mschwett 

i ride ebikes for reasons too long to get into here, but i supply the vast majority of the power myself, like 90-95% over a 70 mile ride, only turning the motor on for hills. my current bike is 1x11, 46 up front and 11-42 in the back.

today i made the mistake of test riding a non-e road bike (aethos) and it was freaking awesome. the difference between a 28lb bike and a 14lb bike was/is more than i expected. i rode it about 5 miles, 300' of elevation with a max grade of 13%, felt OK climbing but absolutely had to use the lowest gear (36-32). i averaged about 7mph up a stretch which averaged 8% grade, which pretty much exactly matches what my power meter always tells me, sustained output of around 225-250w. i was very sad to give it back.

stock lowest gear on this bike is 1.13 (32 in the back 36 up front), which is virtually the same as my creo at 1.10. with a wider range cassette in the back, it seems like i could potentially dispense with the motor and just spin very slowly up the hills. in practice, what's the speed beneath which it's just not feasible to ride a road bike up a hill? am i missing something in calculating the gearing here - 46 up front and 11-42 in the back on the creo gives 4.18<->1.10 whereas 36-52 up front and 11-32 in the back gives 4.73<->1.13.

(i wouldn't get this spec and color, a little too rich and flashy for my tastes...)

surak

There was a half mile stretch averaging 12% that I did last week on 34/32 at 5 mph, never felt close to needing to unclip although I wouldn't say that was spinning. You can easily get 1:1 ratio these days on a road bike without much hassle, although it's better to start with a compact chainset because then there isn't much you'd need to do for a medium cage RD to accommodate the max rear sprocket.

63rickert

You got a good result on a borrowed bike that was not optimized for you. On your own bike it would be even better. Yes, merely being light makes a bike far more comfortable and a lot more fun. The difference between sitting on a 28 pound hammer and a 14 pound hammer

superdex

to answer directly, 3-4mph? Below that, you'll be walking. And it'll be a 22% grade. In other words, the 52/36 and 11-32 is plenty. You could go with a 50/34 up front if you want a little lower, or go with a "mullet" setup which is a mtb derailleur and cassette with road shifters. Considering you're able to put in 225-250 watts, if there aren't other limitations to ditching the e-bike, you'll be fine.

My ftp is under 250w, and I spent last week at Ride the Rockies: 418mi and 29k ft of climbing. Not a lot over 8%, but when it was, 60-70 rpm with 36-32 was very doable (for me, anyway). Only once did I wish I had the 34 up front, but that's because it was 100*F and it mile 98....

sean.hwy

For my knees on hills above 10% that are a mile+++ long I want a one to one ratio. 34 front 34 rear. or 32 front 32 rear etc....

If it's just a short city block I am fine with standing.

I have a gravel bike with road wheel set just for this reason. I prefer the lower gears plus it's dual purpose bike with two wheel sets.

The aethos is sick!

mschwett 

thank you, very helpful. i may be putting too much faith in the bike calculator, but it tells me that at 195lb plus 15lb of bike it takes 225w sustained to go up a 12% grade at 4 mph. not sure what cadence that would be, but i’m guessing too low for me to actually sustain 225w for long enough… definitely not in 100 degrees weather, at which point i’d have long since called an uberXL 😂😂

mschwett 

yeah i’m thinking 1:1 is a must. mullet!

and i really loved the aethos. i know it’s not what people here think is hot, but damn if it didn’t ride like it wasn’t even there, without any fitting. felt perfect.

