My heart broke with my boom today

Frank Costantini

Active Member
As the second picture shows, both upper clamp bolts were fully tightened which caused bending of the bolts as well on the slider. When correctly tightened, the clamps should have an equal gap on top and below.

I’ve been thinking for a while about buying a torque wrench, and this encourages me to follow through!
Any recommendations for a good one?
 

mzweili

Guru
A torque wrench might be useful for some more important bolts. For an aluminum handlebar clamp it's not really necessary. Hand tightened with the allan key does the job. For a carbon fiber handle bar I would be more careful.
 

Vicki C.

T50 Trailblazer and Silvio newbie
Following up, theparts ready to ship. Sadly I will be buying a new slider AND boom, I assume because my Silvio is on older model and the specs changed. The free trade is getting more costly. :) But, I love riding the Silvio.
 

dtseng

Well-Known Member
I would suggest that you replace/renew the chain stay as well if it won't strain your pocketbook much.
The newer chain stay clamps on the BB shell, which gives you freedom to use other type of BB and cranks.
These replacement works are straightforward for any one to DIY.
 

Vicki C.

T50 Trailblazer and Silvio newbie
I would suggest that you replace/renew the chain stay as well if it won't strain your pocketbook much.
The newer chain stay clamps on the BB shell, which gives you freedom to use other type of BB and cranks.
These replacement works are straightforward for any one to DIY.

Pocketbook is griping at me right now with my sideways fall costing me probably $280 in parts plus labor. :) This bike was hardly ever been ridden because the previous people had trouble, not their thing. I hate replacing functional parts, but I can check with the LBS. And I appreciate any and all advice.
 
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Vicki C, If a new style chain stay fits a Silvio 2, I have a like-new (200 dry-road miles) standard length chainstay from my 2018 V20 that I would be willing to part with. It’s left over after swapping my V20 to the long chainstay. Bill
 

Vicki C.

T50 Trailblazer and Silvio newbie
Vicki C, If a new style chain stay fits a Silvio 2, I have a like-new (200 dry-road miles) standard length chainstay from my 2018 V20 that I would be willing to part with. It’s left over after swapping my V20 to the long chainstay. Bill

It sounds as if it would not work. Thank you for the offer. I will certainly ask when I pick up the bike. The parts have not gotten to the bike shop yet so I don't have the bike back.
 

Vicki C.

T50 Trailblazer and Silvio newbie
From that level of crash on your own(not getting run over by a truck) that piece shouldn't have cracked like that but but sometimes the stars align and $hit that shouldn't happen, happen. Get in contact with cruzbike and maybe they'll help you out with a new or discounted boom.

@Robert Holler @Maria Parker @Lucia

Boom and slider both had to be replaced because the slider I needed was no longer in stock. Bike shop said the clamp was not overtightened. The photo is misleading because I took it after messing with it to try to push the bike to town. The clamp bolts bent, which does also confirm the necessary gap existed. But the aluminum still cracked. The new boom/slider is supposed to be improved but is the same at the clamp it seems. Now I just need to stay upright at all times!
 

dtseng

Well-Known Member
The new boom/slider is supposed to be improved but is the same at the clamp it seems. Now I just need to stay upright at all times!

Yes, if you ride an aluminum alloy or carbon fiber bike, you need to stay upright at all times.
 

Vicki C.

T50 Trailblazer and Silvio newbie
As the second picture shows, both upper clamp bolts were fully tightened which caused bending of the bolts as well on the slider. When correctly tightened, the clamps should have an equal gap on top and below.

Actually, the photos are not representative of how it looked immediately after it broke, as I messed with it trying to get it to hold together to get me into town as I scooted along the highway. And the LBS who made the repair did confirm his observation that the bolts were not tightened with no gap because absent a gap the bolts would not have bent, and they did bend. So, it is simply that for whatever reason the metal piece broke from a sideways fall from a dead stop onto soft sand. It scares me to think what might happen if I had been moving or REALLY took a fall!
 

Vicki C.

T50 Trailblazer and Silvio newbie
Yes, if you ride an aluminum alloy or carbon fiber bike, you need to stay upright at all times.

Apparently. My carbon Specialized from the 1990s hit the ground and fortunately nothing broke. But ALL the bike wasn't carbon, just the frame.
 

dtseng

Well-Known Member
Actually, the photos are not representative of how it looked immediately after it broke, as I messed with it trying to get it to hold together to get me into town as I scooted along the highway. And the LBS who made the repair did confirm his observation that the bolts were not tightened with no gap because absent a gap the bolts would not have bent, and they did bend. So, it is simply that for whatever reason the metal piece broke from a sideways fall from a dead stop onto soft sand. It scares me to think what might happen if I had been moving or REALLY took a fall!

Perhaps there was a damage or hairline crack there before from the previous owner. When you buy a 2nd bike, you assume the risk.
This is a design problem. Aluminum alloys such as 6061 and 7075 are weak and brittle. They should beef up that clamping area. It is too skimpy.
 

dtseng

Well-Known Member
Titanium and chromoly steel will never ever have that kind of problem. (photo shows my Ti steering column handlebar clamp. I call it "steering column" because it won't make any "boom"ing sound.) DSCF5309.JPG
 
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Vicki C.

T50 Trailblazer and Silvio newbie
Perhaps there was a damage or hairline crack there before from the previous owner. When you buy a 2nd bike, you assume the risk.
This is a design problem. Aluminum alloys such as 6061 and 7075 are weak and brittle. They should beef up that clamping area. It is too skimpy.

Anything is possible. If there was, it was not evident to the mechanic who worked on my bike a week or two before I fell, which likely included dealing with the handlebar clamp. The previous owner says he didn't fall and there is no evidence, but he got it from another person who couldn't ride it (or the wife couldn't). So, I have no way of knowing other than the bike has virtually no other damage. But, not under warranty and not the original owner. Thank you for agreeing that the clamping area could be stronger. Unfortunately, the new one looks the same as the old in that area. I wish I knew a way to beef it up. Several people have offered suggestions but others say there is no alternative to make changes that would work. I kept the old boom and slider. Maybe I will have friends I know who work with aluminum and modeling bits and pieces and welding give it a go to see what they can come up with. Then I would have a spare. :)
 
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