Commuter bike for better performance: less weight, or internal gear-hub?

Question

Background

I commute daily to work, the ride is about 10 km each way, across the city. The path is mostly streets with intersections, and a few long cycling lanes. Some hills here and there: Strava cycling app says 'Elevation Gain' is 80m.

I'm currently riding a Trek Valencia hybrid bike (2011), it's getting a bit old, and I'd like to replace it. I'm looking for the same kind of acceleration / responsiveness / sporty ride, but possibly getting me to make less effort to get the same performance (or get earlier at work).

Options

I want hydraulic disk brakes, good quality gear set, and rather an aluminum frame.

I checked what local bike shops recommend, and I'm now hesitating between two options. Unfortunately, trying the bikes is not an option, as no shop has them in stock.

Stevens Strada 900 (2019)

product page

It has quality components and is lightweight. I'll need to add mudguards and a rear carrier though, so it will be a bit heavier than the announced 9.4 kg.

Gears: 2 x 11 Shimano Ultegra R8000

Cube Editor black'n'purple (2019)

product page

This one looks interesting to me because of the belt drive. This would make the rides smoother, and avoid loss of efficiency in the long run.

Gears: Alfine 11 gear hub

Questions

I read posts with figures about the gear ranges of both systems, but I'm having trouble getting a clear picture. Some articles: stackExchange post, internal gear rations measurement, this post and that one.

1. How likely am I to get in situations where the speeds of the Alfine 11 gear hub don't switch correctly anymore?
2. Are the 2 kg less from the Stevens likely to make a noticeable difference in terms of energy efficiency?
3. Will any of the bikes above provide a range of speeds comparable with what I currently have (mid-end 3 x 8 derailleur)? I had the opportunity to try a bike equipped with a Shimano Nexus 8 gear hub, and there were definitely not enough 'high' speeds. This would prevent me from riding fast enough on flat lanes, or downhill.

Or to summarize, perhaps: more lightweight bike with derailleur or Alfine 11 gear hub, which would you recommend for my use case?

Any input and tips appreciated.

Thanks,

P.S.I also read the answers to How to improve my performance on a commute? and will probably follow some of the recommendations in there, like getting clipless pedals.

Answer 1

When you use your bike every day, reliability is as important as weight. I use 2 bikes, with a train ride in between. The bike I use at my work town rarely gets maintained. I take it home 2 times each year. The only things I do regularly is pump the tires and lubricate the chain. Even then it keep riding as good as new. The derailer bike I had here before that needed a lot more care.

The things I learned over the past years:

• The simpler the better. If the terrain is flat enough to get by with a bike without gears, do so. 80m elevation is on the edge, and depends on your physical condition. If you feel the upper gear on a Nexus 8 is not large enough, you're riding quite fast (35Km/h+) already. I ride a bike with an Alfine 11, and have no problem doing 35 in 8th gear. Another thing is adjusting your style to spin faster (85+RPM), which generally is also better on the knees.
• No front shock absorber. The good ones are too expensive, and the other ones too heavy and crap
• No V-brakes or cantilever brakes. At least hydraulic rim (Magura) or disc brakes
• Mudguard!
• A rack to hang bags (I am very happy with bags like this). No backpacks for me.
• A IGH is a lot more carefree then a derailer.
• being able to shift at red lights is very handy
• The lights have to be driven by a dynamo and fixed to the bike (battery lights get empty or forgotten at the worst possible time)
• No NuVinci. It is heavy, and you can't shift when stationary

So I would not use either of the bikes you suggested, but something like this or this

I don't have an opinion on chain vs belt. My girlfriend has a bike with a belt, and that tends to stay cleaner then the chain on my bike, but I don't know whether it is worth the extra expense.

Answer 2

I have only three things to add:

• I would definitely get a bike with hub dynamo and fixed light. Even if you ride during daytime, having the lights on gives you added visibility in traffic and the price you pay in weight and added resistance is negligable.

• If your hills are not as steep to need all the lower gearing of the Alfine, you could make it faster by simply exchanging the chainring for a larger one.

• Don't buy the bike without a test ride.

I disagree that you should use a cheap bike for commuting if you can afford a better one, as long as you have a safe place to put it at work. Simply because those 100 km/week will probably be a major (if not the biggest) part of your overall cycling, and why use bad equipment if you don't have to? Compared to using a car, even a mid-upper range bike is still very cost-efficient.

Answer 3

An extra two kilograms on your bike would weigh against your total mass (you plus the bicycle plus your backpack plus your water bottle plus your helmet and sunglasses and ...).
When rolling slowly (and not accelerating) or climbing hard, there's little difference between my fat bike and my road bike with 25mm tires, with the difference in mass being 105 to 110 kg (rider, water, backpack, bicycle, helmet, ...).
(when accelerating, the 26x4.0 wheels on the fat bike gives it a majestic and ponderous feel - fortunately, braking performance with hydraulic discs is superb).
As for the efficiency losses... current top of the line chain and gears are 97+% or so percent efficient (based on numbers thrown by the GCN for CeramicSpeed bearings and that new gearshaft transmission for bicycles), so any improvement on that is worth only for races (you might choose the "no maintenance" mode of belt drive and internal gear hub, but any efficiency deficiency can be ignored).

Answer 4

I have an Alfine 8 with the Gates belt as pictured on that Cube. I use it for commuting, and carry about 5kg of stuff in my rear panier, bringing the total weight up around 15kg. I haven't ridden on a derailleur bike in almost two decades because the internal hub is so much more reliable in the weather. Add on top of that the Gates belt, and you're avoiding most of the issues that come along with a chain.

I don't know the quality of that specific brand of bike, but the components are top notch. With the Alfine 11, you may find that you skip pretty quickly past the first couple gears, but they'll help your acceleration and reduce the amount of torsion you place on your crank.

The internal gear hubs do sometimes take a bit to switch, just like an automatic transmission in a car. If you keep your foot on the gas pedal, you're less likely to have it gear up; similar to this, the bike hub will typically avoid switching while there's active force being applied through the system. Stop pedalling for a split second while you switch gears and you shouldn't have any issues.

In my experience, the gear ratio between an internal hub will out pace a typical derailleur commuting bike. You likely won't be able to compete with a road bike. Typical cruising speed is 20km/h. My Alfine 8 tops out at around 35km/h, where the pedals just don't do anything in top gear after that. The 11 might have a bit of a higher top speed, but commuting tends to be a lot of stop signs and red lights that you will stop at.