I am having trouble keeping the cranks tightened on my uni. I will tighten the crank, ride around for less than a minute and the crank would be loose again. Some people have told me to get loctite. I dont know which to choose from though. I heard that red is supposed to be permanent, but it will still come off with a little force. Blue is temporary, and ive also heard that it comes off. Ive heard that you turn the seat 180 degrees so that when you ride forward you tighten the crank, or at least not making it loose. But wouldnt this just make the other crank come loose? Im not sure what to do, and i dont want to mess up my uni. Anybody have any suggestions?
Re: Red or Blue Loctite?
On Sun, 8 Sep 2002 12:04:39 -0500,
Scott Stephens <Scott.Stephens.ao8na@timelimit.unicyclist.com> wrote:
> I am having trouble keeping the cranks tightened on my uni. I will
> tighten the crank, ride around for less than a minute and the crank
> would be loose again. Some people have told me to get loctite.
I’m not sure how loctite helps cranks.
Do you mean the cranks are becoming loose on the axle? If so, (and
assuming thay are cotterless) take them off, clean both axle and crank
socket very carefully, apply a thin smear of grease to the axle
surfaces, then do them up very VERY tight. Generally a ‘normal’ size
allen key is not enough - get a long one, or slip a metal tube over
one to give yourself about a 8 to 10" handle.
If it comes loose after that, I’d say the seating surfaces are
distorted and it’ll never work.
If you just mean the bolt comes loose, that’s normal (though not
normally that fast). It’s not uncommon to put cotterless cranks on,
then the bolt loosens after a week or so of riding. If it does,
tighten it, if it comes loose again, tighten it again. If it comes
loose a third time, something is wrong, and keeping tightening can
cause problems (and can reputedly lead to split cranks).
> know which to choose from though. I heard that red is supposed to be
> permanent, but it will still come off with a little force. Blue is
> temporary, and ive also heard that it comes off.
Blue is best. If blue is not enough on a bike or a unicycle something
is badly enough wrong that I don’t think loctite is an appropriate
solution.
> Ive heard that you turn
> the seat 180 degrees so that when you ride forward you tighten the
> crank, or at least not making it loose.
Not on normal cranks. In theory if someone came up with a threaded
crank, but I’ve never heard anyone suggest such a thing. Are you
talking about pedals coming loose from teh cranks? Then I’d say
loctite might help, though personally I’d go teh clean - grease - do
up tight route, and have never had problems with that on bike or
unicycle.
regards, Ian SMith
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A few of my friends have had this problem
I’ve been told to do this if it happens to me:
Take the nut off the axle so only the crank is on the axle.
You then take a 2x4" and a sledgehammer.
Put the 2x4" on the crank and give it a good whacking with the hammer.
I haven’t done it so I don’t know how well it works.
If anybody else has done it please tell how it worked (or didn’t)
been there done that
yeah, ive hit it with a malet, thats what i do every time. You can get the nut on a lot tighter that way. I would reccomend it too. A malet is a good idea.
I use a little grease on the taper and red Loctite in the nut. On larger bolts and nuts the red Loctite is still easy enough to loosen up using regular hand tools. However, if you put red Loctite on a small nut or bolt you would have difficulty getting it undone. Save the blue Loctite for the small diameter bolts.
Put a little grease on the taper. This lets the crank slide on fully on the taper and gives you more consistent results when pressing the crank on. Don’t get any grease on the threads, nut, or on the area of the crank where the retaining nut clamps down. Press the crank on using either a large C-clamp or a 2x4 and a hammer. Get the crank seated as far on the taper as it will go without using excessive force. Put Loctite on the threads and nut. Tighten it all down. Do the same for the other crank.
The purpose of the Loctite is to keep the nut from backing off on its own due to vibration and other forces. As long as the nut doesn’t back off, the crank will stay tight.
In the absence of a 20 ton press, I install all my cranks with a three pound brass mallet and follow the other’s advice as well with a bit of lube on the axle taper. I use a piece of wood under the bottom crank as well as one on top to protect the surface of both cranks. Working one side at a time, I give the crank couple good whacks then install the axle nut tightly, whack the crank again (on the wood of course) and tighten the axle nut again. We’ve never experienced a crank coming loose with the one exception of the Lascos when Ben was doing 3’ drops, but that’s another story.
Bruce
I’ve found John Child’s advice great on freestyle, mountain, and Coker unis. On my Pashley MUni I used red Loctite instead of grease on the spindles.
Use blue on the axle nuts and on the pedal threads as well.
I’m sure you regularly rotate your tires to distribute the wear; one way to do this is to rotate the cranks instead. This approach also allows you to periodically ensure that the cranks are on tight and straight. Be sure to clean all the surfaces before you reinstall and use more Loctite etc.
Re: Red or Blue Loctite?
Lot’s of great advice so far in this thread. Here’s something else to check… If you’ve ridden with the cranks loose any amount of time the square hole where the crank slides over the axel may be damaged. If you have Lasco cranks the aluminium is soft and will deform easily. If the square is deformed no amount of tighenting, clamping, pounding, or loctite will help. You could have the crank all tightened down and still feel movement when you ride. If this is the case, you will need new cranks.
Re: Red or Blue Loctite?
On Sun, 8 Sep 2002 16:40:53 -0500, The Homey of Uni
<The.Homey.of.Uni.aoldm@timelimit.unicyclist.com> wrote:
>Take the nut off the axle so only the crank is on the axle.
>You then take a 2x4" and a sledgehammer.
>Put the 2x4" on the crank and give it a good whacking with the hammer.
I just re-installed cranks and did the same thing except that I did
not remove the nuts before the bamm-bamm. The outer face of the nut
did not protrude from the hole in the crank so it seemed safe to do.
But I now doubt whether the “protective” wood did not deform
dynamically and still pushed on the nuts. Next time I’d better remove
the nuts before whacking?
Klaas Bil
If you had this signature, I have forged it.
my solution
WELD IT ON!
Re: Red or Blue Loctite?
On Mon, 9 Sep 2002 23:36:38 -0500,
brokenframe <brokenframe.aqz9c@timelimit.unicyclist.com> wrote:
> WELD IT ON!
Difficult, assuming the cranks are aluminium (they probably are) and
the axle is steel (it probably is).
I’f you’re really determined, you could glue them on, but it’ll make
replacing the bearings difficult when the time comes.
regards, Ian SMith
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