How much are the Spinergy PBO spokes going to cost me as far as aerodynamics? I’m a MOP and usually average in the 18-20 mph range on mostly rolling to hilly courses. On flat terrain with little or no wind (a Rails-to-Trails path with little change in elevation) I’ve managed to do traiing rides in the 20-22 mph range (I’ve yet to race anywhere but close to home so far, so I have never raced on a flat course). My current wheels are a set of Shimano WH R535’s. I found a good deal on a set of Spinergy Stealth PBO’s but don’t want wheels that might make me slower than I already am.
Here in north GA there is not much wind to contend with and very little flat terrain. I am entering my 4th decade and comfort is also a factor in reducing my recovery time from rides- (what the hell happens to your body when you hit 40?!!) and from what I’ve read here these wheels are really good at soaking up road vibrations. Is there any real significance aerodynamics -wise for someone at my level?
I’d have to guess you won’t notice much difference between the 535’s and the Stealths speedwise. (The 535’s were nice wheels.) There may be a slight comfort diffence between them, but I haven’t ridden PBO, so I can’t say for sure.
Not an expert, but I have the same 535s and Tilliums. I can’t tell a difference in speed, but the Tilliums sure are comfy and that probably counts a lot more than aerodynamics in the long run. Oh, and the Spinergy hubs are real loud when coasting - kinda reminds you to keep pedaling.
Besides, the difference between the worst (resonable) wheel and the best is perhaps a few seconds over 20 miles.
The main factor in absorbing road vibration is tire inflation pressure on a road bike. If you want something to soak up road vibrations get a suspended seatpost.
The slower you are, the more important aerodynamic differences are - it’s a greater relative improvement in time for a slow person versus a fast person. If you can go over about 14 mph, you should always go with aerodynamics if performance is important to you.
This explains the gist of it for frames courtesy of Cervelo.
For wheels - aerodynamics is the major effect on performance, weight is a much less signficant effect unless one is doing a hill climb, and inertia (of commercial wheels) has almost no impact. http://www.biketechreview.com/archive/wheel_theory.htm
Switching between my two wheelsets (R535s and Tilliums), using the same tires and pressure shows a marked difference in ride quality. I particularly noticed on a rough downhill section (35 to 40 MPH). The 535s just about shook my eyeballs out of my head. I could actually see the road with the Spinergys. There are factors, other than pressure, fork, frame, seat and seatpost that affect ride quality.
Again, I cannot notice any difference in ‘speed’ between the two sets. Since I have virtually no experience with any other wheelsets, both the 535s and the Tilliums could be poor aerodynamic performers, but they are, in my experience about the same.
I can tell you that there is definitely a difference in comfort with the PBO spoked wheels. I’ve ridden both the Tilliums and the Xaero Lites and would put both sets of wheels in the tops of the comfort zone of all wheels I’ve ever ridden. On the other hand…logic would say that the PBO spokes should be less aerodynamic…but I’ll say that I certainly never felt “slow” on the wheels. They are also a bit prone to wind-up…which is not good if you are a crit rider…but not really a factor for triathletes. I’ve also never broken a PBO spoke, nor even had to true a wheel…though a friend had to true his all-carbon rimmed PBO spoked rear wheel (don’t remember the model name but they are from the year before Tilliums were introduced)
I wouldn’t much advantage from an aerodynamic standpoint for the PBO spoke… but, I’ve never seen a study to say exactly what is the aerodyamic advantage/disadvantage.
What I noticed with the Xearo Lites… The typical spoked wheel has about twice as many spokes but are smaller. So… I guess you could make a WAG is that you might have about the same aerodynamic characteristics.
But, quite honestly that’s not why I ride PBO spokes… Nope… It’s all about comfort. They are by far the mot comfortable wheel set I have ever owned.
Thanks everyone. It sounds as if those of you riding on the PBO’s think there is a more comfort factor compared to regular spoked wheels. That is one of the more important reasons I’m considering a set of Spinergy Stealth w/ PBO spokes. Road vibration in the saddle is not a problem for me so a suspended seatpost is not going to help, but it’s a moot point anyway since I have a Cervelo Dual with an aero seatpost. Tire pressure is also something I’m not willing to lower to get a little more comfort- I’d just fatigue my legs faster and lower my speed with the higher rolling resistance.
My problem is just fatigue in my neck/ upper back after riding in the aerobars after about an hour. Despite all my strength training, stretching, massage and chiropratic, I still get fatigued in these places. I think any reduction in vibration coming through the front of the bike will help. I am also looking for a more laterally stiff wheel. I’m 180 lbs. and when I climb out of the saddle my Shimanos are a bit flexy. Besides that they have been great wheels. Plus there’s just that cool zoomy look of a more aero rim as well.
If you are uncomfortable on your bike it seems a bit overly optimistic to think that the flex in your wheels is going to relieve this problem. Any wheel that flexes enough for one to notice is one that is probably going to flex right into your brake pads when you are climbing.
Yes, I have been set up professionally on my bike- it was the first thing I had checked out after the fatigue began setting in on my longer rides- I was really proud of myself too since I already had myself set up nearly right where I should have been :). I don’t expect to get rid of this through changing equipment, just to reduce it as much as possible. I have not been riding longer rides ( for me 30+ miles ) for very long so it’s also a matter of more time in the saddle. And I’m certainly not looking for a flexy wheel to solve this problem- I am interested in these for the supposed vibration dampening qualities of this material, much like a carbon fork dampens vibrations compared to steel or aluminium. A carbon fork is definetly not more flexy than other materials, but it still has the ability to dampen road vibration due to the characteristic of the material. I was wondreing if the PBO has that type of characteristics as well.
