Tag Archives: rims

Oh no, oh no, oh no….my Zonda rims are cracked

Dear Rouleurs,

MMT had a dreadful trip to his friendly neighbourhood bike shop, Good Bikes’ last week.  MMT’s venerable Wilier was making a few awful noises from the vicinity of the bottom bracket.  May be it needed replacing as it had been ridden on for nearly six years.  Similarly the left pedal was behaving very weirdly under power.  All in all, it seemed high time for a service.

So MMT rode his Wilier to work and dropped the bike off.  A few minutes of explanation ensured.  The mechanic, Nathan, was advised to ring me if the price of repairs was exceeding $300.  Nathan called MMT a few hours later and his news left MMT aghast.  Apparently the rear rim was showing signs of cracking and needed replacing…..crap….Keep in mind that these were the $800 Campagnolo Zondas, bought just over 2 and half years ago.

Fortunately, MMT had kept the original Fulcrum rims.  MMT had spent a frustrating Saturday afternoon, a few weeks ago, fitting spoke reflectors and had intended to use these as his winter wheels.  So the Wilier stayed at the shop, until the old rims were retrieved and fitted. Nathan showed MMT the cracks and MMT was horrified at what he saw.

MMT reckons he’s done about 15,000km on these rims and can’t believe how these stress fractures have occurred. For starters, they are all on non-cassette side of the rim. One of them has cracked clean through, with clear daylight visible. MMT can only shudder at the thought of what may have happened had the spokes given way entirely.

MMT is not a happy camper…

Until next time, ride safe.

MMT

Product Review: Campagnolo Zonda Clincher Wheelset

 

Dear Rouleurs,

I’ve almost recovered from the dizzy flu and the national disgrace of our male cricket team. This meant, I’ve finally spent some quality time on my bike and the new Campagnolo Zonda clincher wheels, I purchased in mid-July. As my readership would know, I’ve been suffering from severe upgraditis triggered by SBS cycling coverage. I’ve previously swapped out my pedals and shoes.

Marv's Wilier with Zondas fitted.

Marv’s Wilier with Zondas fitted.

After much ‘umming’ and ‘ahhing’ I decided that I really needed new wheels. As an aside much of what is written about wheel weight borders on twaddle. However, Leonard Zinn at Velonews seems to have a good grasp of the physics. For the record, lighter means faster…period and in wheels, heavier rims means they are harder to accelerate. So I swapped out the Fulcrum 7s for Campy Zondas. In theory, I should have reduced the overall weight of the bike by 300g.

I bought the wheels last month from Cecil Walker’s Elizabeth St for $750. As, the wag in the bike shop said, ‘Mate, you’re swapping fake Campy’s for real ones’. I didn’t have the courage to attempt the fitting of a new cassette and the bike needed a service. So I forked out the $250 difference on Wiggle price. Unfortunately, the maintenance order I put at the front desk must have been communicated via ‘chinese whispers’ and the mechanic didn’t fit the Gatorskin tyres that I wanted. I changed over the tyres later.

After 4 weeks of riding, I can say they were a good purchase. Initially, I had the tyres over inflated, so the combination of the new rigid rims and new tyres, gave a very harsh ride. The handling experience felt very jitterly. I was feeling amplified road conditions transmitted up the seat post, out of the rear frame geometry. It was only when the bike was travelling over smooth bitumen did the ride improve. Initially, I was thinking that I had wasted my money and was a bit grumpy.

Happily as the Gatorskin tyre pressure decreased, the ride quality improved. I’m inclined now to inflate the tyre to 5-7 kPA lower than suggested by the manufacturer. In the last week, I’ve felt that bike is much quicker. The times on my Garmin seem to evidence this.

 

Here’s the tech specs:

 20150814-Zondas-BR Front wheel weight: 670g
Rear wheel weight: 880g Campagnolo hub
Rim height: 26mm (front), 30mm (rear)
Rim width: 20.5mm
Spoke count: 16 (front), 21 (rear)
Compatibility: 9/10/11 speed.

Here’s what I think the pros and cons of the wheelset are:

Pros:

  • Quite light 1550g or there abouts.
  • Very robust, the moulded rim looks and has so far been indestructible.
  • The sealed rim doesn’t require a rim strip.
  • There was visible build quality difference between the Fulcrum 7s and Zondas.
  • They seem to accelerate well and thanks to the hubs spin very smoothly.
  • The front rim is slightly shallower than the rear, this seems to provide more responsive, windproof steering.
  • The G3 spoke pattern on the rear wheel is IMHO aesthetically pleasing and seems to keep the rear wheel very stiff.
  • The paint scheme also matched the silver, black and red scheme of my Wilier’s frame.

Cons:

  • Harsh ride if your tyres are over-inflated.
  • If you break a spoke, you’ll need to have it fixed by your bike shop mechanic. The sealed rim means the use of magnet to re-thread a spoke.
  • The spokes are proprietary, can only be sourced from Campy re-sellers.
  • Being Campy, replacement parts are pricey, particularly compared to the Shimano.

