Durham Cycling Club

Articles

Memorial to Janie

JANIE. . .

Janie Siegelberg, a wonderful dear friend and avid cyclist died of a massive heart attack May
16th while on holiday in France and Germany. Janie was a great cyclist having in recent years
toured in France, Germany, Canada and the United States usually doing three different tours
each year, besides weekly club and charity rides here at home.

Janie had a marvellous, sometimes cheeky, sense of humour, an impressive intellect and could
speak French and German fluently and adequately get by in Dutch, Portuguese, Japanese,
Swahili and Bantu having been educated in Switzerland and lived for six or seven years each in
Brazil, Japan, Holland and South Africa. Janie was a prodigious map reader, and heaven help us
if we made a wrong turn although she did once in a while lead us astray.

Janie leaves a very sad but immensely proud husband, two daughters, a son and two gorgeous
granddaughters, and many very distraught and saddened cycling pals.

Janie. . . we will always love and remember you

Cycling Information for Newbies

Click for great cycling information from our good friends at Mountain Equipment Co-op!

Drafting safely and effectively

Riding safely and effectively in a paceline takes discipline, concentration and co-operation, however if done properly it can significantly increase your average speed with no extra effort, and can make a huge difference when riding into a strong head wind.

Have a plan!
Decide how the riders will change positions. One of the easiest ways if for the front rider to move to the left (after checking that the move can be made safely) and let the following rider advance to the front. The former front rider moves to the back of the paceline.

Agree with your fellow riders how long the lead rider stays in front, two minutes for example, so that all share the load equally and everyone stays fresh.

Taking into consideration the strength of the participating riders, a speed should be agreed upon and strictly maintained. This is to avoid the tendency of the speed to rise higher and higher until the paceline inevitably breaks up.

To draft safely have a plan and:
When learning how to draft in a group pick a road with light traffic.

For amateurs like us a minimum of two foot spacing between bikes should be maintained. Never overlap wheels.

Try not to fixate on the wheel ahead, instead watch for upcoming conditions that could cause the paceline to slow. Watch the cadence of the cyclist ahead of you. Watch for cyclists reaching for their brake levers.

When participating in a drafting group it is essential to maintain a steady even pace and cadence. It is a must to warn cyclists behind when slowing down or stopping.

This drafting technique is not recommended!

Cycling and the Law

A bicycle is a vehicle under the Ontario Highway Traffic Act (HTA). This means that, as a cyclist, you have the same rights and responsibilities to obey all traffic laws as other road users. Cyclists charged for disobeying traffic laws will be subject to a minimum set fine and a Victim Surcharge fine of $20.00 for most offences (the set fines below are subject to change). Here are key sections of the HTA concerning cyclists.

TRAFFIC SIGNALS AND ROAD SIGNS – HTA 144/136
Cyclists must stop for red lights and stop signs and comply with all other signs. Set fine: $85.00

ONE-WAY STREETS – HTA 153
Cyclists must ride in the designated direction on one-way streets. Set fine: $85.00

SLOW MOVING TRAFFIC – HTA 147
Any vehicle moving slower than the normal traffic speed should drive in the right-hand lane, or as close as practicable to the right edge of the road except when preparing to turn left or when passing another vehicle. Cyclists, you must ride far enough out from the curb to maintain a straight line, clear of sewer grates, debris, potholes, and parked car doors. You may occupy any part of a lane when your safety warrants it. Never compromise your safety for the convenience of a motorist behind you. Set fine: $85.00

SIGNALLING A TURN – HTA 142
Before turning, look behind you and clearly signal your turn. Cyclists may use their right arm to signal a right turn. Set fine: $85.00

CROSSWALKS – HTA 140(1) 144(29)
Cyclists must yield or stop for pedestrians at crosswalks. Set fine: $85.00
HTA 140(6)/144(29)
No bicycle riding in crosswalks. Cyclists must walk bicycles when crossing at a crosswalk. Set fine: $85.00

STREETCARS – HTA 166
All vehicles, cyclists included, must stop two metres behind streetcar doors and wait until passengers have boarded or departed and reached the curb. Set fine: $85.00

STOPPED SCHOOL BUSES – HTA 175 (12)
All vehicles, cyclists included, must stop for stopped school buses when the upper alternating red lights are flashing and/or the stop arm is out. Set fine: $400.00

