Super high geared 24"/ 19"?

all the geared unis I seen so far are 1:1 or 1:1-1/2 but say there was one with a realy high gear? Wouldn’t it be cool if someone was ridding a bike and a person came wizzing past on a uni? :sunglasses:
Oh yeah if it was splined roll hop drops would be sick!

I recently saw a giraffe built on a 16" wheel. With a giraffe it’s pretty easy to have different gear ratios. The one I saw had a seat height that looked about equal to a Coker so it should be pretty easy to mount and ride.

true but a uni would be nicer

a highly geared 20" would be great for long jump.

Kris say 1.5 is already higher than you might want for riding; 1.3 would be more general purpose. But it gets you to/from a trail quicker.

You can experiment with a low giraffe and different-sized sprockets to see why the geared hubs on the market stick with relatively low ratios. In other words, once you gear it up too high, the unicycle stops being fun (or safe) to ride. Sure, you might go whizzing past a person on a bike, but if they come upon you a minut later all tangled up in a bush, it loses a lot of its impact. :slight_smile:

Hey, there already is one with a high enough gear to overtake bikes, you just have to pedal hard to do it.

A higher gear would be nice, but the current high gear feels pretty high to me, I wouldn’t want that much higher.

Yeah, 1.55x mode on a trail is kind of scary, is mostly for riding to the trail. I find on many trails 1.55 mode is actually slower than putting it in 1:1 and spinning harder. It is good if a bit scary for bombing down fireroads though.

Joe

I have now made 3 giraffe unis from bikes, my last 1 a highly geared 26" firstly it was I think 1:3 and that was imposible to ride, because it was like starting off on a bike when it is left in a high gear, on a uni you still have to push so hard on the pedals but you basicly just end up jumping off, I have now changed it down to a 1:1.5 and have tried it quickly but havent got anywhere on it yet so i might change it to a 24" wheel and a 20" or 16" untill i can ride it then maybe change it up as i get used to it, the problem is when trying to ride it you pedal a tiny bit and the wheel moves alot so you have to be very sensitve on the pedals and have very quick reactions, also it didnt help that there is a tiny bit of slack in the chain drive so the transition between putting force into pedaling forward and then back is slightly harder, i think the dreams of flying past a bike on a unicycle is going to stay a dream untill maybe it is posible to change up a gear in small incrments wilst still riding.

Greg Harper told me you can’t take the gears INSIDE the hub higher than about 1.5 or 1.6 because you can’t make the wheels inside the hub any smaller. You can make a heavier gear system using Pete Perron’s design or similar designs. For road riding you will want a bigger wheel for extra stability, myself I am a fan of saying 29ers are cooler than 36ers but they’re not really because I like my coker 10x better than my 29er (but don’t tell Pete I said that because he will laugh)

the ones i have made are giraffe unis so i have just used the gears on the sprockets therefore being able to get a good high gear ratio

That doesn’t make sense, as there’s no technical limit to the size of the hub (well, up to the rim size anyway!). And even if you wanted to keep to standard sized flanges, there’s nothing to stop you from making the middle bit of the hub larger diameter.

STM

It is not a mater of size but of ratios between the center gear and orbital gears.

edit: A very small orbital gear would not have enough teeth to run smoothly unless you made the teeth smaller, then it would not be strong enough.

Is all about ratios of gearing. As gearing approaches 2, the ratio of gears required in an epicyclic gearing system approaches infinity. I think.

You can do higher gears by having multiple sets of gearing in a row in the hub, I think bike geared hubs do this. But it’d all get complicated then.

Joe

unisk8ter

He’s a link to a guy who set a world 1 hr. uni speed record on a homemake 36" with a hub geared close to 1.9/1. Check it out !
http://www.unicyclist.com/forums/showthread.php?s=&threadid=38555

That’s externally geared, rather than a gear in the hub, which is why he can run such a high gear (he can run even higher if he wants to) .

On the 29" Schlumpf it is relatively easy to ride faster than that hour record. The hour records that have been set since then (by Dustin Schaap and Patrick Schmidt)are a bit hard though, they were both on 36" ungeared unis I think. The current record of something like 27.2km is a bit of a monster, almost 17mph. I think it’s still in the range that a 29" Schlumpf could hit, 20mph/30kmh is maybe where it’ll start getting big wheel only.

Joe

Correct this info if it’s incorrect: the 2007 U.S. Guinness Book lists Ken Looi as the 24 hour record holder, but it was also later shown to Guinness that he went faster than me for the hour. Ken went over 25kph during his fastest 60 minute period. That appears to be the recognized Guinness record.

Several have tried to best it, like Zach Warren, but he had equipment failures. Others are preparing to best it this year. Joe exactly what source are you citing for the current record? Did the IUF publish something other than Guinness?

Gunis are still an unknown quantity as far as standard equipment goes. No one that I know of has attempted the record on a Schlumpf.

DustinSchaap beat Ken’s one, by a little bit (it’s on here somewhere, am too busy to search)

Patrick Schmidt got 27.18km at Unicon.

http://www.unicon13.ch/uni/cms/front_content.php?client=1&lang=3&idcat=12&idart=128&m=&s=

I dunno if they bothered with Guinness, but are certainly certified IUF records, and I know Ken considers them to be proper records cos he posted somewhere that he’d like to get the record back from them.

On the Schlumpf with 150mm cranks, on smooth roads, I can cruise at 24km/h currently, and hit speeds faster than that for short periods. I think I could do 25 for an hour on a track, but that other 2.5 km/h to beat the record would require someone that bit faster than I am now. If only I’d been this fit 2 years ago.

Joe

Yeah, I have to say, now that I’ve done a lot of riding, I think Gunis, while being fab to ride, give you less advantage than you’d expect as far as this record goes. Currently the record is well within speeds coker riders can spin.

Although having said that, the lightweightness of the Schlumpf 29er wheel, I think might just give a bit of advantage over a coker, whilst it is still within sensible spinning speeds. I think maybe even (shock horror) a lighter tyre than a big apple might make sense for this record. Makes it not such a fun ride in general, but for pure track speed, I think may be the way to go.

Joe

I don’t mean to like have the uni in a fixed gear but more like the Shur… with the two buttons

Thanks; that’s why I began with “correct this info…” :o

And as for this thread topic, has anyone tried making such a thing yet - a 20" guni with more than 2:1 ratio?