|Hot weather tire patch n pump||hdnoise|
Sep 24, 2003 4:44 PM
|I generally ride in the cool Bay Area hills. Rode in the valley this weekend, 70mi, 100 degrees.... flatted at end, not a puncture but melted (?) tube patch glue! Removed, repatched (Park fast patch, clear) and ... Silca pump dead. Tried a blackburn, also dead. Later at home the old Silca worked fine. My guess; the pump cylinder/tube expanded in the heat more than the plunger, hence no pressure, and the patch simply heated up over a day of constant riding until it failed. What's the answer for patches and pumps from the hot weather country???|
|You've analyzed the problem incorrectly, twice!||Kerry Irons|
Sep 25, 2003 4:40 PM
|Unless the first failure was of a Park patch, it was not melting glue. Either you had too much glue when you patched or the glue job got contaminated. The heat was a minor contributor to the problem. A properly done glued patch will not come off just because it's 100F outside, otherwise there'd be hundreds of such failures in rides like RAGBRAI and H&H - it just doesn't happen. Park patches are OK but they are strictly a "get me home" fix.
Your pumps failed to work because the leather washers "went floppy" in the heat. The amount of pump barrel expansion is tiny compared to the size of the leather washer. Keep the leather washer greased and you won't have this problem. A quick fix is to put your thumb over the outlet and stroke the pump really fast. This will flare the washer and get things working. A slower, but still reasonably fast fix is to unscrew the end of the pump, flare the leather washer with your finger, and put the pump back together.
|Thanks for the thoughts....still questions tho.||hdnoise|
Sep 26, 2003 11:02 AM
|The patch that failed was a Park, long time in place, not contaminated (tube roughed and wiped with alcohol prior to patching)and ridden a hundred or so befor the failure. What patches do you recommend at home and on the road. Sounds like you would pull a Park and redo at home?
Re. the pump, i did the "quick fix" you suggested, also disassembled, flared and reassembled, to no avail. In any case, any suggestion on a modern pump that is more reliable?
|Parks are not for the long term, and overhaul your Silca||Kerry Irons|
Sep 26, 2003 4:40 PM
|By definition, a PSA (pressure sensitive adhesive) has a softening point. Any "instant patch" uses PSA instead of a fixed adhesive like rubber cement. This is why, no matter how well applied, a Park patch is going to be sensitive to heat. It has to remain soft at pretty cold temperatures to be useful to a cyclist - who wants their patch not to work just because it's near freezing? As a result, the adhesive will get softer and softer as the temperature rises. As stated above, instant patches are a "get me home" device. Take them off and replace with a conventional patch when you get home. Any standard patch kit works for me, whether it be the reference brand (Remo) or the cheapies you can get from Nashbar for $1 or so. The key is using rubber cement, which dries and does not have a softening point in the range of human-tolerate temperatures.
I am a big fan of Silca pumps, whether it be for the bike or the shop. I've used Silca frame pumps since the early 70s with great success. I think if you just grease the leather washer in your Silca, you'll be fine. The reliability of these pumps has been excellent for me.