I was playing around with best bike split this week as I was interested in getting a disc wheel. I copied my bike and only changed the rear wheel from a 90mm to a disc. I then tested on courses I did last year. One was the oly nationals course, which is most flat. The other was ironman ct 70.3, which has ~4000 ft climbing. BBS gave me no time improvement on the olympic course and 2 seconds on the 70.3 course. I emailed BBS about this and they told me that they recently changed their modeling as modern 90mm deep wheels are as good as discs until the yaw angles get rather extreme. I'm all about the math here, but I'm wondering if this is actually true? What is the yaw break point to make a disc worthwhile? What is everyone's opinion? Thanks.
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Re: BBS: disc v. deep wheel [AndrewL]
[ In reply to ]
FLO and others also estimate the benefit of a rear disc to be just 30-40 seconds for an IM ride compared to a deep wheel. Discs are mainly bling with that kind of difference.
Re: BBS: disc v. deep wheel [AndrewL]
[ In reply to ]
I sold my disc at the end of last season and am running the old 606 setup so 404 up front 808 at back, i like the feel of the bike, my race splits this summer have been good and the bike is lighter as my disc wasn’t that light. I was reading data saying 808 to disc was like 20sec per 40km at specific yaw, so in real world with a range of wind angles then Im not worse off, and that is tested at 50kph, I might average 38kph on a flat 70.3 bike course so also believe the gains just arent there with a disc for me and my setup. Everyone is different though so just go with what you think is your best set up.
Re: BBS: disc v. deep wheel [AndrewL]
[ In reply to ]
So to recap, a disc is faster.....it's just that the gain is nominal enough that it might not be worth buying a n+1 wheel. However, if you are looking for a race-only wheel, or already own a disc then use it.
BBS also has to add into calculation that the rumble of a disc is worth at least 5W in motivation.
ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)
BBS also has to add into calculation that the rumble of a disc is worth at least 5W in motivation.
ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)
Re: BBS: disc v. deep wheel [AndrewL]
[ In reply to ]
AndrewL wrote:
I was playing around with best bike split this week as I was interested in getting a disc wheel. I copied my bike and only changed the rear wheel from a 90mm to a disc. I then tested on courses I did last year. One was the oly nationals course, which is most flat. The other was ironman ct 70.3, which has ~4000 ft climbing. BBS gave me no time improvement on the olympic course and 2 seconds on the 70.3 course. I emailed BBS about this and they told me that they recently changed their modeling as modern 90mm deep wheels are as good as discs until the yaw angles get rather extreme. I'm all about the math here, but I'm wondering if this is actually true? What is the yaw break point to make a disc worthwhile? What is everyone's opinion? Thanks.BBS is a simulation and the results are only as good as the assumptions they program into their model. If they show no difference between a disc and a deep spoked wheel in shorter races, I'd question their assumptions rather than assume that their simulations accurately reflect reality.
The difference between a disc and a 90 mm wheel is undoubtedly small but there's no reason a difference would show in long events, be proportionately much less in medium distance events, and totally disappear in shorter events, even if that difference is only a few seconds.
Re: BBS: disc v. deep wheel [AndrewL]
[ In reply to ]
One other thing to keep in mind.
In windy conditions 2 deep wheels are going to stall more than a deep front and a disc in the back. The disc makes life a lot easier when racing in windy conditions.
Brian Stover USAT LII
Accelerate3 Coaching
Insta
In windy conditions 2 deep wheels are going to stall more than a deep front and a disc in the back. The disc makes life a lot easier when racing in windy conditions.
Brian Stover USAT LII
Accelerate3 Coaching
Insta
Re: BBS: disc v. deep wheel [desert dude]
[ In reply to ]
What does "stall" mean in this context?
Re: BBS: disc v. deep wheel [DBF]
[ In reply to ]
Dumb question but does a disc favor faster riders or slower riders or is it similar gain either way?
Re: BBS: disc v. deep wheel [Animalmom2]
[ In reply to ]
Slower riders gain more time. Benefits both on a same percentage basis.
Re: BBS: disc v. deep wheel [AndrewL]
[ In reply to ]
I'm currently racing on some 404s. I was going to buy some 808s this year but would I be better off just buying a disc on the back and leaving on my front 404?
Re: BBS: disc v. deep wheel [desert dude]
[ In reply to ]
How windy do those conditions need to be to make the disc show a time savings?
exxxviii wrote:
Slower riders gain more time. Benefits both on a same percentage basis.Thanks. Santa!!!!