Troubleshooters.Com and Steve Litt's Guide to Transportational Bicycling Present

My CityBike

Copyright (C) 2007 by Steve Litt


        
CONTENTS:

        
LINKS:
  • Installing a 7 plus coaster wheel (not yet written)

        

DISCLAIMER

The information in this document is information is presented "as is",  without warranty of any kind, either expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. The entire risk as to the quality and performance of the information is with you. Should this information prove defective, you assume the cost of all necessary servicing, repair, correction or medical care.

This page discusses coaster brake bicycles. Unless there's an effective front brake, loss of coaster brake effectiveness could lead to death or severe injury, especially on hills or in traffic. If the chain falls off (a fairly common occurrence), the coaster brake becomes inoperable. Even with a functional coaster brake, constant braking on a hill can cause heating and subsequent brake failure. Without a front brake, when the back brake is hit hard, weight shifts forward and braking force is reduced, often leading to a back wheel skid which can cause an instant crash, especially if on a slippery surface like snow, ice, algae, or even a wet pavement.

This document may not clearly express the use of coaster brakes, or may even contain errors. We are not responsible. If you use the information in this document, you take full responsibility for the outcome. If that is not acceptable to you, please do not read this document.

In all cases, I strongly recommend you install a front brake so if the back brake goes out, you can still stop. If such a front brake is installed, it must be installed in such a way that it will not fall off, which in itself could cause death or severe injury (through flipping the bike).

In no event unless required by applicable law or agreed to in writing will the copyright holder, authors, or any other party who may modify and/or redistribute the information, be liable to you for damages, including any general, special, incidental or consequential damages or personal injury arising out of the use or inability to use the information, even if such holder or other party has been advised of the possibility of such damages.

If this is not acceptable to you, you may not read this information.


Introduction

I'm Steve Litt. I created the Universal Troubleshooting Process (UTP). I create and license UTP courseware, as well as teaching the UTP onsite. I've written five books on troubleshooting: "Twenty Eight Tales of Troubleshooting", Troubleshooting: Just the Facts, "Troubleshooting: Tools, Tips and Techniques", "Troubleshooting Techniques of the Successful Technologist", and "The Manager's Guide to Technical Troubleshooting". Past professions include software developement, electronic repair, corrosion engineering, and bicycle repair.

I hope you've read the disclaimer of this document. I'm serious, you must have functional and powerful brakes on both wheels, or you're playing Russian Roulette.

This document describes my city bike, its benefits, drawbacks, quirks and joys.

My CityBike


Photo of my CityBike
        This a trimmed quarter-sized picture of my city bike. You can see also a half-sized and full-sized picture.

This bicycle's features, and the origin and cost of the parts, are described below.

The central feature of my bike is a 7 speed internal hub with coaster brakes. Multispeed internal hubs have fallen out of favor here in America, but they're big in Europe where people actually ride for transportation. Multispeed internal hubs, especially those with coaster brakes, are extremely practical. Here are some benefits:
You can summarize the eight preceding benefits into these two:
The rear hub is a Shimano Nexus 7 speed with coaster brake. I bought it laced on a 26" rim, with the shifter cable and trigger shifter, plus a front wheel, for about $250.00 from Orange Cycle. This is more than I've ever paid for any previous whole bicycle. And it's worth every penny!

Shimano Nexus 7 speeds take two different kinds of shifters: Twist-grip and trigger (Rapidfire). I'd have preferred the twist-grip because it's a little faster and you can downshift multiple gears with (when coming to a stopsign, for instance) with a single motion, but the trigger shift came with the set, and that's good enough.

This bike is built for simplicity. It has the old style "American" one piece crank ("Ashtabula") with a 48 tooth front sprocket. The rear brake is, as mentioned, a coaster brake. The front brake is a extra-long arm side pull with plenty of clearance when not pulled.

The wheels are 26", with a Continental 26x1.7 80psi tire in back, and a Specialized Armadillo Nimbus 26*1.5 80psi tire in front. The handlebars are off my old Gary Fisher bike. The extra long microadjusting alloy seatpost was purchased at David's World Cycle. The chain is a 1/8" chain purchased at Orange Cycle.

The basket is one of those little detachable baskets. A paperboy basket will be installed later, but because of the bike's geometry, installing a paperboy basket will require a lot of retro-engineering with angle brackets and the like.

That leaves the frame. After all my ranting and raving about compact frames, you might be surprised to see this bike employs a compact frame. It was a choice of convenience -- I had this Roadmaster Mt. Fury frame lying around doing nothing, but all my other frames were hosting working bicycles. I bought an extra long alloy seatpost, and will improve the riding position later. As a matter of fact, if I find an old American non-compact frame in a dumpster, I'll probably switch out the frame. But for now, the bike works well.