Bicycles must be equipped with a bell or horn in good working order. Set fine: $85.00

BRAKES – HTA 64(3)
Bicycles must be equipped with at least one brake system on the rear wheel. When applied the rear brake should be able to bring the rear wheel to a skid on dry, level pavement. Set fine: $85.00

IDENTIFICATION – HTA 218
Cyclists must stop and identify themselves when required to do so by police officers for contravening traffic laws. The police officer will require, and the cyclist must provide, valid identification including correct name and address. Set fine: $85.00

PASSENGERS – HTA 178(2) –
Passengers may not be transported on any bicycle designed for one person. Set fine: $85.00

ATTACHING TO A VEHICLE – HTA 178(1) -
Cyclists are not permitted to attach themselves or their bicycle by any means whatsoever to another vehicle for the purpose of being towed. Set fine: $85.00

HELMETS – HTA 104
Every cyclist under the age of eighteen must wear an approved bicycle helmet. Parents or guardians shall not knowingly permit cyclists under the age of sixteen to ride without a helmet. Set fine: $60.00

DISMOUNTED BICYCLIST – HTA 179
Cyclists are required to ride on the right-hand side of the road. If however a cyclist is walking a bicycle on a highway where there are no sidewalks, the cyclist is considered to be a pedestrian and should walk on the left-hand side of the road facing traffic. If it is not safe for the cyclist to cross the road to face oncoming traffic, the cyclist may walk the bicycle on the right-hand side of the road. Set fine: $35.00.

Bike Travel Cases for Rent!

Cadence

Cadence is a comfortable RPM on the flats, up & downhills & like today into the wind! You should be able to maintain a conversation with the riders around you. You don’t need a fancy cyclometer to measure your cadence. You will know what feels comfortable to you.

Below is an article from http://www.cptips.com/tech.htm

If you’re relatively new to cycling, you are probably riding at a cadence that is below your optimum. Most new riders think they are getting a better workout if every pedal stoke is a strain and the quads are burning. Although there’s a place for low-cadence workouts, during our Sunday morning rides, aim for a smooth spin at between 85-100 rpm (pedal revolutions per minute) which is much more efficient — and easier on the legs, especially the knees.

Lance Armstrong has popularized high-cadence pedaling. He spins at about 90 rpm on even the steepest climbs, and he’s regularly over 100 rpm in time trials. Does this mean you should be pedaling at a high cadence as well? Although your cadence can be increased through training, it may not fit with your personal physiology and biomechanics.

The make-up of your leg muscles (the ratio of fast-twitch to slow-twitch fibers), combined with your fitness, will self-select your cadence. For most experienced riders, ideal cadence is in the range of 80-100 rpm – and most tend to automatically pedal at around 90 rpm in normal conditions. Non-cyclists tend to spin a bit lower at around 60-70 rpm.

Try this to see what cadence may be the best target for you.

1. Locate a protected 2- 3 km stretch of road without any significant cross streets or traffic. Ideally slightly rolling downhill. Enfield Road between Mitchells Corners & the hamlet of Enfield is a good road for this.

2. After you warm up for 15 minutes, ride the 2- 3 km stretch hard in your hardest gear. Note your finish time and your heart rate if you have a monitor.

3. Recover for 15 to 20 minutes with easy spinning. This is extremely important!

4. Ride the course again at the same heart rate (or perceived exertion if you don’t have a monitor). But this time choose a rear gear that’s one or two gears easier & allows you to keep your cadence about 100 rpm. Note your time for the same course.

5. After a day or two of rest, do the test in reverse – easier rear gear first.

6. Compare your times. For most riders, the easier gear and higher cadence will produce faster times for less perceived effort.

Here are two drills that may be helpful in increasing your cadence and maintaining the smooth spin of a veteran.

Use a down hill to practice. Again Enfield Road between Mitchells Corners & the hamlet of Enfield is a good road for this.

Spin in an easy gear on a slight descent, then gradually increase your cadence until your pelvis begins bouncing on the saddle. Back off about 5 rpm or so until the bouncing stops. Hold that cadence and concentrate on a smooth pedal stroke for one minute. Cruise back up the hill and do it again. Relaxation is the key to pedaling at a high cadence without bouncing. Keep your elbows, shoulders and hips loose.

