Spoke Nipple failure

Helpful information and requests for assitance and advice
Member
Posts: 136
Joined: Tue Oct 22, 2019 2:42 pm
Location: florida

Spoke Nipple failure

Postby asterysk_usa » Thu Nov 14, 2019 6:28 am

I am experiencing something strange , I’ve had 5 Spoke nipples disintegrate 3 on back and 2 on front. The wheels are off the bike, no tyres. The only thing that is happening is polishing of the hub and rim with a soft rotary polishing wheel

1) is this likely to be a batch of faulty spoke nipples ?

2) could it be a nipple - rim mismatch somehow

3) if I decide to remove all the spokes and replace then nipples , is there a technique for releasing the tension on the spokes so that the rim doesn’t buckle

4) where would i get reliable nipples from and should I buy new spokes from same place as I buy nipples




Image


Sent from my iPhone using Tapatalk
1954 AJS 18S Cyprus export (frame decode says 1954 but many components match a 1955).

Member
User avatar
Posts: 1411
Joined: Sat Oct 09, 2010 8:17 pm
Location: SWANSEA UK

Re: Spoke Nipple failure

Postby cbranni » Thu Nov 14, 2019 6:38 am

Hard to say without physically looking at the wheel but rough guess I would say over tensioned spokes.

Colin
only dead fish go with the flow

Member
Posts: 136
Joined: Tue Oct 22, 2019 2:42 pm
Location: florida

Re: Spoke Nipple failure

Postby asterysk_usa » Thu Nov 14, 2019 6:51 am

cbranni wrote:Hard to say without physically looking at the wheel but rough guess I would say over tensioned spokes.

Colin


Is this something I could test by tapping the spoke ?


Sent from my iPhone using Tapatalk
1954 AJS 18S Cyprus export (frame decode says 1954 but many components match a 1955).

Member
User avatar
Posts: 121
Joined: Sat Sep 14, 2019 4:50 pm
Location: Bristol & East Devon

Re: Spoke Nipple failure

Postby Rosy » Thu Nov 14, 2019 9:05 am

All the spokes should have a similar ring to them when tapped with a spanner or the like, any dull sounding spoke should be tweaked up, any with too high a pitch backed off. It's best to do any wheel work with the wheel mounted so as it can be spun and checked for runout.
When spoke nipples are installed a slight drop oil can be used on the nipple head and thread to prevent stiction, there is a special oil for this purpose but I can't think what it is.

The spoke you show as Colin noted looks like the result of over tightening and this stiction taking place and putting stress on the nipple head. You can do one spoke at a time but I think you will have a problem threading one over/under the other.
When truing to pull a runout one side you need to slacken slightly the opposite side, don't just tighten one side thinking it will pull the wheel over, that will cause stress on the nipple head.

Member
Posts: 1115
Joined: Wed Oct 12, 2005 9:45 pm
Location: KENT UK

Re: Spoke Nipple failure

Postby alanengineer » Thu Nov 14, 2019 9:29 am

im not convinced the full spoke in your photo is fitted in line with the drilled hole. I think it would be worth your while rebuilding the wheel properly. The spoke holes are all drilled at the correct angle for lacing up into the rim. Find a good wheelbuilder.
i cant see you undoing and replacing the whole set of spokes without losing concentricity and line.

Job needs to be done soon

Member
User avatar
Posts: 1411
Joined: Sat Oct 09, 2010 8:17 pm
Location: SWANSEA UK

Re: Spoke Nipple failure

Postby cbranni » Thu Nov 14, 2019 9:47 am

Well spotted Alan, it doesn't look right.

Colin
only dead fish go with the flow

Member
Posts: 2133
Joined: Mon Mar 24, 2014 5:44 pm
Location: Aberdeenshire

Re: Spoke Nipple failure

Postby Mick D » Thu Nov 14, 2019 4:42 pm

alanengineer wrote:im not convinced the full spoke in your photo is fitted in line with the drilled hole


Hi

I'm not sure I agree with this - it would be almost impossible to lace the wheel with the spokes reversed:

Spoke Angles.png


Are the spokes newly fitted? if so then I'd suspect over tightening - If not I'd suspect galvanic, (dissimilar metals), corrosion and replace all spokes and nipples.

I'd buy a set of replacement spokes and nipples from Devon Rim Company and re-lace the wheel myself, but if you're not confident get a wheel builder to do it for you.

If I were stripping a wheel with the intention of keeping the rim I'd I go round loosening the nipples half a turn for the first revolution, one turn for the second and then two turns each rev until they are loose.

Rosy wrote:You can do one spoke at a time but I think you will have a problem threading one over/under the other.


No - because these spokes are straight I don't think there's any issue replacing them in situ.

Regards Mick
You do not have the required permissions to view the files attached to this post.

Member
Posts: 136
Joined: Tue Oct 22, 2019 2:42 pm
Location: florida

Re: Spoke Nipple failure

Postby asterysk_usa » Fri Nov 15, 2019 4:23 am

Mick D wrote: I'd suspect galvanic, (dissimilar metals), corrosion and replace all spokes and nipples.



I checked back through my email history and found that I bought the SS rims, SS spokes from Devon Rim Company in 2013. The wheel was built in 2014 and the spokes have been fine until recently. Your suggestion of galvanic action would make sense

You mention replacing the both the spokes and the nipples: I had a look at the threaded end of the spoke under a microscope and the threads look perfect, it just seems to be the "top hat" part of the brass nipple that just pulls off .

Any suggestion on how I can reduce this galvanic action on the rebuild ?

I need to get a spoke key to dismantle the existing wheels, any suggestions on what kind/make/size to buy ?
1954 AJS 18S Cyprus export (frame decode says 1954 but many components match a 1955).

Member
Posts: 2133
Joined: Mon Mar 24, 2014 5:44 pm
Location: Aberdeenshire

Re: Spoke Nipple failure

Postby Mick D » Fri Nov 15, 2019 4:21 pm

Hi

I bought my spoke spanner from DRC.

Your spokes and nipples are relatively new and I wouldn't suspect galvanic corrosion as you don't se any between the nipple and spoke - looks like a case of over tightening at build.

Regards Mick

Member
Posts: 136
Joined: Tue Oct 22, 2019 2:42 pm
Location: florida

Re: Spoke Nipple failure

Postby asterysk_usa » Sat Nov 16, 2019 3:39 am

Image

That’s a consistent shear at the same place on the nipple.

I’m throwing away all the nipples and will get wheel rebuild using a different wheel builder.


Sent from my iPhone using Tapatalk
Last edited by asterysk_usa on Sat Nov 16, 2019 8:39 am, edited 1 time in total.
1954 AJS 18S Cyprus export (frame decode says 1954 but many components match a 1955).

Next

Return to Help

Who is online

Users browsing this forum: No registered users and 16 guests