Login required to started new threads

Login required to post replies

808 wheel in the front and 404 in the back?
Quote | Reply
Do any of you put a wheelset on like that? Say a zipp 808 in the front wheel and a 404 on the rear wheel? What is the advantages or disadvantages of doing this?

Thanks
Quote Reply
Re: 808 wheel in the front and 404 in the back? [ironslave] [ In reply to ]
Quote | Reply
The disadvantage is that there is no reason not to put an 808 on the rear. A deeper rear wheel does not create a handling issue.
Quote Reply
Re: 808 wheel in the front and 404 in the back? [SBRcanuck] [ In reply to ]
Quote | Reply
SBRcanuck wrote:
The disadvantage is that there is no reason not to put an 808 on the rear. A deeper rear wheel does not create a handling issue.

Even in heavy crosswinds?
Quote Reply
Re: 808 wheel in the front and 404 in the back? [ironslave] [ In reply to ]
Quote | Reply
in heavy crosswinds you want the front wheel to be shallower than the rear.

____________________________________
Swimming Workout of the Day: http://forum.slowtwitch.com/...ost=5784860#5784860;
Favourite Swim Sets: http://forum.slowtwitch.com/...m.cgi?;post=5004659;
Winner of the 2017 50 fly east coast Smackdown. http://forum.slowtwitch.com/...ost=6294538#p6294538
Quote Reply
Re: 808 wheel in the front and 404 in the back? [ironslave] [ In reply to ]
Quote | Reply
ironslave wrote:
SBRcanuck wrote:
The disadvantage is that there is no reason not to put an 808 on the rear. A deeper rear wheel does not create a handling issue.


Even in heavy crosswinds?

The rear wheel doesn't turn, its fixed straight in your frame, plus your body weight on top of it.
Quote Reply
Re: 808 wheel in the front and 404 in the back? [ironslave] [ In reply to ]
Quote | Reply
If you can ride an 808 in the front you can handle a deeper rear... better aero capabilities with a deeper rear. The front is more of a concern with wind and handling vs. the rear.

The disadvantage is that you're going to be slower... here's a chart that illustrates various wheel combos in relation to time saved at various distances... albeit these are Flo wheels. Scroll to the bottom of the page....
http://www.flocycling.com/aero.php
Quote Reply
Re: 808 wheel in the front and 404 in the back? [ironslave] [ In reply to ]
Quote | Reply
I think the legendary 'Twitcher jackmott once put a super-shallow climbing wheel on the rear and a deep-ish front wheel on his wife's bike for a hill climb (she was a pro). They reckoned they could hit the weight limit with one deep wheel so it might as well be the front, since the rear mattered less for aerodynamics.

But I think that's the only case I've heard of.

ZONE3 - We Last Longer
Quote Reply
Re: 808 wheel in the front and 404 in the back? [ironslave] [ In reply to ]
Quote | Reply
Doing this is going to pull the center of lateral resistance forward and is going to make the bike more twitchy. If these are the wheels you already own, put a wheel cover on the 404 and the resulting 808/disc will be more stable than the 808/404.

I used to ride with an H3 trispoke front and a wheel cover in the back. Sometimes before a race I'd want to use the H3 but hadn't put my cover on yet and just had a shallow rimmed rear wheel. It didn't take much crosswind for that setup to be sketchy as heck. Put the cover on the rear and the handling improved dramatically.


PS, It would also look silly to have a deeper front than rear.
Last edited by: kdw: Dec 6, 17 5:45
Quote Reply
Re: 808 wheel in the front and 404 in the back? [tessar] [ In reply to ]
Quote | Reply
Think of it as a static side-on profile to the wind. <caveat that i only half remember what the clever-sounding man on the podcast was saying> The bike would pivot around the middle (roughly) depending on what the front and back of the bike look like to the oncoming crosswind. If you have the front being given hard pivoting sideways movements by a crosswind then you might pucker-up a lot more than the equivalent turning effect hitting the more stable rear of the bike.
Quote Reply
Re: 808 wheel in the front and 404 in the back? [ironslave] [ In reply to ]
Quote | Reply
I think 2 years ago Nils Frommhold from Germany, a Reynolds sponsored athlete, went to Hawaii with a 80mm front and 65mm rear wheel because Reynolds told him it would be best. If I remember correctly the reason was that there was no advantage of that rear wheel being deeper, so might as well save the weight. He ended having a flat in the front tire and riding a spare Zipp 808 front and Reynolds 65mm in the rear.

