Replace rims?

[cyclegranny]

Hi
have just watched the video on replacing rims.  Just wondering what the indicators would be that you needed new rims.  The video gave no info on this.  Just curious.
Thanks
Colleen

[nfmisso]

Hi Colleen

You need to check two areas:

1. Around the spoke holes for cracks leading away from the holes or growing hole to hole.  If you find any under a 1/16" (1.5mm) long, take a close up picture to document, and mark that spoke nipple with a Sharpie or similar so that you can find it quickly again.  Check it after every ride.  If you find any that are more than 1/8" (3mm) long, replace the rim as soon as possible.  If you find a crack that is more than 1/2" (12mm) replace the rim IMMEDIATELY - do NOT ride on it.
2. Brake track.  If there is a crack through the brake track, replace the rim IMMEDIATELY - do NOT ride on it.  Brake tracks also wear, using a short metal straight edge (I use a 6" stainless steel ruler), lay the edge of the ruler across the brake track from the outer diameter of brake track to the inner diameter of the brake track (this is typically 1/2" or so distance).  If there is a gap in the middle of more than .020" (0.5mm), replace the rim as soon as possible.
   

If your rim is cracked in the brake track area, you will often here a once per wheel rev clicking noise.  If you have that symptom, check the rims immediately.  There are many many other causes for once per wheel rev noises, none of the others can lead to immediate catastrophic dangerous failure.

To check for cracks, wipe the area you are looking with paper towel or clean rag, dirt will get caught in the crack.  Alternatively, you can wipe on then wipe off some contrasting penetrant (diluted India ink for example).  If you think there is a crack, but not sure, you can apply the penetrant with a Q-tip to the suspected area.

If you decide to replace rims, I strongly recommend Velocity rims, they are worth the extra money to me.  They are rounder and flatter than most.  They also have thicker brake tracks than many others.  I have built wheels with Sun, Alex and Velocity rims.

For spokes, Wheelsmith.  http://www.peterwhitecycles.com/spokes.asp

[Painkiller]

(02-28-2015, 12:31 PM)cyclegranny Wrote:  Hi
have just watched the video on replacing rims. Just wondering what the indicators would be that you needed new rims. The video gave no info on this. Just curious.
Thanks
Colleen

Depends on the rim and type and a little about the bike or project involved. Some rims will have a wear groove machined in the surface and when worn enough to make the groove disappear, it is time for a rim or wheelset. The indicators of which you ask would be more common sense than anything but as follows, cracks at seams/spoke nipples. excessive grooves in surface, dings/dents, wobbles that cannot be removed by truing, or any cracks in the surface. And of course if you just wanted to upgrade from steel to alloy. The key is not to run the rim surface to that point. keep brake pads fresh. if they sound and feel like sand paper on the rim, they are dry and should be replaced. This may help cause premature rim failure. Even so it takes a long time to wear a rim to this point for the average rider (less than 1000 miles a year).

[GeorgeET]

ANND, unless you want to build special custom wheels, you are better off just replacing the wheels . Get a new hub, bearings, etc all in one package.

[cyclegranny]

(02-28-2015, 08:46 PM)GeorgeET Wrote:  ANND, unless you want to build special custom wheels, you are better off just replacing the wheels . Get a new hub, bearings, etc all in one package.

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(02-28-2015, 09:48 PM)cyclegranny Wrote:  

(02-28-2015, 08:46 PM)GeorgeET Wrote:  ANND, unless you want to build special custom wheels, you are better off just replacing the wheels . Get a new hub, bearings, etc all in one package.

Thanks guys
I have a new to me bike, 9 years old, 7 k on rims. I think they are still quite good, Mavic xc 717's 26 inchers, now I can inspect them with a more discerning eye!
Colleen

[Painkiller]

The Mavic XC717 Are some of the lightest Boxed section 26in rims made. I did have a problem with one hoop sometime ago when the internal brace at the seam came loose creating a ticking sound that took some time to track down. I was able to actually slide it back and forth inside the rim. First time I have ever seen this happen to a rim. It only had around 100 miles on it. I ended up coating it with epoxy and sliding it back in place, then set peened like it originally was to lock it in. Took some doing but saved a $120 near impossible to replace rim. My only other option was to drill and plug weld it in place. I chose the cleaner option and it seems to have been holding perfectly. If yours is Silver and you ever need one I do have one new old stock left. laced to a DeoreXT center lock disc hub. I also have 2 in stock that are black, hoops only. Should the day ever come.

[cyclegranny]

(02-28-2015, 11:11 PM)painkiller Wrote:  The Mavic XC717 Are some of the lightest Boxed section 26in rims made. I did have a problem with one hoop sometime ago when the internal brace at the seam came loose creating a ticking sound that took some time to track down. I was able to actually slide it back and forth inside the rim. First time I have ever seen this happen to a rim. It only had around 100 miles on it. I ended up coating it with epoxy and sliding it back in place, then set peened like it originally was to lock it in. Took some doing but saved a $120 near impossible to replace rim. My only other option was to drill and plug weld it in place. I chose the cleaner option and it seems to have been holding perfectly. If yours is Silver and you ever need one I do have one new old stock left. laced to a DeoreXT center lock disc hub. I also have 2 in stock that are black, hoops only. Should the day ever come.

Thanks!
Mine are looking pretty good with the criterion that has been given here. They are black ones with xt hubs. I'll keep those black ones in mind.
Colleen