I’m planning to buy a geared KH29 or KH36, primarily for street or light trail riding and commuting. I live in Colorado and my main concern is getting a 36 and not being able to climb hills. Most of the hills where I ride are about 5-6% grade (rise about 300 ft per mile, 150ft per half mile). I have zero problem on these grades with my 26" and ride it 35 miles per week but this uni is too slow for me as I want to do 15 miles a day or more. Any advice on helping me choose the 29 or 36 would be greatly appreciated. Thank. Rob
36" will climb those grades with ease, but the difference is a much heavier wheel. 29" will work on dirt and on pavement, with a lighter wheel, but a lower top/cruising speed. Also it fits in the car/bus/closet better. 
I was in this kind of situation when I decided to switch my geared hub from my 26er to a bigger wheel.
So I was hesitating between a g29 and a g36, knowing that where I use to ride (urban conditions: lot of complicated area, uphills, downhills, curbs, walkers, cars, and muni/xc) .
I took the decision to go for the g29.
I would probably have went for a g32 if a 32" fork with 100mm bearings to bearings space and the possibility to put maggies was released.
To be the closest to a 32er as possible I chose a knard 29x3" 120 tpi tire, so that I can do muni and when I inflate it well I can consider it as a g30 (30,5" when i’m not on the uni) which becomes a 46.5 " in high gear.
I use spirit 137 cranks to keep the ability to climb uphills and to ride at very low speed if i’m on sidewalks full of people, and also for more muni kind of ride, and I have a dual positions handlebar made out of spare parts, which allows me to ride straight above the uni or to lean more forward in a more aerodynamic position, like most 36er have (cause a guni is like two different unis in one).
I think i’m still under 10 rides with this one but I can say that when the track allows to ride in high gear, I ride at about a bike speed, cruising at a speed that goes from 13 to 16 mph, and if I want to go faster I can hit 17 and 18 mph but i’m not relaxed enough to reach the 19 mph yet and this cadence is tiring on those not-so-short cranks .
Generally g36 riders use 150mm cranks, sometimes even longer, so I also tried 150mm cranks on my ungeared 36er before taking the decision.
I found that it takes me at least as much effort to go at 20km/h (12,5 mph) with the 36x150 than with a 29x137 so i’m not sur I could go much faster on a g36 than I do with my g29+ and I guess I would be faster on mine with 127mm cranks.
So if cruising at about 15/16 mph on flat roads/bikepaths/easy trails sounds enough for you I would go for a g29 or a g29+
I don’t recommend to learn geared unicycling with the big wheels though.
The better strategy is to build a g24 or a g26 to learn, and after 500-1000 miles you can put it on a bigger wheel with less risk of falling at high speed.
Thanks for the replies guys. I’ve been riding regularly for just 3-4 months. I think I’ll go with the geared 29er, I can always rebuild it later onto a 36er. Thanks
Rob
Smart choice, but I must warn you, riding a geared unicycle is very tricky at first, you’ll probably start to feel it more “natural” after a good 1000 miles.
At the very beginning you’ll probably try to mount in second gear before getting the hang of shifting in the fly, and it will probably be like learning unicycling from zero, cause riding in high gear at low speed is the hardest part.
It’s the hardest past but not the more dangerous one, cause the real danger is riding at a good speed in high gear, feeling yourself leaning a bit too much forward to the point that you 're going to fall from the front if you don’t accelerate, so you accelerate but if you fail to accelerate enough you just increase the speed at which you’ll have this UPD anyway.
So I strongly recommend all the protection you’ll need to survive a bad UPD without any injury.
I can ride my ungeared 29er without any protection, but each time I ride my G29 I look like robocop.
This is because I have had several very bad UPDs while learning to ride my G26, though I don’t know if it’s my skill that has greatly improved or if it is due to the higher stability of bigger geared wheels, but I haven’t had any bad UPD since I ride the G29, except once when I anticipated a bump (that was just an optical illusion) by voluntary getting of the guni by the rear while I was still going at a good speed.
I just feel the G29+ much more natural and stable than when I was riding a G26, but I also go faster with it, so body protections are not an option for me.
Good ride, enjoy! After 500-1000 miles it is really worth it.
I am very happy with my geared 32". Just to have a third option. 
Me too! It’s a great size! (But I think a G32 is closer in “ride feel” to a G29 than a G36. Just my opinion. I think the OP made a good choice, given his riding goals. )
I also agree that it takes about a thousand miles in overdrive to get comfortable with it. YMMV. Cheers!
How is it to go from a g29 to a g36?
Note: to answer my question you can skip my blah blah speech and directly answer.
You made a good choice, and as you said you still can build a g36 when you want.
The irony is that I gave the advice to go for a g29 instead of a g36, (nothing wrong with this advice) but the more I look at some videos with g36s the more I feel appealed by the idea of going for a g36x150 instead of my g29+ (why is this hub so expensive?..).
With my g29+(let’s say g30) I can keep up with most of the cyclists I meet (not the fast ones) and even pass the slowest ones but to do that I still have to pedal way faster than they do (and I am not a fast spinner).
Giving the fact that like you (OP) I have a lot of relief around home I can’t go smaller than 137mm cranks.
I can cruise at 25km/h (or go faster if I want, 27-28km/h top speed being around 30) but this cruising speed still involves a rather high pedaling speed with my rather short legs but not-so-short cranks.
I do like this speed, riding at 25-30km/h on a uni is priceless, but that’s where a 1.5454 gear ratio becomes limited on a “30 inches” wheel.
