Flexy Stem

[Spibblo]

How flexy can I expect an old Cinelli 1a stem to be?

It flexes around the handle bar clamp area, allowing the bars horizontal movement across the length.

All this retro road biking in new to me so maybe it's supposed to be like that?

..is it safe?

 

[Toff]

I assume that you are using the correct sized handlebar, with a diameter of 26.4mm, not a modern 26.0mm or smaller bar.

There should be no noticeable flex in the stem, and only the slightest flex at the extreme ends of the bars if you really really try to push down on them.

Take the fixing bolt out, make sure the threads are clean and are not damaged, and then retighten it in place using about as much torque as a hand held allen key will allow. If you still get flex, I reckon there's a crack somewhere. Even if you can't see the crack I would not be riding on the bars or stem. Fatigued aluminium has a proclivity to fail suddenly and catastrophically. Not what you want from your front end whilst riding...

 

[roadking]

How flexy can I expect an old Cinelli 1a stem to be?quote]

Give they were used extensively BITD by the pros, and I have used the 1a in preference to the"Record"for many years and never experienced a problem with flexing.

Can only assume (a), you not using a matching (i.e Cinelli) handlebar, or (b) the stem has a fault.

Or finally (c), the bar is damaged around the clamping area (although it is sleeved - double thickness - if a Cinelli.

Rk.

 

[Spibblo]

cheers for the replies

the stem and bars have same clamp size.

I've removed the stem and cleaned up the clamp bolt and refitted it with a greater force applied to the clamp- it's loads better.

just to clarify, there are 3 brass washers, am I right in saying 1 washer goes each end of the clamp bolt in the clamp recesses and the other goes with the main long shaft bolt?

 

[Jonny69]

Doesn't sound right to me. Even cheapy alloy 25.4mm kit doesn't flex much at all.

 

[Spibblo]

Nay nay nay it's still too flexy. I'm not going to use it, not worth the risk. Thanks to those who helped me out with this one.

 

[fiks]

Are you sure the bars and stem match? Cinelli changed the bar diameter some years back.

The only other thing is something's damaged, as others have already said.

 

[Spibblo]

Are you sure the bars and stem match? Cinelli changed the bar diameter some years back.

The only other thing is something's damaged, as others have already said.

seller from here said both 26.4, but I will check. you can see the nose of the stem moving left to right when I pull/push on the ends of the bar, also the nose of the stem does not look straight, I think it may have been twisted too far at some point, maybe been in a crash?

 

[Matt_wood55]

I have the same issue with one of my bike.

It's not the frame (apparently) and the flex seems to some from the stem insertion into the steerer. If a second person puts pressure on the bars whilst you hold the stem / headset you can feel the movement. I still haven't sorted it. Tried a different stem and bars, now going to try a new headset.

Have you had any luck?