travelinhobo

The set of rims I have on my bike constantly give me pinched flats. Don't know how many new tubes go in the trash after one flat because the pinch is too long. I've got 2 liners on the rear one now, which seems to work. When a mechanic looked at the depth of the rim interior, he said he'd never seen one so deep. Now the front is giving me problems. I removed the makeshift electrical tape and dried out liner and being nowhere near a bike shop, covered each nipple with 2 layers of electrical tape. Should this be good enough or does it still need a liner? And can you use a strip of a tube as a liner? Thickness seems about right. I should add that some of the nipple heads are broken or missing a side, thus sharpness, thus the possible problem. Thanks.

Andrew R Stewart 

Nipple condition has nothing to do with pinch flats. Are you mistakenly confusing interior cuts with pinch ones? Pinch flats are usually considered to be when the tire is compressed so hard against the rim, due to overloading the tire's capacity (width and pressure) from too much load or when the tire encounters a sharp edged road surface (curb, pot hole, rock). The side of the tire is crushed/pinched between the road surface and the rim edge. Interior cuts are usually from a sharp something inside the tire/rim enclosure that isn't adequately covered by, typically, the rim strip. (Tire liner is usually a term used for a thick and resistant ribbon between the tube and the tread cap of the tire, Mr Tuffys being the most common brand). Rough nipple tops, spoke too long and protruding past the nipple top and nipple access holes in the rim's upper wall (of a double walled rim) are the common causes. Rim strips cover these items, more or less... Rim depth tube flats are usually from the tube being locally stretched due to portions having to fill the available space. This space is beyond the tube's stretchiness and the thin walled result more easily blows out. Star burst shaped holes are common. The area around the valve's base can be particularly sensitive to this as there's different thicknesses of the tube wall in addition to tube stretch. Andy

rhenning

The plastic electrical tape may be compounding you problem as the liner needs to be flexible and follow the curves inside the tire. If you have old tubes you could cut new liners out of them. Roger

madpogue 

Can you post a pic of the interior of the rim? If I recall, BITD, with rims that had a deep center channel, you could get a narrow rope (think: clothesline rope) to fill in the channel.

You should be able to file down any jagged/sharp bits of the nipple heads.

fietsbob

Thorn resistant, heavy duty tubes are molded thicker on the outside, than the side facing the rim.. buy those ..

travelinhobo

THanks to all the responses. As for a pic, I should have taken one last week when I cleaned it all out, but didn't think of it. I like that clothes rope idea and filling in the space. I wondered if the tube could get into that spacing and thought no, but I guess I was wrong. TR tubes are too expensive and I'm not looking for more weight. Rim strips are what I was referring to when I called them liners. The "pinches" are always long cuts, not a hole, not a star, etc. Something is rubbing against the tube (which I find weird since with the psi, it's in there nice and tight).

Elvo

Can you try going tubeless? That way pinch flats are nearly impossible.

fietsbob

regular type tubes are increasing in price, closing the difference ...

travelinhobo

I know nothing about tubeless tires. When I have time, I'll read up on it.
I know tubes have been increasing in price, but I know that there is a big difference in price between TR and non. About $7-9 which maybe when you take into account that you get less flats, equals out, but when you're poor, you're poor. And here's something interesting...Wallyworld sells tubes for under $5, RiteAid for $6 and a hardware store I found in the middle of nowhere, Quartzsite, AZ, sells them for $3.70! Go figure.

rumrunn6

do you want to line the rim or the tire? my rim tape moved a cpl years ago & I got this flat





fortunately I carry rim tape with me just in case



recently needed more & had to trim some wide tape I had. laid it our on a door sized piece of cardboard & used a fresh utility knife blade. worked fine. but I think trimming an old tube would be pretty labor intensive. so, just go buy the good stuff & be sure it's narrow enough for your rim

fietsbob

I was Pleasantly surprised, 1st time I replaced the (559-47) tires on wheels with Mavic EX 721 Rims ....

they designed them to have a channel , that the fused plastic loop rim strip snapped into and would not shift....

Midnite

wow thats great

travelinhobo

Rum- I already have tire liners in both tires (which have proven to be a waste as I've had 3 goatheads easily get past them to give me flats. Luckily someone gave me the liners and it wasn't my wasted money). We're talking rim tape here even though it's not necessarily tape. And I've already cut up a tube as a rim liner when it goes flat again, so I'm not sure how labor intensive you think slicing a section off a tube is and detailing it when it goes on.

CliffordK

The old rubber rim tape is only supposed to be used on single-wall rims, not double wall rims.

I don't think I'd use a tube, unless it was in a severe pinch of not having parts, or on a single-wall rim.

You can buy new rim tape pretty cheap. I'm not quite sure the perfect brand. I have come to not like the cloth Velox tape as it is too thick. I've been using some form of plastic tape on most bikes.

I have used electrical tape on one bike in a pinch, but I believe it is only a matter of time before it will poof out and fail. I should probably replace the tape eventually.

On one bike, I've used Velocity Velo Plugs for all the holes. Then as the plugs are narrow, covered them with a single layer of electrical tape (off-center rim with asymmetrical pressures on the plugs).

travelinhobo

I deflated my front tire yesterday and found that the tube was about to bust. Pics below are the 4 bad areas on the tube (2 on either side of the valve stem but 3-4 spokes away. Valve stem area had no problem). As you can these are splices. Also inc 2 photos of the rim interior. You can see the depth of it and my taping. I used a part of an old tube as a rim liner, tho it was too long so I had to end up cutting off some inches and then taping the 2 ends together. Feel free to comment.

rumrunn6

nice save! still think some thick cloth rim tape is in order