Just remember this story because it seemed so strange to me, first because he/Reynolds seems to be the only one in the world going down this path, and also because Reynolds is selling 80mm wheelsets which as per that logic would be useless....

If you go to https://reynoldscycling.com/ and see the "shop" menu you can still see a picture of that setup, with the deep yellow front wheel and the shallower red rear wheel
Quote Reply
Re: 808 wheel in the front and 404 in the back? [SBRcanuck] [ In reply to ]
Quote | Reply
SBRcanuck wrote:
The disadvantage is that there is no reason not to put an 808 on the rear. A deeper rear wheel does not create a handling issue.

^This

But I dare to state that 404 front / 808 rear is slower than 808 front / 404 rear
Quote Reply
Re: 808 wheel in the front and 404 in the back? [ironslave] [ In reply to ]
Quote | Reply
ironslave wrote:
Do any of you put a wheelset on like that? Say a zipp 808 in the front wheel and a 404 on the rear wheel? What is the advantages or disadvantages of doing this?


Thanks


Your biggest disadvantage would be stability. Here's an explanation.


1. Your front wheel connects to a steering axis—your fork and handlebars—and as a result, is affected more by crosswind than your rear wheel. Crosswind not only pushes your front wheel side to side, but it can also turn your wheel left to right just like your handlebars do. You feel the effects of crosswind more intensely the deeper your wheel gets. Having the wind turn your wheel while descending in the aero bars at 40mph is an unsettling experience. Riders in this predicament often sit up on their hoods to control their bike. Doing so, takes their body from an aerodynamic position and puts it directly in the wind. Your body is the biggest source of drag on your bike. If you are sitting up on your hoods to control your bike, you are losing time.


2. The depth ratio of your front wheel compared to your rear wheel matters when talking about stability. As your rear wheel gets deeper in comparison to the front wheel, your center of pressure moves towards the back end of the bike. To visualize this, imagine you were looking at a picture of yourself riding your bike from the side. If you had to find the center of the "area" you create, that would be your center of pressure. As you increase rear surface area with a deeper rear wheel, the center of that area moves backward. As your center of pressure moves backward, you reduce the force on your front wheel, and in turn increase stability.


Chris Thornham
FLO Cycling
FLO Blog | Facebook | Instagram | Twitter
Last edited by: Canadian: Dec 6, 17 12:28
Quote Reply
Re: 808 wheel in the front and 404 in the back? [ironslave] [ In reply to ]
Quote | Reply
ironslave wrote:
Do any of you put a wheelset on like that? Say a zipp 808 in the front wheel and a 404 on the rear wheel? What is the advantages or disadvantages of doing this?



The Fix is in.

Do any of you put a wheelset on like that? Say a zipp 808 in the front wheel and a 404 on the rear wheel with a wheel cover? What is the advantages or disadvantages of doing this?

http://www.wheelbuilder.com/aerodisc.html

Cheers, Neal

+1 mph Faster
Quote Reply
Re: 808 wheel in the front and 404 in the back? [ironslave] [ In reply to ]
Quote | Reply
  
An 808 front/404 rear should outperform a 404/404 or even a 404/808 combo. Unless there are strong crosswinds -- those produce the legendary "lift" on an 808 rear, but are likely to make an 808 front twitch more.

In any case, 808/404 is just wrong for aesthetic reasons. It may be more efficient. But it's wrong. Just like running around with your zipper unzipped is wrong -- even though it's more efficient.
Last edited by: jens: Dec 6, 17 16:28
Quote Reply
Re: 808 wheel in the front and 404 in the back? [ironslave] [ In reply to ]
Quote | Reply
Only if you grow a mullet to balance out the esthetics of that set up.
Last edited by: endosch2: Dec 6, 17 17:13
Quote Reply
Re: 808 wheel in the front and 404 in the back? [jens] [ In reply to ]
Quote | Reply
jens wrote:

An 808 front/404 rear should outperform a 404/404 or even a 404/808 combo. .


