You may be right. For all you novice mechanics out there, if you feel the urge to buy a torque wrench, by all means do so. If you think it’s too much to spend for tightening cotterless/square taper cranks, you’ll be okay by following tholub’s advice. I’m sure I messed up the tightness on a wheel or two back in the day (when the only two choices were cotterless and cottered), mostly this was not the case. With a normal-sized ratchet wrench handle, just tighten it real good; even better if you have just a slight amount of grease on the tapers first. More important is to test for tightness after the first ride, and from time to time after that. With practice you’ll learn to feel when a cotterless crank is not tight.
If you’re using splined axles (ISIS and other types), the rules are different. I don’t own enough of those to offer advice here.
Sitting on the wheel? I usually just roll the unicycle up to a wall, tree or other vertical thing, and work the wrench in the direction of that thing. When new to doing this, ride for a few minutes after tightening, and then tighten again to see if it turns any more. Repeat as necessary.
The rules vary depending on the type of bearing cap. On cheaper unicycles, you will very often see a pressed-steel cap. These are found on the UDC Club and many others. See image below. The key thing for these is that the two halves of the bearing holder don’t connect when you tighten the bolts; there is always a gap. So the amount of torque is important. Tighten a little bit past finger-tight, then spin the wheel. If it spins freely, tighten a bit more, and repeat. If the wheel slows down immediately after you stop pushing it, that’s too tight, so make it looser. Repeat until you feel just a little bit of friction as the wheel spins.
The other type are machined bearing holders, which are usually solid metal. Some are designed to close until both sides are touching, and some not. So basically the rules are the same, but if the sides do close all the way, you can usually go a little bit tighter as long as the wheel still spins freely. Nobody likes to lose their bearing nuts/bolts!
Pressed steel bearing cap. Note the two halves don’t touch when it’s tight, so it’s squeezing on the bearing:
They make torque wrenches for bikes, preset to 4 or 5nm (it’s metrics, no idea what it is in imperial). Worth having one in the tool box as they don’t break the bank.
Which maker is doing such cups? We had a discussion in the German forum about putting washers in between the cups in order to close the gap and being able to tighten bolts properly without squeezing the bearing itself. KH, Nimbus and Quax have a gap in their machined bearing holders.
This has been covered before but the main things are a 5mm allen key for saddle height and bearing cap adjustment, a pump, tyre levers and patches.
In my pack I also carry a 4mm allen key for adjusting my handlebars and a spoke key. I also carry a spare tube if I’m going far on my 36, as it uses a Foss tube which can fail in strange and unpatchable ways.
I don’t bother carrying a pedal wrench or crank tools because they’re heavy and bulky and I rarely ride more than an hour or two from home. If I had a serious mechanical failure then I’d just call my wife to come and collect me :D.
One other thing I carry is some basic first aid supplies to treat road rash. It’s let me ride home in an injured state without having to walk or call for a lift.
Obviously if I was doing something like a long, multiday, unsupported ride then I’d pack more comprehensively.
A multi-tool (the Alien is my favorite) is the basic thing.
Tire levers if your multi-tool doesn’t include them (or if it can’t really get your tire off).
A patch kit.
A pump (Lezyne is by far the best)
That’s really all I have on a day ride. Maybe, maybe a spare tube if I’m doing MUni, but MUni tubes are really heavy. I often have a spoke wrench but that’s just because they’re light, you can get by on the trail without one.
Do people really use a torque wrench for (non-schlumpf) ISIS cranks? I just get a massive wrench and push down until it stops turning I also put a bit of grease on the spline so I can remove it with just as much ease in future.
when playing around with my 29er I bring nothing, the bottle is attached to the uni and I’m never extremely far away from home.
When taking my G36 it’s another story. on my camelback I have:
2 L water bag.
hex keys (2 for schlumpf button and its other special tool,4,5,6 for schlumpf cranck bolt)
digital manometer
mini pump
emergency pump in case of flat.
FOSS spare 36er tube (29er tube is in the tire)
tire levers
15mm key for the pedals
my phone, some energy stuffs to eat
I will take the same stuffs if I plan to go far away with my 29er, except the tools I need for the schlumpf hub and the 36er tube.
Yes, I’d bet that some do use a torque wrench on ISIS cranks. Engineers and manufactures do recommend torquing the fastener to a specific torque for the best performance, but what do they know?
[I][B]What are the consequences of using too much or too little pre-load?
If a crankarm has too much pre-load it will not bottom out against the crank stop on the spindle when initially installed. This will lead to the crank arm “walking” up the taper during some initial rides and a consequent loosening of the crank bolt. If the bolt is not constantly tightened until the crank finally contacts the stop, the result could be the crank falling off while riding or damage to the interface.
