As for what freewheel to use, I found a 16tooth left hand freewheel. But does using a right handed freewheel work on the left side? With normal multispeed freewheels, there is only threading half the way into the freewheel and only on one side. So it would have to be flipped over to be put on the left. This would mean it would spin in the wrong direction.
But most BMX freewheels including a few I already have (I have an 18tooth freewheel currently installed and a 16tooth freewheel that came with the kit) have no obstructions on them that would prevent them from being screwed on the opposite side without being flipped and thus would freewheel in the correct direction.
Bolts can be flipped over and still be screwed on. So I think the same can be said for freewheels since they screw on in a manner similar to bolts. I could just use one of my right handed freewheels. Since they have no flanges or obstructions on either side, they can be screwed on from the opposite face of the freewheel then normal and it would not have to be flipped over to screw onto the hub.
couple things. 1 you already said this earlier in your thread:
Originally Posted by Apache Thunder
Flip Flop hubs won't work. The threading on the left side is right handed and the freewheel/fixed gear would unscrew off the hub if power was applied to it on the left side. Flip Flops were meant to be "flipped" when a user wants to use the other gear. Each side was intended to be used on the right side and both can't be used at the same time. Thanks though.
2 threading on a freewheel onto the left side of a flip flop the way you describe above (assuming you could) would not allow you to use a freewheel tool to tighten it, b/c the tool notches would be on the inside of the freewheel, and thus inaccessible.
Here's two pictures. They are a bit outdated now. I have a headlight on front and a battery meter installed in the battery box and a ratchet cable instead of bungee cable holding the box to the frame. Also, the multi-speed freewheel shown has been removed and replaced by a 18tooth single speed. It doesn't have alignment issues anymore or if it does, it's not enough to cause excess noise with the chain. The chain hasn't derailed or broken in the past 2-3 weeks, so it looks like it will hold up now. The single speed freewheel definitely freed things up a bit.
The bike will currently go about 20 miles an hour. (22-23miles in hour if I use a 16tooth freewheel) So given that I only paid about $140 for the entire kit minus the batteries/battery box. I thought it was a pretty good deal.
Couldn't find anything near that price range that I could afford and would have the power I need. It's a 36v system by the way. Gotten from eBay by the way. Sure a few risks associated from that, but the parts I got seem to hold up well for me so I did manage to find a good seller. (except for the freewheel extender thing that came with the kit. That was the only piece that seemed below par quality wise)
I thought about finding a way to put the batteries within the frame for a lower center of gravity, but right now that's where my bike lock is mounted. I have no planes on changing it now since the bike rides fine for me as is and lithium batteries will soon replace the SLA batteries. Box is larger then the batteries by a good 3-4 inches on each side and 4-5 inches from the top. So it's a bit larger then it needs to be, but I didn't have a whole lot to chose from in terms of battery boxes so it was either this one or a smaller one that might have been too small. (note that the speed controller is also inside the battery box) I designed it like that to be a bit more weather proof. I've ridden it in wet weather without issue thus far.
I have a second ratchet cable tying down the batteries inside the box. So rest assured, nothing is moving around in there.
(click to enlarge)
It ain't pretty and some here already said it may be tough to ride but I've had no problems with it. (especially now that I got a double leg kickstand installed). It may ride a bit like a tank, but I don't mind that at all. I've used it like this for the past month and had no issues other then the chain alignment which seems to be solved now.
I never had to use a freewheel tool to "tighten" a freewheel. Simply pedaling it (or in this case having the motor drive it) would act to tighten it. Perhaps your confusing the freewheels with cassettes. They attach to the hub differently and do require tightening with a tool I believe and I've never heard of a single speed bmx bike using a cassette. Only multi-speeds seem to have those.
The couple freewheels I do have, don't even have notches for a freewheel tool. A tool is only needed for removing them. Since the rim and freewheels I do have were cheap, I don't fathom why I would bother trying to remove them.
Last edited by Apache Thunder; 01-15-12 at 12:53 PM.
Yours looks like mine did in the beginning...
I opted for a "lockable file folder box" from Office Depot/Staples as it looks better and weighs less..
Albeit at $50 a pop, probably too expensive for you.
I never had to use a freewheel tool to "tighten" a freewheel. Simply pedaling it (or in this case having the motor drive it) would act to tighten it.
Yup, in full agreement if were talking about the right hand side with a right hand freewheel. I was trying to help you see the problem with what you described in post #25 where you described moving a right hand freewheel with threading all the way through over to the left hand side of a hub without flipping it (right hand threads)...in order to make this work on the left hand side, you'd have to tighten this with a tool, which you could not use, b/c the tool notches would be inaccessible. Anyways, the next problem would be keeping the freewheel in place once it's back on the left hand side. You might have luck locking it down "suicide hub" style, by finding an old british threaded bottom bracket lockring and threading it on there to keep it from unthreading when installed back on the left hand side...follow?
The main fact would be that I still won't need a tool to tighten it on the left side. Because if I did, it's not a true left side threading and once tightened it would become unscrewed by the motor driving force onto the freewheel. The hub I'm getting has reversed threading in respect to the threading on the right side. So when I screw on the freewheel on the left side of the wheel I will still would not need a tool to do that as screwing it on should occur in the same direction that the motor would spin the freewheel under power. If it does not tighten in that direction, then the threading is incorrect and the freewheel will unscrew off the hub when I use the motor.
As I said the hub I'm getting has the threading on the left side reversed so that a freewheel can be screwed on in the opposite direction. Since it's on the left side of the wheel, screwing it on would occur in the same direction that the motor would spin the freewheel to power the wheel.
Some models of Currie eBikes have such hubs.
Here's a picture of the hub I'm getting: (I will be buying without a freewheel since I already have one)
(click to enlarge)
Looking closely at the picture I can tell the threading on the left side moves towards the hub. This would mean that the left side freewheel will tighten when under power which is what I want it to do. I should be able to use a normal free wheel on this side just as I would on the right side.
Last edited by Apache Thunder; 01-16-12 at 02:45 AM.
1989 Krapf (with Dura-ace) road bike, 1973 Sputnik (made by XB3) road bike , 1961 Peugeot fixed gear, 2010 Trek 4400
Apache, great, but one thing:
On a freewheel there are 2 different thing to look for (and one is critical):
the rotation it is meant to go
and the threading (a RIGHT thread will ALWAYS be a RIGHT thread, no matter what side you screw it in!!! )
The rotation can be revered by flipping it, but the threads remain right threaded even if you flip it!
If you want to make it the proper way with no risks, you need a left thread freewheel, that will more likely have the natural rotation direction reversed also, with a left threaded hub on the left side.
As I and others said before: a flipped freewheel will make you use "suicide flip-flop hubs"
To be honest, another idea is to weld (or something) a one-way coupler on the motor shaft, and put a flip-flop hub with a fixie gear on the left side.