Commuter bike efficiency questions
 

Hi all, I'm thinking about a more commuter specific bike, and I have some questions. I think these have been addressed seperately in various threads, but it would be nice to recap them all, especially for my specific needs.

I have a bit of a long commute, 35 mi / 56 km round-trip. So efficiency matters. Right now I'm using a mountain bike with slicks, and I make acceptable speed on it, but the fine touches are lacking. My question is, if I put down $700 for a "real" commuter bike, are the "fine touches" going to suck away lots of speed? If so, I'm not sure I want them.

Let's take the Breezer Villager as an example:

1. How much speed will the dynamo lights suck away? If I would normally cruise at 15 MPH, what could I expect? 13 - 14 MPH?

2. How much speed will fenders suck away, given a no-fender speed of 15 MPH?

3. Is the Shimano Nexus internally geared hub as efficient as derailleurs? If not, how much power loss is anticipated? I live in a climate without snow and ice, no road salt. So are there compelling reasons at all for me to select an internally geared hub?

Thanks for all of your help. I know that some of these questions have been asked many times, but a new summary may be useful to have.

Lord deliver me from "commuter" bikes. When a mfr calls something a commuter bike they mean something for noodling a couple of miles. You need a road type bike, preferably something along the lines of a touring bike like a Surly Long Haul Trucker.

I agree with Rainman. Breezers are great for toodling a few miles, but your ride requires something more efficient.

Look at the Surley's LHT, as well as the Cross Check and other cyclocross bikes. You want something that can handle thicker tires that the standard road bike. I use 28's now, but I think they are too narrow for commuting. I'll probably go up to 32's in the spring. Fenders are a must for commuting. The your bike's engine will run much better if it isn't covered with road muck. What tiny bit of drag they create is not that big of a deal.

The Surley is on the heavy duty side for a commuter, you may find something like the Soma Road Sport a bit livelier, but it still has all the features of a serious long distance commuter road bike
http://www.somafab.com/extrasmoothie.html.
I have both styles of bike in my stable, and prefer a light tourer for commuting/day rides and a proper tourer for expeditions.

1. The dynamo lights on the Breezer from what I heard is the weakest component on the bike. You're better off disabling these lights once they break down and use rechargable.

2. The fenders will suck speed but what is a major issue is the geometry. The Breezer is fine for short commutes (less than 15 miles) because the straight up sitting position will mean every wind will end up being a head wind. I also believe that a road bike with 700 cc wheels are more desirable than one with 26' inch. If anything, performance will be much like riding a mountain bike.

3. The Nexus 7 speed is not as efficient as a cassette. The only reason you would go this route is if you had to deal with rain, snow, salt, mud and ice. Since these are not an issue, you would never choose a hub geared bicycle. The Nexus 7 (which has no direct drive) feels like I have a couple of water bottles attached to the rear wheel.

The Breezer Villager bikes have weight and stiffness where you need flexibility for a comfy ride, and they flex where you need stiffness for efficient power transfer to the back wheel. A normal dynamo will feel like cycling up a constant 2 or 3% grade. The expensive dyno hubs have no noticable drag and have a good light output. If you are commuting on lit streets I would recommend 4 AA battery LED lights (2 or 3) like the Cateye. Fenders will have no noticable impact on speed

1 My guess is that you will ride at a comfortable cadance. Therefore, unless there is enough drag to force you to shift down a gear, there will be little change in average speed, although you may be more tired at the end (this could be important over a 35 mile round trip). In my experience, sidewall dynamos do not produce enough drag to make this happen. Back when my bike had a sidewall dynamo, I was never able to find any speed difference between dynomo engaged and dynamo not engaged.

2 I can't imagine that adding or removing fenders could have any effect on speed. It is possible that the pound or so of extra weight might have some trace effect on the required exertion required on hills. I'm confident that fenders produce far less drag than an engaged sidewall dynamo.

3 Studies have shown that internally-geared hubs are less efficient than derailleurs by several percent. Swithching between my internally-geared bike and one of my derailleur bikes, I don't notice any improvement in travel times. The derailleur bike has a crisper subjective pedaling feel that is pleasant.

