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Tech letters for April 3, 2003

Edited by John Stevenson

Confounded by carbon fiber? Need to sound off about superlight stuff? Tech letters is the forum for your gear-related questions and opinions.

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Codes on bolts
Bike engine
Spinergy Spox
Roof rack bike holders
Crank length and knee angle
Campy 10 speed chain links
Headlight computer interference
Play in Campag wheels
Simplifying a bike frame
Speedplay problem
Tacx IMagic
Triple cranks
TT double chainsets
Tyres
Zipp 303 hubs

Codes on bolts

What do the numbers and letters on bolts in the stem, headset, seat collar etc mean? Do they tell strength and material?

Frank Cook
Tuesday, April 1 2003

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Bike engine

Stephen Katsaros may feel he's landed on something new, but clip-on motors for bicycles is really old (and discarded) technology. Both Honda and Ducati started vehicle manufacturing by making clip-on motors to use on bicycles following WWII, fulfilling a need for cheap transportation in war-devastated Italy and Japan. Unlike Stephen Katsaros' model they both used cleaner four-stroke motors instead of unburnt fuel spewing two strokes. After people could afford actual motorcycles and scooters the market for these motorized bicycles collapsed - it's difficult to imagine such an item being successful in the affluent US.

Evan Adams
Friday, March 21 2003

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Spinergy Spox

I just picked up a Spinergy Spox front wheel at a local bike swap meet for what seemed a good price. After the purchase I decided to look into the product a bit and found a fair amount of very poor reviews mixed in with the good ones. These reports seemed to allude to catastrophic failures of the wheel often resulting in accidents. I see that no recall has been enacted, so I wonder if this is a legitimate complaint, and certainly I wonder whether I ought to ride on the wheel . . . anybody out there have a clearer picture of the reliability of these wheels?

Robert Nagoda
Saturday, March 29 2003

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Roof rack bike holders

I recently purchased a Peugeot 307 and was all set to buy a Peugeot Bike Carrier to go with the Peugeot roofracks. Turns out they aren't available in Australia. My brother in law went to a U.K. Peugeot dealer to get them for me and was told they didn't recommend them as there had been "problems".

Anyone know what these "problems" may be, and any advice re roof mounted bike carriers, that will preferably fit the Peugeot roof bars.

Peter Shuttleworth
Melbourne
Monday, March 31 2003

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Crank length and knee angle

I'm 5'5" and have just changed back to 170mm cranks. After reading some of the posts about longer cranks I thought I would give 172.5's a go, but I just couldn't get comfortable with them. I just felt I was peddling too square and did not feel anywhere near as smooth as on the 170's. I persevered for about 3 weeks but could not detect any advantages either climbing or sprinting with the longer crank, so I changed back and straight away it felt better. Yet the guy at the bike shop who has about the same leg length as me rides 172.5's and he tried 170's and couldn't stand them for the same reasons I had for not liking the 172.5's, and the other guy at the bike shop is 6'2" rides 172.5s and has raced all his life on them. IMHO I think crank length is more about peddling style and comfort than it is about mechanical advantage.

Jeff Dart
Brisbane
Wednesday, April 2 2003

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Campy 10 speed chain links #1

I can from my friend's experience answer your question. If you try to fit a 10 speed chain in the 'old tried and tested' method it will break. The only way to fit a 10 speed chain is as the manufacturer states with the correct tool. (it's easy to do once you've bought them). Personally I wouldn't even try to fit one via the old way as it you can end up with a broken chain and no way to get home.

N.B. if you don't fancy using Campagnolo chain a Shimano Dura-Ace also fits and works just as well as these chains are the exactly the same width.

Steve Barlow
Thursday, March 27 2003

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Campy 10 speed chain links #2

The chain is very different and a bit more fragile (narrower and lighter). The link that holds the chain together has a hollow rivet. To install the link you place a plastic insert into the rivet that acts as a guide and the rivet through the chain. The tool also holds the links straight so you don't push the rivet in at an angle.

Eric Lee
Thursday, March 27 2003

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Campy 10 speed chain links #3

The reason you are not supposed to just press the pin back into a once-broken link is that the new 9 & 10-speed chains have such tight tolerances and use such thin-walled link plates that once you have pushed a pin out, the enlarged head has been deformed and won't hold safely again.

Since the master links from SRAM & Campagnolo don't rely on pins being pressed in or out, you can install them safely by hand and they will hold.

