Gear REDUCTION hub

I was wondering if you could get a Gear REDUCTION hub. Having one would be extremely useful going down steep hills. I’m sure anyone who has ever tried M-uni has UPDed because a hill was too steep for them to control. Having this hub would really help this.

I was thinking of using this on my 24 M-uni, or even a 26er.
A quick tap of your foot enables a 24" to suddenly become 12" and a 26er to become a 13".

Discuss:

Howabout a brake? If I’m blasting my way down a steep trail or whatever, I don’t know how practical or safe it would be to try to “suddenly” reduce speed by changing the gear ratio, which might lead to losing your grip on the pedals since you have to move your foot to do so. Now I can see the benifit of changing to a lower gear for going UP a steep hill. :slight_smile:

Exactly what i was thinking.

I spoke to Florian Schlumpf during Unicon, he mentioned that several people had asked if they could get a gear down system. He said that while entirely possible he would understandably need sufficient demand to make a production run viable. Switching it while descending would be a bad idea though.

probebly easyer to just practice/ get stronger

It’d be no use going down hills.

Think what would happen in the situation you describe, you’d be going down the hill at 10 mph, spinning your legs at 150rpm, you think whoooah too steep, kick the button, the wheel doesn’t slow down, so suddenly your cranks are spinning at 300 rpm, and you are falling off.

Alternatively, you could have a brake, you think whoooah too steep, put the brake on slightly, wow, it’s under control, just like riding down a less steep slope. Brakes are cheap, practical and easy to use.

For uphills, it might allow you to ride up slightly steeper slopes. However, at least on all my unicycles, the speed at which you run out of power to go up the slope is way slower than walking speed. Gearing down a 24 or whatever, you’d probably still be going slower than walking speed up anything that required that gear, so you don’t gain anything over walking that section.

The only unicycle gearing down might be even slightly practical on is a coker. However, there is a great solution for this. Buy a geared up 29 instead. Simple. It’s a very practical machine, leave it in high gear most of the time, for a good fireroad and general road unicycle, shift down if things get too steep, or if you hit the technical muni. It’s even slightly faster than a coker, what more could you want.

Joe

I believe in the first issue of uni magazine there was an article about the person with the 36 inch wheeled giraffe.
They geared it down.
You might want to try searching around on here for that aswell because I vaguely remember them posting a thread about it.

I didn’t agree with much of what you said.
You can kick the button easily BEFORE you go down the hill. Why not? Breaks are good, but it is not the discussion here.

I don’t give a rat’s ass how well it goes up hill. I walk or drive up, and if it is a normal hill, I will ride up it easily without the help of gears.

29ers aren’t good for technical m-uni.
Having a gear reduction hub would greatly increase control on long steep descents that I have a hard time with.

The advantage of having a geared down large wheeled uni as opposed to a geared up small wheeled uni is that the geared down one will have the same control as the small uni, but can role over stuff so much easier.

Please refrain from posting useless sht.
At least try and spell your sh
t correctly, with proper punctuation.

There’s no point. It would suck. It would be way worse than a brake.

Why it would suck on a 24" muni, if it is too steep for you to control by back pressure, ie. you physically can’t stop the wheel turning, the moment you use a much smaller gear, you will slide every time you hit the dead spot in your pedalling, which will be all the time with such a small wheel. You’ll also be stuck at a really slow speed, which is bad, for almost all really steep riding, riding it as fast as you can control it is the best way to hit it, you are much less likely to slide out if you are going faster. Plus you’d have backlash with gearing down, where you get a bit of wiggle in the cranks, which is okay in a high geared road machine, but the time you really don’t want it is doing technical muni, I’ve ridden muni on a geared up uni, and the backlash in the high gear makes it much harder than it should be to use the non 1:1 gear.

Compare this to a brake, which lets you go down at a nice controlled but fast speed, without a dead spot in your pedalling, so lets you ride things much steeper without sliding out. Basically brakes will let you ride better, on far more steep terrain than a geared down muni, will cost approx 10% as much, are very very easy to use, and don’t have all the issues with backlash.

The pointless message from thejdw might have some truth though, you say you don’t ride uphill. This is quite likely having an effect on your downhilling, downhilling is made a lot easier with leg strength, and getting driven up hills means you will miss out on building up the strength that you need to really ride well on the downhills. All really good riders, people like Kris Holm, ride uphills too, you’ll not progress if you drive up all the hills.