PeteHski

I run a compact 50/34 chainset and 11-34 cassette. So my lowest gear is 1:1. My FTP is around 300W and I currently weigh around 180 lbs. I can ride up 20%+ slopes on that setup fairly comfortably at a slow walking pace i.e. 2-3 mph. But cadence is very low at that speed, definitely not sitting and spinning! But I can keep moving without smashing myself, while guys on bigger gearing are often having to push power way above their threshold just to prevent stalling out. On an 8% slope I can climb all day at a steady pace on this gear setup. Someone will no doubt come along in a minute talking about spinning at a 1000 rpm and going nowhere, but on any slope above 10% I'm not going to be spinning at more than 80 rpm for any length of time in a 34/34 gear. The reality is more like in the low to moderate 50-70 rpm range. Just to compare, my mtb lowest gear is 30/50 and that is actually about perfect for spinning effortlessly up a 12% slope at about 5 mph. But that's a heavier FS bike with 2.35" off-road tyres. My sustained climbing power is about the same as yours i.e. 225-250W, which I can hold for a couple of hours of alpine climbing. I can push 400W for a few minutes if I really need to, but then fatigue is soon going to put a stop to that!

mschwett 

that's very interesting. i definitely am not seeking hours of alpine climbing and 20% is more than i'd seek out, but there are lots of 1000-2000' 8-15% climbs around here that i'd like to continue doing. as is, i throw about 100w of bike power into the mix for climbs like that.

225-250 is definitely doable for hours, but my power curve falls off very fast because my heart just can't sustain those 400w efforts for more than an anaerobic duration. the below is from my first few months of riding, heart rate never exceeding 125 and average around 110 on a typical ride. i can do better, and will get stronger but not by a huge amount i'm guessing, maybe another 25% or something as i get more "efficient." the bottom line, it seems, is that it should be possible to climb up to perhaps a long 12% grade at 225w for someone my size. 14lb less bike and 10% shorter gearing would make a big difference, i think.

cyccommute 

You may be walking. I’m still pedaling. It may seem like a fools errand but pedaling at that speed is easier than walking the bike. My lowest gear is in the 15” range…and, no, I don’t think a 36/32 low is “plenty”. At 60 rpm, that not quite 3mph and I can stay upright down to zero.

mschwett 

yeah, the math doesn’t quite work out at a “reasonable” cadence.

12% grade, 225 watts, 210 pounds including bike yields 4mph.

i believe the stock aethos sram pro has 35-48 up front and 10-32 in back. 35-32 with 32mm 29” at 4mph is only 46rpm. probably need that to be at least 60rpm to keep the power up. changing it to a 10-36 in the back gets 51prm. i’ll have to see if i can do 250w at 51rpm for 15 minutes. i highly doubt it looking at cadence vs power on my last ride. the zone is 150-300w and 62-88rpm.

superdex

I was basing my response on his qualification of road biking. On a mountain bike, sure, go as low as you can stand (see what I did there?). On pavement, past a certain gradient, you're just gonna have to hump it or walk it. Most roads are <15%, even those that are considered STEEP. Sure, there are the one-offs here and there (like that one ride on the east coast that hits all the 20%+ hills --is that your everyday ride? no, it isn't. Neither is Mt. Washington or the Koppenberg. If it is, well goody for you). Unless the OP is exclusively riding the steepest streets in downtown SF, yeah, I think a mid or full compact with a 32 in the back is plenty*. Shrug.







* I'm 6'3", 185lbs and ride 3000mi a year and I have a 245w ftp. I'm not a whippet climber with an other-wordly w/kg ratio. I'm more like a great dane. Some days, I'm a St. Bernard, and just happy to get outside.

CliffordK

If your crank can handle 35T or 36T, it should also be able to take 34T which would be a cheap change, although you may not really need it if you give yourself a chance.

A 14 pound bike? That is really light!!! Make sure you actually put it on a scale that you can see.

200+W is good. Just slow down if you need to.

It looks like all you need to do is find hills that you can climb bottom to top in about 10 seconds, and you'll be just fine at > 1000W!!!!

cyccommute 

My gearing is for road biking and my speed is often 4mph for miles at a time. I run low gears on mountain bikes but I also run low gears on road bikes.

