A true improvement

My trusty mountain bike has served me well for about 14 years. It has, however, been increasingly showing signs of wear and tear. Perhaps the most serious problem is that about 3 years ago I accidentally stripped the thread on the bottom bracket shell and since then I’ve had to rely on threadless bottom brackets. These are a handy invention but don’t seem to be quite as robust as the more traditional kind and, in consequence, I’ve had to replace the unit at least once per year since I started using them. At around ¬£20 a pop, it would take a few years to amount to the cost of a new bike but it’s certainly quite frustrating and potentially takes the bike off the road for several days at a time (and necessitates a fairly long walk home pushing my suddenly non-functional bike if the component fails suddenly mid-ride).

Therefore, when the bracket went again a couple of weeks ago as I was cycling up a steep hill (fortunately within half a mile of home) I decided the time had come to get myself a new bike. This is actually a move I’ve been considering for at least a year and I had more or less decided to go for a hybrid bike this time. These are, as the name suggests, somewhere between a mountain bike and a racing/touring bike in style, generally with a relatively heavy non-suspension frame (the lack of suspension is actually a good thing if you’re sticking mostly to road riding, as suspension tends to soak up a lot of energy that would otherwise be translated into forward motion), fairly large, narrow wheels (again, more efficient on-road, though tough enough to withstand light off-road use), mudguards, a luggage rack, straight handlebars (positioned relatively high) and a wide, comfortable saddle.

I found a reasonable looking bike for a reasonable looking price on eBay, ordered it and was excited when it arrived a few days later. Putting it together was fairly straightforward and all seemed to be well.

I was somewhat less impressed the next morning when I set off to ride to work and discovered that the front tyre, which I’d pumped up the previous evening, was pancake flat. With no time to fix it, I leapt on my trusty reserve bike and headed in to the office. On my return, I checked out the inner tube and concluded that it had a faulty valve, so I threw it away and installed a spare.

For the next couple of days the bike functioned fine but I did notice that the front wheel had a very pronounced wobble. The hub and rim both appeared to be fine, so this was evidently a truing problem caused by improperly tensioned spokes, although a quick inspection didn’t turn up any that were obviously significantly tighter or looser than the rest. A quick google search indicated that this is not an uncommon problem on new bikes. One helpful video I watched (along the lines of “Top 5 maintenance tasks required on almost all new bikes” – which listed truing the wheels at no. 1) suggested that if a wheel was out of true it should be taken back to the seller to have them put it right; however, the video’s presenter conceded that this isn’t necessarily practical when you’ve bought the bike by mail order so this left me with the alternative of doing it myself.

In the past I’ve occasionally tried truing the wheels on my other bikes, with limited success (and only based on trying to understand written descriptions of the process rather than watching videos on how to do it). This time I watched a handful of videos and quickly came to the conclusion that the job should be reasonably straightforward and I wouldn’t need to invest in a wheel truing stand but probably would benefit from getting a reasonably sturdy bike maintenance stand (another purchase, like the new bike, which I’ve been considering for some time). I returned to eBay and found a decent looking one within my budget, so I ordered that (and a new spoke key for good measure, as my old one’s one of those cheap circular ones with about 8 different slots and it’s a real pain to try and get the right one – for the new one I went for a triangular thing with only the 3 sizes I’m likely to actually find on any bike in the wild) and sat back to wait for it to arrive (well, obviously I did other stuff while I was waiting, but none of it involving my new bike).

The spoke wrench arrived within a couple of days and the stand was here by this Monday, so I quickly assembled it, clamped up the bike and had a go at truing the front wheel following the advice in the videos I’d watched (supplemented by a quick glance in my bike maintenance book to check I’d correctly understood which way to turn the spoke nipples in order to tighten them). I won’t go into details here – if you want to true your own wheels (or just understand the process) you can easily google instructional materials for yourself. Suffice it to say that, within about half an hour, I’d got the wheel running more or less true. It’s not quite within the half millimetre that professional wheel builders apparently strive for, but considerably better than it was.

For the last couple of days I’ ve been riding the new bike again and so far it’s been working fine. Having a more or less true front wheel definitely seems to make quite a big difference, and I’m hoping it won’t require too regular adjustment (the back wheel seemed fine as it was, and again I hope that won’t need tweaking for a good long while yet).

