Wheels

Kieren McDonald

Hi all,

Only just joined - I'm pretty new to the game - I have a Cannondale Synapse 105 disc. Strangely it doesn't roll anywhere near as well as a couple of others on their bikes (understand weight etc would play a part) when just free wheeling down hills, yet there is no rubbing and it's all rolling true and tight.

I'm looking at changing the wheels and have been recommended by few to go for these: Mavic Ksyrium Pro Disc wheelset.

I have seen great reviews, although I have also seen reviews where people slate Mavic and the price so was then unsure.

Please help me choose the right thing for the right price :-)

Thanks,
Kieren

ugo.santalucia

The price point of the Ksyrium disc is simply laughable... they cost 2-3 times as much as a decent disc upgrade and on paper are not better than the competition.

cycleclinic

What do you mean it does not roll as well. If the tyres are different that could be reason. Not trying to be facetious but
all hubs comsumes very little power and not enough to make any difference to how fast you go (less than 1W at 25mph) and all wheels are round they all roll as well. What makes a difference to how the bike feels is weight if the difference is big and lateral stiffness of the wheel and what tyres are mounted. Rim width helps for ride comfort and lateral grip but the only thing that makes a real difference to how fast yoj can ride is how aerodynamic the wheel is and that is a small gain. The krysium disc wheels are very expensive and for under 1/2 the price you can buy something that weighs nearly the same and performs the same.

Kieren McDonald

Yes I was a bit wary of the price and I've seen similar posts saying a similar thing. Sounds like it was good that I didn't just buy based on recommendation from shop!!

I guess I want a worthwhile upgrade and not just do it for the sake of it...here is what is on their currently as standard as taken off shop website:
Rims: Maddux RD 3.0 Disc, 28-hole (32h 58 -61cm)
Front Hub: Formula, DC-20 front, DC-22 rear
Rear Hub: Formula, DC-20 front, DC-22 rear
Spokes: Stainless Steel, 15g
Front Tyre: Schwalbe Lugano PP, 700×25c
Rear Tyre: Schwalbe Lugano PP, 700×25c

Any suggestions to what I should look at as worthwhile replacement. FYI, I have done one sportive so far and plan to do more, including likes of London to Paris.

Thanks

Kieren McDonald

Hi thecycleclinic,

Yes sorry, guess that's me being a newbie - I was wondering if there would be any resistance from the hubs? What you say makes sense. So the first time I had a ride out with one friend who was riding a Giant Defy he was out in front and he was able to keep free wheeling but I was still pedaling to keep up - I didn't quite understand how when, if anything I should have been able to whilst being shielded by him and it wasn't just on steep hills. I was a bit baffled especially as he was on a Giant Defy that cost around £400. His build isn't far from mine, I am more stream lined, he has a bit more weight.

The second instance was with my father in law (no idea what he rides as lots of custom bits) and he was behind me. When it came to rolling down hills, he would overtake and continue quite a bit faster. He is a similar build but his wheels have a deeper rim.

Again, sounds like a relief I didn't hand over my card in the shop for the Mavics!! I've been browsing and trying to read so many reviews but a bit baffled at what I should change to...if I should change to anything that is?!

Thanks

JayKosta

How does your weight, and position on the bike compare to the others?

Weight (gravity) provides an assist to heavier riders on down hill.
And being able to assume an aero position on the bike gives a huge speed increase.

The front wheel should easily spin for quite a while with the wheel off the ground.
The rear less so due to friction in the cassette, but it should slow gradually.

The bike specs all look ok, just make sure the tires are fully inflated.
Also, clothing that 'balloons' or flaps excessively in the wind will cause higher wind drag.

Deeper rims can have an aero advantage, but can also add weight, and stiffness that can cause a harsh ride. Front wheels are generally fully interchangeable between bikes, so maybe ask if you can try some 'swaps' on rides to see if there is a benefit.

Jay Kosta
Endwell NY USA

Kieren McDonald

Thanks Jay, some good pointers and advice.

Our positioning is similar but they both weigh a bit more than me, which was the only thing I could think of when downhill. It just didn't answer how when it was near flat.

I've spun the wheels when on a bike stand - both wheels moved as you described so that sounds ok.
On both occasions both tyres were well inflated and only tight clothing worn.

Good idea on the swapping of wheels, although not sure if that will work when I'm the only one with discs?

Thanks,
Kieren

keezx

Downhill speed is a matter of weight and position on the bike (aerodynamics)
Hub bearings play no role and wheels and tyres a very small one..