Ever since building wide carbon fiber wheels for my El Mariachi Ti I’ve had quirky issues with the rear wheel holding air. The front, with a Schwalbe Racing Ralph, has been fine, but the rear with a Continental Race King (Protection, 29″ x 2.2″) would be unexpectedly flat. After two rapid-succession low pressure events at Stony Creek yesterday and an attempt at fixing the tire last night, it was still leaking. Today I decided to try a new rear tire; a Specialized Fast Track Control 2.2″. The new tire seated up quickly without soap, and some Orange Seal tire sealant has it holding air nicely. Unlike the Continental Race King…
From my second ride on the Race King I’ve had issues with the tire losing air, to the point where I would find it dead flat after sitting overnight. After adding more sealant helped, but I noticed a clear liquid (the carrier for Stan’s sealant?) leaking out of the tire along the edge of the rim as it sat, making the bead constantly appear wet. I’d put more Stan’s sealant in it a few days ago, then during yesterday’s ride at Stony Creek I was barely able to go five miles without the tire being so soft that I could hit the rim on flat ground. Reinflating the tire and shaking would seal it up, but then it’d begin leaking again.
Last night I pulled the tire apart to replace the tape and sealant, this time with Orange Seal, and the tire seemed sealed until this morning, when I found a small pool of clear orange liquid beneath the tire (photo). After picking up a new tire today I washed everything off to take a serious look at what was going on. This showed a slice-like mark along part of the bead on the drive side of the tire, with the most heavily cut part being where the tire was leaking most heavily. When first installing the tire I noticed that this part looked a bit threadbare, but I didn’t think it was actually going to be a problem. Apparently it was. The cut can be seen above (or here) and has a corresponding ridge of latex built up on the inside of the tire as sealant permeated through this area (photo).
Because this line directly matches the edge of the rim, I suspect that some of the damage is from riding the tire at low pressures, which may explain why the problem seemed to compound: more low pressure events resulted in more inadvertent hitting the rim, resulting in more places to leak. Since the bead was wetted from my second ride, I believe this started with the threadbare area that I’d initially noticed and compounded from there.
As with the Schwalbe Racing Ralph on the front wheel, the Specialized Fast Trak that I installed today seems to have a good deal more rubber on the bead area than this tire did, so I hope it fares the same as the Schwalbe and just works. I’m getting tired of having a bike whose rear wheel isn’t reliable…
(The biggest downside thus far to the new tire is that it’s 4mm narrower than the Race King. I really liked the Race King’s generally smooth triangle pattern and huge volume, so going to something else is a bit displeasing. The Race King has loads of traction, grabbed nicely on pretty much every surface I’ve ridden, but was still super smooth when on dirt roads or the occasional paved routes. The Fast Trak seems to roll smoothly in the basement and the tread pattern looks promising, so I’m willing to give it a go. This review from 2012 is quite favorable as well. Maybe there’ll be a little more side knob traction than on the Race King as well…)