I have - in a pinch - carefully joined a chain in the manner you describe. With a standard chain tool. But this was only on a MTB ride where we had a mechanical and there was no choice. Because I was careful, it help until we got to the car. That said, I recommend you carry one or two master links in your seat bag from now on. I have seen TONS of chains blow apart and this was the reason.

Here is blurb from SRAM on this topic:

http://www.sram.com/tech_info/faq_display.asp?faq_id=15

Campagnolo does not do such a good job of explaining this but they hint at it here:

http://www.campagnolo.com/pdf/C10HD_L_CHAIN.pdf

"The slight protrusion of the small pin is normal, NEVER try to eliminate this protrusion"

Martin Criminale
Thursday, March 27 2003

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Headlight computer interference #1

It would definitely be from the change in current / change in time and it is interfering with your computer. The newer brighter flashing lights are most likely have a faster switch on time and faster switch off time (that is the time it takes for the transistor to switch from on to off and vice versa) I would check for CE compliance marking on both the computer and light which covers 'Electromagnetic Compatibility' or EMC which covers both susceptibility and radiated.

If both are marked 'CE' then one of the manufacturers may be lying. As a quick fix move the light away from the computer with it flashing and see at what distance it stops. Wireless computers are a pain as having fairly broadband antennas (they have to) the are more susceptible to noise. If the interference mechanism is capacitive or far field radiation shielding can be done with foils that are earthed (tied to the negative side of the battery) If it is inductive interference (which is my guess) it is not easy as you would need ferrous material to work as shield.

There are methods of recourse against manufacturers who sell electronic equipment without a Ctick or CE compliance.

James Hall
Radio Frequency Electronics Engineer
Melbourne Vic
Wednesday, April 2 2003

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Headlight computer interference #2

Davern White asked about interference between a computer and a flashing LED light. Any change in electrical current generates a radio signal, and the more powerful the current, the more powerful the signal. It appears your front LED is pumping sufficient current through the LEDs to cause a signal that interferes with the signal from your wireless computer.

Possible solutions are to increase the separation between the computer and the light, or to try shielding the light. Putting the LED under the bars (i.e. mounted upside down) may be sufficient, especially if you don't have carbon fiber bars. Otherwise try opening the light and putting aluminium foil around the inside of the plastic shell, particularly near anything that looks like a circuit board. You may also see similar effects on a heart rate monitor.

Dave Hughes
Australia
Tuesday, April 1 2003

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Headlight computer interference #3

As the former Customer Service/ Tech Manager for NiteRider, I can say that this is a common problem. Sadly, it has also proven to be one that is very hard to correct usually. The flasher you are using (though I don't know the brand) is emitting a very weak signal, as most electronic components do while in use. This weak signal, as you have figured out, is the source of the problem. At NiteRider we tried many things, some as low-tech as wrapping the system components with aluminum foil... no luck. It has been a few years since I have been with the company, so I don't know if a solution ever was developed, but the last I heard nothing had been found to remedy the problem. You might want to contact the flasher maker and see if they have any ideas. Distance was always the key before, but bars are only so wide. Many manufacturers are now going to digital signals for their wireless computers and I believe I saw somewhere that that was a good fix. It is worth looking into, if you are unable to find a solution to your problem with the existing equipment.

Tim Jackson
San Diego, CA
Friday, March 28 2003

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Headlight computer interference #4

In the past I also had a Sigma BC800 (wireless) that would eventually start giving incorrect readings and then fail altogether. In my case I traced the interference to passing underneath overhead high voltage power lines. Others have also noted that Sigma wireless computers receive interference from hub and bottle dynamos. My solution was to buy the Cateye wireless, which has not suffered interference from any source after nine months of use.

Mike Verstappen
Warsash, Hants
Thursday, March 27 2003

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Play in Campag wheels

I had the same problem with my Record rear hub. The bearing surface on the inside of the hub on cassette side was cracked. A local bike shop replaced the bearing surface with a new one and everything is fine now. I kept riding with the extra play on the back wheel for about 6 months. Not knowing the problems I just thought that the cones just kept getting loose and I kept adjusting them before each ride. I had stripped down the hub a few times but I was not looking for a broken bearing surface.

Joe Pio
Toronto, Canada
Monday, March 31 2003

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Simplifying a bike frame #1

I used to work in a shop that built custom steel & titanium frames so hopefully I won't steer you wrong.

If you really want to 'sanitize' your frame, you will need some help. You can probably cut off the rear derailleur hanger with a hack saw and then grind/file it smooth but I'd stay away from the front derailleur hanger and the shifter bosses. I recommend having a frame shop that does brazing remove these.