Yes. But then if a rider can control the 808 up front then might as well get 808/808. If for no other benefit at least there'd be just one valve length to deal with for easier flat repair......
Last edited by: Dilbert: Dec 6, 17 19:29
Quote Reply
Re: 808 wheel in the front and 404 in the back? [Canadian] [ In reply to ]
Quote | Reply
Canadian wrote:
ironslave wrote:
Do any of you put a wheelset on like that? Say a zipp 808 in the front wheel and a 404 on the rear wheel? What is the advantages or disadvantages of doing this?


Thanks


Your biggest disadvantage would be stability. Here's an explanation.


1. Your front wheel connects to a steering axis—your fork and handlebars—and as a result, is affected more by crosswind than your rear wheel. Crosswind not only pushes your front wheel side to side, but it can also turn your wheel left to right just like your handlebars do. You feel the effects of crosswind more intensely the deeper your wheel gets. Having the wind turn your wheel while descending in the aero bars at 40mph is an unsettling experience. Riders in this predicament often sit up on their hoods to control their bike. Doing so, takes their body from an aerodynamic position and puts it directly in the wind. Your body is the biggest source of drag on your bike. If you are sitting up on your hoods to control your bike, you are losing time.


2. The depth ratio of your front wheel compared to your rear wheel matters when talking about stability. As your rear wheel gets deeper in comparison to the front wheel, your center of pressure moves towards the back end of the bike. To visualize this, imagine you were looking at a picture of yourself riding your bike from the side. If you had to find the center of the "area" you create, that would be your center of pressure. As you increase rear surface area with a deeper rear wheel, the center of that area moves backward. As your center of pressure moves backward, you reduce the force on your front wheel, and in turn increase stability.

I like this explanation. But is there a tipping point to where putting the center of pressure too far backwards becomes a disadvantage? If not, why isn't everyone running super shallow front wheels, with discs in the rear?
Quote Reply
Re: 808 wheel in the front and 404 in the back? [robegan99] [ In reply to ]
Quote | Reply
robegan99 wrote:
Canadian wrote:
ironslave wrote:
Do any of you put a wheelset on like that? Say a zipp 808 in the front wheel and a 404 on the rear wheel? What is the advantages or disadvantages of doing this?


Thanks


Your biggest disadvantage would be stability. Here's an explanation.


1. Your front wheel connects to a steering axis—your fork and handlebars—and as a result, is affected more by crosswind than your rear wheel. Crosswind not only pushes your front wheel side to side, but it can also turn your wheel left to right just like your handlebars do. You feel the effects of crosswind more intensely the deeper your wheel gets. Having the wind turn your wheel while descending in the aero bars at 40mph is an unsettling experience. Riders in this predicament often sit up on their hoods to control their bike. Doing so, takes their body from an aerodynamic position and puts it directly in the wind. Your body is the biggest source of drag on your bike. If you are sitting up on your hoods to control your bike, you are losing time.


2. The depth ratio of your front wheel compared to your rear wheel matters when talking about stability. As your rear wheel gets deeper in comparison to the front wheel, your center of pressure moves towards the back end of the bike. To visualize this, imagine you were looking at a picture of yourself riding your bike from the side. If you had to find the center of the "area" you create, that would be your center of pressure. As you increase rear surface area with a deeper rear wheel, the center of that area moves backward. As your center of pressure moves backward, you reduce the force on your front wheel, and in turn increase stability.


I like this explanation. But is there a tipping point to where putting the center of pressure too far backwards becomes a disadvantage? If not, why isn't everyone running super shallow front wheels, with discs in the rear?

I can't really see a case were too much rear pressure is a bad thing. I think the point of no return is going too shallow on your front wheel and losing time as a result.

For example, most people can confidently control a 60mm wheel in most wind conditions. Being overly cautious and using a slower front FLO 30, when it's not required to maintain control of your bike, would be crossing the point of no return.

Does that make sense?


Chris Thornham
FLO Cycling
FLO Blog | Facebook | Instagram | Twitter
Quote Reply
Re: 808 wheel in the front and 404 in the back? [JasoninHalifax] [ In reply to ]
Quote | Reply
JasoninHalifax wrote:
in heavy crosswinds you want the front wheel to be shallower than the rear.

they makes sense. so why doesn't ironman place depth limits on the front wheel instead of nor allowing disc wheels on the rear wheel at kona?

2018 Races: IM Santa Rosa, Vineman Monte Rio, Lake Tahoe 70.3
Quote Reply