adlai

I’ve been thinking some about how to better build a bike suited for hill climb. Besides light weight, what else can be done? Something with bearings? Also, is it better to have a really small granny gear in front or a large cog in the back?

livedarklions

Or both? Don't have an answer, but that would seem to be a third possibility.

Jughed

Road, offroad? Race or just a bike easier to climb with?

If its just for fun - a 1x11 or 1x12 Cyclocross groupset is great. My CX bike is 42 front, 42 rear for 1 to 1 ratio, makes climbing easy. Can even go smaller in the front if top speed isn't a concern. And its just a tad lighter than a 2x setup.

GamblerGORD53

Get serious. Go ride a bike.

PeteHski

Gearing depends entirely on how steep the climbs are and your fitness level. If in doubt go for lower gearing. My lowest climbing gear is 34T/34T on a Shimano compact double, but if I were building a specific hill climb bike I would go even lower and probably build it as a 1x with something like a 40T chainring and wide-range cassette

prj71

Work on your physical fitness. It's the rider...not the bike.

terrymorse 

To minimize drive train friction, bigger is better. The reason: big cogs and chainrings require the chain to bend less [EDIT: And the chain tension is lower with big cogs.]

Let's say you want a 1:1 gear ratio. A 50 chainring with a 50 cog will be more efficient than a 34 chainring with a 34 cog.

What else can be done?

• Tires with the lowest rolling resistance you can find, inflated to the optimal pressure
• Newly waxed "race day" chain

badger1

Here you go; lots of inspiring ideas here!
https://www.cyclist.co.uk/in-depth/2...pionships-tech

79pmooney

#1 Fit. Reach (both horizontally and vertically) to the handlebars and levers. Handlebar shape. Lever shape and placement. A frame that is stiff enough to work for you.

Hill climbing is the end result of the work of the engine driving you up that hill (your body) and the forces opposing - weight, wind resistance, tire and mechanical resistance. On steep hills, wind resistance goes to close to zero if there is no (weather induced) wind. Tire resistance gets pretty small. Mechanical - keep your bike in good working order. Weight - well the bike is only (say) 10% of the whole package. Yes. lighter is better but 10% lighter on the bike isn't cheap and that's only 1% of the total.

But the engine - if you can nurse 2% more power out of it, you just doubled what spending thousands would have gained you on the bike. Look to make your (current or future) bike feel like the ultimate climbing machine every time you head uphill one where your body simply comes alive. That bike in my avatar photo is it for me. That photo was taken at Cycle Oregon, 2014, going up a grade of 14% in places (and that photo). The bike's a fix gear and I missed flipping the wheel around to the big cog so I was muscling a 42-17 gear, but - the bike fit me perfectly! It took everything I had and laid it down on the pavement. That bike isn't super light; 19 pounds when new and naked, considerably more in that photo. But it was all there to support the engine.

Calsun

A bike frame with shorter chainstays and enough distance between the seat post and the handlebars to be able to stretch out on the bike and use as much of your upper body as possible, which also means using drop bars. For most of my bikes I have owned I needed to replace the handlebar stem to get the correct amount of reach for the hills.

For grades I need at most two very low gears and which one I use depends on the length of the climb. For very long grades that continue for miles I want an ultra low "granny" gear and can go as low as a 34T cog these days. In the past I had a 26T and a 28T cog on the cassette. The inner front chainrings have gotten a lots maller over the years and so the rear cassette configuration has needed to be adjusted accordingly. My 22 year old regular bike has 53/39 and a 12-25T cassette. My first custom touring bike had 52/46 chainrings and a 14-28 freewheel. My current e-bike weighs 10 lbs more and a single 44 tooth chainring and I replaced the original 11-42t cassette with a 11-34t one to have tighter spacing.

So it depends on the type of riding, the load planned, and the weight of the rider. If someone has a BMI greater than 25 they are going to be carrying a lot more weight up the inclines than a thinner ride (look at the builds of the pro riders noted for their ability in the hills on the pro races). As I am not racing anyone or doing a time trial I use as low a gear as I will need to be 100% certain of continuing up a grade or grades without having to get off the bike or doing damage to my knees.

kommisar

I suggest a 350w hub motor in the front wheel with a battery strapped to one of the fork legs. This will increase speed without effecting the efficiency of the drive train.