The reason being it's just too easy to damage your tubes with household tools. If you do crack or thin the wall or dent the tube, you will have an unsafe bike unless you replace the tube.

To fill the dent I'd use bondo (http://www.bondo-online.com). The same stuff that auto body shops use for cars. JB weld is not really designed to be filed and painted.

To check the shifter bosses, remove the shifters and see if you can look through the downtube. If you can, or if there is a bolt holding the shifter boss to the tube, it's drilled through. MOST steel frames have brazed-on bosses. It's just most aluminum and titanium frames that have bolted-on bosses.

If you decide not to remove the shifter bosses, I have seen lots of good uses for them besides mounting a shift lever. Stuff like mounting a bicycle bell, a switch for your lights, etc.

Martin Criminale
Thursday, March 27 2003

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Simplifying a bike frame #2

Get in touch with sheldonbrown.com - he has done lots of mods like this and may be able to help.

Incidentally I am thinking of doing something similar. I normally ride a 53/54 cm frame, but came across a 61 cm steel frame when I was stuck for a hack bike about 2 years ago. I used it with a fixed wheel, and did quite a bit of riding on it. As you can imagine, the saddle was almost on the top tube, but it was fine for traveling to work, and some short easy spins. Anyway, what I am going to do now is to get it modified by my father, who is a welder.

We plan to cut the head tube, remove the top tube and reposition it further down the seat tube. We have done this before with a similar large frame, making it into a lo pro which my brother used quite a bit. I have since given it to a friend, and it is still working fine, 10 years later.

I was also thinking of removing the dropouts and reversing them, as I have had some problems with the wheel pulling forward, and also removing the derailleur hangers.

I hope to video and photo the process and will post them here if anyone is interested.

John Moran
Ireland
Thursday, March 27 2003

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Speedplay problem #1

I have had a similar experience with Speedplay pedals. The problem is most likely with the bearings in the pedal. Hold the axle firmly and try twisting the pedal body about an axis perpendicular to the axle (not in the direction it usually turns). I suspect you will find there is some play. If this is the case, every pedal stroke, the cleat will rub the axle. This is very bad. The pedal can actually unthread itself from the cranks if it's not in tightly. Not to mention that eventually the bearings will fail altogether and the pedal will either seize or fall off. Good luck.

Geoff Rapoport
Saturday, March 29 2003

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Speedplay problem #2

I've ridden Speedplay pedals for years and have experienced this same problem and seen it with other riders.

It seems to be a combination of worn cleats and flexible shoe soles. If you have really stiff shoes and new cleats, the problem goes away. You also need to make sure the cleat is mounted totally flat on the sole of your shoe. Sometimes the shims that people put under the cleats are not perfect at leveling out the shoe surface. When the cleat is 'bent' or 'warped', it will accelerate wear and then you get enough slop so that you touch the pedal axle.

I'd start with a new set of cleats and make absolutely sure they are being mounted to a level surface. If there is undo resistance when you engage your pedal, it's not level. They should be super easy to engage.

Martin Criminale
Thursday, March 27 2003

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Tacx IMagic #1

I've been using the iMagic since January and love it. It took a while to set it up and my steering was erratic and frustrating until I finally figured out a way to keep the steering cable from loosening. Since then, with the exception of occasional electrical interference of some sort that causes the unit's heart rate monitor to hit 240 bpm, I have had no problems.

I dedicated an old road bike with about the same geometry as I use outdoors to the iMagic. This saves a lot of time and effort versus setting up and taking apart when the weather turns good or bad.

You can download courses from their web site or create your own. I created a few that I really enjoy ranging from 30 minutes to about 2 hours. For my created courses I included some hills and wind which is fun (it can be more or less fun depending on which direction you are going of course).

The terrain is limited; so, to do long rides you essentially have to repeat parts of the terrain.

For me the best part is riding against myself or downloading courses from the web and riding against others. I can cheat if I am tired and "draft" on windy courses or I can try for a personal best on the trainer. You can have up to 5 opponents riding at the same time as yourself.

There is an "Analyzer" software package which stores all of your ride data -- elevation, speed, power, heart rate, cadence. You can export this data if you wish. You can also graphically compare two rides.

