Bike Forums - View Single Post - Weinmann LP18 Geometry Causes Flats?

11-04-17 | 01:13 PM

#46

DQRider

Old Boy

Joined: Jan 2016

Posts: 2,127

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From: Minnesota

Bikes: Mostly 1st-generation, top-of-the-line, non-unicrown MTBs/ATBs: All 1984 models: Dawes Ranger, Peugeot Canyon Express, Ross Mt. Whitney (chrome), Schwinn High Sierra, and a 1983 Trek 850.

Quote:

Originally Posted by dweenk

I love a good mystery, and this is one of them.

This might sound stupid, but I would install a 700 x 23 or 700 x 25 tire on the rim and see what happens.

No, that's not stupid at all. It says right in the rim specs: SIZE：700CX18C/23C <-- So I was using a tire that was two sizes larger than the specified max. The tubes were of different specs, but basically ranged from 25 - 32c, also larger than the Mfgr's rim spec.

As I said previously, I exceeded the spec because: 1) I have done this with other rims from Mavic, Araya, etc. without any problem, and 2) Sheldon Brown's chart has that disclaimer at the bottom.

This being the case, these are clearly not the right rims for my bikes. I want minimum 28c under me, and I prefer 32s when they fit. CR18 is a good, solid rim and has never given me any trouble. Not having any 23 or 25c tires around, other than dry-rotted takeoffs, I'm not going to buy tires I won't use just for an experiment.

I might try this combination of untested advice you all have given me:

1) On one pair of wheels, fill the channel with narrow rim strips, reducing the volume and eliminating the shoulders as a factor, but not extending out towards the bead track.

2) On the other wheels, fill the channel, then add 1 layer of hockey tape* to plug any gaps on the sides, and trim that carefully so it doesn't enter the bead track.

3) Use the next size smaller tube, since I have effectively reduced the volume the tube has to fill - there will be less material to get into little gaps and cause mischief. Or it will simply fail.

4) Inflate all tires to 90psi, well within the safety limit. Then let the bikes sit for the winter, one on the floor, weight-on-wheels, and one hanging up. Of course I'll check them periodically and "top them off" to 90, just to keep the pressure on - pun intended.

If they are still inflated come spring, I will ride test them and update this thread.

*(My mentor's answer to expensive rim strips: 1 layer hockey tape over 1 cheap rubber rim strip

)

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