Yesterday I tried to downshift before the final climb home, and the hub skipped. This resulted in coasting for a few feet, and I could feel the hub go click-click-click with my feet stationary on the pedals, like the low gear was trying to engage but didn’t. I wasn’t going very fast, and I was able to gracefully dismount off the back. I followed the recommendation in the manual to do 24 shifts while cranking the wheel, and everything seems to shift okay still. I guess the hub just got stuck between gears. Anyone else experience this?
Also, the manual mentions that the warranty doesn’t cover damage due to improper oil maintenance, but it doesn’t appear to say how to do this. All I see is a recommendation to oil it once or twice a year. I’m assuming adding oil is done by removing the flathead screw and squirting some grease in there. I keep wiping down oil that seeps out of the side of the hub–doesn’t this mean the hub is losing oil? Is once or twice a year really enough?
I had that happen once. I really don’t like that it’s possible.
Also, Tom had a very scary situation yesterday. He had an issue with some Qu-Ax cranks coming loose. On two seperate occassions, the loose crank had pushed the button in just enough to cause it to go into neutral. This was while climbing, and NOT while trying to shift.
Did Tom torque the cranks on? I haven’t had any problems with my cranks loosening since I applied my torque wrench to the bolts at 25-30 ft-lbs. I think I’ll just stick with the KH cranks because I know they’re plenty strong and so that I don’t have to mess with changing them.
I’m not exactly sure where my feet were when the gear slipped, but I’m thinking now that maybe my shifting foot was holding the button halfway in when it happened.
I probably didn’t have enough torque in the crank bolts, because I was trying to be careful when installing, because these were the replacement bolts I got after one of the initial bolt heads stripped out. But the on the road, I didn’t really have the tools to get enough torque into the bolt; I had to keep tightening the crank every few miles (which is annoying on the Schlumpf due to the shifting button). I’m going to get a good long wrench, some degreaser and some Loctite together to hopefully make things solid.
It is clear that loose cranks are an extremely bad thing on a Schlumpf.
There’s often some neutral mode when I shift on the road, but I haven’t had it get stuck in that mode. I did, however, have it get stuck in neutral a couple of times when not on the uni; I had pushed the button to shift to low gear in preparation for mounting, and the wheel kept moving but the cranks didn’t. This was on the Cañada Road ride, I was with Corbin at the time. So it’s clearly possible for a shift to result in coasting; it probably depends on a combination of how far you push the button in, combined with how much pressure you have on the pedals at the time.
Aside: Mike and I did an approximation of the Grizzly Peak Century, doing about 100km with an assload of climbing (probably between 1500 and 2000 meters). My first century on uni! Photos at http://www.flickr.com/gp/83189681@N00/T48MJS.
There are great cycling roads all over the Bay Area.
Yesterday’s ride took us almost 9 hours start to finish, although we stopped a lot, had lunch at a local deli, and had a few mechanical problems (mostly this dang crank). The hilliness also kept our rolling speed a lot lower than it was during last week’s Napa ride, where we averaged over 13mph in RTL simulation mode (relaying) on our geared 29 and 36.
I lived in cali for a few years and the bay area is very nice. I was in the Riverside,Chino area and that was before I rode UNI. Michigan has some nice areas that when i get my coker or 29 i look forward to riding.The only downside in michigan is the cold weather + snow.
Hmm- i can see how scary a period of freewheeling must be when you don’t expect it. But at the same time i can’t help but think of the possibilities of a KH/shlumpf with an extra gear, or clutch position for coasting on downhills…
Maybe it is just me but most of my unicycling dreams have mee riding a uni at really fast pace that can also freewheel when i will it to- wierd but maybe worth a discussion? would a caliper brake give a rider enough control to negotiate a coast on a desent?
Yeah, I had a lot of trouble on that first long distance ride that we did. After that ride, I torqued them down to 25 ft-lbs (I think that was it, but maybe 30). Since then, they haven’t come loose at all!
The torque wrench was essential. I wasn’t getting it nearly tight enough with the provided allen wrench.
Coasting is hard enough when you’re doing it intentionally (I’m guessing since I can’t actually coast).
If you find yourself suddenly freewheeling at speed, you’re going to go down in an unpredictable way, and you’re probably going to get hurt (eg. Ken Looi’s compound fracture).