The seat is from the same Roadmaster Mt. Fury as the frame. Although hard and retro (no little groove down the center), it's surprisingly comfortable -- more so than my old Gary Fisher seat.

Timeline

Some bikes are purchased brand new and fully formed. Others take shape over months or years. This bike is an example of the latter.

Initial Reaction (written 9/8/2007)

I've ridden this bike three days now (writing this article on 9/8). I like it and am disappointed at the same time.

Disappointments

Subjectively, either this drive train is not very efficient, or I've gotten weaker in the 2 years I've been riding a 1 speed. With 48 teeth in front, 19 teeth in back, here's the gearchart:

Front chainring teeth 48
Back sprocket teeth 19
Back wheel diameter 26
Inches travel at 1 to 1 65.68
Gear Mult Inches Jump percent
1st 0.632 41.51
2nd 0.741 48.67 17.247
3rd 0.843 55.37 13.765
4th 0.989 64.96 17.319
5th 1.145 75.21 15.774
6th 1.335 87.69 16.594
7th 1.545 101.48 15.730

In neutral conditions (no wind no hills), at first I was most comfortable in 3rd or maybe 4th gear revving 70 to 80. A gear of 65 inches is very small. Now, after a couple days, in neutral conditions I'm comfortable in 4th or 5th gear at 70 to 80 rpm. Even 75 inches is not an especially high gear. Back in Los Angeles with my Niko Marina, neutral conditions would find me in an 87 gear between 70 and 80 rpm.

Bottom line, I'm going very slowly in neutral conditions -- I think slower than on my 1 speed -- maybe 12mph. Subjectively, it's like riding with only 30psi in your tires.

The good news is, however, that downhills and tailwinds provide an opportunity to go up to 20mph, and also the opportunity to momentum hills, which can really save time.

I'm hoping as the hub breaks in and tolerances loosen, the hub will consume less power. Another hope is that now that I'm peddling hard downhill or with a tailwind, and pushing hard all the time, my strength and conditioning will improve, so if the problem is with me rather than with the hub, that too will be solved over time.

My low gear is a little higher than I'd like. When I'm fresh, the 41 inch first gear lets me pedal up almost any hill Orlando offers. When I'm fresh. When I'm wiped out from a tough ride and just want to relax up a hill, it's too high. I find myself straining to torque it up the hill. If I were back in Los Angeles, I could not take this bike up Sepulveda Pass or Santa Suzanna Pass -- 41 inches is just too high for mountains, as far as I'm concerned.

My coaster brake lacks control. Backpeddling lightly produces almost no braking action. Moderate backpeddling produces only slight braking action. But if you stand on the backpedal, it locks your rear wheel. Experimentation revealed that if you know in advance, you can kick back on the brake to get past the resistance, and then it has good control.

My Odyssey 1999 front brake is disappointingly anemic. Part of that is because I have the pivot set a little loose for friction reduction, and the arms pull forward on hard braking, which turns the brakepads. Hopefully I can tighten the pivots without harming centering, turn the brakepads so they're flush with the rim on hard braking, and if necessary get normal length brakepads instead of the long ones on there now.

The riding position isn't right. The compact frame is short and undersized. An elongated extension on the stem will help to some degree.

One final problem is the design of the gear linkage between the shift cable and the hub. It's all plastic, and it's all between the hub and the right fork tip. If the chain pops off while riding, the chain will rip this linkage apart. That's $30.00 worth of hard to find parts destroyed every time you lose a chain. I'll be checking chain tension on a regular basis. Luckily, I have a low eccentricity machined front chainwheel, which helps a lot in keeping the chain tight enough not to fly but not so tight as to create friction.

What I Like About It!

This bike shifts like a dream. Shifts are quick and sure. They can be done coasting or peddling moderately. Shifting this bike while peddling hard can grind the gears, but that's true of a derailleur bike too. It's trivially easy to let up on the torque for the 1/4 second it takes to shift. If I get caught in unanticpated traffic or an unanticipated red light, I can stop, and then while stopped shift down to first gear, so that I can accellerate hard when the light turns green.

It has a wide gear range, with 7th gear a whopping 101 inches. In the flatlands and rolling hills of Orlando, Florida, I'm never going to outspin that. Switching from my 1 speed to this 7 speed, I've rediscovered the joy of momentuming hills.

As mentioned, it would be nice to have a lower first gear, but 41 inches suffices for all but the steepest hills around Orlando.

Is it Worth It?