4 In my experience, the real disadvantage of the Shimano Nexus internal hub is that it does not provide as wide a range of gear ratios as does a contemporary 21 speed derailleur bike. This means that you cannot simply spin up steep hills. If you are in a really hilly place, this could be a showstopper. However, I've yet to find any non-climbable hills in the Washington, DC area.

Non-winter advantages of internal gears:

It is possible to mount a chainguard. This means that you can just hop on the bike and go, making it more convenient than a car for short trips.

There is a lot less regular maintenance required. I rarely lube or clean my chain, and it still lasts 2,000-4,000 miles -- and a lot of that is in snow/salt/grit.

You can always shift into any gear when stopped. This means that you can always be in low gear when leaving a stoplight. You can also shift very quickly to desired gear ratio. This has urban benefits - I never have another cyclist pass me within 100 feet of leaving a stop. My downtown travel times are quicker than with either my wife's road bike or my hybrid because of this.

Basically it comes down to this.

Ride in normal clothing, hate to tinker, want maximum convenience, ride with many stops, think of cycling as transportation-- hub gears.

Ride in bike togs, enjoy mechanical tuning and adjustment, want best possible efficiency, ride with few stops, think of cycling as a sport -- derailleur.

"Horses for courses".

It would be good if your LBS would let you borrow/rent a bike for an afternoon so you could see what works best for your commute.

Paul

PS

Why not consider a road or touring bike if efficiency is your key goal?

Paul

I'm with Paul. The ultimate long commuting bike is a touring bike. Tough enough to handle potholes and curbs, comfortable enough to ride every day, and better body geometry for cruising than a mountain bike. Plus you have the advantages of all the braze ons if you you decide to haul panniers, etc.

As for the light, if it's just for personal visibility go for a rechargeable battery powered LED light. So much less fuss.

That's a good point, a Specialized Sirrus with fenders would be just about ideal. I still want semi- heads up posture, due to extreme wigginess of traffic here.

Thanks for the feedback on fender drag (or lack of)

If those dynamo lights are going to break over time, sheesh, I don't want them. Then you're spinning an unused dynamo.

Yes, I can't see much reason for internal gearing, based on your points.

I agree, 'cause I use a road bike for most of my time on a bicycle. There are days when I have to go to work and need to take more things with me, so, I install my quickmount seatpost rack and bag. On days when the roads are wet, I install my SKS raceblade fenders. I have L&M HID light for the front and flashing LEDs in the rear. I wear reflective/hi-viz jerseys each time out. IMO, there really is no need for a so-called commuter-specific bike. I also like having multiple possible positions for my hands when riding.

Another efficiency consideration is to ride wearing the most efficient of apparels, lycra shorts/tights, jersey, road shoes, cleats and pedals.

On weekends, I remove all the commuting gear off my bike and then I ride as fast as I can. :D

Peter Great questions!

From what you have told us I would reply as follows:

1. I use a NightRider Storm HID on the helmet and find that better than any dynamo light. I have tried. My problem with a dynamo is tires. Here in MN it is nice to have summer wheel/tires and winter wheel tires and a dynamo can be a pain when you switch wheels out .

2. Finders will suck some speed no doubt. But if you live in a urban area with little wind it is not as bad as you can be if you are out on the plains. If you only have one bike the key for me is removable fenders. I might leave the back one on but I have a fender that works with a quick release bracket on two of my bikes. Do you really need fenders in Houston full time?

3. Haven’t gone to internal. Even with snow here in Minnesota gears are okay for the most part. But I have thought about the Shimano and the German 14 speed hub but haven’t heard enough to know for sure if they are for me.

What I would like to know from you is.