I also purchased the "Forest Park" terrain for mountain biking. It is fun; and, if you keep "collisions on" and cycle outside of their basic routes, challenging to go fast without crashing (I have been nailed by deers and trees). However, this terrain is much smaller than the road terrain and quickly became monotonous for me until I ventured "off road". It is a little unrealistic in that you can pedal underwater (under quacking ducks) and on really marshy type ground. Still, all in all, fun.

There is another set of programs (Catalyst) that comes with it that can mimic some really tough tour climbs. You can modify the climbs (steeper and longer) to make them even tougher if you want. There is another Catalyst program that I have used to help me spin better. You can also use the Catalyst program for testing purposes and it has a wide variety of programs already set up (I haven't used them all) that can modify for your own purposes.

Harry Pugh
New York
Tuesday, April 1 2003

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Tacx IMagic #2

The iMagic is not a substitute for getting out on the road but when you can't . . . it works. I have not been able to verify the power (watts) against real world performance however this is not really an issue. All of the data collected is useful in establishing a baseline and tracking your improvement.

So far the unit has been reliable and hasn't caused me any problems.

The best feature is that it occupies your attention, especially when using the steering unit for free cycling. If you don't pay attention before long your in the rhubarb and skidding along the turf!

For me, it meant being able to train longer indoors than on a conventional trainer. I regularly rode 1.5 to 2 hour rides this winter where last year that was a torture test.

Another interesting feature is the ability to ride in cyberspace with other riders with iMagic and similar trainers. Using NetAthlon software you can hook up for a ride with riders from all over the world. It's only now starting to catch on but I imagine that the number of available rides will increase each year.

Hope this helps.

Ride hard.

T.J.Cobey
Canada
Sunday, March 30 2003

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Tacx IMagic #3

Unless you do 90 percent of your riding inside. Invest in a PowerTap or a SRM crank.

Greg Brown
Thursday, March 27 2003

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Tacx IMagic #4

I recently bought an I-magic and had an incredibly frustrating time setting it up, but once I had all the software issues addressed and got it working properly, it works really well. I run Windows XP pro with a geforce 4 graphics card and I would say it is definitely worth getting if you are interested in indoor training. If you pick opponents, racing is quite realistic and there are a couple of riders who are not quite at LA's standard so you can beat them. You can also save one of your rides and race against yourself the next time to compare performances. The other parts of the package (Catalyst and Analyzer) are also great training aids, though there is no scenery on these, just data such as cadence, heart rate etc. It is worth joining the Tacx Imagic user group on Yahoo! to see what problems and solutions others have found. If you get one and encounter problems setting it up, contact me and I may be able to help you sort it. One other point is that the steering frame I got arrived with a faulty part which Tacx replaced free of charge when I let them know. It also shipped with a very old version of the software, but the latest versions are downloadable from the Tacx website.

Philip Bouscarle
UK
Thursday, March 27 2003

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Triple cranks #1

I would go with the double chainring and a 13-29 cassette set up if this is your first "good" road bike. Why? Having a triple and not having it in perfect adjustment will drive ya nuts! Sometimes simpler is better.

George McNally
York PA USA
Date: Tue, 01 Apr 2003

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Triple cranks #2

I use a Bianchi road bike with a Campy drive train consisting of a 53/40 chainring and a 12/29 10 speed cassette. I have climbed some big hills with this (e.g. Alpe d'Huez, Galibier) and think it is a good setup. My worry about a triple is that you will be spinning very fast and not getting anywhere very quickly. Best to practice keeping up your cadence on a double I would say. I am 47 years old and weigh about 150lb.

Philip Bouscarle
UK
Thursday, March 27 2003

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Triple cranks #3

I would definitely go with the triple at your age and weight. Campagnolo makes some real nice triple setups. I have a triple myself and it works great. Once you set it up correctly it will work just like a mountain bike. Mountain bikes are generally used with triple cranks and they shift just fine. The same thing with a road bike.

Orlando Sanchez
Thursday, March 27 2003

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Triple cranks #4

This Spring I decided to go to a road triple for the first time and I'm very happy so far. I don't notice the extra weight, and love the added gear range. I went with a Shimano Ultegra triple and it shifts even better than my 105 double did. Hopefully I won't get too much harassment from the local roadies during the weekly rides.

I think it was a combination of getting into the Mtn Biking and doing a century that included Mount Greylock (in North Adams, MA - try it sometime!) that convinced me to try a triple. I remember my horror after reaching the base of the mountain and realizing that I was already in my lowest gear. I spent the whole climb just ticking the pedals over again and again, struggling to make the switchbacks. After that I wanted to be able to actually spin on climbs like on my Fisher.