Is it worth the expense and effort of putting together this 7 speed? This is really two questions:
  1. Would I go back to a 1 speed for city riding?
  2. Would I go back to a derailleur bike for city riding?

Would I go back to a 1 speed for city riding?

Heck no! The past three days on this bike remind me of what I missed while using my 1 speed. For the first time in 2 years, I can momentum hills. For the first time in 2 years, I tailwinds are a significant benefit.

Would I go back to a derailleur bike for city riding?

This isn't such a simple question. It could be interpreted one of two ways:
  1. Would I go back to the derailleur bikes of the late 70's, 80's and early 90's?
  2. Would I go back to present day derailleur bikes?

Would I go back to the derailleur bikes of the late 70's, 80's and early 90's?

Yes I would. The Schwinn Continental I rode through the mid and late 1970's, and the Niko Marina I rode all through the 80's were city bikes through and through. Schwinn S6 rims to absorb potholes and resist cardoors. Smooth and quick shifting Suntour rear derailleurs, and works-every-time Shimano Thunderbird front derailleurs. Legendary Weinmann centerpull brakes with the nipple to keep the arms synchronized (and therefore centered), with my own special modification -- a coaster strap between the bolts to eliminate brake pivot spread. The result was a front brake that could consistently stand the bike up or flip it over when needed (like when some fool throws open a car door 10 feet in front of you when you're going 20 miles per hour).

Starting in the early 1980's, Suntour sold mix and match rear cogs so you could assemble the cog of your dreams. In the early 80's these were 5 gear cogs, but by the mid 80's you could get six cog freewheels. Here was the way I set up my Niko Marina for the ultimate in gear control in the early 80's, with a 52/40 in front and 14/15/16/17/26 in back:

Back wheel diameter 27
52 40
14 100.29 77.14
15 93.60 72.00
16 87.75 67.50
17 82.59 63.53
26 54.00 41.54

As you can see, there's an almost continuous range decreasing by 5% to 9% starting from 100.29 down to 63.25. Only one of those shifts, the one going from 82.59 to 77.14, required a double shift. The "extreme" chain angle with 40 in front and 14 in back was handled well, and yes, my wide range Suntour rear derailleur was able to jump from the 17 tooth sprocket to the 26 tooth sprocket. The 52/26 combo was a rarely used chain-stretcher. Using this setup, for anywhere remotely near neutral conditions I could match my leg strength and spinning ability to the road conditions to within 5%, resulting in very fast transportation. The only problem was lack of a granny gear, making Sepulveda Pass and Santa Suzanna Pass very difficult. Then Suntour came out with their six gear "build it yourself" cluster.

Here was how I set up my six gear Suntour cluster:

Back wheel diameter 27
52.00 40.000
14 100.29 77.14
15 93.60 72.00
16 87.75 67.50
17 82.59 63.53
24 58.50 45.00
32 43.88 33.75

Here you see that I have the same gears from 100.29 through 63.53, and back in those days if I had to go below 63.53 a very serious hill was involved. Los Angeles winds never exceded 25 MPH, so winds alone could not knock me back that far. This setup made the 52/24 combo a little less of a cross-chain. 52/32 was, of course, impossible, but it replicated 40/24 so who cares. What this setup really did for me was give me the 33.75 granny gear to scale the passes even when exhausted.

Back in the 80's, spare parts were easily available, and there was parts interchangability across the Schwinn line, and across the European/Japanese bikes. One part didn't depend on another (no index shifting, all frame tubing diameter standard), so you could build exactly what you wanted. As far as I'm concerned, 1976-1992 was the golden age of bicycles, and I could cheaply build the ultimate city bike with a 27 inch frame, Schwinn S6 rims, a custom rear cog, and non-indexed derailleurs.

My internal 7 speed shifts quickly and accurately every time, and would have been superior for bopping around Venice and West LA. But for trans-city transportation, I'd have to pick my Niko Marina for its supurb peddling efficiency.

Would I go back to present day derailleur bikes?

Heck No! They stopped making Schwinn S6 rims in the late 80's or early 90's, so sturdy 27" wheels became a memory. Then, just for fun, they switched to 700c. The Suntour company withdrew from the American market in the mid 1990's. Now, instead of custom building your own freewheel, you accept the gear ratios dictated by a Japanese executive prioritizing maximum sales at maximum profit.

Today, every bike has different diameter tubing. Some even have square tubing. Down tube shifters are a vestige of a better time. Index shifting sounded so wonderful, but in my opinion what it really does is sell more parts. Change to a differently spaced cog, you need to change your shift levers. And now that shift levers are built into brake levers, you change them. Who knows, if the new brake levers pull more or less cable, you might need to change your brakes.

