Mavic GP4's

In 1983 I bought my first custom built bike. A bright yellow machine with 753 tubing put together by a frame builder in the German town of Detmold. The group set was Campagnola, Shimano was only a baby and no one wanting to avoid mechanical problems would touch it. I can't remember the type of wheels that came with it other than they were Mavic. Again, there was no choice if you were serious. I also remember it cost me about six months wages so it was fortunate that it could be straightened out after a crash. All that remains of this dream machine is a few fading photos of me killing myself in various locations including a ride of over 1600 miles around Germany.

What I do remember clearly is, even before I bought it, I was planning to save for a set of race wheels and they had to be mavic GP4's The 80mm Zipps of the day. You see back then you had (at least) two sets of wheels for your bike. One set for training and one set for racing.

That trend is starting to return. There is no point in asking a cyclist if he is planning to upgrade his wheels. We all want to upgrade our wheels. And like my ode to the TDF the best way to do it is buy a good bike with cheaper wheels and upgrade later. You can't build a bike piece by piece for the same price as buying it whole. So for economic reasons buy the race ones later.

Now in a previous blog I mentioned that wheels aren't necessarily the best bang for your buck in the pursuit of speed. That doesn't mean that it isn't worth upgrading your wheels it just means there are other options. So with a pair of wheels costing more than the alloys on your car (as they should) how much should you spend and why? Well the answer is spend what you want but it may not be worth it. The French at the end of the 2012 Olympics famously complained that Britain had cheated. That their wheels were rounder giving them an edge. Amusing considering team GB use mavic wheels, made in France. But seriously, it is hard to get a perfectly round wheel. Even at a basic level of cycling you can feel quality in a wheel. Put simply it takes less watts to push a better wheel conserving your energy for the final sprint. Even I know the difference between my Mavic Elite's and my carbon spinnergy. I believe I have bought close to a 2mph average though I will always claim I am benefiting from the placebo effect.

So simply put a bike will accelerate better and climb faster with lighter wheels by reducing a wheels mass. If you think of it this way, climbing and accelerating are the same thing. When you climb you constantly accelerate its gravity fighting you to keep the speed constant. Here is the science bit though. A reduction in weight in the wheels will improve performance more than the same weight loss in the frame; because the wheel rotates you notice it more.  The mass is all at the rim and tyre, the result being it has twice the resistance to acceleration than the rest of the bike. Carbon helps this but you also need the wheel to be stiff to transfer the power and prevent rub. This of course can be difficult with alloy rims on carbon wheels but full carbon changes the braking temperatures requiring different brakes.

So all you need to do is get the lightest wheels, perhaps those shallow rim GP4's still have their place.
Err... not quite, aerodynamics and inertia are also very important. Think of the fly wheel in a car. Almost perfectly balanced so once it's moving it spins faster and faster under its own weight raising speed and improving the MPG.
It's the same with [particularly carbon] wheels. When you are riding on the flat without accelerating weight doesn't matter. This is the key point. At 15mph aerodynamic drag and rolling resistance are the same. Approach 25mph and aerodynamic drag is far higher, rolling resistance is only around 15%. So your wheel choice depends on terrain and your average speed.
The carbon wheel can actually push the bike along supporting my feeling that the spinergy wheels were adding around 2mph.

So do we all dash out and spend 4k on wheels? Well its a law of diminishing returns. In other words wheels between 800 and 1400 will make a significant difference to your speed and make that jump of a couple of MPH. Go from 1400 to 2000 and it may help you improve .25mph or even less. So are you prepared to pay 600 to 2600 more of your pounds for a quarter to a half MPH average? Well if you are a pro rider then without a doubt. If you just want the best possibly. Before you make your mind up it is important to mention that the most expensive wheels will also be more stable in a cross wind with an 80mm feeling like 35 in windy conditions. In other words pay a bit more to stay on your bike.

So before you decide....

1. Think about what you need. Unless you can afford a range of wheels is the best first purchase a rear disk? 30 to 40mm will make a significant difference.
2. Make sure you have the same type of brakes for each wheel set.
3. Check the weight limit for the wheel. Particularly if you are over 90kg.
4. Watch for brake wear particularly on carbon rims.  
5. Carbon rim tyre pressures are often lower than alloys, check for the recommended pressure.
6. Get suitable tyres to match your investment. More on this in the next blog.
7. Check spoke tension before riding.

So it is up to you, do what I did and trawl the net, look at forums to see what people think of the wheel before you buy. Set a budget and stick to it.

The wheels I can comment on are the following,

The mavic Kysirium elite retail around £550 but shop around. They originally came with my orbea. I have to say I love them. Thousands of miles without being straightened for a reasonable price and a reasonable speed and weight. They are great in cross winds with little deflection even in high winds. On the downside they are a bit slower, the water gets in the hubs in heavy rain and that's it. They are an upgrade from most wheels but if you want good carbons they make an excellent training wheel.

 

 

 

The spinergy stealth PBO carbon wheels. Ceramic bearings, 40mm rims, spokes spun from nylon to keep the weight down. Round about £1400 a pair I have these on my orbea and they look fantastic. They are the ones I believe add around 2mph avg. I managed to borrow a pair before buying them and flying down a hill I hit cobbles and a rail track at around 30mph. I snapped two spokes in the rear wheel. I managed to tie them out the way and finished a difficult ride with lots of climbs with no buckle in the wheel. After buying a pair I have thrashed them and had no problem with spokes or buckles though I have lost nearly two stone in weight. So they are at the top end of what I would like to pay but worth every penny. A quick warning, they aren't stable in cross winds, you need to change them to the elites. They do, however, take full advantage of centrifugal force and want to push faster and faster at high speed. They are excellent value for money with the only downside being a creak from the nylon spokes when climbing after about 1000 miles. They have very little flex and maintain their good looks.

 

 

Hopefully I will soon be picking up the time trial bike and I have decided to upgrade to the Mavic Carbone SL for around £800. I've heard great things about them but can't comment any more until I try them. If I'm unhappy they will go on the Foil and I will try something else but I have a feeling I am going to love them and don't think the small loss of weight  justifies the £500 extra for the SLR's

 

 

 

 

So I have bored you with the science, talked about value for money and ultimately would suggest you need the resources of team sky to get exactly what you want when you want....There is always-