todayilearned

So ~5 miles into my ride today I needed to adjust my seatpost a bit higher. Unscrewed it, adjusted the seatpost height and then tried to screw it back on but it started turning.

Took out the screw and saw this:



The collar says 5Nm which is ~45in*lb. Having installed my stem using a torque wrench at 5Nm I'm sure there is NO WAY I was near that.
If I had put too much torque on it wouldn't it have gone further or damaged the seatpost before doing this?

Before I contact the manufactuer I'm trying to rule out error on my part. What do you guys think?

DScott

Probably user error. Maye due to repeated tightening over time, too.

I say this because 45 in-lb is about 3.5 foot pounds, or the equivalent of 3.5 lb force on a lever 12" long. That's not a whole lot of force.

However, I personally crank on the seatpost bolt until it feels tight, and it's probably way above that spec. It is a collar type seat post bolt, maybe that's different.

What kind of a seatpost bolt setup is that? I'd think it would be easy to strip the bolt if it had a steel barrel nut like that, instead of screwing into an alu. alloy collar...

climber7

yeah, but an allen key is maybe 2 inches, so we're talking 20-25 lbs of force. if you torque something to 5 Nm with a torque wrench and then test it with an allen key, it's pretty darn tight. it'd be tough to go over that if you were being at all careful.

i can't really tell from that picture how the setup works, though, so it's hard to know what happened.

urbanknight

I've done it with one of those tri allen wrenches before.

caphits

I didn't strip threads, but I did break the seatpost collar.

DScott

The pic is pretty telling, really. Unless the screw is made of pot-metal derived from the factory slave children's leg-braces and crutches, it can only be stripped via over-torqueing. Work on stuff long enough, you'll do it, too.

wkg

This happens. Take it to the shop where you bought your bike or a local shop that is a distributor for that manufacturer and have them submit a warranty claim.

todayilearned

On my other bikes I've put on quite a bit more torque and they have held up just fine. The only reason I'm questioning this is because the seatpost was still wiggling side to side when I got it this tight...

It's on my BMC... I guess CC will help me out?

Commodus

You're going to warranty a $10 collar?

Go to LBS. Buy collar. Install. Ride bike.

Try not to be so ham-fisted this time. Unless you're a millwright, then I guess you can't help it.
- just kidding. some collars suck, don't sweat it.

AlexZ

^^^ this !!! ^^^

todayilearned

Didn't know they only costed $10.

What's a good collar to get?

rogerstg

Whatever fits. No need to over analyze this.

jdon

That bolt (not a screw) was cross threaded on installation. Replace it and the nut.

DropDeadFred

at least its not stuck, and the head didn't round out! you can easily replace the collar.

DropDeadFred

[QUOTE=todayilearned;13398555]Didn't know they only costed $10.

/QUOTE]

wut

Yotsko

Not too hard...I've done it on my mountain bike 5 minutes before loading up to ride. But on the bright side, I'm pretty sure I'm the ONLY dude within a 100 miles that has campy comps on a mountain bike. That's the only one the lbs had on hand to replace the one I broke...

Grasschopper

Here you go https://fairwheelbikes.com/tune-wurge...ar-p-2911.html



That's definitely the one you need.

Or maybe this one.

DScott

Honestly, get the correct one that fits your frame. There are different sizes and styles, depending. I'm used to the collar style, not sure what kind of mechanism that uses a barrel nut like that.

What's that from?

daven1986

Same! My next seat collar I bought was more sturdy!

mmmdonuts

Sort of like this. I have the same kind.

todayilearned

[QUOTE=DropDeadFred;13398960]It was a long day... shut up.

---

Can I use one of those clamp style collars or is that only for MTBs?

Seatpost is 31.6 so I should be getting a colla a bit bigger than that correct?

Commodus

You gotta get the right one for the frame. It doesn't necessarily correlate with the seat post size. Take in the broken one to match it up is maybe best.

Mine are all 29.8s, but yours is probably 35mm.

zigmeister

Easily, I hit 7-8nm on my bike several times with a TW1 torque wrench, it finally went, pop! Got another collar, I don't go over 4-5nm now. All it good.