Modern bikes have bigger diameter tubing, meaning the wall thickness has been reduced. Be careful sweating on your bike -- you could rust through the frame rather quickly. In the early 2000's I bought an American mountain bike from a bikeshop for $220.00 (on sale). The bottom bracket failed within 1 year (1500 miles). I asked whether it should be covered under warranty. They said it wouldn't -- I bought a cheap bike, and cheap bikes' components wear out. One bike shop employee told me a bike of that "quality" is manufactured to go 700 miles during its life, and few purchasers of that "quality" bike exceed that 700 miles.

I could spend a thousand bucks for a present day derailleur bike specially built for the city. It would have fenders and mountain bike handlebars. But I don't trust modern bikes at any pricepoint.

Conclusion: Is it Worth It?

Is it worth the expense and effort of putting together this 7 speed? Yes. It's head and shoulders above a 1 speed because you make time on downhills and tailwinds, and because peddling constantly keeps you in better shape. I got pretty lazy on my 1 speed.

It's better than any present day derailleur bike, with the possible exception of the very expensive derailleur "city bikes", and I have a feeling those are just as delicate as their cheaper brethren. The only way to do better than this 7 speed with coaster brakes is to be a master with Ebay and dumpsters. If I ever find an intact Schwinn Continental, I'll use it to the day I die. But until then, my 7 speed is a really fun and excellent bike.

September 9, 2007

Today I adjusted the chain tension as tight as could be without binding the pedals. I also cleaned and lubricated the chain with Mobil One synthetic oil. I tightened the front brake to limit the arms twisting (and therefore the brakepads misaligning with the rim). And I twisted the brakepads so that when the arms twisted on hard braking, the pads would twist INTO alignment with the rim. 

Work Yet to be Done

This bike needs major improvement in three areas:
  1. Improvement of riding position
  2. Improvement of braking power
  3. Improvement in Steve Litt's conditioning

Improvement of riding position

This bike is built on a tiny compact frame more suitable for someone 5'3" than my 5'8". Jacking up the seatpost 9 inches gives me adequate leg extension, jacking up the stem 2 inches means I'm still assuming a city position, but the bike is short lengthwise. This puts my center of gravity behind the pedals and reduces my power.

Soon I'll try a longer stem from my spare parts box. It might fit. If not, perhaps I can buy a longer stem, or even use comfort bike handlebars, turned up, to elongate my torso over my bike.

In the long run, I'll probably find an old, properly sized diamond frame in a dumpster, and transfer the whole kitten kaboodle to that. Until then, an longer extended stem seems the most likely way to get more length.

Improvement of braking power

This bike needs better brakes. This bike can stop, but the front brakes won't stand up the bike. When someone throws open a car door 10 feet in front of you while you're going 20mph, standing up the bike means the difference between going over his door and going through his door's glass (I've done both and prefer going over).

In the long run, a properly sized Schwinn 3 speed frame with a 27" front wheel and Weinmann center pull brake in front will stand up the bike. In the short run, incremental improvements such as cleaning the front rim with fanbelt cleaner should improve braking power.

Improvement in Steve Litt's conditioning

I'm 30 pounds heavier and a lot weaker than when I gave up 12 speeding in 2004 or 2005, 40 pounds heavier than my 80 mile per week days of 2003. My cadence is a little faster (that's good), but I can't push the big gears from a couple years ago. I need to lose weight and get stronger before a cross-Orlando trip is an errand rather than an all day bike ride.

The Ride

My legs burn, I feel hot even soaking wet in the air conditioning, I'm dizzy and not thinking straight. This afternoon (9/9/2007) at 12:47 I took my 7speed out on my old training run. The half of my training route closest to my house is streets, mostly the fast and dangerous 434, and the half farthest from my house is a beautiful bike path, unfortunately interrupted every mile or so by stopsigns. It's a roundtrip ride.

On my Gary Fisher mountain bike in 2003, my typical time was about 1:17 (an hour and seventeen minutes). Once, trading drafts with a bikepath buddy who could rev 100rpm all day, I did it in 1:06. My fastest run without drafting was 1:08. I considered anything over 1:22 poke slow. I weighed 40 pounds less than today.

Here are the statistics for today's ride:
As is typical of me, I didn't pace myself and ran out of gas about 2/3 through the ride. Coming back on the 434 I used overdrive gears on downhills, saving what little I had left to get up the other side. I did a fairly decent job momentuming hills.