A. Do you carry stuff in your commute?
If so what is it backpack, bag on rack etc?

B. Being in Huston. What is are the extremes that you will ride in.? 40 – 110 heat? And rain?

When I read your post without knowing for sure what the answers are to my questions I would point you to a road bike if you are a no gear or backpack user and need finders (youll have to get a bike that will take them), or a cyclocross if you need to put both a rack and fenders on. I don’t think you need the internal gears for weather reasons but you might like them if the bike is stored in a place where external gears can get damaged

Peter:

There are two types of dynamos -- the sidewall (bottle) dynamo and the hub dynamo. The Breezer Villager appears to have a sidewall dynamo. My bike originally came with a sidewall dynamo, which worked quite well until the metal roller wore out from the sand and grit. However, in a sand-free environment, a good one can last for many years. It might be a good match for your riding situation. I wouldn't rule it out -- however --

The one big problem is that you need to have european touring tires, with a special "dynamo track" on the sidewall for them to work well in rain. Continental and Schwalbe both make great tires that have this -- however, the fact remains that a sidewall dynamo will limit your tire options. For example, the Specialized Armadillo -- a popular commuting tire -- is not compatible with sidewall dynamos.

My primary bike is a German Kettler -- an internally geared "trekking" (touring) bike. I switched to a hub dynamo from a sidewall unit a year ago and wish I had done the switch earlier. It is hassle-free, quiet, very efficient and happy in rain, mud, and snow. The sole disadvantage is the price.

I see a lot of the Specialized Sirrus around here at office bike racks. I have not ridden one, but a many people seem to like them. That must mean something.

Paul

you have a MTB and want a more commuter-based bike... why not just put on a rack and fenders?

sd

I will never tell my wife this… I convinced her that I needed a commuter specific bike. I bought a Fuji Royal, a relaxed road bike with mountain style bars. My thought was more upright = comfort… Unfortunately, it also means “wind drag.” It came with 26c slicks which I have yet to replace, but will soon. Something closer to 32c (i.a.w. 1.25”) I ended up putting on an aero bar to help cheat the wind.

Bottom line, I was equally as fast commuting on my mountain bike with 1.25” slicks! Everything I use to commute with, with the exception of my rear rack (they make these quick released also), is quickly removed if and when I want to use the mountain bike for its intended purpose.

My recommendation is to buy a bike that you want to ride. Then make sure what you add to commute with is easily removed.

As far as gear:
My commute doesn’t include street lights so I need plenty of light. I really like my rechargeable halogens (two 10W headlights). If the lights are so people can see you I would get a couple LED lights.

I would stay away from sidewall dynos, they are to limiting as far as tire selection and creates drag.

Based on my 26mile round trip commute and $0.30/mile that I am saving by not driving my car, to date it will take me another 107 commutes to pay for a bike that I really didn’t need. sshhhhh!

There are also bottom bracket generators that fit behind the BB & under the chain stays. They run off the tread of the rear tire and have the same drag as other bottle generators, I have bikes with both types & find the drag is barely noticeable but my commute is only 4 miles each way. In my experience, road & touring bikes will be at least 2-4 mph faster with less effort due to the aerodynamic characteristics & higher gearing. You should ride several bikes & pick the one you are most comfortable with.

I bought a Hardrock Comp Mountain Bike this summer because I wanted something strong enought to take the bump of my commute. The small potholes the few curbs I have to climb etc. Then this week I really started commuting, going the whole way via bike rather than drive and bike combo.

My bike has knobby tires. I rationalize to avoid the glass and flats that I assumed would occur more quickly with slicks(?). Now I am wondering how much speed am I losing with the knobbies? I covered my 12 mile commute in 41 minutes this morning.

My question is this, would slicks offer me more speed, how much more, and still hold up against the debris that we all encounter on the road?

Slicks will do as least as well on road debris as knobbies. I see the point about using mountain bike tires on bad roads. There are major roads I will generally only take on my mountain bike because they have so many potholes and patches (and patches of patches).

There are good thoughts and suggestions here.

My thinking is this. Your commute is long. 17.5m each way. The default bike for you should be a road bike. Nothing's faster than that.

Give away speed only when it's absolutely necessary. Can you get away with a messenger bag, or a small set of panniers that can attach to a seat post rack? Are clip-on fenders enough for the weather conditions in which you'll ride? If yes to both questions, then stay with a road bike.