Joe

Yeah, before you start descending would work. I thought you meant during the descent. Sorry.:o And I know lots of people who ride their tirals unis offroad, so maybe gearing down from a 24" (1:1) to more like a 20" would be helpful without too drastic of an increase in pedal revolutions.

The problem with steep descents is that the tire loses traction. When that happens, the only solution that I’ve found is to go with it and spin it out. If I were geared down, I’d have to spin even faster. And that would be just plain ridiculous.

I’ve gone down hills of about a mile in length (leading into downtown lafayette IN from any angle) and they get you going pretty quick. I use my 36er and 110mm cranks without a problem, so you may want to practice putting back pressure on your pedals. I recently added a brake to make life easier downhill, but learning to place even and consistent back pressure on pedals for hills is a must.

How are those 110’s on the way back up? And how steep is it? I have very strong quads and do at least 1 mile steep uphill climbs 5-6 days per week now for over a year, and I run 165’s on my KH 24 muni. Some sections are so steep, that I’m standing up on the pedals doing half revs to keep moving. But then again, there are so many degrees of steepness, what you’re doing may be way less steep than what I do.

Gear reduction

A shiftable gear reduction would be nice for off roading. When you hit that rock at the exact moment your peddles are at top dead and bottom dead center (one peddle up the other down). if you could shift into super low maybe you could wind the peddles around to a better position and power over/throurgh the rock. I think a planetary type reduction would be the way to go as you could use band brakes or regular bicycle brakes to shift. The brakes hold the planets to the frame or planets to the ring gear. the crank would be on the sun gear. It might also help going up hills but I think it might be scary going down I think I’d use brakes.

The 110’s arent bad on the way up. I can push about 12MPH without a problem.

http://hillyhundred.org/Route.html

The saturday 48 and the sunday 50 was no problem on my uni except for one hill on the first day. ( I made it up that second day hill that looks like a nightmare :stuck_out_tongue:

Haha cool. I only know that on the return climb of my usual trail, I routinely pass experienced mtb-ers who are either walking their bikes back up, or in the lowest gear where for every 4-5 revs they’re doing, I’m doing only one and covering the same distance.:smiley:

i thought the changing gear before attempting the hill was pretty obvious, like when you see signs on roads at the top of long hills telling trucks to stay in a low gear…if it works for cars and trucks then why not unis? and also very usefull for uphill.

im guessing there isnt an easy way to open up a geared hub and just swap the cogs round?
cant a hub be made where you swap the sun and planet gears round to give a reduction rather than a gear up?(assuming they are epicyclic gearboxes yeh?).

and can someone explain why my old bike geared hub has 3 ratios but all unis seem to have 2? surely 3 ratios is the norm for an epicyclic gearbox?

firstly ‘all’ unis, well there’s only one mass produced uni epicyclic hub in the world, and the button shifting system would make it very hard to select one of three gears, whereas two is relatively easy.

I don’t think it works like that. A single stage epicyclic gear system has three parts - sun, planets(+planet holder) and ring (outer) gear. It can allow three proper gear ratios - one part is held in place, one part is the input gear the other is the output. The schlumpf cheats by only using one proper gear - the other is just with the the whole hub fixed so the gears don’t spin relative to each other. The way the hub is built means the ring gear has to be the output (it’s got the hub flanges on it), the sun has to be the input (it’s got the axle), so you’re a bit stuck.

It could be interesting if you could swap it around to use the alternative ratios, particularly given that one of them is a reverse gear. When you get tired you could switch it over and pedal backwards, thus using your muscles differently while still being able to see where you’re going.

They tell cars & trucks to stay in a low gear so if there is a brake failure the engine braking of the vehicle acts to stop a runaway situation (a bit like putting pressure on the back pedal of a uni). More often than not, when out doing muni, I can already put enough pressure on the back pedal to either come to a halt or entirely lose traction on most hills. I wouldn’t want to ride steep stuff geared down, the backlash would make it very unsettling, IMHO.

29ers are perfectly good for technical muni. My 26er with a 3" tyre is almost as large as a regular 29er, and my friend rides muni exclusively on a KH29er with a larger tyre and has done every trail and technical section my friends and I ride on 24’s and 26’s.

By definition (at the moment) geared hubs REDUCE control, due to backlash and play in the gearing system. you would have to overcome that drawback before any improvement would be seen, and it would be cheaper, more efficient, easier and more practical to use a brake with a nice predictable operation, like a Magura. My 36er, geared up, is harder to ride than an equivalent 36er with shorter cranks, because of the indirect contact between rider and wheel.

Loose.