I put the same effort into this ride that I put into my 2003 1:08 ride, so I've declined by roughly 26%. I'm thinking that 2/3 to 3/4 of that decline is my 40 extra pounds and my reduction in strength and conditioning. If that's true, my 7speed is between 6% and 9% slower than my (pretty darned fast) Gary Fisher. Some of that 6% to 9% can be recouped with an improved riding position. I could end up paying only a 5% penalty for the convenience of a 7 speed with coaster brakes. To me, that's a good deal.

One could argue, and perhaps credibly, that my 1:08 performance was at 7:00am when it was cool, while today's subperformance was in the 96 degree midday sun. All other facts being equal, that has to make a noticable difference.

Obviously, the real bottleneck, as well as the low hanging fruit, is my conditioning. Hopefully, if I ride 80 miles a week like in 2003, I can lose a little weight and gain a lot of strength. Unless and until I do that, my transportational riding will be of the "bring the groceries home from Walmart" variety or the "take the books to the post office" variety, rather than true trans-city full transportation.

One other thing: Subjectively, my front brakes worked better after this morning's adjustments.

Gears and Conditioning

The amount and type of exercise you get on a multispeed bike is very different than on a one speed bike.
One speeds get you out of your cadence comfort zone. You'll need to pedal over 100rpm to go 20mph. And you'll need to stand up and pedal with uncomfortable force to climb a 2 degree hill. I think it's excellent exercise to get out on a 1 speed once in a while.

Once in a while...

When using a one speed for daily transportation, I coasted hills and didn't work very hard in tailwinds. After all, the way my legs are built, above 90rpm most of my energy goes into simply reversing the momentum of my legs. I do a lot more work for a negligable increase in speed. So instead of spinning my wheels (or more literally, spinning my legs), I loafed for the two years I used a one speed as my daily driver.

My deconditioning became obvious upon switching back to the seven speed. Even on a geared bike, I no longer have the energy to average 15-17mph on an hour ride, and I now lack the strength to push the big gears. I've already said that I can't steadily ride 90rpm or above. What do you call a guy who can't spin and can't push?

SLOW!

I expect my conditioning to improve with the 7 speed. Now, rather than taking it easy in tailwinds and coasting on downhills, I push during the entire ride. It's a lot more exercise per hour ridden, and I expect it to pay off.

The internal hub has considerable friction. No matter how much my conditioning improves, if I want to ride with a fast group I'll need to pull my 12 speed derailleur bike out of mothballs. But if 7speeding improves my conditioning, I won't be too embarrassed when the 12 speed makes its appearance.

Meanwhile, the seven speed is convenient, fun, always ready for action, and it gives a great workout.

A One Speed With Seven Gears

In my The Joys of a 1 Speed article, I describe the carefree life of owning a one speed. No derailleur adjustment problems, minimal problems with parts interchangability, no back caliper brake to constantly conflict with a continuously bashed rear wheel. Just jump on it and go.

For the most part, a seven speed with coaster brakes has all those same benefits. The only gear shift adjustment is cable length, which is seldom needed once stretching has occurred, and it's easily accomplished with the barrel adjuster on the shift lever. As on a one speed, the only brake caliper brake is the front brake, reducing many adjustment headaches associated with a back caliper brake.

As far as the front caliper, cantalever or V brake, maintenance is whatever it is, based on the front fork, drillings, bosses, wheel diameter and tire fatness.

A seven speed coaster brake hub is easy to mount, unmount and adjust. Assuming you have the right Shimano non-turn washers, you can slap your Nexus wheel on just about any frame with reasonable rear fork spacing. You can determine and purchase the correct non-turn washers here. If your non-turn washers are correct, the long cable housing stopping mechanism (known as the cassette joint in Shimano's instructions) will be approximately parallel to the right chainstay, approximately 1 inch below it:
Cassette joint       The picture on the left (click it for full sized image) shows a correctly mounted cassette joint. The cassette joint is the thicker black protuberance between the fork end and the hub, roughly parallel to the chain stay and roughly an inch below it. The thinner black thing coming out of the cassette joint is the cable housing.

The hub's axle is not completely round, but instead is flat on both sides with a threaded round portion in the diameter between the flats. The cassette joint is always a certain angle relative to the flats, and so is the non-turn washer, so if you install the correct non-turn washer for the rear fork cutout geometry, the cassette joint will point in the right direction.

With almost no extra maintenance work, the seven speed with coaster brakes gives you speed in beneficial conditions, shifting quick enough to take advantage of those beneficial conditions even if they only last a hundred yards, fairly low gears for hill climbs, and the always-peddling riding style necessary to build conditioning so the rider can go even faster.

In summary, the seven speed with coaster brakes has all the advantages of a one speed with coaster brakes, but it has a full complement of gearing, suitable for all but the hilliest terrains, with all the benefits gained from full gearing.

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