Stripped Clamp Thread

[hurri47]

Silvio 1.0 pivot clamp threads are gone.

Things to try:

1. Longer bolt with nut and nylon washer (attempt to compensate for slope) - no modification to clamp (FAIL) Result: bent bolt (stainless!) and no clamping force anyway

1a. Longer bolt with nut and wedge washer (make/buy)

2. Counterbore (tool $$) sloped surface to nut OD for longer bolt and nut

3. Grind flat (Dremel) on sloped surface for longer bolt and nut, being careful to avoid stress concentrations

4. Replace the clamp. Robert, are there any available? (Not looking forward to the disassembly required)

5. Replace with a different clamp - maybe something like the QR one that came on the conversion kit - source? What would I even call it for search purposes?

6. Helicoil? Does anybody still use these?

-Dan

 

[John Dorlon]

It might not be as pretty, but wouldn't just any clamp of the right size and strength work? I guess that's choice 5. That's what I'd try.

Maybe one of these is strong enough?
http://www.discountmarinesupplies.c..._Clamps.html?gclid=CMaEpbmUzckCFQqpaQod8u0AZA

 

[Doug Burton]

As I remember, that's a 6mm bolt. You could tap it out to 1/4 inch (6.4mm) and used a high-strength 1/4 inch bolt...

Might avoid disassembling everything that way.

 

[Bruce B]

"As I remember, that's a 6mm bolt."

I just measured and it is a 6mm bolt.

 

[hurri47]

As I remember, that's a 6mm bolt. You could tap it out to 1/4 inch (6.4mm) and used a high-strength 1/4 inch bolt...

Might avoid disassembling everything that way.

Love the idea of not disassembling, but I think the thread depth would be precarious, especially in aluminum. I would bow to anyone's experience though.

-Dan

 

[hurri47]

It might not be as pretty, but wouldn't just any clamp of the right size and strength work? I guess that's choice 5. That's what I'd try.

Maybe one of these is strong enough?
http://www.discountmarinesupplies.c..._Clamps.html?gclid=CMaEpbmUzckCFQqpaQod8u0AZA

I had actually considered hose clamps, but this looks better.

-Dan

 

[VenRiderGuy]

I had actually considered hose clamps, but this looks better.

-Dan

Why not just use a stainless bolt with washers and a locknut, maybe first drilling out and cleaning up the hole?

 

[Doug Burton]

Check the hole size with a 13/46ths or 7/32nds drill bit. If either of those are a tight fit, you can tap to either 1/4-20 or 1/4-28 with confidence.

https://www.boltdepot.com/fastener-information/US-Tap-Drill-Size.aspx

 

[Robert Holler]

On that older Silvio you should just be able to use a standard clamp. I have an Origin 8 one on my own personal early model Silvio.

 

[hurri47]

On that older Silvio you should just be able to use a standard clamp. I have an Origin 8 one on my own personal early model Silvio.

The 34.9 mm version of this, I assume? http://www.amazon.com/gp/product/B002MKJTA8/ref=olp_product_details?ie=UTF8&me=

It's inexpensive enough I can afford to be wrong, and I could even try a QR version. The magic words I was looking for were "seat post clamp." I should have known Tolhurst would select an off-the-shelf part. Thanks as always, Robert.

-Dan

 

[Robert Holler]

Take a look for the Origin 8 Seat clamp:

http://www.amazon.com/Origin8-Pro-Fit-Seat-Clamp/dp/B00R6S5WAW

That clamp is basically an off the shelf item on the older models. For the pivot clamp it is the 34.9.

 

[hurri47]

I live walking distance from a Performance Bikes store, so I picked up a Forte clamp for $5 instead of waiting for Amazon to send me the Origin8. It's a perfect fit. Thanks everybody for all the help and insight.

-Dan

 

[Bentas]

For interests sake ,where would I find a 50 mm Alu boom clamp?