Larry Sherman
Thursday, March 27 2003

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Triple cranks #5

I once calculated that my Ultegra triple is 120 grams heavier than a double - not much of a weight penalty. I've dropped my chain twice in the three and a half years I've been on my triple, and most of my riding buddies have dropped a chain at some time or another. One friend put a Dura-Ace triple on a Kestrel 200SCI and could not keep it from derailing off the little ring until he put a deflector on the seattube. On the flip side, another riding buddy with the same bike, but with an Ultegra triple, has had no problems, derailing only once that I recall. So overall, it seems to be a relatively rare occurrence, of no consequence unless one is racing. The upside of the triple is that we have numerous climbs around here in Northern California USA that have sustained pitches from 12 to 20%. With a double, some of those hills were functionally off limits, while with a triple, one fears no evil.

Steve Rempel
Mountain View CA USA
Thursday, March 27 2003

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Triple cranks #6

I was worried about this when I purchased my first road bike a year ago, but I can say with a great deal of certainty that the double chainring set up is sufficient for 99% of my riding. I do quite a bit of climbing (we live near the alps around Mt Kosciusko, Australia) and the double is fine. I came from a mountain bike background and was initially skeptical of such large gears compared to that of the mtb, but I was convinced by the shop to try a double and believe me, it isn't worth the weight and sloppy shifting of the triple. As a compromise, I fitted a 13-28 cluster at the back to match the 39/53 front, but I have since fitted a 23, as even the 28 was an overkill.

Tim Lee
Australia
Friday, March 28 2003

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Triple cranks #7

Hi, i just changed my triple Campagnolo Record chainset for a Stronglight "Granfondo" 50/36 double (with additional 48/34 chainrings for extreme adventures...) and it's great. I know that TA makes a similar chainset called "Zephyr light" and I've heard about an Italian company called PMP which is supposed to do a 50/36 as well. Paired with a 13-29 cassette you'll be fine.

Frederik Krantz

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Triple cranks #8

Setting up the front shifter can be more difficult, and you can get chain rub if itīs not right, so get the shop to set it up for you (takes them two minutes) and, if itīs Shimano then that will be all the adjusting youīll need for at least the next six months (depending on mileage of course). 52-42-30 with 13-25 should be good enough for the mountains, and close enough for the flat.

"Club"
Saturday, March 29 2003

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TT double chainsets #1

Assuming Cyclingnew's correspondent has been looking at pro bikes, then it's worth noting that time-trial routes in professional races are frequently not at all flat. The inner front ring could well see some use. Even if it doesn't, the front shifter will prevent the chain coming off the chainring over bumpy surfaces. The performance penalty is any case negligible. As far as I know the UCI hasn't yet mandated on this score but let's not give them ideas.

On the other hand here in the UK where we have a strong time-trialing scene, many events take place on flat out-and-back courses. Your more obsessive amateur tester often does run a single chainring. For myself I like competing in 'sporting' (twisty and hilly) events as well as flat events, so I have a conventional two-ring setup.

Roderick MacFadyen
Reading, UK
Thursday, March 27 2003

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TT double chainsets #2

For maneuvering around at the start and for warming up a small chainring is very useful. The usual set up for a (professional) TT bike would be something like a 42-44t small ring with a 55t big ring and a straight block cassette (11-19 or 11-20) With such closely spaced (and tall) ratios a small ring would definitely be helpful if there was any more than 1 small hill on the course.

Jacob Borger
Australia
Thursday, March 27 2003

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TT double chainsets #3

Double chainsets are not a UCI requirement. This picture shows a competitor at the UK national championships (Run under UCI rules) last year clearly with only a single chainring.

http://www.britishcycling.org.uk/images/news_lead/2002/time_trials/0_tt_23.jpg

Stuart Dangerfield the UK's top national time trialist is most often seen with a single chainring and a 5 speed block during flat time trials.

http://members.aol.com/VCCumbria/index-zpic11-SDangerfield.jpg

Also during the Tour of Spain a lot of riders used triple chainrings on the Angliru. I imagine that most people use double chainrings during time trials as they only have one time trial bike and they may need it for a hilly or mountain TT as well. Weight is not so much of an issue when it comes to a flat TT so there is much more effort to change than benefit gained. Saying that changing a chainset is not a big job.

