Changing a motorcycle tyre usually would not involve a Stanley knife, but this was something of an extreme case. I got hold of a spare back wheel for my Cagiva – all it needed was a wipe clean and some sprocket bolts. And some fresh rubber.
I have changed the tyres on my bike several times in the past year and was actually looking forward to putting my skills to the test once again. The more you practice, the quicker you’ll be on the side of the road in less than ideal conditions.
Well. First, Richard and I used his tried the conventional method using the centrestand of his F650. Then we tried the sidestand. Neither worked, and now the sidestand is bent (Richard charitably noted that there was already something wrong with it and he needed a new one anyway).
So I stuck the wheel in the vice and deployed the home workshop method demostrated by Trent and me in this episode. The bead broke nicely on one side, but on the other it stayed stuck.
OK then – out with the tyre levers, and hopefully if I can get the loosened side over the rim it will pull the stuck side inwards, thereby breaking the bead. The loosened side popped over no problem, but the other side was as stubborn as ever, hard up against the inner lip on the rim.
This is where things started to get ugly. I tried variously jumping up and down on the stuck bead; jabbing it with levers; and sitting with my back to the wall, wheel stood on end, feet on the hub, heaving on the loose side with my hands to try and pop the other bead inwards.
Nothing worked. I was feeling deflated, but not defeated. And by this stage I was very very angry.
The red mist lifted for long enough to realise that I should salvage the tube, so I pulled it out under the free bead.
Then I got medieval with the Stanley knife.
I hacked my way across the tyre until I hit the steel belts on each side. Then I cut around the circumference of the sidewalls, well away from the bead and just below where the tread begins. This area seemed the thinnest and easiest to cut.
The sidewall I had already freed simply fell off, and because I had cut across the centre of the tyre I could peel the tread away as well.
But you guessed it – the stuck sidewall still wasn’t budging, even with so little of it remaining, even with my full weight on it, and even with the carcass of the tyre no longer providing resistance. I could not get a tyre lever in there for the life of me.
Out with the Stanley knife again. On the inward side I ran the blade in between the bead and the rim. Then I managed to force a lever in from the outside until the tip poked through under the bead.
Another tyre lever followed. Then some elbow grease. Then sweet release. The bead finally broke.
From there it was a relatively simple matter of conventional tyre-lever work, levering a lip of the bead and sidewall remnant back up over the rim, anchoring it with that lever and repeating the process.
One good thing came out of this. For the first time I had a good look at the way a bead seats on a rim. And now I understand why you have to first pop it into the centre of the rim before you can lever it off.
When the bead is seated, it is at full stretch around the full circumference of the wheel. You have got no chance with your levers of stretching it any further.
The bead sits on a shelf. The raised outside lip of the rim stops the bead moving outwards, and the shelf has a smaller lip on the inner edge to stop it moving inwards.
When you break the bead, you’re forcing it back over that inner lip. Once this is done all the way round, the bead ‘relaxes’ from its fully stretched position and there’s enough flexibility for you to stretch it up and over the rim with your tyre levers. Not that this is necessarily an easy task.
Now to get the new tyre on, hopefully in a fully orthodox manner. Though I have to admit, hacking away with the Stanley knife was kind of fun …