Cyclist Down Cradle Today Sun 21 July

[love2fly]

Not a post I ever dreamed I'd make.

After watching me ride for all of his 24 years my son eventually got the urge. We bought him a used Scott Spark 940 ALU dual suss this week.

I took him for his first ride this morning at about 10:00 from Bidon as we're both dealing with fluey chests etc. On the hill down from Bidon to Nedbank I drifted ahead and he suddenly wasn't behind me.

On turning a kind motorist alerted me that there was a cyclist down.

Appears he suddenly just got some serious head shake/speed wobble at about 50kmhr and was thrown into the shoulder - HARD.

He complained of serious lower back pain, hip and right shoulder. He thinks he dislocated his shoulder but it relocated when I rolled him over....

After scans he has a huge haematoma bleeding up his back causing pain and a torn glute, but thankfully nothing broken. Paramedics bound his pelvis as they suspected pelvis injury. Ambulance had to drive below traffic pace due to pain.

He's been admitted and likely a couple of days but it could have been so much worse and for that we're truly thankful.

I'm going to high speed test ride his bike tomorrow as there's nothing obvious when spinning the wheels.

My current theory is that being a used bike it's stood and there's a ball of dried sealant that's filled with recently added sealant when the wheel rotated and hugely out balanced the front wheel.

Suggestions welcome.

I want to thank everyone that stopped and I'm missing many names.

Special thanks to Quintin from a security company, Ewan and his colleague from the ER24 ambulance who arrived and started the process, Karen the ALS Paramedic from EmergMed who made with the Morphine and rode with my son and provided care right into the emergency ward.

Thank you to the runner who fetched KB and my car and the host of others I can't name. Plus the vigilant security guard in cammo to make sure our bikes were safe. 

As a 60 year old guy I've never had an emotional day like today, but I'm eternally thankful to everyone that helped plus the staff at Life Fourways 

Be safe. 💪

[Rowl]

Glad all is relatively ok, and thankful for all the help you received. Good luck!

[RobynE]

Very glad to hear you have a positive outcome for what happened. Terrifying when our kids get hurt whether 4 or 24! 
 

My only suggestion is: 

 

Don’t try sort this out yourself. Your son still needs his father. If there’s something fundamentally wrong with the bike a high speed test will only end one way. 
 

Rather take the bike to a good bike shop and tell them what happened and see what they can find. 
 

Could be one of any number of things or nothing at all. 
 

I have watched my kid speed-wobble and nearly lose it at speed because she was too heavy on the bars, hit a little bump in the road (very small bump), flew left, ramped a pavement and landed up in a cactus just about sitting on her bars. I myself nearly lost it the other day over two humps I forgot about and was standing up with locked knees. Did a proper superman/aero manoeuvre (unintended) but thankfully didn’t panic so didn’t bail. Would have been very sore doing 40km/h downhill on a dirt track. 
 

Point being that things can happen and at 50km/h they happen really, really quickly especially if your skills are yet to be discovered. 
 

When your boy is better I strongly recommend an outing to Lion and Safari. Hardly anyone goes there on a bike, the roads and tracks are super, and you can work on skills including speedy descents and take all the time you need without worrying about making space for other riders or dodging cars. Just watch out for the big male giraffe. His name is Stomp and I didn’t ask how he got that name. 


Hope your boy is back to feeling hundreds in no time at all! 

[Thomo]

Terrible first ride experience for both of you.

Hoping he recovers quickly and that this doesn't turn him off cycling.

[love2fly]

38 minutes ago, Thomo said:

Terrible first ride experience for both of you.

Hoping he recovers quickly and that this doesn't turn him off cycling.

Thank God we've already discussed next ride. Plan was a short Caves and back road ride but he's keen for a part of Northern Farms. We'll just stick to the roads and no single track. Still got 6 - 12 weeks to decide according to surgeon....☺️

[Furbz]

Sorry to hear. 

Check the headset bearings. Might be loose or worn. 

[love2fly]

11 minutes ago, Furbz said:

Sorry to hear. 

Check the headset bearings. Might be loose or worn. 

Thanks. I did the "hold front brake and push-pull" and turn lock to lock tests and seems ok but it's worth opening.

Appreciate the suggestion.

Going to open front tyre after a careful high speed ride by yours truly today.

[NotSoBigBen]

Maybe unrelated since it was road bike specific but I went through a period where it happened to me every so often. After it happened on 2 different bikes (so not bike related) ,turned out I was just holding the bars to tight, focused on relaxing and hasn't happened since.

[love2fly]

Thanks. I've had it on my MTB when I tried to ride no hands just lightly gripping with thumb and finger.

I'm also going to check for play in rear triangle. Checked wheel play yesterday and they are ok.

Earlier comment suggested bike shop but without sounding disrespectful to the poster, I don't trust LBS with that and I'd rather assess myself on road and in my garage. I've looked after most of my bikes for the last 24 years.

[Dusty]

I hope that the recovery goes well. Some good info here. 

 

[love2fly]

Thanks I'll give it a read. I'll report back tomorrow after a test ride. If indoubt I'll throw one of my older but proven tyres on.

[David Marshall]

Sorry to hear of your sons accident.  I hit the Cradle tar on Saturday and am nursing a broken rib so I can relate to his pain.

