I bought some Conti Supersonics in the 650x20 size for my Rocketwing. These were going to be my race tires for 20k time-trials at Fiesta Island which is flat with a good smooth surface.
Well, I’ve had 2 blowouts already. The front tire blew out right after I aired it up with a CO2 cartridge. The other tire blew out after being ridden a couple miles as a back tire. It had been inflated to 160psi.
Continental says the tire can be inflated to 170psi so I’m wondering why they blew. Maybe I’m too heavy at 205lbs to use one as a back tire?
I’m putting my Michelin Ironman 650x23 tires back on for my time-trial tomorrow!
Where are the blow outs happening and what type of wheels are you using?
160psi is probably too high. The number quoted is ~120psi for LOWER rolling resistance, better comfort, and in your case probably less blow outs. The reason for lower rolling resistance at 120psi compared to 160psi has been discussed extensively before. The tire rating is not the only limiter of tire pressure. The rim manufacturer sometimes specifies a max pressure that their wheel can handle.
That would be my guess. I dont have much experience with HED3 wheels though. You might check their website and see what their max pressure recommendation is.
I feel that you are too heavy for the delicate 20mm supersonics. I’ve had the same results that you had and I’m 145lbs.
Your pressure was correct, there are many that don’t agree with the tire pressure discussions that were mentioned. With that narrow of a tire, a higher pressure is needed to hold the sidewall up since it is so small.
The Michelins that you mentioned are very fast tires and with that width (23mm), 120psig is probably all that you will need.
I have used supersonics a lot and never had a blowout. They do wear out more quickly. I do inflate them anywhere from 120-160 psi. At around 120 psi they don’t corner as well as at higher pressures. I suspect you are either blowing them off the rims, or there is a burr or something in the rim puncturing the tube. I have had other tires blow off a specialized tri-spoke, maybe the rims are smaller.?.
yeah, I gotta say that maybe you should try something else. supersonics are sweet by the numbers but something a little more durable might be a good call for racing on the open road. Now blowing off when you inflated them, that’s definetely something wrong there. Do your rims let other tires blow off as well? Could be the rims but I’m guessing it’s the tires.
Does anyone else here use Supersonics? I’m not putting you down for it, just asking. I’ve never actually seen anyone that I’ve raced with use the supersonics, GP3000s are all over the place as are the Attack tires from Conti. I thought supersonics were more of a track tire if anything.
Funny thing is, supersonics actually have pretty poor rolling resistance to begin with. There are cheap sturdy tires you can buy from Nashbar or Performance that roll much better.
Actually what happened to mine was I ran over some small rocks and pinched the tube because I only had 120psig in them. I feel that if I had more pressure in them I wouldn’t have had the problem, (or not hit that small rock!)
I’m glad they work for you, it’s possible that my rim selection was wrong. The rim it was on was slightly wider than my Alex 300’s. They were on a FIR SRG 30.
I was pretty excited about running a new fast racing tire and was dissapointed with my personal results. I think Conti makes some very good tires, some of which I am very happy with.
Actually what happened to mine was I ran over some small rocks and pinched the tube because I only had 120psig in them. I feel that if I had more pressure in them I wouldn’t have had the problem, (or not hit that small rock!)
I race on Continental Supersonics (20 mm). I ride them on a smooth asphalt parkway road surface. No potholes and almost no loose gravel. Yes, there are a few rough patches that I hate to ride through but what are you gunna do?
I weigh 175-180 lbs and pump the tires up to 170-175 psi. I run the tires on Hed3 trispokes, a Renn 575 disc and on Rolf Vector Pros. I have not ever had one blow off my rim. In fact, I have never had a flat on one, knock on wood.
Now I am not advocating anyone follow my lead pressure wise. I am just communicating that I think something else is the issue here other than the rider’s weight in jshelton’s case.
First, you shouldn’t be using anything other than Velox rim tape. Period. If there is anything else on there other than Velox tape, change it. Especially as you increase tire pressure above 120 psi.
Are you just getting flats or are the tires/tubes exploding? The only time a tire will explode is when the casing fails or is compromised. Then the tire is trash. Since you have not questioned how poorly constructed you believe these tires to be, I will assume you are just having tube failures.
When you check the tube, is there an uneven tear in the tube (jagged) or does it run along the seam of the tube? If hole in the tube runs along the seam of the tube, then you have some tubes from a bad lot. Use different tubes. Problem should be solved.
If the tube is failing at the valve stem, You could still have tubes that were defective at the valve stem. Or, you cold have an issue with your rim’s valve stem opening.
When you mounted the tire on the rim before you experienced the failure, was the tire properly/evenly mounted on the rim? The easy way to determine this after you replace a tube/tire is to simply spin the wheel and look to see if the tread wobbles from side to side or if the tire hops up and down. It is most unusual for a tube to expand out from under the bead of an improperly mounted tire, fail/explode and then have the tire remount itself so that it appears the tire was properly mounted in the first place.
What I heard is a pop like a tube blowing out. The tire was still on the rim and I couldn’t find any tire damage. The tube had a small split. Oh well, I used my Ironmans yesterday and felt they were fine. Frankly, right now the biggest performance improvement I can make is to upgrade the ‘motor’ on my bike! I’m working on it…
Last 2 rows at the bottom. At 130 psi, the rolling resistance is a little higher than it is for a Corsa CX, a much, much beefier tire; and it’s vastly greater than for the Michelin Axial Supercomp - a tire that can be purchased for $7.00.