Front blowout, bad crash!! any thoughts on prevention?

[millzebub]

okay. So I was enjoying the amazing weather hear in the SF bay area yesterday. I was on my way home down a very fast descent and inexplicably my front tire blew out with a bang! I was going 38mph. I now have a lot of road rash and a broken collar bone. Needless to say, I am bummed out. I was going to race this weekend. Arrgh!

Anyway, has anyone hear experienced this type of blowout? My friend said my tubes may have been over inflated. I thought riding the front brake may have caused a lot of heat that caused the tube to pop. The tire seems fine while the tube is split down the center for at least 18 inches along it length. Any thoughts? I really would like to prevent this from happening again in 4 to 6 weeks

 

[kennf]

okay. So I was enjoying the amazing weather hear in the SF bay area yesterday. I was on my way home down a very fast descent and inexplicably my front tire blew out with a bang! I was going 38mph. I now have a lot of road rash and a broken collar bone. Needless to say, I am bummed out. I was going to race this weekend. Arrgh!

Anyway, has anyone hear experienced this type of blowout? My friend said my tubes may have been over inflated. I thought riding the front brake may have caused a lot of heat that caused the tube to pop. The tire seems fine while the tube is split down the center for at least 18 inches along it length. Any thoughts? I really would like to prevent this from happening again in 4 to 6 weeks

That's scary. I assume clinchers? What kind, and what psi did you have them inflated to?

 

[wiredued]

Sounds like the bead on your tire was seperating allowing the tube to escape...old tires maybe. BTW I just bought some Specialized Armadillo Elites can't wait for the snow to melt so I can use them. Armadillo tires are probably the best flat protection you can get.

okay. So I was enjoying the amazing weather hear in the SF bay area yesterday. I was on my way home down a very fast descent and inexplicably my front tire blew out with a bang! I was going 38mph. I now have a lot of road rash and a broken collar bone. Needless to say, I am bummed out. I was going to race this weekend. Arrgh!

Anyway, has anyone hear experienced this type of blowout? My friend said my tubes may have been over inflated. I thought riding the front brake may have caused a lot of heat that caused the tube to pop. The tire seems fine while the tube is split down the center for at least 18 inches along it length. Any thoughts? I really would like to prevent this from happening again in 4 to 6 weeks

 

[TheDarkLord]

okay. So I was enjoying the amazing weather hear in the SF bay area yesterday. I was on my way home down a very fast descent and inexplicably my front tire blew out with a bang! I was going 38mph. I now have a lot of road rash and a broken collar bone. Needless to say, I am bummed out. I was going to race this weekend. Arrgh!

Anyway, has anyone hear experienced this type of blowout? My friend said my tubes may have been over inflated. I thought riding the front brake may have caused a lot of heat that caused the tube to pop. The tire seems fine while the tube is split down the center for at least 18 inches along it length. Any thoughts? I really would like to prevent this from happening again in 4 to 6 weeks

How long was the descent? Any possibility that the rim overheated from braking? That could also cause a blowout.

 

[millzebub]

That's scary. I assume clinchers? What kind, and what psi did you have them inflated to?

Yes, clinchers. Specialized presta turbo tube - 700 x 18/25. I usually inflate to 120 psi. I guess the pain killers are working, I misspelled "here" as hear. oops...

 

[millzebub]

Sounds like the bead on your tire was seperating allowing the tube to escape...old tires maybe. BTW I just bought some Specialized Armadillo Elites can't wait for the snow to melt so I can use them. Armadillo tires are probably the best flat protection you can get.

the tires are not that old, but maybe they are worn. they look ok to me. they are continental gp 4000's. I had vittoria tires before and they fell apart, after two crashes.

 

[millzebub]

How long was the descent? Any possibility that the rim overheated from braking? That could also cause a blowout.

it is a couple of miles, but I was less than halfway down. I think the rim could definitely have been over heating. this is the kind of descent where it's hard not to go over 30mph. I was riding my front brake with less on the rear. Maybe I should rethink that technique...

 

[sogood]

How heavy are you? 120psi is a tad high if you are just average weight. But I agree with others above, you've probably overheated the rim and induced that blowout. Incorrect tyre mounting is another possibility. For tubular tyre riders, overheating a rim can soften the glue on tubular tyres and allow it to roll off too.

 

[kennf]

If there's no hole in the tire itself, then something else is going on, like the bead not seating properly (as someone else said). I never go to 120 psi for training rides. I'm usually closer to 105--seems to cut down on flats. Descents can blow a tire from overheating, but yours doesn't sound long enough. I've blown out clinchers before, but not for a long time, and it was a combination of low quality tire and a road hazard. But on those occasions the tire itself was destroyed. Back in the old days, when everyone was on sewups, seems like there was a blowout in every crit. Sounded like a gunshot.

