourite gear on my 20" was 46-17.

On my 24, I normally ran 42-18, and if it was a short tight track, I would run 41-18.

I do recall the 26" cruisers running 39 or 40-18.

This is a great thread!

I'm putting together a 26" right now, so I'll be referring to this info...

Seems like using a larger rear sprocket makes the chainline feel smoother. Has anyone else noticed this or is it just a matter of chance? When I use smaller rear cogs there seems to be more chain noise... maybe it's because the chain has to bend at a harder angle?

If you want to really "geek out" over this stuff, check this out - http://www.machinehead-software.co.uk/bike...calculator.html

If you want a simple calculation, check this one. You can compare multiple sizes with one calculation. choose "gear inches" and try to get to 55-65 as stated previously http://www.sheldonbrown.com/gears/
edit - use the "nominal" wheel sizes. the 20" bmx one is off for some reason but the 20, 24, and 26 "nominal" sizes are right on.

30/14 on my 26er.