Anyone Use One Of Those Huge Excercise Bike Front Sprockets?

sometimes i used to see the occassional alt/rat bike with the big 60-someodd tooth sprocket from an exercise bike on it. i picked up one of these today and i'm considering what i might use it on.

but i'm also wondering, if anyone has one, how practical a rider you've been able to make it. seems like you'd need pretty flat going as a single speed, or a cluster with huge low gear sprocket.

anyway, just wondering if anyone has any experience with one.

 

50+ T rings are common on folding bikes and mini velos,you need taller gearing to make up for the small wheels. If you build a bike with a rear wheel smaller than a 26",you'll want a big front ring to keep from spinning out even on the flats.

 

Yes, my folding Bike Friday with 20" (451mm) wheels has a 60t front ring to partially compensate for the smaller wheel size.

 

the Gear ratio will be Huge with a 26" wheel, unless you get clever and put a really large cog on the back wheel , like a 42t. ..


My 54t turns a 16" wheel 3 speed IGH in wheel has 15t cog on It.

 

They are out there, I just picked one up for $40. Even brand new they're only $170 or so. Gotta open them up and re-grease them though, they don't put any grease in these things from China. Nice cruiser- comfortable- feels like a little kid riding your dads bike! Can't imagine how he pedals that thing with a 65t, but I do plan on experimenting with the gearing. It's tough to peddle with the 32" wheels on a grade but if I get stronger with it I might want to bump it up a bit. I was cruising the other day about 17/18 mph stock but my cadence was up there. It's a beast but fun.

 

On a 26" bike, a 60t front with a 30t rear would give the same ratio as a 44t/22t-- this equals about 52 gear-inches. I set up cruisers for cruising on the street with 44t x 18t, which would be roughly equivalent to a 60t x 24t. 24t is far easier to source in the 3tab configuration than 30t; either size is totally attainable with hg-compat cogs. (A 6ox42t, as another contributor suggested, would result in a 37-inch gear, which would be crazy-low.)