Use a that tailwind that you have stumbled across. Shift into a moderate gear and gradually increase your cadence until you’re at 100-110 rpm. Hold it there for 30 seconds, then gradually ease back to 80 rpm. Repeat several times.

How do you estimate your cadence if you don’t have a cadence function on your computer? Set your computer display to show seconds. Using your right foot, count how many times it is at the bottom of the stroke during a 15 (or 30) second interval. Then then multiply by 4 (or 2). That will help you develop a sense of what 90-100 rpm feels like.

Cycling Performance Tips

April 2009

Frequently Asked Questions

You rode HOW FAR?
Long-Distance Bike Riding FAQs

When I tell friends about this bicycling club, they are shocked at the distances our members ride. While 40K sounds like an amazing ride to them, it is but a season starter to us. So, are we a club of high end athletes? Far from it.

Here is a brief introduction to long distance bicycling through a series of questions and answers.

1. Why ride with a club? Riding in a group makes the ride more enjoyable, safer, and helps new riders learn the techniques to successful distance riding. There are techniques that make 40k a short ride, and 100k and up achievable by mid-summer.
2. Why do people ride racing (road) bikes? The answer surprises most who don’t ride long distance – they are more comfortable. The purpose of down-swept handlebars is to provide a variety of hand positions. A properly set up racing bike distributes body weight. About 1/3 is on your butt, 1/3 on your feet and 1/3 on your hands. In a traditional “comfort” bicycle, almost all of the weight is on your butt, which is why it gets sore quickly. The setup on a road bike is different for distance versus racing. Racers crouch over much more to lessen wind resistance, but it is a less comfortable position.
3. My legs tire out so fast, how do you do it? Another critical factor in long distance riding is seat position. On a ride last year, one rider was complaining of a sore back. He looked too far back and I suggested a movement of his seat by about an inch forward. He was amazed at the change and how good his back felt on the next ride. Bike setup is far more complex for distance. What you can get away with riding to the corner store is different from a long ride. Seat height is key, in that if your legs are not extended to their full length, you waste the strongest part of the push. Also, your knees will quickly hurt if the seat is too low. The right seat position for distance is not the right position for mountain biking. A mountain bike seat is much lower so that you can raise out of the seat on bumps. Beginners like to have their seat so low that they can comfortably stand with their feet of the ground when stopped. This is far too low and makes for tough pedaling.
4. How old are members? We have members ranging in age from their 20′s through 60′s and even some in their 70′s (you should see them go!).
5. Do I need an expensive bike? In our group you will see bicycles that span from several hundred to many thousands of dollars. A proper road bike is built for comfort and more distance for the same effort. Mountain bikes are not recommended,  they require much more effort, especially the ones with knobby tires and suspensions. Those knobs steal a lot of energy, as do shocks. Mountain wheels and tires are also heavier. Weight saved on the wheels is more significant than on the bike. You have to spin the wheel, not just move it.   Narrow seats are more comfortable, as wide seats tent to chafe the inner leg.  If you are planning on buying a bike it is highly recommended  to purchase one from a specialty bike shop rather than a department or sports store.  Department store bikes are assembled with poor quality components and will not prove satisfactory in the long run.  Our club membership will entitle you to a discount at many local bike shops.
6. Do I need special clothes? You do need a CSA-approved helmet. Again, bike clothes are built for comfort. They are designed to breathe, shed perspiration and be seen by car drivers. As 1/3 of your weight is on your hands, riders usually wear bike gloves to prevent blisters. Cycling shorts provide padding for the groin while bike shoes make pedaling easier by not flexing. Our club has special jerseys that make us look like a team on the road, but usually you’ll see members in a variety of outfits.
7. Will I get left behind? We try to never lose a rider, especially a beginner. (We do, however, have a few advanced riders who are famous for getting lost.) I saw first hand the value of riding with a group last year when my bike broke down. It was not something that could be repaired on the side of the road. Ross rode back and got my car. We loaded on my bike, then caught up to the group, where he unloaded his bike and continued. This was especially nice for me, as I was 15 km from nowhere. It would have been a long walk back, made worse by my racing shoes. The ride host and everyone participating are responsible for making sure no one is left behind. Usually a rider will stay with the new people and coach them on technique as well as morale.
8. Does everyone ride in one group? No, usually there are two or three groups depending on rider speed. We usually have two (or more) ride distances to choose from. We reqroup frequently to allow slower rices to catch up.
9. Where do we eat on the rides? Food is a big part of a ride. On each route, we  plan for a snack or lunch break. Some people bring their own food; some buy food where we stop. Every rider is responsible for his/her own drink and snacks.  On the Century Ride, while snacks are supplied by the SAG wagon, it is recommended to pack a lunch (will be carried by the SAG wagon).
10. What is a “Century Ride”? This is the key ride of the season. A metric century is 100 km in one day, an English century – 100 miles (160 km).  If it is your first year of distance cycling 100 km is an achievable goal.  Support vehicles (SAG wagons) are deployed for the century ride to provide snacks and help stranded riders who can’t finish the ride or have mechanical difficulties.
11. How fit do I need to be to ride with the club? If you are presently fit enough to ride take your bike on a 20 to 30 kilometer ride you are fit enough to join us in the spring when our rides start at 40 km and progress upwards from there. If you are presently participating in an endurance sport such as running you are probably fit enough to make the leap to cycling with not to much difficulty (and it’s much easier on the joints!).
12. How do I start? See our joining page for information on participating on our rides.

