small ding, now leaky front rim - temporary fix?

[dcstrom]

I noticed a small ding in the front rim the other day - not the first, had a bigger one taken out in El Salvador, result was perfect. I don't know where I picked up this most recent one, but I'm losing a bit of air from it, about 3-4 psi per day. I inquired at one of the main MC stores in Cochabamba, they said there was no-one in town with proper equipment to fix it properly.

So, I'm about to fit a new front tire, I have a bottle of Slime... I don't want to Slime the whole tire just to fix a small leak on one part of the rim, and anyway I'm balancing with Dynabeads and I imagine they don't play well with Slime! So what if, when I install the tire, I put a dab of slime just on the part of the rim that's leaking?

Worth a try right? Then get the rim fixed when I find someone who can do it.

 

[Dallara]

~


You can use the method we often did with MX and enduro rims when at the track... and that I even used to straighten my BMW R1150R's cast rims when they got dinged...

A rubber mallet.

After all, you only have to get enough deformation out of the rim to stop it leaking, and as long as the spokes are good and tight you shouldn't knock it out of true as long as you restrict yourself to the specific area of the ding.

The last thing I would do is try the Slime. Trust me, it is completely ineffective if applied externally, and even if you decide to put it in the tire you've got problems. If it doesn't work you've got a hell of a mess. If you can't knock the ding out with a mallet and a couple of pieces of softer wood then I'd put a tube in it until you can get the rim properly straightened.

Just my two centavos... YMMV.

Dallara


~

 

[squarebore]

Can you put a tube in until you can get it fixed? Better than slime in my opinion.

 

[Ironhand]

Can you put a tube in until you can get it fixed? Better than slime in my opinion.

+1. I'd tube it until you can get it properly fixed.

 

[dcstrom]

Thanks guys, never straightened a rim using the Dallara technique and worried I might do more harm than good. On the other hand, the rim probably is only 1mm or 2mm at most out of line, so maybe it wouldn't take much to put it back in line enough to seal.

I have a spare 18" tube just for this occasion (18" so it can be used in front or rear in an emergency), but because it's not the "correct" size I'd be reluctant to leave it in long term. Will search and see if I can find a 19".

Thanks!

Trevor

 

[Checkswrecks]

Hi Trev -


I used to ride into the SoCal desert on street bikes to get to parties.
(You & me WUZ kids once)




The bead of a tire is a series of steel wires that can bridge a bend in the rim, unless this is a really sharp indentation. So take the one side of the tire off and simply bend the bead slightly to conform to the shape & location of the bend, then re-inflate. Don't forget to make sure the rim is clean of old tire rubber before re-mounting the tire.

If it doesn't work, you still have the tube.

 

[dcstrom]

Thanks for that idea mate, sounds like it's worth a try...

Yeah I used to ride my R90/6 everywhere, long before the term "adventure bike" was invented. Desert, no problem!

Hi Trev -


I used to ride into the SoCal desert on street bikes to get to parties.
(You & me WUZ kids once)




The bead of a tire is a series of steel wires that can bridge a bend in the rim, unless this is a really sharp indentation. So take the one side of the tire off and simply bend the bead slightly to conform to the shape & location of the bend, then re-inflate. Don't forget to make sure the rim is clean of old tire rubber before re-mounting the tire.

If it doesn't work, you still have the tube.

 

[Dallara]

Thanks guys, never straightened a rim using the Dallara technique and worried I might do more harm than good. On the other hand, the rim probably is only 1mm or 2mm at most out of line, so maybe it wouldn't take much to put it back in line enough to seal.

I have a spare 18" tube just for this occasion (18" so it can be used in front or rear in an emergency), but because it's not the "correct" size I'd be reluctant to leave it in long term. Will search and see if I can find a 19".

Thanks!

Trevor

If a rock or edge of a hole can ding a rim enough to leak, but not crack or otherwise damage it, you won't hurt it with a heavy rubber mallet (I've also used both a leather or plastic mallet before, too) and some pieces of wood used judiciously. And in this case the Super Tenere's front rim is stronger for it's dimensions than the rear (due to the two rib design). Just start with easy taps and work up from there. You will quickly see just how much force is required to start to push the rim back into shape (you'll see it takes a pretty healthy whack)... And again, you only need to get it back enough to seal.

As I said, I've done a bunch in the field this way, and when I bent the front *AND* rear cast rims *BADLY* on my BMW R1150r (big blind hole at high speed) I straightened them via the same method, and the result was so good and so true I rode it that way for another 4,000 miles. The bike has been through two owners since, both friends and riding buddies, and it is still on those same straightened rims... And remember, as a rule, cast rims, like on my R1150R, are much more brittle and likely to crack than the extruded aluminum rims on the Super Tenere.

And it's actually easier to use this method of straightening while the tire is *ON* the rim.

Just FYI...

Dallara



~

 

[Don in Lodi]

This has worked in the automotive world; several layers of patch cement on the rim, layer, let dry, layer, let dry, then a fresh wet layer on the tire and seat it. The cement is an adhesive of course, but it also softens the rubber so it will mold itself to a new shape just a little. Small dings mind you. The sealing portion of the bead is just inside of, and right where the rubber is making the 90 degree turn to become sidewall.

 

[EricV]

What Dallara said. I've used that method in the field, later getting a more professional repair. If you can't find a hard rubber mallet, a 8 ounce steel hammer will work too. Don't use too large or heavy a hammer/mallet, it's too easy to do more damage. And do remember the wood block, it will help avoid marking up the rim, and spread the blow and conform as the wheel goes back into shape.

 

[dcstrom]

So, I never did fix this ding - the amount of air that leaks out of it tends to depend on the particular front tire. Many of you will not be surprised, the Heidenau leaks the worst. 3 non-heidenaus I've had on since then have leaked little or not at all. Since I have no plans for any more heidenau fronts (they don't work for me, and don't last anything like as well as the rear), I'm not going to worry about it.