I I asked the other day for some help with free mounting my Garaffe 5ft. I got some answer. I watched a video also.
NOW I also have another question
One my unicycle The giraffe has a lower sprocket. The chain goes from the pedals down to it. Well sometimes when I start off and I pull the unicycle under me the lower sprocket unscrews. Does anyone have this problem also. What can I do to fix it. I have tightened it but I haven’t done it to tight yet.
Wow, the lower sprocket unscrews? Usually, due to the nature of controling a unicycle, the lower sprocket is permanently affixed to the hub, at least it is on the giraffe uni’s I’ve seen. Is yours a homemade uni or a factory built uni?
Can you post a picture here or multiple pictures in the gallery? I’m sure a lot of us would be very interesting in seeing the problem.
Bruce is correct that it makes no sense for the sprocket to unscrew. From the photo it looks as if there are no threads and the sprocket actually just pops off. It looks as if the manufacturer failed to weld the sprocket to the hub unless there are some parts missing. Are there any threads on the inner boss of the sprocket? Are there any threads on the hub? Can you show us a closer view?
The first is my original Schwinn Giraffe hub, it has a spin on sprocket and a lock ring that spins on the other direction to hold it in place. Even this arrangement was prone to slippage as the rings were steel and the hub aluminum. Most have welded these.
The second is an early 80’s bolt on schwinn sprocket, this one has never slipped.
The third is probably like your hub with a spin on sprocket, this one has been spot welded.
If my memory serves, the Savage giraffe I saw at the LBS the other day had a spin-on that was welded to the point of over-kill.
Sounds like someone didn’t finish the job when putting your hub together. Know any local welders?
You need to get a lockring that tightens up against the sprocket and keeps it from spinning off. Your local bike shop will have a lockring of the correct size. You’ll also need a special wrench to tighten the lockring.
My Schwinn giraffe uses a screw on sprocket and a lockring. It’s not the best system because it can come loose and that is a very dangerous thing. The alternative is to weld the sprocket on the hub, but that means you’ll never be able to rebuild the wheel.
If you decide to use a lockring instead of welding make sure you use red Loctite to hold the sprocket and lockring. First clean off the threads on the hub with Loctite primer. The primer cleans off the threads and also improves the strength of the Loctite. Use red Loctite high strength thread retainer to keep the sprocket and lock ring on. Make sure everything is very tight. Let it wait 24 hours for the Loctite to cure. If you decide to have a local bike shop put the lockring on make sure they follow these exact instructions including using the primer. It is critical or you will end up getting hurt.
I used the Loctite on my giraffe hub. If it ever even shows a hint of slipping I’m going to weld the sprocket on or find a Schwinn hub that uses a bolt on sprocket.
Wow, Wheels, you dug up a pretty interesting thing here. Our one and only lonely giraffe is a Savage (which would make it a chain driven unicycle instead of a giraffe since giraffes are Schwinns). Now I’m gonna have to look at the lower sprocket setup. I wouldn’t want to invoke our club insurance policy because of a loose tooth.
Great point, JC, on the wheel rebuild comment. Hadn’t thought o that.
This is a well known problem that occurs with chain drive unicycles.
Loctite or lock rings are only going to result in a temporary fix.
The only solution is to weld the bottom sprocket to the hub.
The hub has to be steel, not alloy.
Spin the sprocket as tight as you can onto the hub
Remove axle, bearings, dust covers, tire, tube, rim strip, etc.
Have a welder weld the sprocket to the hub (Being careful as they go to weld
where the threads meet.)
Replace the axle, bearings, etc., etc.
Install the wheel and tighten the chain
After that, no chance of getting hurt. If you don’t do this, ride at your
own risk !
I don’t sell a tall unicycle that hasn’t had the sprocket welded…
and no one else should either !!!
> I I asked the other day for some help with free mounting my Garaffe 5ft.
> I got some answer. I watched a video also.
> NOW I also have another question
> One my unicycle The giraffe has a lower sprocket. The chain goes from
> the pedals down to it. Well sometimes when I start off and I pull the
> unicycle under me the lower sprocket unscrews. Does anyone have this
> problem also. What can I do to fix it. I have tightened it but I haven’t
> done it to tight yet.
> Wheels’s Profile: http://www.unicyclist.com/profile/3183
> View this thread: http://www.unicyclist.com/thread/22472
This is true for riding forward. But many folks love to do more than just ride forward, i.e., idle, which means the sprocket will loosen during the backpedaling motion.
So the sprocket should be welded in place to prevent it from coming loose. Then for the comment offered by John Childs, should the wheel need respoking, how would one ever accomplish the task for the spokes on the sprocket side without breaking the welds free and removing the sprocket? Sure seems like more maintenance hassle than I would want to deal with.
Applying my ‘riding a unicycle is like being in orbit’ theory, all you need to do is keep pedaling faster and faster and faster and faster and the sprocket will never unwind. Remember, it will only unwind if you slow down. Now the question is, will you reach terminal velocity or escape velocity?
of course it should be welded. my unicycle factory girafee is. the cheaper ones i’ve seen are just held on by the lockring. i would bet that if you ride it backwards long enough and jerky enough, it’ll spin off. tighten it on as tight as possible, use locktite, or have someone toss a weld or two on there.
Dustin Kelm has mentioned before that he used to use red Loctite on the lockring of his 6" giraffe. It would work for a while and then start to slip. He now has the sprocket welded on.
Welding is the safe way to go. Just make sure that your wheel is in good condition, the spokes are all good and it is a rim that you are happy with because after welding the sprocket on you are never going to be able to rebuild the wheel.
If you’re lucky you only get broken spokes on the non-sprocket side of the wheel.
Peening the lock nut to the hub boss in several spots might be a reversible solution. I have not tried this I am only suggesting it.
Unlike John, I could rebuild a wheel with a welded-on sprocket blind-folded and with one hand set in a bucket of concrete. I could do it with my lips if I wanted to. I could even do it with John beating me with his mini-giraffe while singing along to Britney Spears tunes in the wrong key.
One way to make a weld somewhat reversible is to weld a tab (bridge) across
the two components. Welding is done at the opposite ends of the tab so that
when you want to take it apart you just grind the tab in half.
Maybe three tabs in a circle? Tabs can be also be bent to reach around