Front derailleur to a coaster brake?

[Jpromo]

Has anybody does something like this? I'm assembling a quick klunker type bike to bring on vacation and not worry about bopping around in sand and leaving outside. I knew I wanted a coaster brake just to not worry about cables or anything hanging up when chucking it around and for simplicity's sake but it got me to thinking one could retain multiple speeds with a derailleur up front and coaster in back.

I know there would have to be some creative work done to match the tooth spacing up front to back since the link length would be different between the two drive sprockets. Also, front derailleurs are a PITA compared to rears. But still.. it'd be kind of neat to get 2 or 3 speeds with a coaster hub if one has these type of parts laying around in droves like I do. I only have a couple days to throw something together so it won't be done now but it's something to consider if the bike serves me well.

 

[Bicycle808]

Has anybody does something like this? I'm assembling a quick klunker type bike to bring on vacation and not worry about bopping around in sand and leaving outside. I knew I wanted a coaster brake just to not worry about cables or anything hanging up when chucking it around and for simplicity's sake but it got me to thinking one could retain multiple speeds with a derailleur up front and coaster in back.

I know there would have to be some creative work done to match the tooth spacing up front to back since the link length would be different between the two drive sprockets. Also, front derailleurs are a PITA compared to rears. But still.. it'd be kind of neat to get 2 or 3 speeds with a coaster hub if one has these type of parts laying around in droves like I do. I only have a couple days to throw something together so it won't be done now but it's something to consider if the bike serves me well.

I don't see how you could retain chain tension AND actually make use of the brake.

 

[Wildcat]

I tried that with my Mongoose beast, it is a problem with any slack in the chain, even with a derailleur to take up the slack. I was going to make it 2 speeds with a front shifter, but it wouldn't work with a coaster brake. A freewheel with handbrakes would probably work even making it 3 speeds, with front and rear derailleurs.


viewtopic.php?f=74&t=72428

 

[deorman]

Just use a 1-spd free-wheel and hand brakes. You'll still need a spring tensioner.

 

[outskirtscustoms]

Or find a 3 speed coaster brake hub and go to town re-lacing the rear wheel.

 

[ozzmonaut]

I built one with front derailleur to make two speeds and used a coaster brake. I put the rear derailleur on but adjusted the screws so that it kept the chain in one position. Basically when you pedal backwards the top half of the chain pushes the rear cog back to stop, while the lower half of the chain goes slack. But once you pedal forward the rear derailleur takes up the slack and you are on your way. I never had a problem with chain tension or alignment, but when I would brake the lower half of the chain would slap the frame scratching the paint. Otherwise it worked beautifully. Just remember to adjust the rear derailleur with a little more tension than normal so it will take up the slack when the chain is shifted to the smaller chainring. Mine was a 60's straightbar schwinn frame with mtb bars and alloy wheels, and I had it painted yellow and black. I wish I still had pics. The front shifting setup was off of a 24" huffy 2-spd from the 80's with the lo/hi click shifter

 

[mikeeebikey]

Or find a 3 speed coaster brake hub and go to town re-lacing the rear wheel.

^^^^^^^^^^^^^^^^^^^
This above is your correct answer!


I am usually not such a stickler for SAFETY but with the chain loose or even tensioned with a pseudo derailer it will still slip when you have to stop, especially stop fast.....
I am going to assume you are going to a beach and plan on riding sand, gear low!!! Pedal fast and go slow, only way sand works, big fat cruiser tires help.

 

[Bicycle808]

I think a kickback would be eminently more pimp.

 

[deorman]

Something's wrong with your memory, chain can only pull, not push. :? When you back-pedal, the top run of the chain goes slack. :|

 

[frameteam2003]

Dina 3 speed Bottom Bracket.
2/3 speed coaster hub
or kick back hub.

 

[wheelbender6]

Seems to me you are looking for the least expensive solution. You can go with a front derr and rear handbrake to do that. You will also need a chain tensioner, as mentioned above, or use a rear derr for that. You can use the rear derr without a cable, keeping it in a constant position with the adjustment screws, If you are planning to ride at the beach, I would definitely want 3 gears to help combat the wind.

 

[Bicycle808]

The cheapest solution is to run the CB hub as a singlespeed, as Jah intended. :mrgreen:

 

[Jpromo]

Ah yes, chain tension is important isn't it? :mrgreen: I was more curious than anything and I just had plans of a single speed anyway. Small front chainring for low gearing for sure but there will be some open road riding too so I'll have to get a happy medium on the gear ratio.

Good to hear from you guys who are more well-versed with experimenting than I am!

 

[ozzmonaut]

Something's wrong with your memory, chain can only pull, not push. :? When you back-pedal, the top run of the chain goes slack. :|

You're right. I should have thought that first because the top chain slack is what scratched my paint, and it has been a few years since that experiment. The Schwinn forum was still in full swing when I did it.