I initially rode my niner with the nanoraptor tire (that’s the way it comes off the rack). In fact, I rode it in a Crosscountry MUni race and it did fine.
Big Apple carries more air and so the ride is smoother. Absorbs the road/trail even at 60psi. Trying to get a smoother ride out of the NanoRaptor, I let a bit of air out to 30 psi or so. The NR has a thinner sidewall and so it would fold over coming off of the [little] drops I’m capable of. And so, needs to be pumped up tighter, but this makes for a more jarring ride.
The NR is light. So I feel less stable on it. But I think I can do something about that. (I’m also very interested in the results from the 29er tire test currently in progress, as are most of us 29erists.)
The BA has more mass. So it produces a more solid feeling flywheel effect. I like it as is very much.
But I have suggested in the past a theory that I’m now (as of yesterday’s trip to WalMart) prepared to test. For $1.47 I picked up some stick-on lead strips. These are actually designed to be stuck to one’s golf club head. Eight per pack. I plan to put the NR on the Niner and place 8 or 16 of these little fellows around the wheel perimeter and see if I like it. With a tiny snip here or there on the lead strip, they fit nicely between the spokes on the rim. I’m hoping to get a smoother flywheel feel. Somewhere in between a Niner and Coker. One of the benefits of the 29er is idling and responsiveness. Thats why I find idling a Coker difficult and the niner easy. Simpler to change the direction of the tire rotation if it is less massive. But then cruising a Coker easier and a 29er takes more concentration (I’d rather not think too much while cruising, thankyouverymuch). I’m hoping to get a bit more of the Coker’s momentum without too much loss of quick response. I believe the two aspects are at odds. A sliding scale from one to the other. And stopping a more massive niner wheel with shorter cranks will be affected. Everything is tied to everything else.
Coker-folks sit tight. I’m not trying to make the 29er be a Coker. But there are aspects of the big C that I would like to incorporate to some degree. A more massive “object in motion will remain in motion” even as it blasts over the hills and bumps of a Crosscountry/MUni trail.
Makes sense to me as a theory. I’ll let you know what reality feels like.
Tommy, if it works the way I think it will, you will get some of the benefits associated with the BA even if it won’t fit your new frame. My guess to the result: better flywheel, but the NR will still feel harder. (Should I be so open with my experiment’s results since we will be racing these contraptions head-to-head in only 32 days?) (to the casual reader: racing Tommy is more like head-to-hey, where’d-he-go?) (So, I only hope to win my class: age 0-46. He’ll certainly take the age 47+ class hands down)
Increase the flywheel effect and reduce the effect of minor variations in the ground. The unicycle will become less twitchy.
However, you will also introduce enhanced directional stability… which is a polysyllabic way of saying it will get harder to steer.
And idling will get harder.
And accelerating will become harder
And stopping
And hill climbing
And descending hills under control…
So you are making things worse in a lot of areas for a small gain in one specific area.
In practice, I expect all of these effects will be very small.
The best way to get that smooooth feeling is to ride and ride and ride. Feel at home in the saddle. Get used to doing other things while riding. On the Coker, when training, I used to remove my helmet, take off my back pack, remove my sweater, replace my helmet, place my sweater in my back pack and replace my back pack, all at a steady cruising speed of around 9 - 10 mph. It took practice to get to this standard.
Seriously, even on a less massive wheel, you should be able to get smooth and confident without resorting to sticking bits of toothpaste tube to the wheel rim.
Nevertheless, I’ll be interested to read the results. :0)
That’s my goal. But add the word “somewhat”. I want to increase or decrease to customize for the terrain du jour.
Yes. And I think that is ok for this specific course. It is mostly crosscountry with several tough sections. 5 miles of Singletrack crossing Rolling hills and gravel roads accented by 1.5 miles of singletrack with switchbacks and loop-di-loos.
I refer back to that sliding scale. The more mass, the worse all of the problems you mentioned. But the better I’ll do on the long flats. I’m looking for a way to tailor my machine to a specific course. In fact, I think I could eventually come up with a way to add or remove lead at will. Perhap folding and pinching the strip around the outter end of the spoke instead of using its sticky tape. I show this course as 76% easy, so if I had nothing but free time, then trials would show a slightly heavier wheel advantageous.
[B]
I raced the 29er with its light nanoraptor on this course last yr and did fine. I might determine that its the better alternative. But I’ve always been one who had to touch the fire. You could easily be right.
But I’ve got to do everything in my power to maximize my equipment or I don’t stand a chance against Tommy. (So, I might have to falsify my findings. Don’t believe anything you read until after Apr 4. Shhhhh, don’t let on.)
I just saw this thread. Laughing out loud, here in LA!
