Do we need springy wheels?
Wheels are one of the least comfort improving parts of the gravel bike. At least according to Cervelo. But still there are companies that make claims of improved comfort when using their wheels or rims. Spank with Vibrocore foam is one of those examples. Spinergy with its unique spokes is another. After a Spank handlebar fiasco I decided to give Spinergy a chance and I bought from them a set of gravel specific GX 700c wheels. Let’s find out how well they performed in my tests!
During my testing of different carbon gravel bikes I was constantly amazed how well those bikes accelerated. Power transfer was simply two leagues above my steel Jamis Renegade Exploit benchmark bike. Yet when I was talking with others about my subjective feelings I was constantly reminded that wheels are crucial thing contributing to the feeling fast on the bike. So one of the most important reasons of buying a new set of wheels was to find out if they will indeed make my bike faster. Up to this point I was using a rather standard and not so light wheels based on ATX470 rims and stock Formula hubs and 32, also rather standard spokes. Spinergy wheels have 24 very light spokes (we will talk about them in a second) and overall, the whole wheelset weights only 1475 g. So they should make my bike faster. But in real world I honestly did not feel any significant improvement. Yes, bike felt a tad quicker when accelerating and in general a little more alive but once again I was proved that steel frame is not the best one for the effective power transfer. Because wheels only work with what the frame is giving them and the flex of my steel frame was simply not helping Spinergy wheels. On the other hand, I have read reviews saying that Spinergy unique spokes behaves somehow like springs, and they have some sort of lag in power delivery. Yet again, due to the fact that steel frame behaves in a very similar way, I was not able to detect this springiness of the wheels. So, there you have it. Wheels may be important (and I truly believe there are important when the power transfer is considered) but first you have to have a stiff frame to feel the difference.
What about the comfort?
Spinergy is famous for its unique fiber PBO spokes. They are claimed to provide 3-times more strength than a steel spokes at the half of the weight. But the weight is not the only benefit. PBO fiber spokes are like springs that are flexing, and by this, absorbing impacts for improved comfort of riding. The spring is a crucial word here. Lauf Grit suspension fork is also a spring and during my testing I found out that spring is no magical solution and energy it absorbs have to be release somewhere. The more energy the more pronounce rebound that has to be absorbed by other bike parts like tires or the rider himself. Lauf Grit suspension fork worked quite well on a bumpy forest road (where you and the tire are working together to absorb bigger hits) but on a fast gravel route with high frequency constant vibrations the spring suspension becomes less effective. I was very interested in finding if this will be also true for Spinergy, springy wheels. So I went for a ride. On a benchmark bike without any other comfort improving parts (so rigid FSA seatpost with a rigid Accent saddle, 90 mm FSA rigid stem and rather stiff Zipp Service Course SL Ergo 70 aluminum handlebar).
First impression when riding on a bumpy road was rather underwhelming. I did not feel any real improvement and to be honest, maybe I felt even more impacts than on my standard, low-end ATD 470 wheels. Could this be the springiness effect? Maybe, but the more I rode the more I got accustomed to the feeling and started to feel the positive difference. Not big, but it was there. And I could feel it both at 25 psi and 50 psi so it was definitely the wheelset and not the tires. But it was no magic carpet ride even at the 25 psi tire air pressure. Far from it.
So to find out how the comfort really improved thanks to Spinergy GX wheels I did my measurements. On a bumpy forest route at 25 psi (Soma Cazadero 42 mm tires) Spinergy wheels reduced the vibration by 5% at the front of the bike. When I raised the air pressure to 50 psi, the springy wheels was more than 6% more comfy thant my standard wheels (both were run with tires set up tubeless). Exactly this level of improvement was also measured at the rear of the bike but when I lowered the air pressure to 25 psi, comfort of my ATD 470 wheels and new Spinergy GX wheels was exactly the same. And no surprise there. It is the front of the bike that generates more vibrations and can show bigger change in comfort when using something like Spinergy wheels.
OK, so on a bumpy road there was an improvement in comfort. But how bout the fast gravel riding? Knowing that Laug Grit SL was less effective in that environment I was not expecting much from Spinergy GX wheels. And indeed, there was no real difference in comfort between standard wheels and Spinergy wheels. Both at 25 and 50 psi. High frequency chatter is a very challenging scenario for any comfort improving parts and especially for those that are based on springs.
Spinergy GX wheels have a very nice rim profile. They are rather wide and shallow (which also promotes more comfy ride). The inner width of the rim is 24 mm and the height is 20 mm. This makes the tire shape more flatten compared to my ATD 470 rims with only 17 mm inner width. Those rims are also very easy to use in tubeless setup. The easiest I have had. I also did not see any noticeable air leakage even after one week of usage. That is very nice and definitely makes you want use those wheels only in a tubeless setup.
Then there is the look. The PBO spokes looks very different to normal spokes. They are bigger and the wholes in rims are much larger. You can also buy them in many colors to make your bike stand out from the crowd. But those difference comes at the cost of much harder servicing. To make the wheel true you need to remove the inner tape from the rim and use special tools (that are provided with the wheelset). And in the case of emergency, you will need to have a replacement spoke that can be very hard to find (unless you live near the Spinergy distributor). But Spinergy reassured me that PBO spokes are very tough so there should be no need for replacing them. Hopefully they are right about that because in Poland, where I live, there is no Spinergy distributor at all.
Would I recommend those wheels?
Yes. I would. I bought them myself and after all of my testing I will keep them. They look unique, they are comfier on a bumpy road, and they are much lighter than my previous wheels. But they are no magical comfort improving solution, they are also very hard to service and for sure, to enjoy them the most, you need a very power efficient frame. So it looks like I will be buying a new frame. But maybe not now…
Now we all need to stay healthy!