Sounds like a classic high speed shimmy.  Can be caused by any number of factors relating to the bike or rider tension or both.  Your approach is the right one - go through one thing at a time and don't expect any one else's experience to be the same.

[ChrisF]

6 hours ago, love2fly said:

Thanks. I did the "hold front brake and push-pull" and turn lock to lock tests and seems ok but it's worth opening.

Appreciate the suggestion.

Going to open front tyre after a careful high speed ride by yours truly today.

 

Best wishes for a speedy recovery.

 

 

A ball of sealant often result in a "heavy spot".  Hang the bike on a bike rack or similar, spin the wheel .... note what part of the wheel stops at the bottom.  Turn by 90-degrees and see if that section drops to the bottom again.  (this is how I spotted a sealant ball in one of my bikes, before I felt anything on the bike, despite some high speeds down Franschhoek pass)

 

 

A "tank slapper" can have so many causes though.....

[love2fly]

Yip. I've spun it but the disc binds ever so slightly stopping it from settling in one position. It could be that it balled and then had sealant added and it after a while collects behind the ball. Going to go through wheels, tyres, pivots, headset etc. I'll start by trying to replicate the onset - carefully of course. Have no desire being my son's room mate at Life 4W. 💪

Edited July 22 by love2fly

[love2fly]

1 hour ago, David Marshall said:

Sorry to hear of your sons accident.  I hit the Cradle tar on Saturday and am nursing a broken rib so I can relate to his pain.

Sounds like a classic high speed shimmy.  Can be caused by any number of factors relating to the bike or rider tension or both.  Your approach is the right one - go through one thing at a time and don't expect any one else's experience to be the same.

Sorry to hear that you hit the tar. Wish you a speedy recovery.

I got hit by a car in the Cradle about 8 years ago and broke a few ribs on the side. Ironically 2 weeks later I could ride carefully but laughter and sneezing were agony. Hugging your pillow will be your friend. 💪

[Mountain Bru]

On 7/21/2024 at 7:49 PM, love2fly said:

Not a post I ever dreamed I'd make.

After watching me ride for all of his 24 years my son eventually got the urge. We bought him a used Scott Spark 940 ALU dual suss this week.

I took him for his first ride this morning at about 10:00 from Bidon as we're both dealing with fluey chests etc. On the hill down from Bidon to Nedbank I drifted ahead and he suddenly wasn't behind me.

On turning a kind motorist alerted me that there was a cyclist down.

Appears he suddenly just got some serious head shake/speed wobble at about 50kmhr and was thrown into the shoulder - HARD.

He complained of serious lower back pain, hip and right shoulder. He thinks he dislocated his shoulder but it relocated when I rolled him over....

After scans he has a huge haematoma bleeding up his back causing pain and a torn glute, but thankfully nothing broken. Paramedics bound his pelvis as they suspected pelvis injury. Ambulance had to drive below traffic pace due to pain.

He's been admitted and likely a couple of days but it could have been so much worse and for that we're truly thankful.

I'm going to high speed test ride his bike tomorrow as there's nothing obvious when spinning the wheels.

My current theory is that being a used bike it's stood and there's a ball of dried sealant that's filled with recently added sealant when the wheel rotated and hugely out balanced the front wheel.

Suggestions welcome.

I want to thank everyone that stopped and I'm missing many names.

Special thanks to Quintin from a security company, Ewan and his colleague from the ER24 ambulance who arrived and started the process, Karen the ALS Paramedic from EmergMed who made with the Morphine and rode with my son and provided care right into the emergency ward.

Thank you to the runner who fetched KB and my car and the host of others I can't name. Plus the vigilant security guard in cammo to make sure our bikes were safe. 

As a 60 year old guy I've never had an emotional day like today, but I'm eternally thankful to everyone that helped plus the staff at Life Fourways 

Be safe. 💪

Sorry to hear about the incident. 

Speed wobbles can have many causes from what I've read/watched. A mate of mine had a huge wobble in front of me on the descent from Bidon towards the satellite climb, but was able to hold it up and come to a stand still. We tightened the headset compression a bit (after losening the stem clamps), and he took it easy for the rest of the lap but it never happened again. 

From the research I did afterwards, it seemed like the culprit is sometimes not a faulty part or installation, but more a combination of factors resulting in a vibration/wobble due to triggering a natural frequency of the bike and rider system. Some solve this by descending with a knee on the top tube which dampens the vibration and changes the stiffness of the system, and therefore the natural frequency. Others just slightly lift their bum off the saddle. Pedalling also seemed sometimes to change the stiffness characteristics and prevent the wobble, as did changing weight distribution on the bike, wheel stiffness etc. 

My point though is that checking the headset bearings, the frame for cracks, the wheels for trueness and balance, etc are all good and definitely things you should do, but at the same time, the culprit might be something completely different, like the bike fit resulting in a lack of front end downforce, or the alu frame having too much top tube flex, or lose pivots or something. So unless you weigh the same as your son, and sit in the same position, your tests might not give you reliable results. 
 

Here's a video of a guy intentionally initiating a speed wobble, and then stopping it by just touching the handlebars and weighting the front of the bike again for reference of what I mean about a single part not being responsible.