If the crankarm has too little pre-load it will bottom out on the crank stop prior to attaining a press-fit with the spindle. Depending on the magnitude of the press-fit, this may result in anything from a slight reduction in the load carrying capability of the interface to a “sloppy” fit between the crank and bottom bracket. This may also lead to creaking of the interface due to the slightly “sloppy” fit between crank and spindle. [/B][/I]
With all that said my gut feeling is that the ISIS connection has enough reserve strength and has proven to be quite reliable that if the torque is not exactly as specified, you would likely be just fine.
Unicycle “ISIS” hubs do not have real crank stops, and our crank splines are highly variable in size and deformability. The KH Spirit cranks, for example, I have installed at spec with a torque wrench, only to have the splines deform, causing crank loosening (and eventually, Schlumpf coasting).
We sometimes use spacers in place of crank stops; my experience of those is that the spacers themselves are not to spec and can be of different widths on the same hub.
Since our hubs are not built to spec, torque specs should be viewed as guidelines, at best. “Crank it down really hard” is probably good enough.
Is the digital manometer actually a tire pressure guage or something else?
I am wondering if a highly accurate tire PSI guage is available, or necessary? Does anyone find themselves adjusting tire pressure on a ride for any reason?
That’s describing preload on the splines, not bolt torque. With our hubs the spline preload is set by choosing an appropriate spacer thickness. Once the bolt is tightened to the point that the crank is seated against the spacer adding torque does not increase the preload. At this point your concern is damaging the bolt/threads, not the splines.
Square taper is a different beast obviously as there is no spacer/stop for the crank to seat against.
When I read these above comments about ISIS problems, it makes me seriously consider whether or not I would be better off to make my next unicycle a QU AX with Q-Axle to avoid the possibility of these problems. It is supposed to be sgnificantly lighter and stronger.
I have read aboout some problems with the QU AX Q-Axle, but those seem to be more rare than ISIS problems and was due to improper assembly.
I most likely want to go for whatever is most bulletproof and trouble free, but still works good, and will be a positive ownership experience. AS I explore this, I do not like external disks nor holes in my rims. So QU AX looks better, at the moment, unless other brands put Q-Axle on their products.
What ISIS problems? Don’t forget that discussions like this will be disproportionately made up of nerds like myself who like to pick every detail apart.
Your bulletproof and trouble free crank option is ISIS. It’s an open standard and you have many crank and hub options.
I’m sure Q-Axle is great. The spline + pinch bolt design is pretty common on bicycles these days (Note that bicycles have mostly ditched ISIS for this design, but it is due to problems with the bottom bracket bearings and not the spindle/crank interface.). The catch is that it’s a proprietary system available from only one company and will limit your options in terms of parts. Standardisation is a good thing IMO.
Maybe one day it will become more common, but for now I can’t really see that it’s solving a real problem. If you’re seeing more failure report of ISIS than Q-Axle it’s probably just because ISIS is vastly more popular.
At the end of the day the most important thing is that you have a unicycle which you enjoy riding :).
My 36" looks like no gap, but maybe there is one. Same might be true for my other close-fitting ones: DM ATU, Wilder and Roger Davies Carbon Muni (circa 1997).
This might be offensive for some of the guys on here, and it’s certainly not true for everyone, but on this forum you will find many not very skilled unicyclists that prefer to spend their time overalizing why they are not getting better or experiencing problems than practicing.
I don’t think a single one of the riders in the Downhill final at unicon uses a torque wrench for their cranks. Or measured their spoke tension. Most of the riders I know could not even tell you what tire pressure they are running, because they just fill their tire, and if it’s not enough, you put some more air in, if it’s too much, they let some air out.
I have heard the following comment from a few very good riders: When they were experimenting with a new tire, they had to get the correct tire pressure “dialed in” before the tire worked properly.
I experiment with tire pressure in the following way. Using my pump, which has a pressure gauge, I pump up the tire to whatever I think is right (a particular value on the pressure gauge), then I go on a ride. I evaluate how I feel about the tire pressure during my ride. I know that everything is a compromise. If I’m happy (if the tire doesn’t suck in a variety of conditions), next time I ride, I pump it up to the same pressure. If not, I experiment going higher or lower, then start the process over.
Sure, you can use the “feel” method. You will have to experiment, however, to get the pressure right. And you won’t be able to test all the aspects of tire performance at a particular pressure–while you’re hanging out next to your pump.
Finnspin mentioned the downhill. On a downhill tire, like the Duro, with its heavy sidewalls, maybe getting the tire pressure “dialed in” is not so important. I use a folding tire, the Ardent, on my 26" muni. Finding the point in tire pressure between what is rock hard…and where the tire starts folding, may be more difficult.
So, personally, I would say that the tire pressure gauge, while not indispensable, is a useful tool. I keep my large tire pump with the gauge at home, and carry a tiny pump in my backpack for emergencies on longer rides. I don’t change tire pressure mid-ride.
Finnspin, you hurt my tire-pressure-gauge’s feelings. Say you’re sorry!
I also put a bit of grease on the spline so I can remove it with just as much ease in future.