I feel I could go faster but I’m not sure I want to pedal faster, I 'd like to go as fast without having to pedal as fast and to go a bit faster without having to pedal like a cooking mixer.
That’s where the idea of building a g36x150 comes from.
Even if it’s rather a long term project, I must be sure I can still ride in 1:1 the places I use to ride with my g30 cause I’ll have to dismount this one.
So I am assembling my unguni 36er again and put some 150’s on it to see how it feels to ride this big thing on the loops I use to go.
Anyway, with Christmas and so on it’s not gonna happen before 2017 I guess, pending I’d like to read the impressions of the riders who when from a g29 to a g36.
The main reason I’ve decided to go with a g29 instead of a g36 are
- a UPD in high gear on a 36er is both faster and higher off the ground which is more dangerous
- a 36er are harder to turn and climb and there are way too many hills in my area
- I ride a lot of varied terrain from sidewalks to mellow single track and a 29er is easier to turn, hop and handle in general
- I’m a beginner (6 months riding), and although I like to ride 35 miles per week a 36er is more realistically a year 3 purchase
Thanks everyone
Rob
Well finally I think your are definitely right, especially considering the place you ride.
Like I said earlier this last couple of weeks I have been kinda obsessed by the idea of making a g36 to replace the G29+ I have, even if my riding conditions are quite similar to yours.
But this idea was only based on a memory of my last try of 150’s on my 36er (unguni), which only lasted few minutes because of a damaged and deflating FOSS tube and this was months ago.
Now that the tube has been replaced by a 29er one and the 36er has been assembled again I just gave a quick test ride, beginning by a up hill.
Well, it’s another world, yes the 36er is easier to free mount and to accelerate with 150’s than it is with shorter cranks, but it’s still a big heavy wheel that has nothing to do with the 30" wheel of my G29+.
The extra energy I have to give to this giant uni was very noticeable, and since it was waking up a pain I have in one leg near the groin, I went home after just 5 km.
Ok, even with 150’s I was able to reach about 22.3 km/h without feeling like I’m pedaling like a crazy, which would make me go at about 22 mph in high gear if I keep this cadence, in theory, and the feeling on this big wheel is … interesting and unique, but it involves so much more energy (and I’m only taking about riding in 1:1) that it tempered my wish of having a G36, at least I was saying to myself “there is no way a G36 could replace my G29+ in term of versatility”.
Once home I decided to test the new polystyrene half balls (wrapped by electrical tape) that I place inside my five tens to help with shifting, so I went outside with the G29+ and this was like the night and day, the wheel of this guni feels so light, easy to free mount and ride, compared with the 36er, and the half balls I was talking about makes the shifting (up and down) process a child’s game, allowing, I presume, a more frequent use of the high gear.
So, yes you probably did the good choice and, on my side, I think I will stay on the G29+ option for a little while before really thinking about a G36.
The old 29 or 36? Question, with or without the gears.
It’s like saying Honda CB600F or Harley? The Honda is lighter, more practical, more manoeuvrable, and wins on every point except (for some) the crucial one that it isn’t a Harley.
The 29 is lighter, more practical, more versatile, easier to store, more tyre choice, etc. etc. etc., but it isn’t a 36.
If “… but it isn’t a 36” gives you a pang when you read it, you will never be quite satisfied with the 29.
Far better to have one of each.
Incidentally, I chose neither the Honda nor the Harley, but the Guzzi.
Hi Eremit, could you do a quick, or even better a complete review of your G32 please?
Have you ridden other Guni sizes, and if yes could you make a comparison?
I’m very happy with my G29, 137/117 cranks, knard 29x3 120 TPI, 30-35 PSI, especially between 0 to 25km/h (0 to 15.625mph) because the flexibility of the tire is more forgivable as soon as the roads/trails/sidewalks have imperfections, and it makes a very versatile Guni.
Though, between 25 to 30km/h (15.625 to 18.75mph) It’s another story, especially when I’m getting close to 18mph, I guess the low PSI/muni profile of the tire brings enough rolling resistance to prevent me from going faster.
I thought it was a matter of being able to spin fast the cranks in high gear, but I don’t go faster with 127’s or 117 cranks, indeed my fastest recorded speed was 29.4km/h (18.375mph) with 137’s , with shorter cranks it’s like I don’t have enough torque to go faster than 17.5 mph.
Maybe it’s only a matter of not leaning forward enough, but I’m already leaning much forward, exploiting my long handlebar, and I’m so aware of the smaller balance window in high gear compared to an ungeared uni (bad UPDs on a G26 learned me that the hard way) that I’m not ready to lean even more forward than I do unless I’m sure it’s not a simple rolling resistance issue.
For now I have never tried a road tire on the G29, I’ll do it if I change my kh47mm rim for another rim than can keep a schwalbe road at High PSI (mine exploded on the kh47 rim at 44PSI after 30 min) but I am curious how it goes on a G32.
The night rider tire can be inflated up to 65PSI so I guess rolling resistance is very low at this pressure.
How fast do you G32er guys manage to go, and with which cranks size?
Buy a geared uni because you want to have a geared uni.
15 miles is somewhere between an hour and 2 hours of steady riding on either an ungeared 29 or ungeared 36 depending on the terrain and your experience. If the terrain is bad enough to slow you down significantly, gearing the wheel up won’t make you go faster.
There is no need to spend a huge amount on gears to ride 15 miles a day.
But if you want gears for the fun or the challenge, then have fun and enjoy the challenge.
A 29 is always more versatile, but a 36 is always a 36.