What, are trying to psych me out or something? What kind of mind games are you trying to pull here? You are the one who has been experimenting - for two years - about the fastest line around that course. You, my dear friend, are sitting in the pole position for the April 4th race. Besides, you have the advantage of being the reigning champion! I’m not buying any of your self depricating hoohie! You’ve got experience, tanacity, and now technology on your side. Dang, my ride is still in pieces in an unopened box stamped with Canadian Postal Service all over it. You are already laps ahead of me.
Now, back to your experiment: How ya gonna turn that thing once you get it wound-up? On the other hand, I don’t ever remember anybody saying that you’ve GOT to ride on the trail.
Mikefeule is right in that you’ll be going against common cycling thought. For performance, the best place to remove weight from a bike (cycle) is from the wheels. The more rotating mass you remove, the less work you’ll have to to do accelerate, steer, brake (in the case of a unicycle), etc. Also, the farther away from the hub that the weight is removed, but better the effect.
Of course your desired effect is a smoother ride. But remember, a unicycle is not a stable device in the first place, even without you on it. Spin the wheel real fast. What does it do? It wobbles side to side. This is from the imbalance of the pedals sticking out on either side.
When you ride, it is up to you to cancel out this wobble with a smooth pedaling style. The weight of your feet on the pedals makes it worse, adding to the problem. That’s why most unicyclists, if they ride through a puddle on pavement, will leave a trail that snakes left, right, left, right. Some more than others. Adding weight to your rim will enhance this wobbling effect.
However, you could try adding the weight to the parts of the rim that will reduce the wobble. At a few ounces each, it will probably be hard to detect any difference when you’re riding, but you might be able to tell if you’re putting them in the right places by spinning the wheel when you’re not on it.
For my own personal preference, give me the lightest wheel possible that can hold up to my riding. I can aim it.
But I keep reading from the Cokerists out there of the wonderful nature of the Beast on a MUni (crosscountry) trail. Isn’t this because it inertias its way over and through anything?
Common cycling thought involves itself with 2 wheels and gears. Unicycles are Uncommon cycles. And are governed by some same and some different rules. To demonstrate a difference: I enjoy Mountain Biking down a muddy trail on a rainy day. I hate that on a MUni. (We have slick gumbo mud down here). Nothing but UPDs all the day long.
I hope we here from a MUni Cokerist. Isn’t it the inertia that helps on the trail?
And I’m only talking about ounces. One of the things I prefer in the Big Apple over the Nanoraptor is the weight. Its a few ounces heavier. I’m just going to push that a little further. I admit that I like the heavier tire on the road and haven’t taken it on the trail yet. Right now its all talk and theory). (and a little Grandmaster 2T psych-out for spice)
keep in mind that (rotary) inertia is proportional to the mass (at radius) and the SQUARE of the radius. so even if you add enough weight to match the weight of a coker tire, you will still only have <~65% the inertia (very crude approximation equation (assumes all weight is at outside diameter) : (29/36)**2)
After doing the tubeless thing on my 36 Hunter, I noticed a drop in my consistant straight line level speed. On hill climbs, going around cars (technical), and downhill, I noticed a huge improvement once I got used to the lack of tube weight. I also have to pump the tire up to 40 psi otherwise it was too soft (ran 32 psi tubed). Would not shortening the crank length give you the desired effect you’re looking for? I tried 125’s before going tubeless and didn’t like the feel, 140’s are on the way. Does somebody make a heavier 29" tube? If so, you could forgo the lead. I can’t compare 29 to 36 cause I haven’t ridden a 29.
I don’t think so. I think he’s looking for the “gyroscopic” increase in stability (and maybe the “flywheel” increase in forward inertia too). Crank length would not effect these (except to the small that the speed increase would increase the “gyroscope’s” and “flywheel’s” speed).
If you want a heavier tube buy one of the thorn resistant ones, the outside of the tube is extremely thick. If you want some weights that could be easily adjustable (I’m not putting much thought into this) you could possibly put them on the spokes to be easily moved further and closer to the hub. But then all that weight is still there for hills.
I was riding through a dirt lot the day after rain and the mud would get caked onto my tire and scraped off onto my frame. With all that extra weight and resistance my tracks in the mud were very curvy from a huge force difference on my pedals. But all that mud did make me look really cool.
I rode this crosscountry course with 125s and the lighter Nanoraptor. UPDs too frequent. The jarring from tufts of grass or dirt clods hard to overcome. Made only one change (like a good little scientist) and observed the diff. I went to 150s and increased my overall time around course (by 18%?). Longer cranks were slower on the flat easy stuff, but increased control and torque helped me stay on the machine. (A good place to be when racing).
Thanks to everyone for input.
A heavier tube would do what I’m after. But would not be easily adjustable. If I don’t like the feel with x-amount of lead, I simply remove some.
