alex.martian

I've tried web search but did not find info on that specific idea. I've found general article how steep bike can go, where main obstacle was stated as low traction (when falling back is taken care of by leaning forward), the limit they somehow got around 40% grade. (I'm new and not allowed to post URLs.. so name of article is how-steep-is-too-steep-when-cycling-uphill, maybe you can find it if interested).

I wanted to test and see how steep I can ride. I could not go even much less than 40% grade uphill today due to not having enough strength to push pedals, traction against grass was not a problem.

My bike has lowest gear of like 22 front x 42 rear (3x9 gears) and in case of "optimal" cadence of 80 rpm I calculated to have speed of ~5 km/h.

Yes, I'm not very strong physically and therefore I think maybe procure small sprockets, like 11T for front. As I now see there are no such cranksets for sale. I have "old" square crankset, 11T would not fit for bolts, too small. Can you advice some cheap/simple solution for custom design of having small sprocket for front? Or maybe simpler to make big one (like 100T) for rear? Would it be feasible to go uphill at speed of 2 km/h? Would load on sprockets be higher than going faster by pushing harder with higher gear?

P.S. by web searches results seams everybody are interested in going faster, not slower (but steeper uphill), no interest in finding lowest gear...

DMC707

its common to run a single 30 tooth sprocket up front with a cassette that goes up to 50 in the back and 52 on higher end SRAM stuff --- thats as slow as walking. - 28 tooth chainrings are also available for the modern SRAM type cranks (SRAM, Race Face, etc etc ) - a 28x52 would be pretty darn low, but then again so is a 22x42 -- i dont have a gear calculator to see how they compare and its also dependent on your wheel size a bit too


Last but not least, and i will say respectfully -- if a 28 x 52 wont get it done, perhaps some time in the gym combined with some more saddle time doing some on the bike strength building exercises would help

alex.martian

I can say then gears are not needed at all, just pedal faster, but then you can reply 70-90 cadence is stated to be optimal for fitness, etc. Anyway I find it "unbalanced" and already mentioned above: inclination toward high speed, I have leverage of 4 times in my gears for speed (44x11), but only 2 for force (22x44). I want more force; usable, convenient for my style and my body gearing.

So many bikes, so many choices and no one for easy going uphill, come on, designers and manufactures, you can do better! So for now I want to manufacture one for myself, hence the question.

Russ Roth

What you want doesn't exist, the smallest I can recall hearing of a front ring is 20t and I don't recall ever seeing one in use.
The problem is, once you get as low as you have, it borders on being easier and less tiring to walk. As was already mentioned, your solution will be a 1x system with a 52t cog. Even if you can only do a 28 front with an 11-50, it will be 2 gear inches easier, need easier then that you'll have to get a motor.

Happy Feet

Something that happens when you gear too low is that, while theoretically possible to climb steeper, it becomes harder (too hard) to practically pedal.

Starting is hard because you cannot use the pedal to balance up off of (it rotates to fast) and in turns you can't balance off of the pedals either. You actually use your legs quite a bit to stay upright climbing by balancing/counter balancing and the rapid revolutions don't provide enough resistance for them to brace off of.

I don't know if I described that well but put your bike in it's lowest gear and try to start off on a steep hill and you'll see what I mean.

dabac

Look here:Mountain Tamer Triple adapter - LOWER GEARS for bikes of all kinds

GhostRider62

5 km/hr on a 40% grade takes around 450 watts for a 170 pound rider on a 20 pound bike.

Two more practical limitations than mere gearing is your power output and the stall speed. How slow can you ride without doing an Artie Johnson

prj71

You are making absolutely zero sense. Common configuration on bikes these day is 30 tooth chainring up front paired with a 10-51 cassette in back. Plenty of gearing for going faster and low end for climbing hills.

Your issue is you need to get away from a 3 x 9 bike...

GhostRider62

He makes perfect sense to me.

