totheDude

A month ago I bought a 1997 Specialized Rockhopper for my son.

Unfortunately, it has been a nightmare in terms of flats. We have had more than one per week. We even suspected vandalism at school, but this weekend it's happened again at home.

With the last 3 flats I noticed something strange: the puncture is facing the rim, not the tire. As an example, here's the latest flat, which is the first one in the front wheel:


The puncture is quite evident, also because the tube has a fluid that oozes out. I am guessing this is some kind of "self-healing" tube:


It looks like this maybe the original tube.
At any rate, I looked on the rim whether I could fine something at the location of the puncture, and sure enough, that corresponds to one of the spokes, which causes a protrusion that I can clearly feel below the liner:



And looking around on the rim, I see that the previous owner put some electrical tape on the liner:


Which brings me to suspect that the rim is what is actually causing these flats. But why?

Here are the other parts:
1. Tubes. So far, I have bought cheap Bell tubes from amazon, and switched to the self seal variety. It is worth investing in better tubes, at ~3x or more the cost?
2. Tires. These are the tires:



They seem in reasonable conditions:


3. Rim/wheels. Can I buy an additional liner for the rim?

Also, I tend to pump the tires to the max. of the 35-65 psi suggested tire pressure, maybe I should back off a little.

Appreciate tips from the experts here.

soyabean

Economy rim tape is just a layer or rubber as seen here.

Real rim tape is much harder, slick, plastic-like

You may also be putting in too much psi. Those tires are best at 35 psi.

If you like max psi, invest in some Marathons, perhaps 1.25's

DiabloScott

I had a wheel once that got a lot of flats that looked like spoke pokes... but the rim tape was good and I couldn't figure it out. Eventually I just gave up and put a second layer of good rim tape over the top of the first one and that solved the issue.

That's what yours looks like too. I'd take off the old stuff though because it is damaged - then go ahead and double wrap since your tires aren't especially tight.

FBinNY 

Start by taking the rim band off and seeing if that spoke is sticking up, then check ALL the spokes.

If any spokes are sticking up to close to the height of the rim, they should be filed or ground down.

Once that's done, consider a ballistic tape that won't stretch into the holes when the tire is inflated. You can buy one made for the job, or use filament tape.

For future reference mark the location of punctures, so you'll know if you have a specific issue or random bad luck.

SHORT CUT. if you have a suspect spoke, try pushing your forefinger down hard through thee rim band and feel for the spoke. If you feel a sharp edge that way, it's likely that that's the issue. If your finger bleeds it's definitely the issue.

tFUnK

Many years ago I thought I was clever by using electrical tape as rim tape. A few spoke side punctures later, I learned that electrical tape should not be used as rim tape. Get some proper rim tape and you'll be fine.

Crankycrank

I always prefer the cloth "Velox" tape. Seems to protect longer against spoke hole damage as it doesn't crack or split over time. Just measure the width of your current rim tape and find the matching Velox. There are a few good quality plastic tapes around too but I just find that the cloth is just a little more protective and can be easily removed and re-used if you need replace a spoke nipple at some point. Either Cloth or Plastic will be an improvement over the rubber/elec tape setup you have now. Some examples here or check your local bike shop. velox cloth rim tape for sale | eBay

dsbrantjr

I use Continental Easy Tape exclusively. It is thinner and slicker than the Velox cloth which makes mounting tires easier. Won't creep like electrical tape or filament-reinforced packing tape. https://blobs.continental-tires.com/...ip-en-data.png
Make certain you choose a width which covers the whole rim base so that the tape cannot shift sideways, exposing the tube to the spokes and nipples.

Clyde1820

I've used the Velox tape with good effect. But that presupposes the rim's spoke heads don't have any protrusions.

+1 on the above suggestions for verifying the rim itself isn't what's poking into the tube, and installing a high-grade set of "tape" for the rims.

totheDude

Thank you for the suggestions. In the meantime, I ordered this one. It will arrive tomorrow. At that point, I will remove the old liner and take some pics of the spokes' ends through the rim.

