First long distance geared 36'er ride with KH schlumpf hub

Unicycles and Equipment
1

Howdy all,
I did a quick write up of a ride last weekend and posted it on my blog:

For those of you who don’t like clicking on links, here’s a copy below.

–corbin

Last Saturday we did “Scalisis’s Death Ride” – a 57 mile ride with 5000’ish feet of climbing. We started at Tom Holub’s house, rode 30’ish miles to the base of Mount Diablo, and then climbed to the top of Mt Diablo (3,849’). The ride started out with six people, but it ended up with just three of us on geared unicycles. Tom on his geared KH 29’er, Mike on his geared Nimbus 36’er with the older Schlumpf road hub and myself on my geared 36’er with the KH Schlumpf hub.

This was the first long distance ride on my Nimbus 36 with a the KH geared muni hub. The geared 36 is an amazing unicycle. I can cruise at 15 mph on flat ground with no effort. I can do sprints at a sustained faster pace (I’d say 17mph, but I haven’t tested that out). I can descend at a madding pace – 21-22 MPH sustained, if it is a smooth light downhill and I’m really paying attention. Going down Mt Daiblo I was averaging 17-18 mph (which is pretty fast down that hill), and slowing down to about 16 mph for the corners (which have a 15 mph speed limit sign for cars). My top speed of the day was about 24.3 mph – and I wasn’t particularly trying to go fast, it was just a speed I hit while going down a hill. All with 150 mm dual drill KH cranks.

The geared unicycle adds more comfort to my riding. With 150mm cranks I have the power to eat up hills, but maintain a comfortable cadence while in high gear. Since my legs are doing less up and down motion, I find that I get less leg pain – especially when at higher speeds, which would sometimes cause my right leg to ache. My bottom felt a little better than usual after such a long ride; the additional force required to move the wheel actually helps relieve pressure from your butt.

Things I noticed: Tom was faster going up Mt Diablo with his geared 29’er / 125mm cranks. The 29’er is really a better machine for such a steep climb. I could go faster on the flats/descents – but that may also be do to my riding style. Learning to shift is essential; I’m getting fairly proficient at it, and hit the shift within a few tries. I generally shift at 10 mph (up or down). We were in geared up mode most of the day, except for a few hills that required shifting.

A brake is really required for a geared 36’er (but Mike survived without one). Mike has the older Schlumpf hub, and it isn’t as wide as the muni hub. The wheel has a significant amount of play due to the hub not being sufficiently wide enough, and it will be hard for him to get a brake that doesn’t rub. The KH hub does NOT have this problem. I should also mention that Tom does really well on his guni 29’er without a brake, but he’s also a really strong rider.

Problems: my right crank kept getting loose. I torqued it up to 30 ft/pounds the next night, and hopefully that will help resolve that problem.

For those that are curious, here is the route:

First half:

http://www.google.com/maps?f=d&hl=en&geocode=12041305658505895597,37.901800,-121.993190&saddr=N+Gate+Rd+%4037.901800,+-121.993190&daddr=walnut+creek+BART&mra=cc&dirflg=h&sll=37.899511,-122.018623&sspn=0.064342,0.159645&ie=UTF8&ll=37.922805,-121.991844&spn=0.160058,0.245476&z=12

Second half:

http://maps.google.com/maps?f=d&hl=en&geocode=3436991316391079430,37.808381,-122.239420%3B7448847631227499509,37.843250,-121.920720&saddr=40th+St+%26+Piedmont+Ave,+Oakland,+Alameda,+California+94611,+United+States&daddr=Trestle+Glen+Rd+%4037.808381,+-122.239420+to:37.813107,-122.217836+to:Mt+Diablo+Scenic+Blvd+%4037.843250,+-121.920720&mra=dpe&mrcr=0&mrsp=2&sz=14&via=1,2&dirflg=h&sll=37.822057,-122.20788&sspn=0.059935,0.057507&ie=UTF8&z=14

corbin

2

Very interesting post.

It seems that most people with the KH/Schlumpf hub are having their right crank come loose a lot.

Mine hasn’t really had this problem anymore now that it has settled.

Have you ever noticed when you shift from low gear to high gear when going downhill it doesnt always egage right away…but rather stays in low gear for quite a long time until you put a lot of forward force on the cranks? Last weekend I was testing it and I was able to do at least 10 full rotations in low gear and then put some forward force into it and it finally engaged.

Was anyone on an ungeared 36 for the ride, and how did they do? I would think between a geared 29, a geared 36, and an ungeared 36, that the ungeared 36 could climb the mountain faster, but I guess that depends on the slope, what was the gradient?

Did you ride the geared 36 down the mountain in high gear or low gear? Having a brake seems necessary for a guni, especially a 36, but I still have yet to figure out how to attach my brake lever with my set up so I haven’t put it on yet.

3

Thanks for the write-up. Are you saying that you don’t have to “pay attention” if you cruise 15 mph on flat ground? I still have to “pay attention” on my geared 29’er at any speed, whereas the (ungeared) Coker rides itself.

4

I had a crash on this ride, on the uphill, when shifting to the higher gear for a flat section. The shift appeared to work, and I started to pick up speed, got about two full revolutions, and then lost it off the front. When I picked up the uni, it had shifted back into 1:1 mode.

I climbed almost entirely in 1:1 mode, only shifting to high gear on the one flat section. My opinion is that a 29er is faster than a 36er, geared or ungeared, on the climb up Mount Diablo, simply because it’s a pure hill climb and you’re carrying 2 pounds less wheel weight.

