Discs vs Deep Section

[ft_critical]

Hi there BNA Track Advisory Team.

Has anyone got any data, links to data on the benefit of discs over deep-section wheels in the velodrome (indoor)?

Using the power of internet search, I found some items on road differences where just a rear disc made a pretty reasonable difference in times. Nothing you find on the subject of aero gains is particularly scientific - as in, a lot of potential for error, e.g., just keeping the same wattage output ...

Discs are a big investment $-wise, for very infrequent use.

Cheers,

FT

[foo on patrol]

Don't know of any links yet but full Discs front and back for Flying 200mtr qualifying but a spoked or a Zipp 808 for heats. In the Pursuit full front and back works and in the 500mtr & 1000mtr TT. For a Team Sprint, a full front if it is lighter than a 808 spoked or a 3 4 or 5 spoke front. Scratch races and the like, only on the rear. The reason for not using a full Disc on the front in Sprint heats, is due to maneuverability for sudden changes of direction. In the Team Sprint as the lead out rider, it's for the ability to wind up quicker, hence why I said about the weight being the factor and this is what has been told to me by a World Champion Sprinter in the Masters category.

Hope that gives you some help but if you're on FB, join the (https://www.facebook.com/groups/567017906702302) and ask questions.

Foo

[ft_critical]

Don't know of any links yet but full Discs front and back for Flying 200mtr qualifying but a spoked or a Zipp 808 for heats. In the Pursuit full front and back works and in the 500mtr & 1000mtr TT. For a Team Sprint, a full front if it is lighter than a 808 spoked or a 3 4 or 5 spoke front. Scratch races and the like, only on the rear. The reason for not using a full Disc on the front in Sprint heats, is due to maneuverability for sudden changes of direction. In the Team Sprint as the lead out rider, it's for the ability to wind up quicker, hence why I said about the weight being the factor and this is what has been told to me by a World Champion Sprinter in the Masters category.

Hope that gives you some help but if you're on FB, join the (https://www.facebook.com/groups/567017906702302) and ask questions.

Foo

Thanks Foo. I noticed at NSW Masters, everyone except me was on dual discs - hence I asked. As you say also, they kept the rear disc for both scratch and points. So, one could assume - based on this observation - it is faster, but I wonder how much over 2000m? $4000 for 2sec, mmm maybe not, but for 4sec+ maybe...

[foo on patrol]

Don't know of any links yet but full Discs front and back for Flying 200mtr qualifying but a spoked or a Zipp 808 for heats. In the Pursuit full front and back works and in the 500mtr & 1000mtr TT. For a Team Sprint, a full front if it is lighter than a 808 spoked or a 3 4 or 5 spoke front. Scratch races and the like, only on the rear. The reason for not using a full Disc on the front in Sprint heats, is due to maneuverability for sudden changes of direction. In the Team Sprint as the lead out rider, it's for the ability to wind up quicker, hence why I said about the weight being the factor and this is what has been told to me by a World Champion Sprinter in the Masters category.

Hope that gives you some help but if you're on FB, join the (https://www.facebook.com/groups/567017906702302) and ask questions.

Foo

Thanks Foo. I noticed at NSW Masters, everyone except me was on dual discs - hence I asked. As you say also, they kept the rear disc for both scratch and points. So, one could assume - based on this observation - it is faster, but I wonder how much over 2000m? $4000 for 2sec, mmm maybe not, but for 4sec+ maybe...

You need too have your speed up and then you gain the benefit of them. I have the same set of Corima Disc that were used by the Great Britain Team and they are $7000+ to replace but I got them for $1500 and they only had 20klms on them. One of my best mates had them, for his son and a vision impaired rider on a tandem, so I was very lucky. There have been some good buys around for used wheels in the last 6wks and that's, what I would be looking at.

Steele Bishop was selling his Mavic's but I can't remember the price or if he has sold them. Another bloke has/had a set of Mavic's also but with a 5 spoke front, I think it was.

Her's another site that I regularly follow and quiz them about things.

https://www.facebook.com/groups/171635342849338/

[Derny Driver]

UCI rules state that
"In track competition, the use of a front disc wheel is only permitted in the specialities against the clock..."
You cannot use a front disc in Points race, scratch, madison etc.

In my opinion, the ideal set ups are:

Double discs for IP and flying 200. However, handing a front disc at high speed takes quite a lot of practice to master and most people would find that they would have great difficulty holding the black line with double discs, and the poofteenth of a second that the front disc was theoretically going to save them has turned into actual seconds in arrears due to inablilty to follow the line of least distance around the track. The front disc tends to steer you bike to the right when you are trying to keep turning left.

Madisons and points races ( and other races with notable increases and decreases in speed): 5 spoke front and rear. 5-spoke wheels accelerate quicker than a rear disc and are almost as aerodynamic. In a bunch race they are preferable.

All other track events: Rear disc and front 5-spoke or front deep dish. Tried and tested and proved combination.

