Does lighter bike make up difference in gearing advantage of heavier bike

#1
Looking at two different bikes. One bike weighs around 42 pounds with 42T cassette. The other bike has Rohloff hub with 50T equivalent and weighs 73 pounds. Does the lighter weight of the one bike make up for the gearing advantage of the heavier bike for hill climbing ability. Assume same rider, motor, tires, and both full suspension. One is a Carbon frame (lighter) and the other is Aluminum. Any thoughts?
 

Ravi Kempaiah

Well-Known Member
#2
Looking at two different bikes. One bike weighs around 42 pounds with 42T cassette. The other bike has Rohloff hub with 50T equivalent and weighs 73 pounds. Does the lighter weight of the one bike make up for the gearing advantage of the heavier bike for hill climbing ability. Assume same rider, motor, tires, and both full suspension. One is a Carbon frame (lighter) and the other is Aluminum. Any thoughts?
If you look at the gear ratio presented on the Rohloff AG website,
https://www.rohloff.de/en/experience/technology-in-detail/gear-range-comparison/

Rohloff has 526% gear ratio

A normal derailleur or 42T rear - 18T Bosch front chainring would have close to ~480% ratio.

In reality, you never get to use the top 2 and lower 2 very often. Rohloff is preferred by traditional bike tourers who carry 100+ lbs cargo and climb steep roads at 6mph speeds. In those conditions, it may be useful but on an eBike, under normal conditions, the advantages of Rohloff as compared to a traditional derailleur from purely gear ratio point of view, is quite limited especially if both bikes are equipped with similar motor systems. A bike with 18T Bosch chainring, 42t rear would be able to climb just about any hill you point at.

Where Rohloff shines is in maintenance and long service life under brutal conditions.

W.r.t weight. 42lbs bike will feel very different and be lot more agile compared to a 73lb bike. No question. Once you ride a 40lbs bike, we intuitively pick the lightest one.
 

Feliz

Active Member
#4
I used to compete in mountain biking back in the early days and I raced motorcycles as well. With racers there's an expression that the easiest way to make your bike faster is for you the operator to lose weight. It's true ask anyone who has studied physics.
 
#5
Weight and center of gravity make a big difference for any vehicle - especially a 2 wheeled one. I know that lots of folks pay big bucks to get a lighter bike - but it's cheaper to shed a couple pounds than buy an expensive lighter frame. :) The total weight including rider is what you are dealing with.
 

Ravi Kempaiah

Well-Known Member
#6
Few years ago, GCN did a nice video about this. I am linking it here.
While it is true that the rider's weight can be a factor. The subjective experience of a lighter bike makes for a lot more enjoyable ride. If everything else equal, people would always prefer a lighter bike. It just comes naturally.

I used to ride a Haibike Super Race few years ago, it was right at 41lbs and I thoroughly enjoyed the experience.
When you corner at high speeds, you don't experience the sideways angular inertia. This lended itself to certain agility that I find missing on my Stromer bike. Stromer rides like a tank and is very stable but heavy bikes don't elicit that feeling that comes with riding a 40lbs bike.

Lighter bike comes in especially handy in the following scenarios:

You need to use multi-modal transport and have to lift the bike up certain # of stairs or metro train.
Living in apartments? be aware of the weight!!
You want to ride unassisted for few miles or if the battery quits, you don't want to worry about pedaling a heavy bike.

 
#7
My Ebike is much heavier with battery and motor than the original mountain bike but it rides great! The assist makes up for the weight. I agree that lifting and carrying it isn't nice though.

Riding up a hill, it doesn't matter if the bike is lighter or the rider it lighter - it's the total weight that you have to move against gravity.
 
#8
Hi Volt.

It will be the same rider and both bikes are Ebike. Total weight difference for bike and rider is 30 lbs. Heavier bike has larger gear range.
 

indianajo

Active Member
#9
The subjective experience of a lighter bike makes for a lot more enjoyable ride. If everything else equal, people would always prefer a lighter bike. It just comes naturally.
I don't ever corner at high speeds. I do a couple of downhill curves at 30 mph, but it is nothing like dodging trees modern bikes are designed for. Scraping the pedal is a P***, I never lean the bike that far. I watched the Olympic bikes in Brazil, those riders are nuts. One bashed himself into a tree.
What I really don't like about modern bikes is how they fall down in the front on the least patch of gravel or bumps. Throwing me on my chin. My mother's 65 lb 1946 Firestone 26" was the last stable bike I rode.
I've added 23 lb to my bodaboda with the motor & battery, really don't mind it very much. I mostly ride without power. I outweigh bike plus accessories 2:1. When I pant far enough on it, I lose weight. About 20 lb difference on my waist from summer, 70 miles/week, winter, 20 miles/week. When I load bike with supplies, weight me to it is 1.4:1 .
I'm not racing on the bike, I don't care enough to speed to bend forward like an olympian. Air drag is much more a resistance than weight until grade gets over ~5%. Riding a bike is more interesting than the exercycle I ride at home or a eliptical machine or treadmill at the gym. The scenery changes. The outdoors doesn't stink like a gym, either. It smells pretty nice in Jeffersonville, really, since the Swift stockyard closed.
 
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#10
I used to have an old e zip bike w/ a currie motor and lead acid batteries. It weighed about what the heavier bike you mentioned weighs. It was a pig to ride. My current e bike is 55 lbs and feels downright nimble compared to that old anchor. No matter what the gearing was, unless I was only using a bike to haul things I wouldn't want a bike that weighed what your heavy bike weighs. If you are going to be mainly hauling things then it's a different matter.

All things being equal, a heavier bike will require a lot more energy from you or the motor to go up a hill.