Now I can concentrate on getting used to the slightly different riding position and gearing that my new bike has from the old one.

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It’s behind you

I was skimming through my blog archives recently and I came across a post I wrote back in April but didn’t get round to publishing. It’s nice and short (compared to my usual essays) and made me chuckle when I reread it (having forgotten all about this idea since I first wrote it down), so here it is for your entertainment and edification:

When I was learning to drive, many moons ago, one of the basic lessons drummed into me was “Mirror – Signal – Manoeuvre”; in other words, before you make any significant change in your motion you should first check that the coast is clear (including, but not limited to, checking behind you with the aid of your mirrors), then signal your intention to other road users.

This is eminently sensible advice. It’s good for cyclists as well as drivers although, of course, it’s fairly unusual to find bikes equipped with mirrors. I know such things do exist but I can’t remember when (if, indeed, ever) I last saw one in the wild.

In order to keep the mnemonic letters MSM but make it a bit more appropriate for cyclists, I’ve taken to thinking of the first word as Monitor rather than Mirror.

It recently occurred to me that a further tweak could perhaps make it even more memorable. My new, and hopefully tastier, mnemonic is MSG – “Monitor – Signal – Go”.

Apart from sharing its initials with a popular food additive and saving a couple of syllables, this has the benefit of not requiring you to remember how to spell “manoeuvre” when you’re writing it down. ūüôā

Something to torque about

For quite a long time now, I’ve had at least a theoretical grasp of the importance of correct torque settings for bike mechanics. Recently, though, I had practical confirmation of this — and of why my recent purchase of a torque wrench was money well spent. In the process I also discovered a handy alternative to my previously limited repertoire of ways of dealing with a stripped screw head.

Torque is essentially a measure of turning force and in this context it amounts to how tightly you do up your nuts (stop sniggering at the back there!). If you want to know more about the gory details, Google can furnish you with many happy hours of reading material.

The reason that torque is important for bike mechanics (and I’m sure also for many other engineering-related disciplines but I’ll try to stay focused here) is that if you don’t tighten up nuts and bolts sufficiently, parts tend to drop off the bike at inopportune moments, while if you overtighten them you not only make them harder than necessary to remove when the time comes for maintenance but run the risk of doing damage to various components. Unfortunately, while it’s generally fairly obvious which bits need to be tightened a lot and which bits can and should be left looser (though there may be a few surprises in store), it is pretty difficult – even with quite a lot of experience – to correctly judge torque settings by feel alone. As a rule of thumb, which seems to be borne out by my own experience, the tendency is to overtighten parts which shouldn’t be too tight and to insufficiently tighten ones which should be good and tight.

Having had a few bad experiences in both directions, I finally got round to getting myself a torque wrench about 3 years ago. I went for a traditional beam-type one since they are relatively cheap and robust. I already had a socket set (probably one of the single most useful tool purchases I’ve ever made, especially for non-specific bike tools) so this, along with a handy chart of torque settings found in the back of my bike repair handbook, enabled me to get at least into the right ballpark with my torque settings. The downside of the beam-type wrench is that it can be quite difficult to accurately read the scale as you need to be able to look at it head on to avoid parallax errors; this is sometimes virtually impossible to achieve while you’re actually using it (or maybe it’s just my poor technique?). Even if you do manage to get it at a good angle, this particular wrench doesn’t have a particularly finely grained scale so the results are necessarily fairly approximate.

I therefore decided a few weeks ago to invest a little bit more in a click-type wrench. This is basically a ratchet driver which is set up so you can set it to a desired torque setting and it will “click out” when you reach that level of torque. They are somewhat more delicate than the beam-type, and may need occasional recalibration, but as long as it’s well looked after a click-type wrench should work well for a good long time. It certainly makes it much easier to achieve a specific torque setting as you can feel rather than having to see when you get there.

The main disadvantage of click-type wrenches is that they tend to have a relatively limited operating range of possible torque settings, and it’s just about impossible to find a single wrench that will cover all the settings needed on a typical bike. I decided to start by getting one that would do the low-torque settings (mine goes up to 24Nm) since I’ve usually found I’m more likely to overtighten than undertighten things and my beam wrench also seems to work a bit better for giving it quite a bit of welly (to use the technical term). At some point I may also get a click-type wrench to cover the higher torque range, but it’s not a very high priority at the moment.