Practical Pedal Power

Reduce your gas bill and your carbon footprint!

Perhaps a bit optimistic but at least it’s a start!

I first dabbled a little with the practical bike concept a few years ago when I removed the hardware from the rotted cloth bag which was initial equipment on the “Hotrod” Dawes Kingpin when I purchased it in 1976. It was a simple matter to graft it onto a “Rubbermaid” plastic box and the outcome was quite successful save for the fact that its capacity was insufficient for anything other than light groceries etc. Consequently, it plus the rack was removed and the bike has been used successfully for general road use including several TCCG rides (see TCCG article).

The recent escalation of fuel costs and increasing economic constraints, coupled with an effort to reduce my carbon footprint -plus ongoing frustration at the pushing and shoving involved in navigating into and out of supermarket parking lots, has provided sufficient impetus to further investigate the serious use of bicycles in the domestic shopping application.

The origial Dawes rack-bag hardware was transferred to the “Rubbermade” plastic container.

Fitted with MTB “riser” bars the result was an attractive, nimble little bike but limited in its load carrying capability.

It was subsequently revamped into the “road” version described in the TCCG article.

The much-modified skinny-tyred Dawes is not really practical for “heavy duty haulin” so I cast around for a suitable cheap bike that would fit the bill. I soon sourced a 1982ish 12 speed Velo Sport in the back store room at Northern Cycle. I found that under all the dust and detritus accruing to it over the years was a quite reasonable bicycle. I stripped it down, overhauled the bottom bracket, and headset. As the local terrain is flat, in the interests of simplicity I turned iit nto a single speed fitting a nearly new pair of wheels that I had on hand. These were mounted with part-used Panaracer 700 x 32 tyres which are ideal for the load carrying role. Next I fitted an clippable wire basket to the handlebars (-the ex Dawes MTB bars)  and a very nice pair of Axiom “Journey” rear racks. I also fitted a two legged stand to prevent the assembly falling over when loading up. Finally, I replaced the seat post bolt with a quick release to make it easily alterable to suit a variety of riders. I had initially intended to paint it, but after some vigorous TLC this proved to be quite unnecessary as can be seen in the photo above.

Initially I used some large cloth panniers, plus a large rear-rack bag which although commodious were very awkward to load and unload.

I then fitted a pair of collapsible baskets to the sides of the rear rack and another clippable basket on the top. Finally, to prevent wet road excrement from spraying onto recently acquired comestibles, I added some Axiom Blade Runner fenders which, like the rear rack are very nicely made and not expensive. This conversion was completed early in 2008 since when the bike has been used very successfully on a regular basis for about 80% of our domestic shopping. It is as simple as possible with no excrescencies of any kind i.e. no computer, water bottles, tools, pump or clipless pedals The aim was to have an instant get on and go machine with no concession to bike-specific attire. The only exception has been a pair of pant clips for use with short socks, a piece of equipment which in my youth, no working class home of Britain would be without!

The next two pictures below give the general idea

Complete with fenders and the four baskets.

Returning with a typical shopping load.

With the two side baskets fold and without the fore and aft clip-ons, the bike is perfectly satisfactory for general purpose riding but although a successful conversion, there remained the outstanding 20% of the more bulky domestic essentials for which the Velo Sport is unsuited. I also had considered the feasibility of doing my “Meals on Wheels” delivery route by bicycle.