Whether or not you could use a caliper brake to intentionally coast at speed is beyond my skill and definitely beyond my courage!
No, you can’t coast with a brake. If you use the brake it’s no longer coasting. when you use your foot, we call it gliding. I’d still think of it as gliding but if more people started doing it we’d probably need a new name for it.
Coasting on a freewheeling unicycle is arguably easier than doing it on a regular one. However shifting into a freewheeling mode adds a level of difficulty that would make the learning curve massively steeper. I know this from shifting on my borrowed Schlumpf 36. Upshifts are almost always fine, but downshifts usually give me a brief period of freewheeling, which I’m just not prepared to ride out of when combined with the awkward foot position of pushing the shift button.
I think you’d need a disc brake to brake smoothly enough at higher speeds. I seem to remember that someone tried a disc brake with a BC wheel, and the transition when releasing the brake was problematic. The transition would probably be easier with fixed cranks than with BC plates, but you’d need an expensive hub just to try it.
You’d also need a lot of courage, like Mike says. Freewheeling on one wheel at high speeds is scary.
I’ve had the same dream a few times too. A couple of mornings I have woken up really believing that all I need to do is knock the Schlumpf in to neutral and the rest is simple. Sadly though that belief is normally gone by the time I’ve actually got out of bed
Anyway, back on topic, yes, there’s a large headed screw on one side of the hub which is where the oil goes in. I know that when I did mine a few months ago (mental note to self, probably time to do it again soon) it really changed the feel of it. It’s hard to describe, but it kind of felt like all the cogs had woollen jackets on in retrospect, and after they were much more metallic and clanky. Although it felt different, it still shifted the same though.
I’ve also had the free-wheel happen just once before, but I think that sometimes it can seem like it’s gone in to free-wheel because you pedal slightly too slowly to catch the next mesh of gears, but not fast enough for the previous one to catch you up - if you know what I mean. I guess it’s as if you are pedalling at 1:1.25 for a bit. You only need half a rev for that to totally freak you out and UPD!
Oh, mine is the original Schlumpf hub, not the KH one, in case that makes any difference.
Evan built a 24" BC w/ a disk. Him and Spencer tried riding it on some trails, but they determined it nearly impossible to control the brake. I think it would be possible to modify one so it would activate gradually enough.
I’m thinking it would be easier w/ plates than pedals. Lower CoG, larger platform, and moves around more predictably.
I think the dream of rocketing downhill in total free wheel mode requires KH like magic skills, and a plus 3 magic dog or something. So maybe something can be done for level one normals, that allows us to keep our feet on the pedals, and coast down hill faster. This would be pretty cool, even if we couldn’t coast as far as a bike. To go 20 mph would be kinda awesome.
So heres the idea. The connection from the axle to the hub would no longer be rigid . There would be a clutch.
And it wouldn’t be on or off. The best way I can describe it is it’s like high end fishing reels. You would be coasting down hill in the sense that your feet are on the pedals, but you might be back pedaling. There would still be some balance control this way.
So the connection between the axle and hub would be in the form of an adjustable drag clutch. Going downhill would be like a fish pulling out line against the drag.
I’m not sure that there is enough fisherman here that know what I mean.
The idea is not to ever go true free wheel. I see someone going downhill on a uni, feet on the pedals, 20 mph, not pedaling.
Controlling speed with a lever for hub drag. But mainly by pedaling. With a drag clutch, there would never be a lose of connection from cranks to wheel, just a relaxation of the one to one mechanical lock.
The concept is interesting. Nice crossover of technology. I imagine this would require regular maintenance to replace the wearing clutch parts.
If you want to go really sci-fi, you could use magnetic liquids that become
more rigid when a current is supplied. Integrated into a fluid clutch…
The fact that people can glide says that it is possible to use a clutch/brake if the mechanism is sensitive enough. A foot on a tire is just a brake with fine
control and feedback (and serious noise).
COnsidering how badly most manual transmission cars are driven, the and the power going through them, a unicycle clutch built along the same lines would probably have a quite a good life.
!
So maybe something can be done for level one normals, that allows us to keep our feet on the pedals, and coast down hill faster. This would be pretty cool, even if we couldn’t coast as far as a bike. To go 20 mph would be kinda awesome.