I’m building my KH 26x3 unicycle wheel this week and I’m wanting to know if any one has a moment to share your experience on the assembling the KH crank arms on a new KH hub? I know the drill on all my square taper stuff all too well, but not sure . . . . how tight, use grease? or locktite, where? and do I need a different type of crank arm puller to remove crank arms in the future? Anything else I need to know?
Maybe there is already another thread that answers these questions?
The splines are a lot less problematic than the square tapers. I would still put some grease or anti-seize on the spline/crank interface, but other than that, just crank the bolt down tight and you’ll be fine.
I recently built a new wheel for my Muni using the Moment Hub. As was already suggested, I used a small amount of grease on the splines before putting on the crank arms. I then tightened up the hex head bolt as tight as I could. After my ride, I found that the bolts had gotten loose, I tightened them both up again. Next ride, 1 bolt had come loose. This time, I used locktite on the threads of the hex head bolt, reinstalled and haven’t had a problem since.
I would be interested if anyone else has had an issue with the bolt coming loose.
Regarding the crank puller, I used the same puller that I would use on my square taper cranks, but with an important change. I installed the hex head bolt loosely into the hub and then used the puller normally. I was concerned with cranking the puller into the threaded section of the hub. By putting the bolt in first, my puller was pushing down onto the outside of the bolt. The cranks come loose with out much persuasion.
My bolt has only loosened up once. It was the left crank, and I was riding down a hill. I feel a little scratch on my ankle, which is pretty weird to feel while riding the Moment cranks. So I look down, and there is a nub, and then it fell out. It sucked, but I got it in, and got back home and tightened it up.
For my cranks though, I have self-extracting bolts, so as soon as the bolt is out, the crank comes off either with it, or you just barely pull and it slides off.
Definitely grease the splines. Maybe I shouldn’t of greased the bolt. On my 05 KH it has come loose a lot. Next time I rotate the cranks I will clean the grease out and put the bolt in with blue loctite.
On the 05 KH, the splines are straight, and the cranks will pull off by hand. The 07 has a tapered spline, and will need a puller.
I like this tool I picked up recently. It will pull square or splined cranks. It actually has a hole in the handle, that the second adapter snaps in for storage, but otherwise is like this picture. http://aebike.com/page.cfm?PageID=30&action=details&sku=TL0585
Thanks for the bit on grease and locktite and crank removal. That all sounds good, but how tight should I get that allen bolt? I’m used to going for 55-60 foot pounds on the UDC square taper hubs, but I know thats not needed with the splined hub, right??
Bolts coming loose
As a general rule: After first installation (or even after “another” installation) the cranks, especially if they are made of aluminum alloy, tend to “give up” a little with each of the following few rides! This means the contact patch between cranks and hub will tend to grow (to a bigger %). In other words the respective crank hole will adapt to the microscopic details of the hub interface, thus will enlarge slightly. So, on tapered interfaces (square, ISIS…) this effect allows the crank to enter deeper on the axle (actually it’s the other way around) thus needing further bolt tightening.
The above saying is valid for all tapered interfaces. As cranks and hub wore-out they will engage deeper and deeper until eventually the bolt/nut will press against the hub end or will run out of thread. Obviously this will not happen immediately - I just pointed out idea…
However ISIS was designed in such a way that cranks will enter on the axle to a certain point only (see ISIS standard…many numbers here). In practice sometimes to reach that “end” point you need to either tighten the bolt excessively from the beginning and risk damaging the threads or wait for the natural “give-up” process of the materials.
Finally, here is how I do it and never had problems: whenever I (re-)install the cranks I tighten the bolts hand-tight (with a 15cm lever allen key) at first and then after every ride for a while. Witch each ride the bolts allow for a lesser and lesser such tightening until eventually coming to a stop. Actually I consider it’s enough to do 3-5 tightening sessions but it’s good to check things from time to time later.
So, generally it’s not the bolts that are getting loose but the interface “gives-up” a little. Then if you use Loctite from the very first time after installation then you may have a false illusion that the interface is tight! I recommend against using Loctite in this case and in all other situations where it’s not strictly necessary!
Instead, you should use grease for both the interface and the bolts!!!
… Crank puller
They are the same for square and ISIS. The same actual tool but the tip should differ only - wider for ISIS (~16mm) and narrower for square (~10mm).
Be carefully which one you use for which application or you’ll lose some money!
You should never use the puller with the bolt inside, on the same side. This is a very bad idea. By the way: the puller has to be fully screwed in the crank. There were cases of puller stripping the crank threads…so watch out!
Finally, KH Moment hub uses M12 bolts and thus has plenty of metal wall to press against - no need for additional gadgets!