Both the Continental ($$$) and Velox are available on amazon.

Kontact 

That stuff might work, but it doesn't say how wide it is. Too wide and you won't be able to mount the tire. Too narrow and the tape will slide sideways and expose the nipple.

Rim tape needs to be the right width and (in the case of the non-adhesive kind) the right circumference.

totheDude

It's 18 mm wide. Hopefully that will work. If not, I will return it.

tendency

Also, check the spoke tension. Significantly under tensioned spokes will cause repeated flats.

Gresp15C

I've had the same kind of flats, with the same mysterious "there's a little dip in the rim tape but it's not huge." When it's happened, it's been on tires that were otherwise flat-free for years thanks to puncture resistant tires. In your case, the sealant-imbibed tubes might have done the same for you. My hunch is if you patch the places that are thinned out, you'll be fine. But you probably have to make sure you've cleaned the sealant off really well before attempting the patch.

Basically once you've eliminated the major sources of flats, eventually the minor sources will get you. I'm OK with that, a couple flats every few years is insignificant in the grand scheme of things.

On the bright side, your son now knows how to deal with flats.

veganbikes

Continental rim tape is not expensive it is a long use item. Yes Multi-Billionaires like Jeff Bezos can sell various products much cheaper and still be the richest people in the world with more money then the GDP of most countries but you do pay for quality in cases like Continental. I use that stuff on many of my wheels and some I have had for over 8 years with no issues and no need to replace at the most expensive I saw it in my brief search it would cost me 2.11 a year for rim tape over those 8 years and it is still going with no signs of deformation or anything like that. At the average price I saw online of about $11 it is even cheaper per year and in the end not really more expensive then the stuff you bought by more than $1 if that.

Only rich folks have the money for cheap goods. I buy initially more expensive stuff because I don't buy it as often because I don't have the money to replace stuff more often. You can think you are saving money in the extreme short term on that one purchase but in the long run it can get more expensive if it doesn't last well or you bite the bullet as they say and pay that little bit more at the start but it lasts and lasts. There are some places that you can save some cash and still get decent stuff but if the item is only a small margin more expensive in the end it is just worth it to spend that little extra getting a known quantity and quality.

79pmooney

To do this right and have a good wheel for your kid from now on: Go to a bike shop and buy two rolls of Velox rim tape. First lift out a bit of the rubber strip that is there now and measure its width. That width, running the full width of the bottom of the channel is what you want. (Two rolls so you have one for the other whether you put it on now or later.)

Now, remove the rubber tape. Look at every spoke tip. Does it stick out? If yes and you really want to get this right, take a narrow file and file each offending spoke down to the nipple top. (You can do less but if the tire is ridden without enough air, it may slide, dragging the tube over the tape and eventually the spoke end will work through the tape.

Last, put that correct width Velox on neatly and pulled tight. (It's quite forgiving. You can re-stick it a few times to get it right.) Mount the tire and tube, pump partially and check to make sure it is mounted evenly. (Spin the wheel and look for lumps and wobbles.) Finish pumping and done. That tape will last 10 years, maybe far longer.

icemilkcoffee 

I can't see any protruding spokes or protruding nipple that would cause a puncture here.
I had one puncture which was also on the inner diameter of the tube. I traced it to the stiff edge of the rim tape that was sticking up slightly out of the u shaped trough of the rim. It rubbed through the tube. I changed the rim tape to a wider tape and all was fine after that.

cjenrick

Feel around the edges of the rim for any rough burrs and take down with #300 wet or dry.

How many holes when you get a flat?

If two, then your rims are the problem.

Certain designs like mavic e2 (way old) and araya 7x (old) have cause me much grief in the past.

One time I got 3 flats on one mountain bike ride. I got so pissed I stripped the tube and tire off and road 5 miles home. Didn't get a flat but every spoke was spaghetti loose and the rim was toast.

I did drop everybody because there was zero rolling resistance but the sound was deafening and the corners were like "look out!"