When my new torque wrench arrived the other day, I was enthusiastic to start straight away on checking that all the various fittings on my bike (or at least the low-torque ones) were tightened to appropriate levels. This went well until I got to one of the bolts holding the brake arms on to the frame. The bolts for these particular brakes (which I put on as replacements for the original front brakes a couple of years ago) appear to be made of aluminium and I discovered that last time I took them off for maintenance I overtightened one of them to the point that the recess had started to deform and the hex key would no longer grip sufficiently to be able to undo it. Looking on the bright side, it’s better to discover the problem now rather than waiting until the brake had seized up and needed imminent maintenance while I was stranded on a roadside miles away from home.

My usual trick when faced with a screw or bolt with a damaged head that will no longer take its usual driver is to use a hacksaw to cut a slot so that I can attempt to use a flathead screwdriver on it instead. Sometimes this works and often it doesn’t (not to mention being a non-starter when the entire bolt head is recessed and you can’t get in to cut it. On this occasion I tried my usual trick and it failed.

Since the brake is a pretty important component to be able to keep in good working order, I didn’t really have the option of giving up on it. I didn’t fancy trying to drill the bolt out in the hope that I could somehow cut a new thread and save the frame to be able attach the brake again. Nor was I quite ready to admit defeat and take the wretched thing to the bike shop, so I used the time-honoured research method known as Google to explore alternative ways of fixing the problem.

This turned up two possible solutions I’d previously been unaware of. One is a little gizmo known as a screw extractor — basically a drill bit that you use to drill into the stuck screw in such a way that it basically unscrews itself. The other is a little bottle of stuff which isn’t quite glue but seems to have the effect of providing a better grip so that your tool can get enough purchase on the damaged screw to be able to turn it. There appear to be several brands, pretty much all of them of American origin, which may or may not be the same stuff under the different labels (it seemed to be pretty vague about what’s actually in it); the cheapest I could find was one called Screw Medic (costing about ¬£3 for a small bottle, but it’s supposed to have a pretty unlimited shelf-life and only require a couple of drops per application, so it should last a fair while). This latter option seems a bit more straightforward to use than the screw extractor but only work on screws with fairly light damage, while the extractor should get pretty much any screw out.

Undecided as to which option to go for, impatient to wait and try one before ordering the other if the first didn’t work, and figuring that knackered screwheads seem to crop up fairly often (perhaps due to my previous lack of care and attention to appropriate torque levels — or making sure I’m not using a Pozidriv screwdriver with Phillips screws or vice versa), I decided to order both. The Screw Medic was the first to arrive and was awaiting me when I got home from work this evening. I’m delighted to say that it worked wonderfully and I was easily able to unscrew the damaged bolt and replace it with the one that I’d saved from the old brake (evidently a steel bolt and much sturdier than the other, though I still took care to tighten it carefully to only the required 6Nm with my new torque wrench).

So when the screw extractor set (there are actually 4 or 5 different bits for different sizes of screw) arrives, hopefully in the next few days, it may be a while before I need to use it. And if I make good use of my torque wrench (and my Philips and Pozidriv screwdrivers) I may never need to use it. Which would be fine by me.

In praise of green goo

An occupational hazard of doing your own bike mechanics is that your hands are liable to get dirty.

Bike mechanics is certainly not the only thing I do that requires a bit of a clean up afterwards, but it’s definitely one of the activities most likely to stretch ordinary soap and water beyond the limit of what they can handle, especially if I’ve been working on the chain or other greasy bits of the bike.

Fortunately there are stronger cleaning agents out there than just soap and water.¬† Over the years I’ve tried several different ones with varying degrees of success.

Recently I’ve returned to swarfega, which I used to use quite often when I was growing up but haven’t touched for probably the best part of 20 years.¬† I discovered that it’s actually just about the most effective hand cleaning agent that I’ve tried.

As an added bonus, its distinctive aroma and green, gloopy appearance and texture give me a nice nostalgia trip every time I use it.¬† And you don’t need to use a huge amount even if your hands are properly grubby, so the small pot that I bought about a month ago should last me quite a long time.