 

[dhk2]

Sorry for the crash MB, but agree overheating of the rim combined with high inflation pressures is the likely cause. Back in the 90s when I used to inflate tires to max all the time, I had a tube blowout just from sitting in the sun while I had lunch.

120 psi is "max rated" sidewall pressure for the 4000s; the box "recommends" 110 psi, and nothing says you need to use that, particularly in front. I saw a test report that showed only a small in RR when dropping all the way down to 85 psi.

Suggest 100-105 psi is plenty on front for training or racing, unless you're a heavy-weight who should be on 25s or 28s anyway. For high-speed descents, you'll go faster with more safety (and less braking) at 100 psi, rather than bouncing off the road with rock-hard tires. Plus, you'll have 20 psi margin to allow for the heat of braking.

Rather than drag the brakes, I try to let speed build up whenever possible on straights, then braking firmly just before the turn entrance. You can slow the bike pretty quickly while still upright, then release the levers as you're leaning in to carve through. It's the faster way down, and may allow for more cooling of the rims.

 

[millzebub]

Sorry for the crash MB, but agree overheating of the rim combined with high inflation pressures is the likely cause. Back in the 90s when I used to inflate tires to max all the time, I had a tube blowout just from sitting in the sun while I had lunch.

120 psi is "max rated" sidewall pressure for the 4000s; the box "recommends" 110 psi, and nothing says you need to use that, particularly in front. I saw a test report that showed only a small in RR when dropping all the way down to 85 psi.

Suggest 100-105 psi is plenty on front for training or racing, unless you're a heavy-weight who should be on 25s or 28s anyway. For high-speed descents, you'll go faster with more safety (and less braking) at 100 psi, rather than bouncing off the road with rock-hard tires. Plus, you'll have 20 psi margin to allow for the heat of braking.

Rather than drag the brakes, I try to let speed build up whenever possible on straights, then braking firmly just before the turn entrance. You can slow the bike pretty quickly while still upright, then release the levers as you're leaning in to carve through. It's the faster way down, and may allow for more cooling of the rims.

Thanks to everyone for the helpful responses. To answer an earlier question, I currently weigh 190lbs. I think my weight combined with over inflation and heat on the rims made for a bad day. I've been riding and descending with that combo for some time though. I guess the tube couldn't take the pressure any more

When I get back on the road I will definitely lower the pressure on my tires and try to brake more efficiently rather than keeping a death grip throughout the descents.

thanks again,
john

 

[daveryanwyoming]

....When I get back on the road I will definitely lower the pressure on my tires and try to brake more efficiently rather than keeping a death grip throughout the descents....

John, Lot's of good advice above.

Tire pressure doesn't have to be maxed out and in most cases running a bit lower tire pressure actually results in lower rolling resistance. Yeah, that's not intuitive, hard tires feel fast because they jump and bounce at every ripple in the pavement but slightly softer tires roll faster in most structured tests. Visit conti's website for recommendations based on weight, Michelin tends to print that right on the packages for their high end tires.

Also double check for pinched tubes when pumping up tires, a quick reseating of the bead with about 20 psi in the tires is a good habit to get into before pumping them all the way up. And of course check the usual suspects including bad rim tape(flats from the spoke holes), old tires, sidewall slashes, etc.

But the big thing is to use brakes like you would in a car, not all that much and only to maintain a safe speed into corners or in heavy traffic. A hard grip on the front brake all but guarantees a crash in the event of a front blowout. I've had a few front flats on fast descents including a few in your neck of the woods like screaming down South Park road in the Tilden Park, on Tunnel road or out on the Bear Creek loop and it hasn't taken me down yet(knock on wood). Sure it's scary, but if you're not actually heeled over into a corner and you aren't locking up the front brake you can usually roll it to a stop without crashing. The key is not to panic and to have a firm but relaxed grip on the bars, the front end will go crazy with wobbles and you've got to get it under control fast but you can ride out a lot of fast front flats if you've got a bit of straightaway to work with.

You live in a great place to work on descending, countersteering in the corners and overall bike handling at speed. Practice on Tunnel Road, Wildcat Canyon, Redwood Road and all the other fantastic descents right in your back yard. It will get easier with practice and you'll use less and less braking while still being able to hold a safe line in the turns.

Good luck,
Dave

 

[millzebub]

John, Lot's of good advice above.

Tire pressure doesn't have to be maxed out and in most cases running a bit lower tire pressure actually results in lower rolling resistance. Yeah, that's not intuitive, hard tires feel fast because they jump and bounce at every ripple in the pavement but slightly softer tires roll faster in most structured tests. Visit conti's website for recommendations based on weight, Michelin tends to print that right on the packages for their high end tires.