And for what its worth, if you need further proof, via wisdom of online reviews

Wiggle buyers rate them – 4.8 / 5
BikeRadar gave them – 4/5
Chain Reaction buyers them – 4.8 / 5

I’m giving them 4 Marvs.

Until next time,

Marv

The correct number of bikes to own

Dear Roulers,

I’ve been having a terrible run of outs with mechanical failures.  My Villier still isn’t back from the workshop due to the non-arrival of parts from whoever the local Conagolo dealer is….bummer.  The yesterday on my afternoon commute home I discovered that the back wheel of Cannondale has a whopping big buckle.

I’ll be buggered if I can figure out how exactly, I did that.  The buckle was so bad that it felt like the hub may have been shot.  Either way I’m be experiencing my own personal walk of shame to the bike shop with yet another tale of woe.  20141020-GiantSedona-SMLHowever the upside is that I still do have a third string bike, my Giant Sedona, purchased in 1997, that bike is heading towards 20 years old. The only bits that I’ve replaced on it have been the saddle twice, the pedals for some shiny one sided SPD clip-ins, the bottle cage and grippy tyres for some slicks.  Its showing signs of age with scratches and rust marks, but it’s still going strong.

I took it out for a ride with my wife this morning and was able to keep up with her on her much newer Giant Defy.  It must have looked a bit odd to the passing pelotons. It’s amazing the difference in power you can put into the bottom bracket of rigid frame bike.  By comparison the head shok Cannondale seemed to be about 2 to 3km slower on the same ride last week. All I can say is thank God I ignored my wife and kept my third string bike. It simply reminds me of the often quoted Velominati law of bike ownership ->

 Rule #12: The correct number of bikes to own is n+1

On http://abicycleculture.tumblr.com/, I found a variation of the law provided by Corkgrips, who clearly has the same domestic “issues”, that I have:

While the minimum number of bikes one should own is three, the correct number is n+1, where n is the number of bikes currently owned.  This equation may also be re-written as s-1, where s is the number of bikes owned that would result in separation from your partner….from Velominati’s Rules

Until next time, see you on the roads.

Flat tyres are irritating – Part 1

The Breakaway

Godamit!!!!….I’ve got another <<insert expletive of choice>> flat. If you ride on the road its inevitable that you’ll have this happen, much taxes, death and Richmond not winning AFL premierships.

The Leadout

This is the first part of a two part blogfest on flat tyres. The first part focuses on the types of flats and the second explains what you might be able to do avoid them.

Slow Leaks

  • First symptom of this kind of problem, is that the tire will need to be pumped up more often than it should and its starting to drive you mad :-).
  • However It is normal for a tube to lose air over a period of weeks. Racing bike owners you should check the pressure at least once per week.
  • Slow leaks that take more than an hour to go down can be tough to find, its better to install a new tube.
  • This type of flat is not normally associated with severe tire or rim damage.

Punctures

  • Typically caused by glass, thorns, nails, staples, screws. Basically anything sharp can cause a puncture.
  • Depending on how big the hole is, the tyre can deflate very quickly. Usually these are easily located and repaired with patch kit.
  • This type of flat is not normally associated with severe tire or rim damage.

Pinch Flats

  • This type of flat is caused by rapid compression of the tube between your rim and a hard surface.
  • Known as ‘snakebites,’ these are dramatic, audible flats that deflate quickly.
  • These are difficult to repair with patches quickly. You may have to replace tube or use oval patches.
  • There’s really good chance you also have rim damage as well.

Blowouts

  • Blowouts are sudden losses of air, usually accompanied by a loud BANG!
  • Since the inner tube is just a rubber balloon, and does take much pressure by itself, it needs to be held inside of a tire to get up to full pressure.
  • If the tire doesn’t hold the tube in all around, the tube will pop. If this happens you’ll need a new tube.

Tire Damage

  • Improperly adjusted brakes can rub through tire and cause tube to blow out of tire.
  • Maintaining proper tire pressure helps prevent flats and maximizes rolling efficiency.
  • Worn tires leave less rubber between the tube and the road, decreasing flat protection

Rims

  • Spokes and sharp spots on the inside wall of the rim can cause flats.
  • Recurring flats are usually caused by sharp metal on the rim or part of a spoke.
  • Use a file or sandpaper to buff off the sharp spot and remove any burrs.
  • Its also worth replacing the rim tape.

Valve Damage

  • Any part of the valve and stem can get damaged through abuse or overuse, through which air can leak.
  • Sealants don’t typically work well on damaged valves. It’s time for a new tube.

Sidewall Cuts

  • The sidewall of a tire is not designed to contact anything, and is not durable like the tread of a tire.
  • This type of damage usually happens when you load your bike onto a vehicle, or leans it against something, like a curb, bench, or wall.
  • Once this happens, you’ll need to buy a new tyre.