Login required to started new threads

Login required to post replies

Prev Next
Re: Would you race on this cut tire? [longtrousers] [ In reply to ]
Quote | Reply
TT rolls faster than the 5000 and while the 5000 is more aerodynamic, combining rolling and aero results, the TT is the faster tire.

https://www.aero-coach.co.uk/gp-5000-data

-------------
Ed O'Malley
www.VeloVetta.com
Founder of VeloVetta Cycling Shoes
Instagram • Facebook
Quote Reply
Re: Would you race on this cut tire? [RowToTri] [ In reply to ]
Quote | Reply
RowToTri wrote:
TT rolls faster than the 5000 and while the 5000 is more aerodynamic, combining rolling and aero results, the TT is the faster tire.

https://www.aero-coach.co.uk/gp-5000-data


1.4W for two tires at 45 kph. For St. George chipseal I'd take the 5000.
Last edited by: trail: Apr 29, 19 7:25
Quote Reply
Re: Would you race on this cut tire? [trail] [ In reply to ]
Quote | Reply
trail wrote:
RowToTri wrote:
TT rolls faster than the 5000 and while the 5000 is more aerodynamic, combining rolling and aero results, the TT is the faster tire.

https://www.aero-coach.co.uk/gp-5000-data


1.4W for two tires at 45 kph. For St. George chipseal I'd take the 5000.

And 2.5w at 35kph. I would think that chipseal would increase the TT's advantage because it will increase rolling resistance. Chipseal itself won't puncture a tire.... Extra debris would be a different matter but last year the roads seemed pretty clean.

-------------
Ed O'Malley
www.VeloVetta.com
Founder of VeloVetta Cycling Shoes
Instagram • Facebook
Quote Reply
Re: Would you race on this cut tire? [RowToTri] [ In reply to ]
Quote | Reply
I love how athletes will dump hundreds of hours, thousands of dollars, and so much effort into racing. And yet I'm shocked at how many people will get to a race and think "meh, I'll just see if this old tire will work out ok."

Get a new tire.
Quote Reply
Re: Would you race on this cut tire? [RowToTri] [ In reply to ]
Quote | Reply
RowToTri wrote:
And 2.5w at 35kph. I would think that chipseal would increase the TT's advantage because it will increase rolling resistance. Chipseal itself won't puncture a tire.... Extra debris would be a different matter but last year the roads seemed pretty clean.

I guess. Though I'd run tubeless Corsa Speeds at 70PSI. My worst day on a bike ever was doing the St George full on 19mm tires pumped to 140PSI. The vibration from the chipseal pretty much destroyed my will to live. (this was ages ago when conventional wisdom was high pressure was better).
Quote Reply
Re: Would you race on this cut tire? [RowToTri] [ In reply to ]
Quote | Reply
The road out from t1 is fairly rough... No way would I use that tire...
Quote Reply
Re: Would you race on this cut tire? [trail] [ In reply to ]
Quote | Reply
haha... either way I'll be on 23's at around 88psi.

Corsa Speeds are even more fragile than TT's.....

-------------
Ed O'Malley
www.VeloVetta.com
Founder of VeloVetta Cycling Shoes
Instagram • Facebook
Quote Reply
Re: Would you race on this cut tire? [RowToTri] [ In reply to ]
Quote | Reply
RowToTri wrote:
TT rolls faster than the 5000 and while the 5000 is more aerodynamic, combining rolling and aero results, the TT is the faster tire.

https://www.aero-coach.co.uk/gp-5000-data

Here
https://www.bicyclerollingresistance.com/...grand-prix-5000-2018
the difference is tiny .1 W
Quote Reply
Re: Would you race on this cut tire? [RowToTri] [ In reply to ]
Quote | Reply
RowToTri wrote:
haha... either way I'll be on 23's at around 88psi.

Corsa Speeds are even more fragile than TT's.....