Also double check for pinched tubes when pumping up tires, a quick reseating of the bead with about 20 psi in the tires is a good habit to get into before pumping them all the way up. And of course check the usual suspects including bad rim tape(flats from the spoke holes), old tires, sidewall slashes, etc.

But the big thing is to use brakes like you would in a car, not all that much and only to maintain a safe speed into corners or in heavy traffic. A hard grip on the front brake all but guarantees a crash in the event of a front blowout. I've had a few front flats on fast descents including a few in your neck of the woods like screaming down South Park road in the Tilden Park, on Tunnel road or out on the Bear Creek loop and it hasn't taken me down yet(knock on wood). Sure it's scary, but if you're not actually heeled over into a corner and you aren't locking up the front brake you can usually roll it to a stop without crashing. The key is not to panic and to have a firm but relaxed grip on the bars, the front end will go crazy with wobbles and you've got to get it under control fast but you can ride out a lot of fast front flats if you've got a bit of straightaway to work with.

You live in a great place to work on descending, countersteering in the corners and overall bike handling at speed. Practice on Tunnel Road, Wildcat Canyon, Redwood Road and all the other fantastic descents right in your back yard. It will get easier with practice and you'll use less and less braking while still being able to hold a safe line in the turns.

Good luck,
Dave

Hey Dave,
thanks for the reply. Yes, there are some great descents around here! Sometimes I like to think of just riding on a flat surface for a while. I think I might do okay My usual descent is tunnel road but this crash happened coming down claremont. It was only my third time so I think I was riding the brakes due to my lack of experience with the turns. Ya know, I don't think I was on the brakes when the blow out happened. There was just a loud bang and then I was sliding on the asphalt. I hope that any future front blowouts are less "exciting" than this one. I will be working hard to implement all the good advice I've received as soon as I get back out there. Somebody just told me that a friend of theirs was back on the bike 4 days after braking their collar bone! I guess I will see what happens.
thanks,
John

 

[kopride]

it is a couple of miles, but I was less than halfway down. I think the rim could definitely have been over heating. this is the kind of descent where it's hard not to go over 30mph. I was riding my front brake with less on the rear. Maybe I should rethink that technique...

If you're honest with yourself, you may realize that you were just braking with the front, it is a bad habit we sometimes get into, particularly with the new combined brake/shifter levers. A lot of us have our left hand, or fingers ready to brake on the front, and our right hand in a position more conducive to shifting, than rear braking. From motorcycles, I learned and now out of habit always brake with front and rear, even on a bicycle. (It is different b/c on a mc your rear brake is a foot brake, but it is the same type of training, keep your hand (or foot) in a position ready to rear brake ) Although most of your braking power comes from the front, the rear brake is critical for keeping the bike under control and stable. If If you are riding the front brake on a descent, if you hit a pothole, suffer a blowout, or hit any obstruction, you are going to do an endo. It is a natural reaction to tense up in panic, and if you have your hand on the front brake, at speed, going downhill, and your weight shifts too far forward, Newton's laws take over and you will be over the bars. Learn to brake with both hands together always, once you really get the hang of two hand braking, play around with a mountain bike and experiment with varying the braking between front and rear. You will see that braking can really alter how the bike handles. The textbook response to a front tire blowout is to brake lightly with the rear, keep the bike straight and upright, and don't touch the front brake at all. You can still crash, but an endo is less likely. It has to be pretty natural, is not something that you want to figure out in a panic situation. If you have trained yourself to shift, then immediately move your hand back into braking position, you are more likely to bring yourself to a safe stop next time. Sorry, enjoy the oxycodone during your recovery.

 

[Felt_Rider]

kopride, that was pretty accurate for my demise back in September, but I purposely did an endo in the last milliseconds because I could not slow down enough and was headed toward the trees at 40 mph. It was either put the bike down or head into a big oak. I think the oak would have won.

My experienced friends told me those are the type of things that you a better rider. What a painful way of learning, but I do find myself braking much like your description now. Before I was a bit more care free and it cost me big time.

Millzebub, though I did not break my collar bone I did have a grade 3 shoulder separation and severe road rash just about everywhere. I was back on the spin bike a few days later and did a group ride the following week. My group did a flat ride so that I could place less of my body weight on the bars and stay somewhat neutral to keep the pressure off my shoulder as much as possible. I don't know if you can be that progressive, but I bet you can still use a trainer even if lightly just to keep from totally detraining.

 

[jsirabella]

Let me ask a totally off topic question, what is it with crashes and collar bones? It seems everytime someone describe a crash it is always a broken collar bone combined with road rash usually facial...is there something in the way we ride that could be corrected or equipment developed to prevent it?