Dirtsurfer, You noticed manouvering improvement by reducing the 36’s weight. You slid down the scale towards me. I’m looking for similar improvement by sliding up the scale towards you. I don’t want the two machines to meet on that scale. I don’t think they could.
What I want to see out of this: Can I go back to those 125s if I utilize either the BA as is, or heavier, or the Nanoraptor heavier, or any of the above with the 150s.
(remember, don’t tell Tommy or Chirokid or Bugman)
For road cruising, I could see adding a lot more weight. But that’s what a Coker is for. I like all of those manouverability benefits of the Niner. We’re just tweeking here.
As a rough rule of thumb if you make it weight the same as a Coker wheel it will have the same “feel” as a Coker wheel. You obviously won’t get the spongy effect of that fat tire or the bridging effect of the large radius wheel, but all of the acceleration-related effects will be very similar.
True, if the issue is inertial for the same rotational speed. But that’s not accurate for rolling wheels. The smaller wheel spins 36/29 times faster, so since the energy stored in the wheel is proportial to square of the rotation rate times the moment of inertial the effect of diameter is insignificant. The (36/29)**2 term exactly cancels out the (29/36)**2 term.
i’ve warned u about my lack of scientific insight before…
the above two quotes made me wonder, if u add the weight around the spokes and make the weights loose enough to be able to slide up and down, wont that add the stabilising-weight when u’re cruising on the flats and the centrifugal forces push the weights to the outside of the wheel and reduce the effective weight when they come sliding back down to the centre of the wheel on the technical sections? (well, half of them anyway)
This sounds like an excellent experiment. Ignore what everyone has told you, put on the weights, try it, and tell us how it feels to you. Even your opinion will be biased and will be only one data point. But it’s simple to do and nay-sayers be damned. I, for one, am VERY interested in what you have to say about it.
Wow. Thanks H. I’m honored, considering the source.
They would not be so loose as to move unless I moved them. Duck tape maybe…
I thought about this driving to work this am: Anyone who has done any fishing knows what “split-shot” is. You crimp it on fishing line and, unless you want it too, it doesn’t move up or down the line. I’d want some sizeable split-shot, but then just crimp it on a spoke or pinch it off at will…
By the way, I’ve always meant to put this lead way out on the spoke AT THE RIM. But it stands to reason that you could slide it in towards the hub if you went into some hilly tech section where high torque and low intertia factor were advantageous. Then when you hit a 3 mile stretch of flat stuff, slide everything back out. If you only used 8 or so, this could be done in seconds. (Probably overdoing this now, but its possible to do)
This is so simple, see if we don’t have 390+ little uni-scientists out there pretty soon.
Originally posted by cyberbellum
Since the energy stored in the wheel is proportial to square of the rotation rate times the moment of inertia the effect of diameter is insignificant.
Man, if I had a nickel for every time I heard that…
Why, in Carlton, we speak of little else.
I used to have a 250 cc motorcycle with wire spoked wheels, and the wheels were balanced with pinch weights like split shot. try a motorcycle shop dealing with small rough and ready bikes, or possibly one dealing with trailbikes, which also have wire spoked wheels.
As for the Coker effect… a Coker is fantastic fun off road as long as it keeps moving. Momentum will carry it through or over a difficult patch, but inertia will trap you if you get bogged down.
The weighted wheel effect would be great for any vehicle which can travel at a steady speed on a flattish straightish course. It would smooth out the minor imperfections in the ground and allow the rider to concentrate on keeping the speed up. (S)he would need less margin for error.
But in all other circumstances, it would be a disadvantage.
I dimly recall an experiment with bicycles, published in the UK cycling press 15 odd years ago. A tiam trials rider rode (?) 25 miles, then repeated the course on the same bike in similar conditions, but with about 3 pounds of lead strapped to the seat tube. It made only seconds difference across the distance.
Another possible benefit of a heavy wheel: stability in gusty side winds.
Riding the Coker in double track is a nice, fun speedy blast, even in the snow and ice. I found riding the Coker on very narrow, winding rooty single track to be frustrating and very tiring, and needlessly scary on the downhills. The massy wheel makes tight control extra work, and the large wheel makes the weak pedal position last longer. And the heavy crashes on rocks made me worry about the wheel. Not true of the 26".
I’m with Harper. Just try it and tell us what you think.
Another interesting experiment would be to put the weights around the rim unevenly. I’m not a good enough rider to notice the difference otherwise I’d try it myself, but it seems to me that putting all the weight at the 6 and 12 o’clock positions when the cranks are horizontal would be better. That way when you are balancing or hopping you can still rotate the wheel quickly, since the masses are on the pivot axis, but when rolling fast the masses would still give gyroscopic stability.