Not in my experience. I haven't flatted a CS in 2 years. Had trouble with Supersonics prior. Plus tubeless solves a ton of risk.
Quote Reply
Re: Would you race on this cut tire? [RowToTri] [ In reply to ]
Quote | Reply
For all of you who say its dangerous to ride that tire, what would you do if this happened to your front tire in the first 10 miles of an Ironman? To be consistent you'd have to DNF.....right? As others have said, if the threads are undamaged boot it, super glue it and put it on the back. As I said, I have booted a couple in the mountains of NC & VA and continued to ride on.
Quote Reply
Re: Would you race on this cut tire? [RowToTri] [ In reply to ]
Quote | Reply
I'd not risk it. I saw this come up a lot, when I wrenched at an age group worlds a few years back (raced too). In the final sessions before bike check in the day before, we got asked this very question by a handful of athletes. I believe my answer was "You are perfectly entitled to do as you pleased, but I can tell you for sure that I would replace my tire in that case, I wouldn't roll the dice on my race over something preventable like that.. it might be fine, but it might not..." The follow up question was always around supergluing it... Again, for getting through some training rides until you can get to the LBS or order some new tires, sure... for an A race, hell no. especially in this case, since the forecast still had a chance of it being wet on race day... We literally had a pile of brand new race tires there, that we were giving them a substantial discount on too...

I was shocked at the number of tires I was changing a day or two out from a world championship race, and the number of people considering gambling on cut or worn out tires... I personally would have checked the rubber before traveling, and if there was anything questionable dealt with it then, so I could get a few tides in to break in the tires... I used to save the tubes with the nicks/cuts in them for trainer riding before I switched to a direct drive trainer...
Quote Reply
Re: Would you race on this cut tire? [longtrousers] [ In reply to ]
Quote | Reply
Those are 25's not 23's.

-------------
Ed O'Malley
www.VeloVetta.com
Founder of VeloVetta Cycling Shoes
Instagram • Facebook
Quote Reply
Re: Would you race on this cut tire? [trail] [ In reply to ]
Quote | Reply
trail wrote:
RowToTri wrote:
haha... either way I'll be on 23's at around 88psi.

Corsa Speeds are even more fragile than TT's.....


Not in my experience. I haven't flatted a CS in 2 years. Had trouble with Supersonics prior. Plus tubeless solves a ton of risk.

I'm actually wondering right now if the 5000 in front and TT in back might be the fastest setup. The aerocoach test assumes both tires have the same weight on them and are exposed to the same wind. There is significantly more weight on the rear tire, and the rear tire is shrouded. So the 5000 with slightly higher rolling resistance will have less weight on it so rolling resistance will matter less, and it will get maximum benefit from its aeroness. The TT in the back will have more weight on it, so Crr is more important and it will be shrouded so it's lack of aero will not be a big deal.

-------------
Ed O'Malley
www.VeloVetta.com
Founder of VeloVetta Cycling Shoes
Instagram • Facebook
Quote Reply
Re: Would you race on this cut tire? [RowToTri] [ In reply to ]
Quote | Reply
RowToTri wrote:
trail wrote:
RowToTri wrote:
haha... either way I'll be on 23's at around 88psi.

Corsa Speeds are even more fragile than TT's.....


Not in my experience. I haven't flatted a CS in 2 years. Had trouble with Supersonics prior. Plus tubeless solves a ton of risk.


I'm actually wondering right now if the 5000 in front and TT in back might be the fastest setup. The aerocoach test assumes both tires have the same weight on them and are exposed to the same wind. There is significantly more weight on the rear tire, and the rear tire is shrouded. So the 5000 with slightly higher rolling resistance will have less weight on it so rolling resistance will matter less, and it will get maximum benefit from its aeroness. The TT in the back will have more weight on it, so Crr is more important and it will be shrouded so it's lack of aero will not be a big deal.

That sounds reasonable!
Quote Reply
Re: Would you race on this cut tire? [HuffNPuff] [ In reply to ]
Quote | Reply
HuffNPuff wrote:
Definitely remove it for a careful inspection inside and out. If otherwise ok, superglue it and race.

Interesting. I typically put a patch of duct tape from the inside to patch a tire with a small cut. And that works to keep an inner tube from bulging out of a tire cut.

But combining that approach supergluing the tread cut on the outside is a great idea. Does superglue do a good job of actually holding the tread together in your experience? Even when the tire is running higher pressures? How does the superglue hold up after few hundred miles on the 'fixed' tire?