All that said, I commute with a touring bike, because I need the room that the large panniers provide. It's easy to underestimate the carrying capacity regular commuting requires, especially at first. For example, you may find it is even more efficient to combine your commute home with some shopping or other errands.

As for the lighting, I never understood generators, sidewall or hub. Battery lights are cheap, light, and much brighter than generator lights. And you don't have to waste precious human energy to produce that thin bit of light.

My estimate is a 15-20% efficiency gain from 2” 45psi knobbies to 1.25” 100psi slicks. You gain traction as well. On my 13 mile commute I am equally as fast on my mountain bike with slicks as I am on my road bike.

I ride a Specialized Rockhopper, and traded in my knobbies for tires called, "Comfort Kevlar". They are completely slick down the center, with a ridge of knobs along the outside that never comes into contact with the pavement. When I need the traction, it is there, and when I don't, it is not in the way. Also, the kevlar keeps them tough so I don't worry about glass all that much. I definitely go around big chunks of the stuff, but the smaller shards roll right under them without a problem.
Just my 2 cents.
Kat

Been there, done that. I was used to generators in the 1970s, 1980s and kept mine until it broke down in 1999. Then went with batteries. Then went with a hub generator. There is no turning back. Why ? The generator has a few advantages:

- It's always there when you need it.

- No problem doing a 5-6 h ride in the dark. No fear of having dead batteries (even with backup) after 2-3 hours.

- No problems with battery duration at -20 C. It's incredible how short lasts the charge of a "2 hour" battery at -20 C. Sometimes not even long enough for a 20-minute commute!

- Less weight to carry around.

- With better hub generators, drag is insignificant, unless you race.


On the other hand, LED-based headlights are very promising technology. A Planet Bike 1 W LED Superspot or a Cateye EL-300 or EL-500 (better light, flimsy bracket) lasts 25-30 hours on the same set of batteries, and you could get a kit of rechargeables at your home renovation centre.

This is the best advice so far. If you are not comfortable during your commute, you'll stop.

That said, I disagree with MichaelW. Surlys are not too heavy duty for a commute. I think they are just right. I especially like the flexibility to use skinny or fat tires and the dual pivot breaks. The Surly Cross Check and LHT are work horses, which is what I want in a commuter. I have not heard from one person who has regretted using a Surly as a commuter.

Why I hesitate to use a road bike for my commute? I ride a combination of 45 MPH roads and their associated shoulders, city streets, multi-use paths, sidewalks (!), and I jump at least two curbs during my commute. It's a frightful hodge-podge. Welcome to one of the most bike-unfriendly cities in the Nation. Glass, metal fragments. I guess I just can't see a road bike's tires standing up to it. I think my 1.5 inch, 80 psi Armadillo slicks are just about ideal for the task. I can't see going thinner than 700x32c.

Cyclocross bike, great idea, it's only money, right? I think I paid $275 (new) for my current commuter. Maybe when this one is dead and buried in another few seasons...

I think I have been thoroughly dissuaded from a commuter bike like a Breezer Villager. Maybe if I lived within 10 miles of work, but not at 17.5 miles out. They look like nice bikes, though.

I think I will stick with rechargable lights, can't afford to divert human power to the lights. It's hot here, batteries won't die from cold. It doesn't get that cold. Might get down to freezing twice a year.

Removable fender - good idea! Keeps me from dragging a fender around unless I need it. If heavy rain is expected, I don't bike commute.

I did put a rigid fork on the commuter mountain bike today, it's fantastic. So much lighter and faster.

I do have a rack on it, and a rear bike police type of "trunk".

Thanks for the help, everyone.

Peter, fellow Houstonian here. Don't rule out a decent recumbent bike... once most people have peddled a recliner they very seldom, if ever, go back. Also, if efficiancy is your thing... remember, all un-assisted human powered land speed records are held by recumbents. See www.ihpva.org

*Sorry Peter, I didn't read your last post too carefully... One of the few things 'Bents won't do is hop curbs! Other than that... at least try one out. Stress management recumbents is on Grant road just off 249 on the northwest side.