Tyres. I should probably clarify that, because such a long stretch - my longest yet - on winter tyres was far more financially driven that weather driven; I could have knocked off a month either side if I’d any other tyres to hand.
Anyway, after six months of winter (tyres) I was very much looking forward to switching to tyres that weigh half as much and limbering, rather than lumbering, along (you see, because it does get easier when you get to spring). Only to discover my rear wheel rim had cracked around nearly every spoke nipple hole and then to discover my front rim had cracked, far more scarily, circumferentially along the wear grooves seemingly merely biding it’s time until it pounced on me with instant death or serious injury. And then to add the dismay I discovered the crack in the mud on my forks was not actually a crack in the mud, but a crack in the forks themselves. So much for the joy of reaching spring - it was looking like my only immediate option was using my wife’s or the eldest’s bike for the short-term.
Fortunately I discovered the rear wheel problem on a Friday morning after getting to work and so only had to hold a fix together enough to limp home that afternoon. Which meant I then had the whole weekend for a spot of wheel building. The only problem being my rear hub is a 36-hole hub and the only spare rims I had were 32-hole.
I’d worked out on the way home that it was theoretically possible because you just have to miss a hole out every 90 degrees and so in my head it sounded really quite feasible and I thought shouldn’t be too difficult given my previous wheelbuilding experience. I sought confidence by searching on the internet and although I didn’t find much at all I did find someone else had done it - that was enough to satisfy to myself that I wasn’t completely crazy to attempt it.
It was a LOT harder than I thought it was going to be.
Getting the basic pattern together was easy, missing a hole every 90 degrees on alternating sides, but I was left with some spokes that were far, far too long, protruding right through where the rim tape would be. I had a go at tightening it up but ran out of thread on the spokes, even if I’d been able to solve the problem of trimming the protruding length of spoke. Perhaps with a wide range of spoke lengths available this would work fine, but I only had two different lengths varying by 5mm; perhaps also using a new rim and hub might make this easier, but I don’t know why you’d be putting new parts together in this way. I’d started dismantling wheels on the Friday afternoon, spent all day Saturday trying to build the rear and got to Sunday morning absolutely non the wiser and pretty stressed. I had one last, I think fifth, attempt at a wheel build, this time using a pattern I’ll explain using the following diagram:
o o o o o o o o o o o o o o o o o o
(The best 36-hole hub ASCII circle I can draw)
+ x x + + x x o o o o x x + + x x +
- I placed the
xs in first using the shorter spokes I had (this isn’t necessarily logical, I would have expected as you move to the next hole round that a slightly different spoke length would be required) on one side of the wheel, thinking of the wheel as being in two halves split about a plane through the
os, i.e. so I placed four spokes in the top-half of the wheel and then four in the bottom-half. I used a 3-cross pattern so, at this point, working on just one side of the wheel there are three empty spoke nipple holes between each spoke on the rim
- I can’t draw a rotated circle, but, rather than try to repeat this as near as possible to 90-degrees out of phase, I did it just one hole out of phase (so 10-degrees) on the other side of the wheel. The spokes connect on the rim so they are in the holes next to those on the other side, i.e. as per the 3-cross pattern.
- Then, back to the first side of the wheel and again thinking of the wheel having a top-half and a bottom-half, I placed the six
+s in; the
xindicates some spokes are coming out of the hub flange and some are going into the hub flange (I really don’t think it matters which way round you do this). I used my longer spokes for these and made them up as per the 3-cross pattern.
- I repeated this on the other side leaving me with eight empty holes.
- I then filled in two of these holes either side as best I could so that my missed holes were 180 degrees apart on each side of the hub and just one hole out of phase either side. So I don’t have a perfect pattern, as you’d expect, but it actually works! It means that on the rim in one spot I have two spokes next to each other coming from the same side of the hub followed by another two spokes coming from the other side of the hub. And I have been able to get fairly even spoke tension, but most importantly my spoke lengths worked out ok-ish.
Re-building the front was a breeze in comparison!
As to the forks. I had a similar clever idea to use my road forks because after a very quick check these tyres would almost fit. Perhaps with some super-truing I’d be ok; due to the huge amount of time spent building the rear I’d rushed the front and just gone for equal tension and laterally “true enough”. I had run out of time that weekend anyway to attempt to do anything with the forks and cycled the following week keeping a careful eye on the crack.
So now I come to getting the forks to fit. I gave up trying to get the crown race off the road forks. What is on there looks even more rusted on than when I replaced the headset for these broken forks. However, the crown race from the broken forks came in useful as an additional headset/steerer spacer as the length of the road forks was just that little bit greater meaning there was not enough gap between the top of the steerer tube and the stem.
Since I’m using an old rim for the front wheel I think perfect radial truing is out of the question and like the rear it is a bit of an egg. This meant figuring out some way to push the axle down a bit in the dropouts to gain a few more millimeters of clearance. I tried using just clamping force for this but as soon as I was on the bike the axle slipped up causing the tyre to rub. I’m now spacing with a roller from a chain perched in each dropout, which, combined with some of the washers from a Vee-brake block on the axle, spaces everything perfectly to the lips on the dropout. This does of course present problems when it comes to mending a puncture when out and about. It’s going to be tricky. Hopefully, though, this doesn’t have to last forever, just until next month (famous last words).
Finally, because I’ve pushed the axle down in the dropouts the brakes of-course do not fit and come in onto the tyres. I’ve had to saw out the calipers so I can push the brake blocks down just that bit further. It isn’t going to be the best braking set-up I’ve ever had.
Sometimes I look back and question whether certain courses of action or endurances were really necessary. Were things really that bad? Did I really have to do two winters with temperatures at around -15 degrees C before I could spend £15 on some mittens, for instance? I’m sure I will look back and question, “What, I really couldn’t afford £20 (sale price, right now) for some new forks, a safety critical replacement, just because I’d already spent £38 on tyres?” and the answer will be, a quite emphatic:
[EDIT: 2015-04-21] In a couple of hundred miles of cycling I only had to adjust my forks three times due to the chain roller spacer slipping a bit, my wheel going every so slightly skew-whiff and as a result the tyre rubbing on the side of the forks. Not bad going, but I decided to make things better and use two chain rollers side by side in each dropout and also “secure” them in place with an old fence staple (going through the rollers and then squeezed around the lug). I then use one additional chain roller on the side of the axle with the least support. This was the side that would slip off the chain roller a bit. The unequal amount of axle protruding from the cone nuts was simply due to me not reassembling the wheel axle and bearings perfectly. Now there should be nowhere for anything to slip or move and my forks are pretty good. Brakes are still crap though.