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook

--
Quote Reply
Re: Would you race on this cut tire? [DarkSpeedWorks] [ In reply to ]
Quote | Reply
Superglue is pretty well useless IME. Doesn't last and doesn't keep the tread together.
Quote Reply
Re: Would you race on this cut tire? [RowToTri] [ In reply to ]
Quote | Reply
As others have mentioned, if the threads are not cut, then I'd probably still use it as a training tire on the back wheel. Probably wouldn't race on it assuming I have a halfway decent tire on hand or can get my hands on one before race day. Tires are not meant to last forever anyway...you will eventually have to buy new ones, so it's not a total sunk cost to replace it now.
Quote Reply
Re: Would you race on this cut tire? [DarkSpeedWorks] [ In reply to ]
Quote | Reply
Although there is a contrary opinion above, in my experience, super glue in a small cut has held up for 100s of miles. It doesn't so much as hold the tire together as it fills the crack. I've never had one reopen where I used superglue. If it does, then in my opinion, it was too big of a cut to save the tire to begin with.

E.g., I had a pair of new tires with a single cut on the rear wheel I discovered the day before Augusta 70.3. I superglued the cut and went through the race just fine. Then I lent that wheelset to a friend doing Kona - pointing out the cut. He rode the tires at Kona without incident. I continued using them for minor races for many miles.

Try this on any pair of old tires if you want to convince yourself. The main objective in my view is to fill the crack so it doesn't pick up anything that might push through the remainder of the way.
Quote Reply
Re: Would you race on this cut tire? [Trauma] [ In reply to ]
Quote | Reply
Trauma wrote:
I'd not risk it. I saw this come up a lot, when I wrenched at an age group worlds a few years back (raced too). In the final sessions before bike check in the day before, we got asked this very question by a handful of athletes. I believe my answer was "You are perfectly entitled to do as you pleased, but I can tell you for sure that I would replace my tire in that case, I wouldn't roll the dice on my race over something preventable like that.. it might be fine, but it might not..." The follow up question was always around supergluing it... Again, for getting through some training rides until you can get to the LBS or order some new tires, sure... for an A race, hell no. especially in this case, since the forecast still had a chance of it being wet on race day... We literally had a pile of brand new race tires there, that we were giving them a substantial discount on too...

I was shocked at the number of tires I was changing a day or two out from a world championship race, and the number of people considering gambling on cut or worn out tires... I personally would have checked the rubber before traveling, and if there was anything questionable dealt with it then, so I could get a few tides in to break in the tires... I used to save the tubes with the nicks/cuts in them for trainer riding before I switched to a direct drive trainer...

I always buy brand new tires for a destination "A" race, but there is a huge difference in supergluing a small nick in a brand new tire that you sadly picked up when breaking them in the first 50 miles versus supergluing tires that have 2,000 or more miles on them for that same race. When I did IM Norway last year, there was an American complaining about the lack of tech support on the course because he blew a tire on a section of road that was being regraded and was unable to finish. I asked about the age of his tires and I think I recall he said about 18 months or so. New tires are a very small form of insurance when you are spending so much money just to get to a race. So I agree with what you are saying in general, but if the tire is new, supergluing a single nick is not a big deal. If the tire has nicks all over it, that's a sign that it's ready for training use only.
Quote Reply
Re: Would you race on this cut tire? [HuffNPuff] [ In reply to ]
Quote | Reply
HuffNPuff wrote:
I always buy brand new tires for a destination "A" race, but there is a huge difference in supergluing a small nick in a brand new tire that you sadly picked up when breaking them in the first 50 miles versus supergluing tires that have 2,000 or more miles on them for that same race. When I did IM Norway last year, there was an American complaining about the lack of tech support on the course because he blew a tire on a section of road that was being regraded and was unable to finish. I asked about the age of his tires and I think I recall he said about 18 months or so. New tires are a very small form of insurance when you are spending so much money just to get to a race. So I agree with what you are saying in general, but if the tire is new, supergluing a single nick is not a big deal. If the tire has nicks all over it, that's a sign that it's ready for training use only.

Jesus, I hope these folks are in my age group... I've seen the same, someone bemoaning the lack of tech support after starting the race on bald tires (like howie mandel bald...)... Shit happens in race, no matter how prepared you are, but the least you can do is to at least control what you can control to minimize the chances of shit happening... case and point, the one and only time I didn't bring a spare pair of running shoes with me to a race was the time that someone "borrowed" my shoes for the run from transition and I was left running off the bike barefoot... it's a mistake that I've never made again...

