How much faster is a DISK wheel? | Tested

I wanted to test just how much faster my new disk wheel and my new front wheel is compared to the stock wheel set which came with my bike.
I go over some of the methods I used and the results in this video.
If you would like any more details about my test data, feel free to ask in the comments or email me via the channel here.
Watts Savings:
(Someone has very kindly provided me with some very insightful data from this test that I highly recommend recommend reading through the whole thing)
Hi Jason. I did a rough calculation. The result is roughly as follows: Disc only: 16 W faster. Disc+83: 24 W faster.
Or in other words: with 55/55 you have to pedal these watts more to be just as fast.
I adjusted for a slight headwind/tailwind, otherwise the values would not have been comprehensible. But why the 83 front wheel is so much slower uphill is somewhat curious. My calculations are not precise enough for this, i.e. too imprecise to the decimal place. Actually, an 83 mm front wheel shouldn't really be slower at just under 30 km/h, but the higher weight of the disc also plays a role (only 5 W gain at 175 W base).
Rear discs are often really fast, especially in crosswinds.
0.8-1 km/h can quickly add up. Higher front wheels have less effect and you can see that here too. However, I have my doubts that the & watts only come from the 83 vs 55 rim. 55 mm is quite a good height, the tire width on the 55 probably plays a role here and the different tires play a very minor role. Your aero gains are all (too) large because they were measured on a downhill section with high wind speeds.
If you calculate with cda values without the downhill section, you get approx. 37.4, 38 and 38.3 km/h at 225W. The watt differences there would be: 9 and 14 watts. I calculated with a slight gradient of 0.1%. The values sound a bit more logical.
Review of the parcours wheelset:
• Parcours Disk and Chro...
Chapters:
00:00 - Intro
00:38 - The wheels
02:05 - Methods
05:02 - Results
07:38 - Discussion
09:56 - Outro

[@fede1275]

Great work and interesting data! Well done!

[@DanielPinkney-fu5nr]

Data shows some serious gains! Got to say Jason, you certainly put some effort into this, great video 👏

[@cyclingunboxed]

It did take the whole day to do the testing! I’m not sure I want to do anymore 😂

[@zachrichardson7099]

Certainly an interesting data set, nice job. I couldn't help but find it funny how fitting it is for a bloke from surrey to have a bike and wheel set like that, but if it's an independent purchase then fair play.

[@zikaperic2133]

very interesting!

[@cyclingunboxed]

I didn’t think I was going to see many results but glad I was proven wrong!

[@chrisnoller7263]

I have the same Ordu as you (same colour too!) and am using it for standard and 70.3 Triathlons. I recently swapped the Vision 55's for the standard Parcours Chrono front and rear (77/86). Running GP5000 28mm with latex tubes and Silca speed shields. I haven't done any proper testing but my average ride speeds have generally increased by circa 1 km/h. For me, the wider inner rim width (22.5m vs 19mm on the Visions) provides a more confortable ride and more confident cornering, which means you can get the same or better time for lower effort, and helps save the legs a bit for the run.

[@cyclingunboxed]

I have had the exact same experience as you with the wheels and tyres. It’s been a very worthy upgrade.

[@travispyle2905]

Thank you

[@drbell7631]

Nice 30mm tyre Choices

[@felixblock1542]

Hi Jason. I did a rough calculation. The result is roughly as follows: Disc only: 16 W faster. Disc+83: 24 W faster. Or in other words: with 55/55 you have to pedal these watts more to be just as fast. I adjusted for a slight headwind/tailwind, otherwise the values would not have been comprehensible. But why the 83 front wheel is so much slower uphill is somewhat curious. My calculations are not precise enough for this, i.e. too imprecise to the decimal place. Actually, an 83 mm front wheel shouldn't really be slower at just under 30 km/h, but the higher weight of the disc also plays a role (only 5 W gain at 175 W base). Rear discs are often really fast, especially in crosswinds. 0.8-1 km/h can quickly add up. Higher front wheels have less effect and you can see that here too. However, I have my doubts that the 8 watts only come from the 83 vs 55 rim. 55 mm is quite a good height, the tire width on the 55 probably plays a role here and the different tires play a very minor role. Your aero gains are all (too) large because they were measured on a downhill section with high wind speeds. If you calculate with cda values without the downhill section, you get approx. 37.4, 38 and 38.3 km/h at 225W. The watt differences there would be: 9 and 14 watts. I calculated with a slight gradient of 0.1%. The values sound a bit more logical. Regards

[@cyclingunboxed]

Hey! This is so cool! I genuinely really appreciate this. Sounds like you did what you could with the data i collected. I’m sure an aero sensor and the ride file would make this more accurate. This is some very cool data. Do you mind if I post these results in the description. I would put a disclaimer by it suggesting that this is an estimate based on the data you had to your disposal.

[@felixblock1542]

@@cyclingunboxed Hi Jason. The 9 (disk only) - 14 watts (disk + 83) mentioned later are the much more logical values for me. They also fit well with my experience of almost 15 years of TT. Of course always relative to the baseline, in this case 225W. These are absolute values. The first 16-24 Watts are almost certainly too high, probably because of the high wind speed, where the aerodynamic values become too important. I think this can be tested without an aero sensor. I personally test routes that are as flat as possible, preferably no (!) car traffic at all, and always take out & back as measured values, flying start. That way you can calculate the wind variable even if there is some wind. At least roughly. If you are going 41 km / h in one direction and 39 km / h in the opposite direction ... Well, the example is very simple :D, but then it's just 40 km/h. Take the average of both measurements and divide by 2. This will give you better results than taking the total average speed, because the headwind part will get a bigger share (which is not what we want in this case). And sorry for the translator English. I was in a hurry!

[@colcob]

Easiest way to test the watt difference of a change is to ride your tests holding a fixed speed instead of a fixed power and just read off the average power it took to hold that speed. It's also way easier to ride constant speed than constant power.

[@cyclingunboxed]

I can see your logic. It’s definitely the better way to find out the power difference between the two rather than calculating it. For me though I wanted to know the amount of time it would save me and I don’t have the mathematical ability to convert watts to time saved. I’m also not so sure that on the course I did, it would be very easy to finish at the exact minute and second each time whereas I did find it very easy with the power as I hit most of them at bang on 250 with only a 1 watt discrepancy. It was around a 4.5 min course

[@PapaPineapples]

Did you do chattanooga 70.3 2024?

[@cyclingunboxed]

I did not. This year I have done Alcudia 70.3 and I have Klaagenfurt in 2 weeks time. Did you?

[@PapaPineapples]

@@cyclingunboxed I definitely saw your twin out there running beside me 🤣

[@cyclingunboxed]

Maybe a long lost brother 😂

[@parfi1959]

Can’t ride the 82 front way to twitchy in crosswinds

[@cyclingunboxed]

As a heavier rider I seem to be ok in the crosswinds. Even with these wheels. I do think they handle themselves really well. I have mentioned this in my review of them on the channel

[@drbell7631]

40sec to 1min over a 40kms Olympic Distance Tri Bike Course With Well Smoothly Matched Tyre Widths of Clinchers the discs Matching Disc Width and Smoothly Theat Transition 30mm parcore Tyres rear disc rime area of that Disc a smoother transition there