Rear disc wheels do not have to be expensive. I paid $500 for mine and a mate won a world title on a $300 ancient Zipp950. Aero does not have to be lightweight. Any old rear disc is fairly aero.
Front discs do cost money because they are rather rare.

[ft_critical]

Rear disc wheels do not have to be expensive. I paid $500 for mine and a mate won a world title on a $300 ancient Zipp950. Aero does not have to be lightweight. Any old rear disc is fairly aero.

Thanks DD, Foo. I found, bizarrely, a rear disc for $300 which is in good condition albeit an old model - almost exactly your advice. I will run my deep section on the front. Looks like I will get to try it on th Annadrome!

I guess from here I can do my own performance testing and report back to you all. $300 is fine, but $2000 would have been quite the experiment

[Derny Driver]

Rear disc wheels do not have to be expensive. I paid $500 for mine and a mate won a world title on a $300 ancient Zipp950. Aero does not have to be lightweight. Any old rear disc is fairly aero.

Thanks DD, Foo. I found, bizarrely, a rear disc for $300 which is in good condition albeit an old model - almost exactly your advice. I will run my deep section on the front. Looks like I will get to try it on the Annadrome!

Perfect!!!

[foo on patrol]

Rear disc wheels do not have to be expensive. I paid $500 for mine and a mate won a world title on a $300 ancient Zipp950. Aero does not have to be lightweight. Any old rear disc is fairly aero.

Thanks DD, Foo. I found, bizarrely, a rear disc for $300 which is in good condition albeit an old model - almost exactly your advice. I will run my deep section on the front. Looks like I will get to try it on th Annadrome!

I guess from here I can do my own performance testing and report back to you all. $300 is fine, but $2000 would have been quite the experiment

My first full disc is an old Zipp 950 double side that cost me $220. It's that old that it takes a screw on 7sp cluster for road use. A set of NSK bearings will set you back around $35 but if the ones in there are butter smooth, just ride it.

Foo

[ft_critical]

My first full disc is an old Zipp 950 double side that cost me $220. It's that old that it takes a screw on 7sp cluster for road use. A set of NSK bearings will set you back around $35 but if the ones in there are butter smooth, just ride it.

Foo

Thanks I will look out for your bike when I am in QLD and say hi.

[foo on patrol]

My first full disc is an old Zipp 950 double side that cost me $220. It's that old that it takes a screw on 7sp cluster for road use. A set of NSK bearings will set you back around $35 but if the ones in there are butter smooth, just ride it.

Foo

Thanks I will look out for your bike when I am in QLD and say hi.

Are you coming up for the Masters? I won't be riding, due to an op the weekend before they start.

Foo

[ft_critical]

My first full disc is an old Zipp 950 double side that cost me $220. It's that old that it takes a screw on 7sp cluster for road use. A set of NSK bearings will set you back around $35 but if the ones in there are butter smooth, just ride it.

Foo

Thanks I will look out for your bike when I am in QLD and say hi.

Are you coming up for the Masters? I won't be riding, due to an op the weekend before they start.

Foo

Yes. That's a shame about the op.

[foo on patrol]

Thanks I will look out for your bike when I am in QLD and say hi.

Are you coming up for the Masters? I won't be riding, due to an op the weekend before they start.

Foo

Yes. That's a shame about the op.

Yeah I'm a bit plissed off about it now, even more than before, because it is now a hospital job.

Okay, I will try and get there, just so I can meet you and have a coffee with you.

Foo

[dalai47]

All you want to know about aerodynamics - Aerodynamics of Track Cycling thesis by Lindsey Underwood 298 pages!

https://ir.canterbury.ac.nz/bitstream/h ... sAllowed=y

Haven't focussed on this for some years so recollections below will need confirming.

At zero degrees yaw indoors the shallower Shamal on the front is just as fast as the deeper 808.

Front disc compared to an aero front wheel offers a substantial time benefit per km. Want to say one second per km but will try and find it for you...

On a side note beware the older discs. My first track disc was a Zipp Predator I was gifted - the alloy of the hub reacted to the glue over the last couple of decades and broke the bond. Wasn't a catastrophic failure thankfully (hub just started rotating) and I had it rebonded by Raoul at Luescher Teknik.

[dalai47]

Found comment confirming 1 second per km, but only at steady state. Therefore less benefit in the starting km.

[foo on patrol]

Found comment confirming 1 second per km, but only at steady state. Therefore less benefit in the starting km.

I think the gear sizing now, is the limiting factor in the 1klm TT but probably, not so much in a Pursuit?

Foo

[ft_critical]

Thanks both. Turned out I won't know how much difference it made as they cancelled the event due to the QLD Covid lock down. Will have to wait a while

[dalai47]

Sorry to hear. Now gives you plenty of time to read through the Journal on track Aerodynamics I linked though...

[foo on patrol]

Thanks both. Turned out I won't know how much difference it made as they cancelled the event due to the QLD Covid lock down. Will have to wait a while

New dates.

AusCycling Masters Track National Championships (postponed until 26 - 29 June, 2021)

Foo