 

To clip or not toe clip?

Just over a week ago, my bike started making some alarming squeaking noises from the vicinity of its transmission system (i.e. chain, bottom bracket etc.).

At first I didn’t have time to properly investigate, so I just slapped on some WD-40 (in case it was a simple lubrication issue) and hoped for the best. ¬†That seemed to clear it up for about a day, but the problem soon came back and in addition to the disturbing noise I was becoming more aware of something feeling decidedly out-of-kilter.

When I investigated further, I discovered that the problem was in the right-hand pedal, whose bearings seemed to be on their last legs.  This was both a good and a bad thing, but on balance mostly good.

The main downside is that the pedal is essentially a sealed unit so there is no way to get in and mend it and the only option is to get a new one (or ideally two, so you retain a matched pair).

The first positive thing is that it’s a lot easier and cheaper to replace a pair of pedals than the entire bottom bracket assembly, which I had feared was about to go the way of all flesh.

The second positive is that I didn’t actually have to buy new pedals as I was able to take the ones off my mountain bike (which is currently and probably permanently off the road due to a bottom bracket shell issue that I’ve previously mentioned) and put them on my road bike. ¬†Fortunately, unlike many of the other fittings of this bike (which is a fairly old French one), the pedals seem to use the same standardised size of fittings as most other bikes.

The third, and possibly biggest, positive is that, as a result of putting my mountain bike pedals on the road bike I’ve finally got round to getting toeclips onto it, which I’ve been intending to do more-or-less since I started riding this bike (or at least since I restarted using it a couple of years ago – I hadn’t become a convert to the joys of toeclips when I first had the bike).

Toeclips are designed to enable¬†both of your legs to exert force the whole time you are pedalling, rather than just the leg which is pushing down at any given time. ¬†This, fairly obviously, increases the efficiency of pedalling and is an especially noticeable benefit when you’re cycling up steep hills (a more or less unavoidable feature of cycling in Wales). ¬†As an extra benefit, they also ensure your feet remain in a more-or-less optimal position for pedalling (assuming you’ve got the bike set up correctly), with the balls of the feet making contact with the pedal.

In both these respects, pedals with clips are better than traditional pedals without clips (which, confusingly,¬†are not the same thing as clipless pedals), while retaining the convenience of being able to use them with more or less any shoes. ¬†The only real downside is that the clips are a bit bulky and can get caught up on passing obstacles when you’re wheeling the bike, but it’s not a great problem.

Clipless pedals are ones which come with some system of cleats (there are also quite a few mutually-incompatible clipless systems), which enable you to attach your feet securely to the pedals to get the same benefits as using clips but to an even greater degree. ¬†I’ve never tried them myself but they are supposed to be better than clips both in taking up less space (in fact, they are usually quite a bit smaller than ordinary pedals without clips) and providing better energy transfer. ¬†They potentially also make it harder for somebody to grab your bike and ride off with it since you can’t easily ride them without the proper shoes. ¬†That, of course, is also the main downside since you need to get a special pair of shoes (in some cases, it’s an ordinary pair of shoes to which you add cleats) to use the bike and, I think, you’d probably need to carry another pair of shoes to change into when you got off the bike as it’s probably not very comfortable (or good for the cleats) to walk far on them.

In any case, I’m very happy with my clipped pedals, which I’ve had on my mountain bike for the past 8 or 10 years and show no immenent signs of wearing out.

 

Fixing it before it brakes

There is an old adage which says “If it ain’t broke, don’t fix it”.¬† Apart from being a great way to wind up prescriptive grammar pedants, there is a lot of wisdom in that remark.

However, there is also an adage which says “A stitch in time saves nine” (i.e. if you fix a problem before it gets too big you can save yourself a lot of work later on).

When it comes to bike maintenance, it’s probably a good idea to find a balance between the two – to avoid unnecessary and potentially counter-productive futzing with stuff that’s working fine but to pick up on developing problems before they get too big, especially when it comes to important systems such as the brakes (arguably the single most important bit of a bike).