Maybe you are math challenged.

alex.martian

I often ride in parks with say several meters high hills, going off and on bike will take more time than continue to ride with say 2 km/h uphill. Still I cannot ride all up just by speeding up before uphill, I do not fall to the side, I feel I cannot push pedals even on lowest gear, so I would like to try even lower.
Plus I ride for fun, not money and/or time competition, I want to ride, not walk!
P.S. Electric is another story, I'll have to no forget to charge it like a phone ...uuu... I think I'll wait until battery tech make some revolution.

alex.martian

Generally you make a valid point, but ... Please see my reply above to other answer, I have nearby small hills where I feel I cannot climb due to gearing/power, not falling to the side, I want to try lower.

alex.martian

By the looks of it seams a great solution to my problem, thanks! But...
My current bike has 5 arm compact 94/58 BCD crankset,
FAQ: "My triple chainring is 22 teeth. Can I get a lower gear?
A. If your crankarm spider has 4 arms, that is as low as you can go. If it has 5 arms and a 58mm bolt circle you can go down to 20 teeth. "
So, the idea is great, but with my crackset as they say I can only go from 22 to 20... Even with some other sets min 17T. Not worth it IMHO, I would appreciate such idea modified to allow for even smaller chainrings. I was glad to find out somebody is concerned with using/making low gears too, maybe I will contact them and discuss further. Do you know them personally?

Russ Roth

Its really just a matter of riding more and getting stronger, or plan to pay for some real upgrades. Hills are always a challenge for everyone, nothing wrong with riding till you can't and then walking. Set a goal on each hill and push yourself to surpass your previous efforts, eventually you'll make them. My last house I could head out in 5 different directions and all of them were hills, the local race ran by my house 3 times, 5 if you did the 50 miler just to drag the racers through the hills. It was tough and crushing but with perseverance they could all be conquered with practice.

alex.martian

I apologize to everyone who replied for misinformation. I knew my crankset because I had problems with it, but for rear I just saw on the web typical cogs were ~ 11x42 so with my 9 speed I assumed around 42. Actually it is only 32T! I have much room for improvement in the rear with stock parts. I'm looked now and wide range 9 speed could be 50T and looks like I would need to change my rear derailleur.
But If I would need even another shifter (and my bike is not so modern hence most probably wide-range cassettes are not available for it), then I again back to my thoughts about small custom chainwheel in the front.

Canker

You are going to start running into chain wrap issues if you want to run a 3x front setup and a 11-50 cassette. In other words the RD won't be able to suck up enough slack in the chain to both handle a 44 front 50 back and a 22 front 50 back. All the setups made to work with a 11-50 or really 11-42 and bigger cassette are made to be 1x.

alex.martian

Beg your pardon, 44x50? I thought such "cross" is "forbidden", or you mean 44x11? Also, what if I wold not use 44 front one at all? I use it very rarely now.

prj71

Happy Feet

By all means I encourage experimentation. I was just pointing out some practical problems with ultra low gearing and hills.

The easiest solution is to go up in the rear cassette. Beyond 22T if it will fit, or maybe the mountain tamer if you can get it, going lower in the front is problematic.

Some mention the problem with chain wrap. It is an issue but you can somewhat work around it by remembering not to run up and down the cassette in the low chain ring. I have a 42-24 and 11-34 on one bike and only use the lower gears of the cassette when in 24T. If I tried to go 24T-11, for example, I would get chain wrap. The 24T is only a bailout gear for big hills so I only run the lower end of the cassette while in it.

Besides the cassettes you can buy, you can also build your own by unscrewing the pins and mixing matching cogs. I am doing that for another bike with a 7 speed cassette that will go up to 40T. You can't buy that but you can build it. Those are big jumps but give a wider range for hills. Some other parts you may need are a Wolftooth road link and a long cage rear derailer.

Have fun and try some ideas out.

zandoval 

Yep... That's about the time I go for my size 12 gear for sure...

Looking close at guys who can get into steep geared climbs I have noticed that they have fantastic balance and proprioception as well as incredible strength.

It's a talented exercise in athleticism...

Happy Feet

Especially a steep hairpin switchback. Up hill riding is it's own sport in some ways.