I had three alternatives to address the problem. Firstly, could either buy one of the new crop of cargo bikes which are appearing. Secondly, I could attach an Xtracycle “Free Radical” kit* extending the rear of the bike by 15 inches -or thirdly I could purchase a bicycle trailer. The first alternative was ruled out by virtue of the cost. The second, whilst being cheaper, it would be somewhat compromised by the extra length for general purpose use and storage. The cheapest alternative was a trailer. After carefully researching the trailer manufacturing industry, I finally chose a product of “WIKE Trailers”* which has the added attraction of being entirely Canadian, being based in Guelph. In addition to variety of child and special needs designs, they include a touring and a shopper trailer in their product line. Using the same technology they have even produced a foldable prototype four wheeled electric car powered by a pack of “A” flashlight batteries!*

My interaction with the company was quite a revelation. After discussing my requirements and associated options which were dealt with instantly, I ordered the unit on a Thursday; on Friday I was told that it was on its way by UPS together with a tracking number and would be here on Monday.

My Meals on Wheels pick up is near Pickering GO station making my total delivery route in Ajax 22km long using the Waterfront Trail. Because of the distance, load and terrain, I decided to revert to the 12 speed set-up. Therefore over the weekend prior to the trailer delivery, I cleaned and overhauled the derailleurs, fitted new cables, repacked the original hubs with grease, straightened a slight wobble in the rear rim and rebuilt it with the original wheels.

The original wheels and derailleurs were reinstalled. Note the attractive Axiom fender and rear rack.

Sure enough at Monday lunch time it arrived, beautifully packaged and so straightforward that within ten minutes (-with no tools required) it was assembled and connected to the bike. I took it on its inaugural shopping mission that very afternoon. I am most impressed by its design and the quality.

Ready to depart on the first shopping expedition.

The generous load capacity limit of 100lb is more than twice the collective load that I have dared to put in the baskets. In addition to its load capability the trailer has the other advantage that it can be converted in seconds into a shopping cart, and for transport/storage it folds flat with the wheels stowed inside.

To make a shopping cart, the tow bar is rotated backward to form the handle and the small “landing gear” wheel lowered as shown opposite

After two or three trailer excursions it became apparent that in very short order that the Velosport had become redundant –Rats!!  Not only can the trailer carry more but it comfortably accommodates the two Meal on Wheels bags. More to the point made it can manage the 20% that the baskets couldn’t!

The missing 20% -all 30 of them!

The simple trailer hitch. The quick release skewer holds it in place.

As they say, what goes around comes around. I have revived the Dawes, replaced the rack and stand and installed a hitch for the trailer. For local shopping, the Dawes has the advantage of being more compact for parking due to the smaller wheel size and can be mounted by simply stepping through the frame. The Velosport requires a very athletic swing of the leg to avoid interface with the rear basket. In fact the best procedure is to push forward, place a foot on the pedal, then swing the leg across. The extra six inches gained makes all the difference.

Rarin’to go!

The Dawes’ six speeds are quite adequate for normal domestic excursions but for lengthy Meals on Wheels routes and for visits to my Brewmaster,I will use my trusty 17 year-old Shogun MTB. This has been converted to touring specification and is the bike of choice on many of my camping excursions where local roads are gravel or in hilly terrain. It’s the best do-anything, go-anywhere general purpose bike that I have ever owned, now replacing my Urbanite Tourer, which has been sold.

The Shogun “Prairie Breaker” all gussied up with Axiom “Blade Runner” MTB fenders, portly tyres, Greenfield stand and Brooks saddle

Gallery

Xtracycle “Free Radical” (U.S.)

Bilenki Cargo Bike (U.S).

Kogswell “Porteur” with BOB Trailer (U.S).

Dutch Bakfiet

Chariot “Caddy” Children’s’ Trailer (Canada)

Kona “Ute” (Canada)

Pashley ‘Delibike” (U.K).

Final considerations.

Whilst I am now a shopping bike aficionado, there are a couple of potential irritants, both of which tend to diminish the overall convenience.

