2019 PRO thread
Moderators: robbosmans, Moderator Team
Some (not all) of the details of the shiv TT bike makes me think of the Walser bikes from back in the day. If I remember correctly, those Walsers were rebadged most notably as Giants and Bianchis under Jan Ulrich, before they were produced by Focus. Even so, the Walsers had the frame much closer to the rear wheel. As @ichobi mentions, spez will tell us the shiv TT is the second fastest behind the non-uci-compliant shiv.
Jungels' position looks pretty dang aero.
Jungels' position looks pretty dang aero.
"If it ain't broken, it could be lighter"
-
- Posts: 2315
- Joined: Wed Jan 27, 2016 1:39 pm
- Contact:
You know, it is a common misconception that the non-UCI compliant bikes are faster... I want to say it was one of the podcasts I heard with Josh Poertner from Silca (formerly of Zipp) and he said that in some cases, they are, but in some cases they are not. Yes, they're shapes appear to be more aero and they don't obey the 3:1 rule, but that doesn't necessarily mean they're faster. On some of the Non-UCI bikes it is very difficult to get a low TT position. They are designed for Triathlon riding to be efficient and preserve muscles and energy for the run, but not necessarily the fastest TT. They're also desined around the fact that they have to be fast while carrying the supplies and hydration for a 100+ mile ride.
Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓ Broad Selection ✓ Worldwide Delivery ✓
www.starbike.com
-
- Resident master of GIF
- Posts: 3405
- Joined: Mon Jul 18, 2011 2:44 am
- Contact:
looks like majka needs moar time in the tunnel.
CrankAddictsRich wrote: ↑Tue May 21, 2019 8:28 pmYou know, it is a common misconception that the non-UCI compliant bikes are faster... I want to say it was one of the podcasts I heard with Josh Poertner from Silca (formerly of Zipp) and he said that in some cases, they are, but in some cases they are not. Yes, they're shapes appear to be more aero and they don't obey the 3:1 rule, but that doesn't necessarily mean they're faster. On some of the Non-UCI bikes it is very difficult to get a low TT position. They are designed for Triathlon riding to be efficient and preserve muscles and energy for the run, but not necessarily the fastest TT. They're also desined around the fact that they have to be fast while carrying the supplies and hydration for a 100+ mile ride.
A "fast" bike needs a rider on it.
IMO it's the UCI bike measurment rules that "limit" performance, based on some random numbers.
If some riders are faster than others, you have to take into account their body measurments fit better inside UCI's limits than others.
Ask a bike fitter to fit a rider based on ideal aero and performance measurments on a TT/Tri bike. Then tell him the bike fit needs to be UCI legal. I bet he'll have to change a few adjustments, not based on aero gains, but just to fit the rules...it's a trade-off...and all depending on the riders body measurments...
Louis
-
- Moderator
- Posts: 3669
- Joined: Sun May 25, 2014 4:57 am
100%it's a trade off. Look at the guys in the UK.
Sent from my SM-G975F using Tapatalk
Sent from my SM-G975F using Tapatalk
Using Tapatalk
Tour magazine did test sometimes ago a direct comparison between the tri and tt version of the same model. i.e. the p5-six (not the latest one) vs the p5x. The old shiv and the old shiv tri - in most case, the TT bikes tested faster if I remembered correctly. The tri bike is "fast" within the context that it usually comes with aero comparment that make carrying food and water streamlined with the bike. But for pure speed, the Tour mag seems to suggest that the 'cleaner' version of the bike wins out.
So I guess from the CdA equation, the TT bike will always have less 'A' by design. The larger airfoil shaped tubes of the tri bikes don't seem to negate larger surface area. (my assumption), at least in the tested bikes but probably don't apply to all tri bike.
The new Shiv looks almost identical to the new Shiv Tri except a few part. (1) Fork being less deep (obviously to comply with the UCI reg). (2) It has a deeper seat tube, probably to compensate the fact that the tri version has a matching water tank attached behind it to delay flow separation. (3) The seat stay is a tad higher to comlpy with uci reg). The headtube shape looks similar.
So I guess from the CdA equation, the TT bike will always have less 'A' by design. The larger airfoil shaped tubes of the tri bikes don't seem to negate larger surface area. (my assumption), at least in the tested bikes but probably don't apply to all tri bike.
