Markj8

I have a Cannondale R500. The back wheel does not spin true but all the spoke nipples are rounded off. They seem to be brass. Where do I get new ones and how do I know the size to get. I don’t have a digital caliper. They are aluminum R450 rims. Any information appreciated, thanks.

Nessism

If you are set on fixing the wheel yourself, I'd start by removing the tire, rim strip, and then extracting one spoke nipple. Use vice grips or whatever is necessary to get the nipple to move. Take said nipple to a bike shop and ask them to match it up for size. Buy a spoke wrench also. You can replace each nipple one at a time, truing the wheel as you go.

ScottCommutes

Danger - this might be a rabbit hole.

I would start by applying lots of WD40 or PB Blaster type product to every single spoke/nipple and nipple/rim junction and spinning the wheel fast to help it penetrate. Then let the wheel sit for a day.

My reasoning for the above is that your nipples are obviously in poor condition. Some or all may be frozen in place and you run the risk of breaking spokes at the nipples as you vice grip the nipples and try to turn them. This will leave the wheel worse than when you started.

Perhaps a little butane torch might be in order to free up a particular nipple that refuses to budge.

You might get lucky also.

Replacing nipples as stated above is relatively straightforward. I bought a box of 100 on Amazon for pennies per nipple. They also make colored ones and such if you are into that this could be your opportunity.

The labor to do this work at a shop is likely not as economical as doing it yourself or simply purchasing a new wheel.

Replacement spokes at my local bike shop are $2 each. These are much cheaper in 100 packs if you know the length to order.

The work is likely to take you a couple of hours. Depending on if you actually want to do the work, consider a new wheel.

Andrew R Stewart 

When teaching people about truing wheels I often suggest they "pick up" a wheel that they can practice on and not worry about their own bike.

I have to admit that I am a bit hesitant to strongly suggest the OP try to fix the R500's wheel. It sounds like it is in really poor condition and I suspect the rim would not be too round or flat if all the spokes were untensioned enough to let the rim seek its own shape but still be able to spin it. Spending the least amount (nipples only and tools as needed) might well be the door of a frustrating path of trying to true a rim that was abused and bent and will never be true or stable enough for very long.

I wonder if the budget allows it if the wheel could be replaced "in total" and the now old one becomes that practice device I mentioned. IIRC these bikes had minimal tire clearances and ran skinny lightweight rims so I expect any repairs done will likely be revisited soon enough. Andy (who would ask customers when they called about straightening wheels "can you lift the wheel off the ground and spin it? How long will it spin for" as a good indicator to the unseen damage they wanted me to magically be able to estimate for)

FBinNY 

I'm with Andy on you might as well learn now, since the other option is to simply trash the wheel.

That said, I'm not a fan of the one at a time replacement method on a tight wheel.

Start by using a dry marker to leave a reference at the nipple on all the spokes. Then use a vice-grip to back off ALL the left side nipples a turn or two, to slacken the wheel slightly. Then replace all the right nipples one at a time, using the reference marks as a guide. Repeat on the left side, staying off the mark until finished. Then tighten to the mark, and finally true, being careful to not overwork any one spoke.

ScottCommutes

Pretty cool method for replacing all nipples.

Duragrouch

First, if you replace the nipples, I recommend typical nickle-plated brass ones, they are less likely to seize on the spokes than aluminum nipples (if they are color-anodized or dull silver, they are mostly likely aluminum).

Second, if a wheel is significantly out of true radially, I like to let tension off on all spokes down to zero, set them all at a good starting point, and bring them all back up to tension slowly while truing, prioritizing radial runout first, and also checking lateral runout along the way, and spoke tension by "ringing", but lateral is easy to correct, whereas a lot of radial runout affects all the spokes. Which is why I find it easier to start at zero, than try to correct if radial is out a lot. If radial is good and just out laterally, you can correct without starting from zero tension.

When you buy the nipples, not only make sure they are right for the spokes, but also that you have a correct size spoke wrench for them.

The comment about putting some penetrating oil on them and wait a day is good advice. Try to get at least a few nipples off to make sure they are not all seized on the spokes. It may help to use both a screwdriver (with tire, tube, and rim tape off) AND a spoke wrench or pliers. I rounded one off by trying to tighten it when the threads had already bottomed out, I thought it was just high force due to tension. Had to cut that spoke off, nipple was hopelessly frozen on.

Markj8

Thanks everyone. I think I will buy a pack of nipples. Someone told me the R450 wheel takes 14g 12mm nipples. I have the tool to tighten them but nothing else. A lot of them are on pretty good so I will use vice and pb blaster.

KCT1986

Don't use too much lube on the nipples. Too much lube can get into the hollow chamber of the rim and is impossible to clean. This will make a mess later on the rim tape as the lube seeps out. Just put some lube in a small container, dip a small stick (toothpick) into the lube and 'dot' a small amount at the spoke/nipple joint & also on the other end of the nipple after removing the rim tape.

If nipples are still stuck, you can add a little more lube as needed.

Bill Kapaun

IF you have a VISE Grip type pliers with good, "sharp" teeth, you can easily peel off the nipples without much strain to the spoke.
Vice is a moral aberration.

FBinNY 

IMO using these on bikes IS a moral aberration.

Bill Kapaun

Not on frozen nipples.

Andrew R Stewart 

In my world vise grips are for holding stuff being ground or brazed more often than not. But they do have their place in the repair world, thankfully that place is small and easy to avoid many times. Andy

ScottCommutes

I would even go beyond the vise grips and say that a big pipe wrench has a place in the repair world as well - for spinning out frozen seat posts.

alcjphil

I am going to say that if your current spoke nipples are rounded off you have the wrong size spoke wrench

ScottCommutes

Excellent point that no one else mentioned, but in defense of OP, he never stated that he rounded them off.

FBinNY 

I can't speak for others, but suspect that, like me, they read between the lines and figured that the OP would have said so if he did it.

Either way, it doesn't matter because it's not about how we got here, but how to go forward.