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Hub flange possible source of spoke ping?

by propagandazoo
Tue, Sep 22, 2020 10:26
7

I am pretty new to cycling, and particularly to rebuilding wheels. 

I have a rear Giant P-A2 Aluminum Clincher 700c wheel that I re-laced but whilst relacing I noticed quite a bit of wear in the flange. Where it looks like spokes have worn towards the centre - with a few holes with slight play. 

Could hub flange wear make spokes ping? 
 

 

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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7 comments

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Miller | 4 years ago
1 like

You should take your rebuilt wheels for a ride and see how they get on. They might just need to settle down.

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Balthazar | 4 years ago
0 likes

It's normal for spokes to have deformed the flange holes, as it is necessary for them to bed in during tensioning. This is why used hubs should always be relaced in the same pattern. A little play in the holes is not a problem.

"pinging" spokes is a consequence of twist remaining in the spokes from tensioning. When the wheel is weighted during a ride, a given spoke's tension momentarily reduces as it passes the bottom of the wheel, and the spoke untwists with a ping. Of course, this invariably leaves the wheel freshly out of true, and an unwitting builder will true the wheel again, creating an endless cycle of annoyance.

Retension the wheel, and relieve spoke twist as you go. It's fairly easy to do by feel, but trickier as the spokes get tighter. Overtighten each spoke by an eighth-turn or so, and then back it off the same amount, until the spoke twist is gone. A bit of tape or marker on the untensioned spoke is a useful guide to get started. Some more advice here:

https://www.roadbikerider.com/basic-concepts-part-2-spoke-twist-stress-r...

 

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propagandazoo replied to Balthazar | 4 years ago
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Balthazar wrote:

It's normal for spokes to have deformed the flange holes, as it is necessary for them to bed in during tensioning. This is why used hubs should always be relaced in the same pattern. A little play in the holes is not a problem.

"pinging" spokes is a consequence of twist remaining in the spokes from tensioning. When the wheel is weighted during a ride, a given spoke's tension momentarily reduces as it passes the bottom of the wheel, and the spoke untwists with a ping. Of course, this invariably leaves the wheel freshly out of true, and an unwitting builder will true the wheel again, creating an endless cycle of annoyance.

Retension the wheel, and relieve spoke twist as you go. It's fairly easy to do by feel, but trickier as the spokes get tighter. Overtighten each spoke by an eighth-turn or so, and then back it off the same amount, until the spoke twist is gone. A bit of tape or marker on the untensioned spoke is a useful guide to get started. Some more advice here:

https://www.roadbikerider.com/basic-concepts-part-2-spoke-twist-stress-r...

Thanks for the valuable input. I have re-laced the wheel, using tape guides to stop spoke twist. the wheel is true on both axis. The spokes are set within a healthy margin of spoke tension for drive and non-drive side. However, there are still noticible regular ping sounds when driving the wheel by hand. 

If a worn flange is not the reason for the sounds, could hub assembly bearing failure be causing the pinging? 

 

 

 

 

 

 

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Balthazar replied to propagandazoo | 4 years ago
0 likes

Well done for doing that: you've prevented future problems and probably built a wheel that won't lose trueness now.

I can only think that the sound is something other than I assumed. Are you saying it occurs when you spin the wheel in your hands, unloaded? If so, it can't be any part of the spoke/hub flange/rim structure. My best guess is the bearings (loose ball bearings can collide with each other with a metallic ping), or could there be something loose in the rim (joint plug, etc)? Depending on the type of bearings the hub uses, they should be easy to rule out. If it uses loose (cup and cone) bearings I'd want to clean and regrease them when the wheel is rebuilt in any case.

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propagandazoo replied to Balthazar | 4 years ago
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Thanks for feedback

Balthazar wrote:

Are you saying it occurs when you spin the wheel in your hands, unloaded? 

I mean when bike is upside down and I drive the crank with my hands.

There is nothing loose in the rim. I also tried ramping the tension up a little bit approx 138kgf on drive side , but the sound remains. 

I will try to disassemble the hub this weekend - and update. 

Its a 6 year old wheel. So perhaps my mistake was not just buying all new components and building fresh... Least I am much better prepared for maintaining some better ones...  

 

 

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Balthazar replied to propagandazoo | 4 years ago
0 likes

Nah- repair first, you went the right way! Better for the soul, and you've learned new skills. Most hubs are pretty basic, especially if you can build wheels, but I'll keep an eye on this thread if you need any more help.

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propagandazoo replied to Balthazar | 4 years ago
1 like

Balthazar wrote:

Nah - repair first, you went the right way! Better for the soul, and you've learned new skills. Most hubs are pretty basic, especially if you can build wheels, but I'll keep an eye on this thread if you need any more help.

Yeah the 'right to repair' approach was the right philosphy... I took the Giant hub apart and found a completely shot bearing, and 100% the source of the spoke ping.

I think it was possibly a sram type, just with a Giant logo, as it had same bearings as an X9/Rise 40/X7.  

I just ordered 1 skf one (£2.99 delivered) as they are reasonably priced, and skf... 

Fitted and wheel is silent again. 

 

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