|Pressure gauge on the Topeak Road Morph frame pump (long)||Old Man Al|
Sep 10, 2001 4:39 PM
|Please forgive my cross-posting of this to several different lists, but I want to get everyone that I can.
I got a new tandem less than 2 weeks ago. My wife and I were on our second ride and I sensed that the rear tire was low. Sure enough, it was low enough that I could begin to pinch it with my finger. So I changed the tube, checking the inside of the tire. As tandems are prone to pinch flats, I wanted to get the tire up to about 100-105psi (the listed maximum pressure was 85psi), but I pumped and pumped and pumped and all I could do (with my new Topeak Road Morph frame pump) was to get it up to about 90 pounds. But it felt plenty hard enough, so I finally stopped pumping and set it aside for a moment. I wanted to check the tube that I had removed to see if I had a simple puncture flat (I didn't find anything in the tire) or a snakebite.
While holding the old tube up to my cheek - BLAMM!! - the tire on the wheel exploded. It exploded with such force that it bent the outside of an Aerospoke rim in two different places. It actually tore the aluminum rim about 2" in one of the two places. I've seen blowouts before, but I've never seen anything with such force before.
That didn't make any sense at all to me. I figured that I must have had a bad tire.
In part because of this, I decided to purchase a tire pressure gauge. So I did a search on http://www.bikelist.org and came across a posting with the following message (in part):
"Has anyone had any problems with the pressure gauge on the Topeak Road Morph frame pump? I just purchased one, and wanted to try it out, so I let some of the air out of a 16" 305 Primo. As I was pumping the tire up I was watching the pressure gauge, and it stopped right on the line between 90 and 100 lbs. and wouldn't go any higher. I kept pumping and the gauge stayed still. My first thought was that I had just bought another useless frame pump, but the tire seemed really hard, so I checked it with my regular gauge. I was surprised to get a reading of 143 lbs. Also, I noticed that before even using the pump, the gauge was already reading 20 lbs. I hope this doesn't mean I actually had my tire up to 163 lbs!"
I thought to myself, WOW!!! My guess now is that I probably had the tire pumped up to 150 pounds or something like that and just didn't know it. I was just lucky that I wasn't near to the tire when it blew.
I contacted the person that made the posting and he referred me to the digest for that list and also mentioned that several other people responded to him privately, but he wasn't willing to share those responses (can't argue with that). As such, what I am interested in is if anyone else has had a credible indication of the same problem that it appears that I had. If so, I would be interested in your response, either privately or to the list. If the response is private, then please let me know whether I can share it with Topeak or anyone else at all. If I can't, then I may include it in some sort of totals, but I won't post anybody's name from a private post on any sort of public list. I figure that you can do that for yourself if you want.
For myself, I'd like to get Topeak to give me a frame pump with a working gauge and reimburse me for a new wheel. If this is a widespread problem, then I think that Topeak should be upfront about it so that others don't suffer from some kind of a mishap as a result. Of course, it is possible that my incident was isolated, but I have no way of knowing without asking. Thank you.
Sep 10, 2001 6:40 PM
|I almost bught the same pump yesterday for our new Calfee Tetra tetra tandem, but I couldn't find a suitable place to mount it and ended up with a tiny little Zefal with a built-in gauge. I'll be sure tocheck the gauge before I have to rely on it.
If not for your post I wouldn't have thought it necessary.
|re: Pressure gauge on the Topeak Road Morph frame pump (long)||bikedodger|
Sep 11, 2001 7:50 AM
|I have a Topeak Joe Blow floor pump that has a gauge that malfunctioned in the same way last week. I caught on that it wasn't reading correctly before any damage resulted and immediately let air out of the tire. The gauge registers 30 PSI all the time now.
I do not know if this Topeak pump uses the same gauge as the Road Morph. I will replace the pump with a non-Topeak pump anyhow.