The bottom half of the mountain averages about 5% grade, the top half about 7% (and the last 100 meters, 14%). Even on the bottom half, 1:1 mode with 125mm cranks is faster for me than geared mode with either 125mm or 140mm cranks (I’ve tried both). On the top half, 1:1 mode is necessary.

On the way down, my setup was a little sub-optimal for the 7% grade; I felt I had to put a fair amount of muscle into controlling myself. However, this was my first big ride on this setup, so it may be that I’ll be fine after a little more practice. On the 5% grade downhill, I was flying, little braking required at all.

5

Yeah I also have trouble controlling the downhills in highgear on those gradients. It really does take a lot of muscle to control it and I need to get a brake set up. On my ride last weekend on the descent of the mountain I shifted into lowgear just so my legs wouldnt hurt as much and I could control it better.

What cranks do you have on your 29? Are you using the dual drilled moments or some light weight qu-ax isis ones?

That is weird about your crash…I have never had that scenario happen to me, but I think that these shifting problems are due to the way we shift. With the 125mm cranks you can get away with sliding your foot inward and using your inside of your foot/ankle as it comes down, but with the longer cranks you are forced to give it a good whack with your heel. Although, I think the problem I posted has to do with the lack of enough forward force on a downhill to engage the shift.

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No – I’ve notice the opposite, which Chuck also was noticing. If I keep pressure on the cranks, then it won’t shift until I let up slightly. But I have done several revs before that happened, and sometimes keep “trying” to shift without realizing it did shift and just had not clicked over yet.

Jim started out on his ungeared 36, but he’s still getting used to it, and building up his fitness. Other than that, it was just us three on gunis.

High gear, of course! I wouldn’t use anything else. It is very nice in high gear downhills, and easily manageable if you have a brake.

What uni? the 29’er or a 36?

corbin

7

I’ve got a ways to go then. I can finally cruise at 15mph, but there is plenty of effort! :slight_smile:

Congratulations on what sounded like a great “death ride.” Also thanks to Mike S. for his advice on riding the geared 36. Now I’ve ridden up to Folsom Dam and back twice, doing all the downhill in high gear with no brakes, and no problems. It’s definitely not as steep as the top half of Mt. Diablo!

Note: That last bit of the Diablo climb is definitely more than 100m long; I’d say more like 250 or so. I remember it well!

8

Perhaps a different button shape would help?

9

Yes, that is correct. 15mph is an easy speed for me where I can be looking around at other things.

corbin

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Right now I’m using the dual-drilled KH cranks in the 125mm hole, but I’ll probably get a set of Qu-ax for RTL.

Corbin actually feels the opposite about shifting, that it doesn’t really shift until you reduce pressure. I think it’s sufficient to say that shifting is still somewhat messy. I’m going to do a day of shifting practice this weekend, I hope I’ll be more confident after that.

11

The geared uni is still in the infancy stage, and many improvements will be made in the coming years I’m sure. What I’d like to see is maybe a servo mechanism that would allow for remote controlled shifting, with a button mounted near or under the saddle for quick, sure and easy shifting.

Especially useful on a geared MUni where you constantly encounter quick ups & downs, where you just can’t shift back to 1:1 fast enough [manually] for a steep climb.

12

…until it gets wet. :stuck_out_tongue:

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Shouldn’t be a problem. The actual electronics would be shielded I’m sure. Just the same I wouldn’t recommend immersing your geared uni in water.

14

Sounds like a good project

15

I don’t know–there’s an awful lot of moisture around here and on a lot of trails. Even condensation could cause a problem. And then there’s the problem of batteries running out.

My experience with shifting thus far is that something is completely wrong about half of the time. When it’s right, I shift on the first try. When it’s wrong, I can’t shift at all.

16

Sorry if this has been answered in another post, but do these hubs work similarily to a normal internal geared hub that you might find on a recumbent or singlespeed etc? In other words, are they completely sealed off and filled with grease or goo of some sort?

17

I haven’t figured out how to attach the brake to my geared 29er. This is because I am using GB4 handles. I was mounting the brake on a bar end attached to a 22.2mm seat post on my regular 36 before and it worked fine, but there are no bar ends that are 27.2mm to fit the KH seat post.

I also can’t attach it to the GB4 bars themselves because the lever would hit first. And finally I can’t attach it to the rail adapter because it doesn’t put it in a comfortable position to use it, and even with a brake lever extension it wouldn’t work because it hits the bars. I have tried a lot of options!

I am actually now looking into getting my friend to have some small tubing welded to the rail adapter to come down off the brake mount that is on there now and then have another piece attach to that bit of tubing so that I can have a brake mount attached to the rail adapter but further out and further down (if that makes sense at all).

18

I don’t think this is the problem, it is just that the shifting doesn’t seem to be consistent. The button goes in consistently when you expect it to, but the actual shift doesn’t always occur when you expect it to. I think this is what others are experiencing too. I am also going to just practice shifting (once my tendon gets better) and see if I can pinpoint anything.

19

Weird, I am definitely noticing the opposite. I find it easier to shift into high gear when going up a slight incline. For me it is always pretty easy to shift into low gear though.

20

Ah, I see your dilemma. I have an old gb4 handle that I’m borrowing from Nathan, and I opted to not use it since I couldn’t find a good place to put a brake onto it.

Your idea sounds like it should work well, and wouldn’t be too hard to do.

-corbin