-Js

John, Lot's of good advice above.

Tire pressure doesn't have to be maxed out and in most cases running a bit lower tire pressure actually results in lower rolling resistance. Yeah, that's not intuitive, hard tires feel fast because they jump and bounce at every ripple in the pavement but slightly softer tires roll faster in most structured tests. Visit conti's website for recommendations based on weight, Michelin tends to print that right on the packages for their high end tires.

Also double check for pinched tubes when pumping up tires, a quick reseating of the bead with about 20 psi in the tires is a good habit to get into before pumping them all the way up. And of course check the usual suspects including bad rim tape(flats from the spoke holes), old tires, sidewall slashes, etc.

But the big thing is to use brakes like you would in a car, not all that much and only to maintain a safe speed into corners or in heavy traffic. A hard grip on the front brake all but guarantees a crash in the event of a front blowout. I've had a few front flats on fast descents including a few in your neck of the woods like screaming down South Park road in the Tilden Park, on Tunnel road or out on the Bear Creek loop and it hasn't taken me down yet(knock on wood). Sure it's scary, but if you're not actually heeled over into a corner and you aren't locking up the front brake you can usually roll it to a stop without crashing. The key is not to panic and to have a firm but relaxed grip on the bars, the front end will go crazy with wobbles and you've got to get it under control fast but you can ride out a lot of fast front flats if you've got a bit of straightaway to work with.

You live in a great place to work on descending, countersteering in the corners and overall bike handling at speed. Practice on Tunnel Road, Wildcat Canyon, Redwood Road and all the other fantastic descents right in your back yard. It will get easier with practice and you'll use less and less braking while still being able to hold a safe line in the turns.

Good luck,
Dave

 

[TheDarkLord]

Let me ask a totally off topic question, what is it with crashes and collar bones? It seems everytime someone describe a crash it is always a broken collar bone combined with road rash usually facial...is there something in the way we ride that could be corrected or equipment developed to prevent it?

-Js

First look at the posture when riding a road bike. Then, look at what happens when a crash causes the rider to go over the handlebars. Such crashes do have a predilection to break the collar bone. Road rash is different. It is just that asphalt is a somewhat harsh surface, and even a fall from standstill (e.g. when you are new to clipless pedals) can give rise to pretty nasty road rash.

 

[jsirabella]

I know what you are saying and I am sure with road rash it is very hard to prevent but I am sure if someone put enough R&D money behind it they could find a fabric
that would be tougher and yet flexible enough for racing to avoid severe road rash. It seems they always seem to worry just about comfort more when it comes to fabric, why not safety?

I agree that it is a postion issue so maybe a piece of very light equipment can be developed to limit the breaking of the collarbone while not giving up too much flexability to the rider.

Just an idea but can be possible??? I see no reason to not try to give max safety to the rider while stil allowing him to get max speed and handling just like a car.

-Js

First look at the posture when riding a road bike. Then, look at what happens when a crash causes the rider to go over the handlebars. Such crashes do have a predilection to break the collar bone. Road rash is different. It is just that asphalt is a somewhat harsh surface, and even a fall from standstill (e.g. when you are new to clipless pedals) can give rise to pretty nasty road rash.

 

[Felt_Rider]

I know what you are saying and I am sure with road rash it is very hard to prevent but I am sure if someone put enough R&D money behind it they could find a fabric
that would be tougher and yet flexible enough for racing to avoid severe road rash. It seems they always seem to worry just about comfort more when it comes to fabric, why not safety?

I agree that it is a postion issue so maybe a piece of very light equipment can be developed to limit the breaking of the collarbone while not giving up too much flexability to the rider.

Just an idea but can be possible??? I see no reason to not try to give max safety to the rider while stil allowing him to get max speed and handling just like a car.

-Js

I thought about that after my last crash. Especially since I have now slid on my left hip a few times and surgery to take care of a hematoma once on that hip. I wonder if something like kevlar/lycra material in the hip panels of the shorts would work. It would be expensive I suppose.

Maybe I should learn how to ride a bike instead of falling off them.

 

[TheDarkLord]

I thought about that after my last crash. Especially since I have now slid on my left hip a few times and surgery to take care of a hematoma once on that hip. I wonder if something like kevlar/lycra material in the hip panels of the shorts would work. It would be expensive I suppose.

Maybe I should learn how to ride a bike instead of falling off them.

MTBers wear pads to prevent some injuries. But I don't think there is any protection for the hip. It would indeed be nice to have some protection. My hip hurt for weeks after my last fall, and for a while I was worried that there was some internal injury although nothing was visible outside.