Firstly; in Europe, all types of practical bicycles are much more prevalent -in Denmark for instance 40% of commuting is done by bicycle. Despite the fact that the wearing of helmets is virtually unknown, the incidence of head trauma is similarly miniscule. With bike lanes and everyone travelling at a moderate speed and in the same direction, there is little risk involved. Whilst I would not attempt to influence any one to change their regular practice, I would merely point out that in my case at any rate, all my missions can be completed with little interface with motorised traffic. The wearing,carrying and stowing helmets can be a real pain. Therefore, I rarely use mine in the shopping role -unless venturing onto Harwood or similar autobahns.

Secondly; the locking and unlocking of the bicycle is similarly inconvenient. In the case of the Velosport, in over 10 months and scores of shopping runs I have never locked it. Its somewhat less-than-cool aspect presents little temptation. Similarly, the Dawes, being highly visible and unique in Canada, also acts as a deterrent. The Shogun, featuring a rigid frame is somewhat of an antique to yer mainstream bike thief.The trailer,requiring a modicum of knowledge and specific actions to disconnect and wheel away, provides some protection. However, all these considerations must be left to the individuals to decide for themselves.

The whole experience has been very enlightening. Having the ability to park adjacent to the door of the store is very appealing and now with the trailer, all purchases are just dropped right into its caverous maw! For lighter loads I still have the Velo Sport (which I might sell) the Dawes/Rubbermaid combination, or even the Shogun with a rack basket.

From the frequent comments and quereis that I receive I may have persuaded others to convert. In fact all the attention is reminiscent of the days when I rode a recumbent! I now find the shopping chore less stressful and onerous than with the car -really not a chore at all. It also makes me feel insufferably self-righteous!

* See Links below.

• http://www.wicycle.com/
• http://www.xtracycle.com/
• http://catoregon.qwestoffice.net/hpm/longhaul4kids.htm
• http://www.pashley.co.uk/products/delibike.html
• http://www.burley.com/
• http://www.konaworld.com/08_ute_c.htm
• http://catoregon.qwestoffice.net/links.htm

The last CAT link includes a huge amount of information on (mainly American) work bikes.

Roy Bird
Nov.2008

Bike Gears

Smart cyclists always choose the right gear!

Most modern bicycles have two or three chainwheels driven directly by the pedals and a gear cassette on the rear wheel containing from five to ten sprockets. By the judicious use of the front and rear derailleur a suitable gear can be found to suit virtually every road condition.

Gear ratios are usually expressed as gear inches. This archaic system goes back to the days of the High Wheeler or “Penny Farthing”. “Gear inches” are equivalent to what diameter of High Wheeler front wheel (in inches) would give that number. For example a seventy inch gear would require a High Wheeler wheel seventy inches in diameter to give the same result.

Most bicycles are geared to give a range of gear inches of between about 25 and 120. To calculate the resulting gear inches from any combination of chainwheel and cassette sprocket, simply divide the number of teeth on the chainwheel by the number on the cassette and multiply by the wheel diameter in inches.

Let us assume that we have a bicycle with three chainwheels of 52,42 and 26 teeth respectively and a five tooth cassette at the rear of 13,15,17, 21 and 26 teeth. This arrangement is shown in the diagram below (this is purely to illustrate of the principle). As an example, let’s assume that we have selected the large chainwheel sprocket of 52 teeth and 13 teeth on the rear, and the wheel diameter is 27 inches, the resulting gear would be:

(52/13) x 27 = 108 inches

This combination is the “top gear,” normally chosen for a fast downhill section. At the other extreme let us assume that the small chainwheel is selected (26 teeth) together with 26 teeth at the rear, the resulting number of gear inches would be 26/26 x 27 = 27 inches which would be associated with climbing a steep hill. Both these examples are shown as yellow squares on the diagram.

You will notice that the ranges of gear inches available for each chainwheel selection overlap. This means that a specific number of gear inches can be selected in more than one way. For example:

52/21 x 27 = 66.8
42/17 x 27 = 66.7

As a general rule it is preferable to avoid extreme choices of chainwheel and rear sprockets which cause excessive wear on the chain, the sprockets and derailleur. As much as possible the chain should line line up with the selection of chainwheel and sprocket. In the above example, the second choice would be preferable since both 42 and 17 teeth lie in the centre of the range of sprockets. The two worst combinations whould be 42/13 (small/small) and 52/24 (big/big). The second is particularly bad. As well as causing excessive wear it also stretches the rear derailleur.

Should you wish to find out your own range of gears, visit www.arachnoid.com/bike which does all of the calculations for you!