Flicking back through my last few cycling-related posts, I notice that the last time I mentioned which bike I was using (just over a year ago) it was my mountain bike.¬† At the time, my road bike was down for maintenance as I was unable to find a suitable freewheel tool to enable me to take the freewheel off the back wheel in order to replace a broken spoke.¬† Fairly shortly after that post, I gave up on looking for a freewheel tool, bought a cheap but reasonably effective pair of new wheels (so they would be a matched pair) and a freewheel with a standard modern fitting, and got the bike back on the road.¬† That was just as well, since a few months ago my mountain bike developed a problem with the bottom bracket (essentially, the thread on the shell seems to have stripped itself) which will probably be quite expensive to fix (if it’s actually possible) and I’m currently operating with just one bike again.

Over the past few weeks I’ve noticed my brakes were getting a bit sluggish (and they don’t have the greatest stopping power at the best of times, as they are only caliper brakes with fairly small pads, not nearly as good as the V-brakes on my mountain bike).¬† A couple of days ago I decided it would be a good idea to adjust them while I was still able to stop the bike (and I had a couple of other minor maintenance tasks to do at the same time).

As well as rotating the brake pads to achieve more uniform wear (there’s still plenty of rubber left on all of them but the front ones were wearing quite a bit faster than the back ones) and adjusting the spacing between the pads and the wheels, I decided it would be a good idea to change the rear brake cable since the old one was beginning to look a bit worn out.¬† I had bought a couple of replacement brake cables shortly after I last changed them (sometime last year, I think) as I usually like to keep spares of that kind of thing.

I’ve replaced quite a few cables on my bikes over the years and it’s a fairly easy job.¬† This time, however, I learned an important lesson about how not to do it.

Having slotted the appropriate end of the (inner) cable into the lever and fed it through the outer cable (which I wasn’t replacing), I connected it up to the brake caliper, adjusted it to give a decent gap between the brake and the wheel rim and then trimmed off the excess cable, leaving a couple of spare inches for adjustment.¬† I then went to test the brake and discovered that the cable had popped out of the lever while the tension was relaxed.¬† In order to get it back in, I had to undo it at the caliper end and pull it back through a bit.¬† Unfortunately it was a tiny bit too short to fasten safely in at that end once I’d got the other end reseated in the lever.

Rather than trying to attach it anyway and hope for the best, I decided the sensible course of action would be to chalk it up to experience and try again using my second spare cable.  This time, I made sure everything was attached at both ends and thoroughly tested before I cut off the excess cable!

The first cable wasn’t wasted either, as I decided to use that to replace the (much shorter) front brake cable which, although not as decayed as the back one, was beginning to show some signs of distress.¬† Hopefully both the new cables will last a reasonable while (at least until next Spring), and I’ve already ordered a couple more spares.

One Summertime (or, Measuring a summer’s day)

As I was saying yesterday, summers tend to be all too short in this part of the world.

This fact was confirmed for me today when, having put on shorts and a t-shirt this morning because this week’s glorious summer weather appeared to be continuing, I found myself having to cycle home from work in my shorts and t-shirt in the rain.¬† As I went along, I cheered myself up by singing a rendition of George Gershwin’s Summertime (with a fairly heavy dose of irony).

This lead me inadvertently to the invention of a new unit for the measurement of distance.

As you may recall if you’ve been reading this blog for long enough or have browsed far enough through the archives, a while ago I ran a series of posts about units of length, relating them all to the span of the Menai Suspension Bridge (NB that link is actually to one of my blog categories; most, but not all, of the posts relate to that particular series).

It just so happened that I started singing Summertime (one complete run through at moderate tempo) more-or-less as I was getting on to the bridge and I finished it at about the time I reached the far end.  Therefore, it occurred to me that I could measure the length of the bridge (or anything else for that matter) in terms of the length of time it took to sing the song.

I therefore (loosely) define a Summertime to be the unit of length equal to the distance traversed on a bicycle while singing the eponymous song.¬† Of course, it’s not a particularly precise definition since it depends on how fast you ride and how fast you sing (which are not necessarily directly correlated).¬† On the basis of one measurement, given that the length of the Menai Suspension Bridge is about 256.3 meters and rounding up due to a combination of the inherent lack of precision in the definition of the Summertime and the fact that I hadn’t actually quite reached the bridge when I started singing, the conversion factor seems to be 1S = 300m approx.

And of course, that’s not all that much shorter than the length of a typical British summer. ūüôā