Ryan Clark
Birmingham CC, UK
Thursday, March 27 2003

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Tyres #1

I'm a user of Conti GP3000s who briefly flirted with the Michelin Pro Race tires. I think the Michelins work well as a race-only tire, but not as an all-purpose training/racing tire. The Michelins have a great feel in cornering, but I found them very easy to puncture. A piece of road debris slit one completely open on only the third ride, and I just seemed to get a much higher number of flats with these as compared to the Contis. The Conti are also easier to mount.

Tom Patrick
Thursday, March 27 2003

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Tyres #2

I used both Conti 3000 and Michelin, and I definitely prefer the Michelin. You can simply feel it is running faster, cause by the lower rolling resistance... I also noticed that the Michelin runs longer, and have fewer punctures. Then you might think they'd loose some grip, on dry road there no difference, but in rainy weather there's a little difference but I'd still prefer the Michelin.

Jacob Keldsen
Denmark
Thursday, March 27 2003 (CET)

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Tyres #3

My father works with Michelin and I get the pro's for $17 shipped to my door. I rode them on my last bike, and had on several occasions pieces of gravel no larger than grains of sand work their way through the threads and into tubes. They were also a very tight fit on my rims, and I didn't trust those rims on super long rides because I knew I wouldn't be able to change a tube out should something happen.

My new bike came with GP3000s. Mine are significantly worn now at about 1600 miles now, along with heavy trainer use, which compromises them a bit. I will be replacing them within the next 1000 miles. Having ridden both, I will most likely buy gp3000s again. Yes, that's double the cost for me (at least) but for the piece of mind of easier tire changes, and the fact that they have not yet flatted is worthwhile. They behaved well in the crits I've done so far, are reasonably light, and the tread has held up well displaying FAR GREATER cut and abrasion resistance than with the michelins. When it comes time again, I will either get the GPs or wait for specialized to come out with their new S-Works Turbo tire. I have friends on a local sponsored team who paid out of pocket for these rather than use their Vittoria sponsorship. They all liked them because they were super durable (Kevlar casing) along with cornering smoothly. They're changing facilities for this tire and it's currently unavailable, until April I believe. Give the Michelins a try if you have extra wheelsets and you can get a good deal, but dollar for dollar, I'll return to the GP3000s.

John Neil
Thursday, March 27 2003

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Tyres #4

In response to Conti Vs Michelin Pros, I have Recently made the switch of which you mentioned, Handing the GP3000 over to Ride on some Michelin rubber. I found that the Conti's were susceptible to cuts and also on the rough roads which I was riding was getting low Km's out of them as well as the sidewalls of the tyres fraying. After 2000km on the Michelins with no evidence of cuts and still looking brand new I am impressed with their performance and will be sticking with them, I would suggest giving them a try next change out.

Ryan Watts
Tasmania, Oz
Sunday, March 30 2003

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Tyres #5

I am sure you are correct in that sponsorship is THE deciding factor in choosing tires, but let me answer your question from the perspective of someone that has tried most of the Michelin and Conti tires that were paid for by me.

Conti makes excellent race tires. The GP3000 is not of them. I often use Supersonics for the front. They are incredibly durable and comfortable considering their weight. For the rear, I prefer a dual compound tire and use either a Michelin or Hutchinson Carbon Pros. Continental has begun to advertise tires sold in pairs designed for specific placement on the front or rear wheels. In summary, you can do much better than the GP3000.

Chris McReynolds
California
Monday, March 31 2003

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Tyres #6

I switched from Conti GP3000 (clinchers) to Michelin Axial Pro and Carbons about 3 years ago.

My main concern with the Contis was that they seemed to wear out quite quickly. The centre section appeared to wear down and the tyre developed a squarish profile in a relatively short period of time. The Michelins seem to maintain the rounded profile and last a lot longer than the Contis.

Carlos Remedios
Australia
Tuesday, April 1 2003

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Tyres #7

Ian, I used Conti GP 23s for years and loved them except for the sidewall fragility after time. I tried GP 3000s once for PBP in 1999 and didn't like the wear rate. Since then I have used Axial Pro 23s in the black grey finish and love them. Light, fast, great grip dry & wet, puncture resistant and strong side walls. I have worn them all out at the tread (about 5000kms with rotating) and sidewalls have been still fine. Give 'em a try, I reckon they're great.

Oliver Portway
Tanunda South Australia
Tuesday, April 1 2003

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Zipp 303 hubs

Zipp's 303s use Zipp's own hubs, the 84 & 202 are the name (which is corresponding to their weight in grams.) This is mentioned on their website.

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Spencer Gray
Wednesday, March 26 2003