When I was wrenching at worlds, there were folks considering racing tires that were worn through the tread down to the core of the tire... (clearly that have ridden the tires for a season or two, including at least one winter on a trainer looking at the ware pattern...). Fair point though about superglue on a nick in a new tire, with the caveat that the race would be dry, since I've seen pile-ups in crits caused by someone racing on a superglued tire where it slid out because of the wet... It's crappy when you damage brand new tires (years back, I had new rubber installed to start the season and literally picked up my bike from the shop and was riding from there to the Crit I was racing that evening (the colors even matched my frame and everything), I flatted about mid-way between, with a 2" screw that went right through my tire... needless to say I didn't race that night, and was buying a new, new tire the next day...
Quote Reply
Re: Would you race on this cut tire? [RowToTri] [ In reply to ]
Quote | Reply
RowToTri wrote:
Those are 25's not 23's.

That's exactly what I did last weekend: I exchanged my 23mm tt for a 25 mm 5000. I measured the width on both at 7,5 bar: the 25 mm 5000 is even a tiny bit narrower than the 23 tt. And 1 mm higher, which furthermore should improve puncture resistance.
Quote Reply
Re: Would you race on this cut tire? [longtrousers] [ In reply to ]
Quote | Reply
I would definitely ride and race that tire. Take it off, clean it up, patch if needed - superglue if needed, use a bunch of chalk with the latex tube. If that's a tubeless tire, it might be trashed...
Inflating it at race pressure will tell you if it's going to bulge out and pop.
If you are concerned about getting punctured in the puncture the odds are in your favor (1/360th of how much time you spend leaning on that side....)
Quote Reply
Re: Would you race on this cut tire? [longtrousers] [ In reply to ]
Quote | Reply
longtrousers wrote:
RowToTri wrote:
Those are 25's not 23's.


That's exactly what I did last weekend: I exchanged my 23mm tt for a 25 mm 5000. I measured the width on both at 7,5 bar: the 25 mm 5000 is even a tiny bit narrower than the 23 tt. And 1 mm higher, which furthermore should improve puncture resistance.

Thanks. I came looking for Crr info on the 5000 vs. the TT. I have been using a 23mm TT in the rear on my Zipp Clincher Disc (2006). Looks like from your experience I could move up to the 25s in the 5000 for less Crr and still be narrower.

In the straight up comparison of 23s in the 5000 and TT used in the AeroCoach analysis linked above the 5000 was about 1.5W slower @90 psi (Crr part of their analysis only). The http://www.bicyclerollingresistance.com compared 25s of the 5000 and TT and found that the 5000 was only a .2 watts slower @ 100 psi.

For the extra durability of the 5000 the difference seems like a no-brainier even before considering that the 5000 is that much narrower that I can run 25s and save Crr vs the TT in 23s.

I will stick with Supersonic 20s for my front. From an aero standpoint it mates really well with my old style Zipp 808 Aluminum Rim Clincher.
Quote Reply
Re: Would you race on this cut tire? [longtrousers] [ In reply to ]
Quote | Reply
longtrousers wrote:
RowToTri wrote:
Those are 25's not 23's.


That's exactly what I did last weekend: I exchanged my 23mm tt for a 25 mm 5000. I measured the width on both at 7,5 bar: the 25 mm 5000 is even a tiny bit narrower than the 23 tt. And 1 mm higher, which furthermore should improve puncture resistance.

I just got around to swapping out my 23mm TT for new 25mm 5000. At 100 psi the 25 5000 was about .5 mm wider than the 33 TT. I don't have a digital caliper so approximating on the .5 mm but definitely had to go a bit wider to slide the caliper over the tire. Its a rear so even a smidge wider won't effect it too much.

Now to figure what I want to run the 25s at for psi. I've been running 95 for the 23 TT. Wish I could remember what I used last year for the Supersonic 20 on the front wheel (narrow rim)!
Quote Reply
Re: Would you race on this cut tire? [Stelvio] [ In reply to ]
Quote | Reply
When I was a boy, we used to race on tires which were more cuts than tires and we loved it. Our tires had so many cuts that there were no room for any more cuts so we couldn’t get any more cuts or punctures.
We also used to live in cardboard boxes on freeway on ramps. We used to get up before we went to bed and do 29 hrs of training before school in the morning.
Sure, it was tough, but those were hard days...
Quote Reply

Prev Next