When I built the Cruzbike V20 in late 2017, I had the opportunity to build my ‘dream bike’. Starting with the naked V20 frameset, I researched and specced the entire bike to be as lightweight and high performance as possible within my budget. I was willing to spend a fair bit, so I went reasonably high end.
I ended up with a very nice pair of custom built wheels from Strada Wheels in England, and a (mostly carbon) Sram Force 22 groupset. The wheels are DT Swiss 240 disc hubs and the rims are Pacenti Forzas, and I had them built with tubeless 25C tyres (Maxxis Padrone) installed. This setup is very comfortable to ride on and also very fast. The wheels are top notch.
Over the past couple of years I have developed a fear of a high speed blowout. I have no idea why, but it has become something that has played on my mind, since I spend a fair amount of time coming down hills at speeds above 40 MPH. My rationale for going tubeless was that this would reduce the risk of such a blowout, and small punctures would seal themselves before the tyre became so flat that I lost control of the bike.
Unfortunately, I failed to consider one particular scenario, and it struck 2 weeks ago. It has never happened to me before so perhaps it was just very bad luck.
I was coming back from a lovely ride to Paddy Slacks and back, a 54 mile round trip. I had put in several PRs and was gunning it. I had earned a 3rd Strava placement for the section from the Granites down to Heriot, and was just approaching the Heriot / Stow turn off at around 25 MPH when I hit something on the road. I have no idea what it was, but I heard a metallic chink and the next thing I knew I was sliding down the road.
The damage from this crash has been terrible. I took a big chunk out of my thigh, one that is still trying to heal 2 weeks later. Similarly for my elbow and forearm. A new Castelli jacket and bib tights were badly ripped. Luckily I didn’t break anything or suffer any serious injury. A few minutes earlier I had been doing 40 MPH, so I count myself lucky I hadn’t come off at that speed.
The bike didn’t get off so lightly though. The left hand (carbon) brifter was shredded by the friction of the road. The left hand (carbon) crank took a similar beating, and the rims were badly scraped. Worst of all, the left hand Garmin Vector 3 power pedal was more or less annihilated, completely destroyed. I’m currently talking to Garmin about a replacement and they need to be replaced as a pair, not singly. It looks like they will replace them for a very modest sum which is fantastic, but still not the cheapest day out on the bike.
When I took a look at the front wheel, I expected to see a big slash down the tyre, something that would be obviously beyond the ability of the internal sealant to repair quick enough to stop a rapid deflation. However, the tyre was untouched. What had happened was this – whatever I had hit on the road had struck the rim with enough force to put a small dent in it. This in turn had broken the seal between the tyre and the rim, which had resulted in an instantaneous and catastrophic front wheel blowout. So the exact scenario I had feared had happened, and the irony is if I had been running tubes I probably would have got home without even realising I had a dent in the rim.
Having now spent time at the side of the road bleeding profusely and slowly freezing in the near zero winter temperatures, I now see what a complete faff tubeless can be, and the mess it makes when your tyre blows out is substantial. I had an idea that it would be easy to reinflate the tyre but I was completely unable to get the tyre to bed correctly, and although I had a spare tube with me I was so cold and sore by this point I ended up phoning my wife for an emergency lift. The idea of putting a tube on with all that sealant mess around wasn’t very appealing, and my core body temperature was starting to drop so I just wanted to get home.
I have gone back to tubes for now – I am trying out the Slime tubes. I have never tried these before so we’ll see how it goes. I don’t think I will be able to trust tubeless again now, given what has happened and the inability of tubeless to deal with small dents in the rim. If the Slime tubes are able to keep enough air in the tyres to bring the bike to a stop in a high speed puncture situation, I will take that and the increased rolling resistance gladly.
I have also learned the hard way just how fragile carbon components are. I had to get a new brifter, and although the crank is fine it has had a nice bit of sanding done to it by the road. Knowing what I know now, I would probably gone with a slightly heavier and lower spec groupset just for the sheer durability of metal vs carbon.
My lovely new shiny steed has been bruised and battle hardened. The good thing that comes out of that of course is that you let go of attachment to the idea of the bike being new and shiny, so that’s also a good thing 🙂
You live and learn!