I use innertape 4616 which is a glass cloth tape used for transformer winding.

You can get 60 yards for 8 bucks on evilbay. Good for 2500 volts so if you get hit by lightening the tube won't pop. Stretch it tight. Maybe 2 laps.

Velox is such a rip nowadays, use to buy it for 50 cents a roll back in 68, now it's ten bucks a roll , save it for the bars.

Kontact 

The hole is very clearly centered on a spoke nipple. I don't see how much detective work this requires.

The tape the OP has coming should be fine if it fits correctly. I like using that kind of tape on lightweight builds in preference to adhesive cloth.

The OP's problem is that his current tape is falling apart, not that there is a conspiracy by the rich.

RB1-luvr

put talc powder in the tire prior to inserting tube. this let's the tube move around and not stick to surfaces.

Schweinhund

Self sealing tubes work on the concept of centrifical force. Your wheel spinning creates an outward force that spreads an even layer of shmoo around the outside ring of the inner tube.
The big caveat is that it won't seal what it doesn't touch and it doesn't touch the part of the tube you need for that puncture when there's pressure in the tube and the wheel is spinning. sealer requires pressure to do it's thing..

veganbikes

I never mentioned a conspiracy but you missed the rest of the quote so I get it it is easy to make a small quote and miss the rest. I also didn't mention adhesive cloth tape

Kontact 

Okay. But it's just rim tape.

totheDude

Update. First, the 18mm rim strip was top wide. It's going back. Instead, I bought the 10 mm Velox tape.
Today we removed the old rubber strip from the front whee, and what we saw is this:



There are no spokes sticking out. But those end pieces are slotted (for a screwdriver?) and those edges can be sharp. Se we filed the tops a bit, then applied the 10 mm Velox tape:



On the rear wheel, we discovered that somebody had already replaced the rubber strip with Velox tape, but it was the 22 mm cut down to size:




We just taped another layer on top of it.

Now we hope for longer times between flats.

totheDude

Update: we had another flat.
Now a pattern starts to emerge. This is, again, facing the rim. But it is not a puncture: it's a slit, about 1/2 inch long. You can see the fluid from the Bell self-repairing tube oozing out of the cut:



And, the cut is in that portion of the tube with small ribs across the tube. This is a small section of the tube, a couple of inches long only.
Looking at the rim:


We can see that the location of the cut corresponds to a spoke, but there isn't anything sharp beneath the new rim tape.

So how was this cut generated? Right now, I am leaning towards a material failure of this crappy tube. It is the second time that I notice this happens in the ribbed section.
Let me know if you agree.

maddog34

pinch from a tire lever.
Cure.. don't get greedy while installing the tire/tube.

tube pinched between the tire bead and rim.
Cure... inflate the tube enough to keep the tube out from under the bead as you lever the tire on. Work the tire on in smaller sections,... no more than 4" at a time.......and don't EVER force the lever over as far as you can, ok?

best cure... learn to remove and install tire/tube combos without using tire irons, if possible..some tires simply won't allow this,but do as much as possible before resorting to the evil levers.

i "break the bead" all around the tire before removing it... push one bead inward into the "valley" before slipping a lever in.... by breaking BOTH beads off the seat, pushing the valve stem in so that it's not holding the bead in it's zone, then grasping the tire opposite the stem and SHAKING IT, the beads drop into the valley and i can USUALLY get the tire off with No Levers...this takes practice and doesn't always work, but wth, eh? some tires REFUSE to allow this... MTB tires sometimes fall off without the "shake' maneuver

good luck.
just for kicks... mark WHERE the flat happened on the outside of the rim. See if it happens in that same spot again, or if it migrates randomly....

another good tip... get the tire/tube on the rim.. then Air the tube up to about 5-10 lbs... THEN, go around the tire and HELP the Bead Onto the rim by grabbing and twisting the tire side to side, in both directions, a bit... this allows the TUBE to pop out from under the bead and will also help Center up the tire... i then help the Stem get in position too..... cool, huh?