The new Shiv looks almost identical to the new Shiv Tri except a few part. (1) Fork being less deep (obviously to comply with the UCI reg). (2) It has a deeper seat tube, probably to compensate the fact that the tri version has a matching water tank attached behind it to delay flow separation. (3) The seat stay is a tad higher to comlpy with uci reg). The headtube shape looks similar.
-
- Posts: 2315
- Joined: Wed Jan 27, 2016 1:39 pm
- Contact:
Yes... actually... that just furthers my point.. On many Triathlon, NON-UCI bikes It can be difficult to get the front as low as you want to ruly be as fast as possible in a TT. The headtubes are taller to get riders to sit up a bit more to be compfortable for 100+ miles. For sure though, there are fit rules that need to be followed for UCI compliance that can take away some aero.LouisN wrote: ↑Tue May 21, 2019 9:00 pmA "fast" bike needs a rider on it.
IMO it's the UCI bike measurment rules that "limit" performance, based on some random numbers.
If some riders are faster than others, you have to take into account their body measurments fit better inside UCI's limits than others.
Ask a bike fitter to fit a rider based on ideal aero and performance measurments on a TT/Tri bike. Then tell him the bike fit needs to be UCI legal. I bet he'll have to change a few adjustments, not based on aero gains, but just to fit the rules...it's a trade-off...and all depending on the riders body measurments...
Louis
- Dan Gerous
- Posts: 2413
- Joined: Sun Aug 12, 2007 6:28 pm
Low enough is not the problem. The problem comes with the front - aft position UCI "limits" ( 5cm saddle front-to-BB center - 80 cm bar end shifters, and only one exemption allowed) , and all the rider morphology problems that come with it.CrankAddictsRich wrote: ↑Wed May 22, 2019 12:51 amYes... actually... that just furthers my point.. On many Triathlon, NON-UCI bikes It can be difficult to get the front as low as you want to ruly be as fast as possible in a TT. The headtubes are taller to get riders to sit up a bit more to be compfortable for 100+ miles. For sure though, there are fit rules that need to be followed for UCI compliance that can take away some aero.LouisN wrote: ↑Tue May 21, 2019 9:00 pmA "fast" bike needs a rider on it.
IMO it's the UCI bike measurment rules that "limit" performance, based on some random numbers.
If some riders are faster than others, you have to take into account their body measurments fit better inside UCI's limits than others.
Ask a bike fitter to fit a rider based on ideal aero and performance measurments on a TT/Tri bike. Then tell him the bike fit needs to be UCI legal. I bet he'll have to change a few adjustments, not based on aero gains, but just to fit the rules...it's a trade-off...and all depending on the riders body measurments...
Louis
Louis
Remember the aftermath but apart from this pic I haven’t seen any video. I guess that’s what happens when you run a disc/ sail on a super windy day!Dan Gerous wrote: ↑Wed May 22, 2019 1:13 amWith the smaller sections, the new Shiv should be much lighter and perhaps easier to handle, especially in windy conditions, something Julian Alaphilippe might be happy with, remember this?
-
- Moderator
- Posts: 3669
- Joined: Sun May 25, 2014 4:57 am
Surely these are pushing the limitsCrankAddictsRich wrote:Custom bars for Roglic, Campenaerts and Nibali in the second TT at the Giro.
Maybe custom bars for Yates, as well?
Shiv TT Disc for Jungels and Majka in the second TT.
Sent from my SM-G975F using Tapatalk
Using Tapatalk
-
- Posts: 3282
- Joined: Wed Mar 17, 2004 1:38 pm
These bars have passed inspection by the UCI Commissars on every occasion they have been used. But, then again, that doesn't mean that on some date in the future the UCI HQ or some commissar in the field won't change their mind and declare them to be illegal.Nefarious86 wrote: ↑Wed May 22, 2019 8:17 amSurely these are pushing the limits
Sent from my SM-G975F using Tapatalk
-
- Resident master of GIF
- Posts: 3405
- Joined: Mon Jul 18, 2011 2:44 am
- Contact:
pushing limits yea, but i can also see how the custom extensions pass also.
Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓ Broad Selection ✓ Worldwide Delivery ✓
www.starbike.com