BMX - What's with small chainwheels?

I'm 32 and looking to start riding again to get back into shap after 10 years off. I'm still torn between an "adult" sized bike or a 20" like I used to ride. As I've been looking around at bikes on the net though, I noticed a lot of bikes with tiny chainwheels.

All though my teens and early 20's I rode a GT Pro Performer and later a Haro Sport. Back then, IIRC most bikes had a 44t in the front and a 16t in the back or something close to that. The dirt/street/flatland bikes I see now though have these little tiny chainwheels. I suppose as long as you shrink the rear along with the front you still end up with a similar gear ratio, but I don't quite understand why riders/manufacturers chose to start doing this. Like I said, I've been out of the loop for a LONG time. Maybe someone can enlighten me.

Thanks.

The old screw-on BMX freewheels can only manage a minimum sprocket size of 16T. I think there was one manufacturer that was able to make a special one with 15 or14?, but that was a special case which needed flip-flop hubs with smaller screw ends.

New Hub designs these days have the ratchet spawls incorporated into the hub body itself so the modern BMX hub sprockets can go much smaller - I think 11T is about standard, but I've seen smaller.

As a result, you can get the same gear/inch ratio of say the traditional 44 / 16 = 55 gear inches, with the modern equivalent of 30T / 11T = 54.5 gear inches ratio.

The advantage? Shorter chain so lighter weight, and higher ground clearance - which the riders these days need to pull off certain tricks. The trade-off is the hub sprockets wear out quicker (and as a result perhaps ruin the chain earlier) but they're replaceable. BTW, the new park-use BMX chains are way - way thicker than those in our day. :)



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A lot of people have a 25T sprocket on the front and a 9T cog as well. And Pocko pretty well covered it.

^ Minichamp, you race BMX right... just curious, what combination do the track boys use these days??

A lot of people still run 44/16. But everything is used. I ran a 41/15 I think last year, but I since I got new wheels, I switched over to a 36/13, and it feels amazing right now. I've seen everything from 45/16 to 25/9 at the track.

I have the "little" haro chainring, I *think* its a 28T... paired up with a regular 16 tooth freewheeel.

Top speed is like 8 MPH, LOL. ...But does sweet effortless ( seated ) skids .

Yeah, its a fixie ... I welded the freewheel up & swaped the whole drive to the other side ... I needed an/a eff-around/cheap mobilty ( got sick off walking to, and from grid & out to the food stand -n-back ) bike for my weekend hobby.

I may, have a pic here somewere ...




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ya 28/16 is way messed up lol.

ya 28/16 is way messed up lol.


For a "pit" bike its the shizz-nit :

http://richard.safier.com/OVR/PT%2011%2008/images/z06_0034.jpg

Old pick , now with 1.50 tires & brooks saddle.

I need to paint it ( a white stripe on the top tube & maybe some numbers ) to match the car ...

http://richard.safier.com/OVR/PT%2011%2008/images/z06_0252.jpg


:lol:

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That VW looks a little angry there man. :p

Wow, I just really looked at it and it does. That's coool.

Thanks ... its called "anrgy tape" for a reason ... :D


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Im pretty sure Odyssey did(maybe still does) make a 13t freewheel at one point. I am too poor and ride my bmx bike too infrequently to update my setup. Im running an Odyssey hazard lite cassete with a 13t cog and a 36 in the front. Not super small, but not ******** looking like the 44/16's were.

They still do, and DK now makes a bearingless 12 tooth.

How is it bearingless?

Uses bushings.

That makes sense.

They still do, and DK now makes a bearingless 12 tooth.

Will either, tread on to a regular wheel/hub ?


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i run a 38 10 but i used to have a 25 9 but my friend has an 18 8 Gear ratio.... its much lighter....

and they dont thread onto the hub... they thread into the hub. there called casset hubs they are alot stronger and lighter

18/8? he must get sick of spinning his legs like ******** and still not getting anywhere

he rides park so i guess its fine for him.

****s crazy tho