Still getting punctures with Velox
 

In an emergency (my last front wheel decided to collapse in half) I recently bought a fairly cheap Mach 1 CFX wheel.

It didn't come with any rim tape and I forgot to ask for any so put in some from the last wheel. The problem is that the new wheel is double walled and the inner tube started puncturing through the spoke holes (the old rim tape was rubbish).

I saw on these forums that the Velox rim tape is highly recommended. I've bought some but the problem persists. There are some dips in the tape on some of the holes but its otherwise intact. However, I'm still getting punctures. The punctures exactly line up with the holes.

I would normally inflate to 110 - 120 but I'm even getting these internal punctures at 60 - 80. Is there anything else I can do?

Thanks, Joe

Seems to me there must be something around the spoke holes that's poking through the rim strip to puncture the tube. I suggest checking the periphery of each spoke hole for little burrs or roughness.

A longer shot is that the tube was damaged when being used with the old rim strip, and now is more easily punctured, or can't take pressure at all.

I've never had a problem like this, and I use Velox tape. There must be something about that rim causing the problem.

Make sure the Velox tape completely covers the hole in the rim. It should extend close to the full width of the channel in between the rim edges. Velox comes in three different widths, get the widest one that'll fit your rim. The smallest size should actually only be used with single-wall rims to cover the exposed spoke-nipples. The middle size is for double-walled road rims and the widest size is for MTB wheels.

Lord Chaos: I've peeled away the tape and found that most of the holes are burred. I'm unburring them now to see if that sorts the problem. I have used two new inner tubes so I think it must be the holes. Thanks

DannoXYZ: I'm using the full width tape - thanks.

Sanding off all the burrs (many - very bad!) did the trick. Thanks

Great! I love a success story on flats being overcome.

filing off the burrs is one step I do when building wheels.

Some one in another tread had suggested a product called velo plugs, they may help more than rim tape in this case it seems.

Aaaarrggghh. Another internal puncture today. Will perhaps look at the plugs - thanks for the suggestion.

I don't get why this is happening though. I even have problems at low (60 psi) pressure.

Joe

I hope you marked the spot on the rim somehow (relationship to valve works) so you can see if it's a burr you missed - or another cause.

Check for a burrs along the inside of the braking surface as well. Basically, check the entire surface of the rim, particularly along the rim's welded or pinned seam. I'm assuming you've checked the inside of the tire.

although rare, if you have a steel bead tire, check that the steel bead isn't sticking through the tire.

I had one tire like this.

I had a good look and found that the tape had slipped (presumably when I last put it on) so part of the hole was visible. Obvious really.

Thanks everyone

If you've peeled off the tape at some point, it won't stick as tightly and may squirm aside. I find a little dab of 3M Fastak #08030 works well to glue it back in place. May not be easy to find that specific formulation, so #08011 or #08014 from automotive parts shops will work as well.

Ah thanks Danno. Maybe that's what happened. I'll look into your suggestion

I wouldn't be afraid to run a layer of electrical (or strapping) tape around FIRST, before putting the Velox back on.

A fairly extreme approach, but ... you're really getting the worst of it ... providing that the deburring was complete and adequate.

This tells me that your tape is too narrow and you need to install a wider Velox. With the proper width, there is no way the tape can slip into the hole and expose the edge.

I often find the 17mm Velox barely covers what I need covered. And I find the 22mm is a pain to stuff into the inside of the rim - need to be very exacting.

I'll take 'very exacting' over 'barely covering' any day of the week. But I do wish they had a few more sizes available.

I think the last time I put it in I must have mucked up. The tape is the full width but in this instance it was half way up the side and slightly folded (and therefore pulled across enough to slightly expose the hole).

I've since gone 60 miles with no more incident. Thanks, Joe