HTupolev

It's possible to build a road bike with gearing that goes far lower than typical "road" options, even while staying mostly within "road" derailleur and shifter ecosystems. Like, it's fairly easy to coax the multi-ring GRX derailleurs into handling 11-42 cassettes (even though they're officially spec'd for 34T/36T), and there are off-the-peg road-q-factor cranksets with small rings in the 20s.

mschwett 

good to know. seems like that's basically what i'd need, something to keep me spinning in the 70rpm range at 4-5mph up a 12% gradient for 30 minutes or so. i don't have the ambition to do climbs bigger than that, and in fact most of the local rides are more like 8-10%. 28 up front, 36 in back, or 34 in the front and 42 in the back.

PeteHski

The stock Aethos SRAM cassette is 10-33 but I think 10-36 would be preferable in your case. You can also go a bit smaller on the SRAM chainrings too (46-33). 250W at 51 rpm is going to hurt your legs and lower back for sure. Standing is easier at that sort of cadence, but still a big grind. Lower gearing makes that sort of effort much more comfortable. A 33-36 low gear would probably get you through that climb in reasonable comfort. I haven’t checked the cadence, but I think it should put you around 60 rpm at 4 mph.

RChung

That depends on how well you can balance without wobbling. I live in Berkeley and I used to ride up Marin every once in a while as a "how far up can I make it?" check. You may know that it was originally intended not as a driveable street but as the track for a planned funicular. Anyway, Marin averages 17% for almost 1.2km, but it has pitches in excess of 25%. I used to struggle up on my road bike with 36-26 gearing and make it roughly half way. It was very unpleasant. One year I was out riding MTBs with a buddy who, on the spur of the moment, decided we should ride up Marin. My MTB has a lowest gear of 26-32. It was drama free, at 2 mph.

So, balance at low speed is one problem; but the greater problem is pedal force. While climbing Marin up the 24% pitches, on a road bike with 36-26 gearing at 30 rpm I was going 3 mph -- but the average pedal force was way more than half my body weight. Max pedal force across the crank revolution is, ballpark, about twice average pedal force, so max pedal force was about 1.5x my body weight -- and that's hard. On the other hand, with 26-32 gearing at 30 rpm I was climbing up the steepest pitches at less than 2 mph, my average pedal force was about 2/3rds that of my road bike, and my max pedal force was *just under* my body weight.

Both the Creo and Aethos are nice bikes.

superdex

You have 2mile-long climbs that average 12%? On one hand, I'm jealous. On the other, eesh, you're right. You want mtb gearing

mschwett 

more like 8-10 sustained, typical california coastal range roads. i live on a 10% slope in SF. but a little headroom is good.

caloso

I never knew that, but that makes total sense!

When I was an undergrad, my GF had an apartment on the north side of campus. I had a Schwinn World Sport and I think my lowest gear was probably 42-26. To be 19 again....

79pmooney

I've been using triple cranksets for almost 50 years. They are getting harder to do simply because marketing has drifted away (and really fat tires make the execution a lot harder). But triples make this juggling act really simple. For many years I rode a 52 or 3, 42, 28 X 12 or 13 to as big as 28. Now in my late 60s, its 50-38-24 in front, same rear, same derailleurs.

Most of the time I ride cassettes with 23 or 25 lows, have a wonderful selection of gears to ride and still get to approximately 1:1.

RChung

Dan Connelly (of Low-Key fame) wrote a blog post about Marin. In the comments to his post you can find something I wrote sort of like your comment about your GF.

surak

Agreed, the nice thing about a lower gear than you (or others) think you need is that if you get tired and need to ease off the power for a bit, you don't have to slow your cadence down. Not every climb is one that you'd want to hold steady power up, even with a steady grade. You might want to take a drink or eat in the middle, and keeping tempo could be tricky with a lower cadence.

ofajen

What’s feasible, with low gearing, is a pretty low speed.

OTOH, I really have no interest in sitting and pedaling slowly up hills. I’m content to stand up and blast up our little hills on a single speed and jog up the few super steep slopes that I I can’t manage on the bike.

I ride with platform pedals and shoes I can run in, so it isn’t a big deal. Obviously that’s not an approach that most folks would prefer. YMMV.

Otto