Polaris OBark

If you make the front wheel a lot smaller than the rear wheel, the bike will still go downhill even when you are climbing up a hill.

Pratt

First, I'm no expert, but I won't let that stop me.
Are the hills short and steep, or longer and more gradual?
What % gradient can you ride for a sustained period of time?
What gearing will give you that much gain in height for the advance distance, to equal the gradient you can ride?
Most, would, I think, agree putting a lighter, fitter rider on the bike will help a lot.
In addition to PolarisO's suggestion, you might add a motor.

Lombard

Pedal harder!

Seriously, work on your fitness and lose weight off the rider. Other than that, tires will make the greatest difference and at the same time hit your wallet the least.

tempocyclist

The big question is, is this hill climb bike for a hill climb race? Or to simply ride up hills quicker (and still needing to ride back down and on flats, etc).

This is pretty interesting:

https://cyclingtips.com/2020/08/6-2-...esting-record/

The bike used by Ronan McLaughlin when he broke the Everesting record. A bit of climbing involved in that.

BTinNYC 

Kropps Hill is a 12% grade, maxing at 18%, and I like the 34 t front and the 36 t rear.

CAT7RDR

Checkout GCN. This seems to be a monthly topic for them.
One came out today that is actually quite good with a female world pro.
I like the fact she mentioned to use the bike in a rocking motion to achieve more power.
Good stuff!

veganbikes

If you are actually serious and crazy enough the UK Hill Climbing scene is all about crazy specific bikes for hill climbing. They cut bars down and remove tape and run things absolutely at the limits. But they want to win.

79pmooney

Yeah! The old out-of-the-saddle full body rock. There is only one piece of your body not rocking. The bridge of your nose between your eyes. (You can roll your head around that point but keep your eyes going straight uphill. And your tires. Everything else is just part of the dance.)

Now, how long you stand is a function of how long the hill is, your riding style, the grade, your gears ... As a hard core fix gear rider, I have done it for miles. In a 42-17, there may simply be no choice. I rode the 16 mile Dead Indian Memorial Highway out of Ashland Oregon with the wheel flipped to a 23 and stood probably 25% of that distance. Much higher percentages climbing to Crater Lake. Those were slow motion dances using much of my upper body.

I love to stand. Raced a 13-19 FW most of my races. Yes, I probably could have done better with lower gears but that was the days of having only 5 and lower meant poorer choices most of the race. And I had the strength to power that big gear and roll uphill at speeds no one liked. Now I am old and slow. But I still love to stand. All my bikes rock and roll. And I still go uphill in a giant weave with my eyes and tires on the shuttle.

mschwett 

if all you cared about was getting to the top of a hill as fast as possible, it might look something like this? a (sorta) fully functional 10lb bike.




https://www.bikeradar.com/features/p...alized-aethos/

RChung

That was for Ronan's first record. He improved that time by 25 minutes. Here's a video. .

Between his first and second records, his power didn't really increase. He changed and refined his bike and especially his procedures. He actually had to do two bike swaps: he got a flat on his primary bike (but kept it upright) so swapped to his backup bike for one ascent, then swapped back after the flat was fixed.

prj71

https://www.bikeradar.com/advice/fit...climbing-star/

wheelreason

And as a plus someone could walk next to you holding your bottles and snacks...

rsbob 

Adlai apparently is MIA. Lots of good questions posed as to intention but just….crickets. Bueller? Bueller? Anyone? Anyone?

Iride01 

Between weight and bearings, weight. Forget about bearings. Most any bike in almost any running condition has good enough bearings.

Gearing ratio's will be your next thing to look at on the bike. But before that you need to look at the person riding the bike. Are they a person that prefers to ride at a high cadence and can do that continuously for the time it takes to climb? Or are they a masher and prefer to have a low cadence for the entire climb? Or can they do both well?

Depending on what the motor can handle will determine the gearing choice. And so too will the steepness of the climb and the duration.