BrownhillsBob's #365daysofbiking

On a bike, riding somewhere. Every day, rain or shine.

Posts tagged ‘Tech’

#365daysofbiking A decent buy

August 7th – I’m always interested when I spot a new bike in any of the client’s facilities I use. This Halfords Carrera is a typical, mid range trail bike. Competently designed with mass market but decent looking equipment, including suspension forks with crown lockout and hydraulic disc brakes, this was obviously a new steed for someone.

It’s a nice bike and shows why Halfords sell a lot of bicycles despite the variable quality of their shop staff – particularly as regards technical knowledge.

I did, however, wince at the way the bike was locked. That really isn’t a great way to use a D lock and extension cable…

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#365daysofbiking Brand bland

May 10th – One of the odder brand crossovers of the last few years has been Land Rover branding bicycles.

Company 2×2 Bikes designs distinctly average mountain bikes and sells them under the Land Rover brand, hoping presumably that some of the off-road cachet is gained by association.

Looking at this one in a customer’s bike shed, it’s a decent, if unremarkable low end steed: Better than a bike-shaped object one would buy from a discounter but not great either.

I’d have expected a bike badged with this brand to be something unusual. I wonder if the bikes are less prone to breakdown than their 4×4 stablemates?

An oddly bland product with a strange association.

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#365daysofbiking Feeling groovy

March 27th – The front brake has been quite noisy in recent days, and is juddering a little, yet the pads are fine.

A quick inspection in the bike shed at my destination showed the reason: The front disc it now severely worn and is starting top ripple on hard barking. The wear surface itself is about 60% of its original width.

A new disc will be about £25. Time to get one ordered I think. It’s seen some life, that one.

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#365daysofbiking Good tradition

March 2nd – The first Saturday in March is always the Erdington Bicycle Jumble, run by North Birmingham Cyclist’s Touring Club.

Sadly, last year it was cancelled due to heavy snowfall, and as a consequence, suffered a little for numbers this year – and I was a little late.

But it was still good to meet old friends and acquaintances, remember old bikes and old riders. The memory-jog provided by some of the stuff there cannot be understated.
A fine, traditional social event I’m pleased to see continuing.

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#365daysofbiking Brake spring broke

February 5th – I have absolutely no idea at all what’s happened here at all.

It started at the weekend – a rubbing on the front disc brake on my current bike of choice. A light rub, no more that a tickle.

As the days progressed it got worse, and defied my attempts to adjust it away.

In exasperation, I removed the brake pads, which were OK at about 60% remaining.

The leaf spring that keeps them off the disc however, was broken. This was allowing on pad to rub.

An easy, 30 second replacement. But I’ve never had a spring fail like that that hasn’t been worn on the disc as the pad ran down.

This is most peculiar. I shall keep my eye on things in case it’s something significant.

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#365daysofbiking On the rebound

January 11th – I’ve had a winter of mechanical problems with the bikes, and one has concerned suspension.

Forks with suspension can be a blessing and a curse, and the ones I use have a sealed air spring with a hydraulic damper, and several adjustments – air volume, pressure, slow rebound, fast rebound – all of which significantly affect the ride.

If you don’t have suspension tuned correctly, you can lose a lot of efficiency in compressing the forks with every pedal revolution. The ones I use can be locked out to make them rigid in use on road, but that’s only half a solution.

Since the forks have had work done, they’ve lost all my fine tuning and I need to start from scratch, so I’ve cheated on the lengthy process of dialling them in – I’ve borrowed a Shockwiz.

Shockwiz is a small electronic gizmo (a bit smaller than a matchbox) that is cable tied to the fork, and connected by a small hose to the air spring valve. It uses pressure and other sensors to detect the motion of the forks over a variety of riding conditions, and it just sits there, logging the data.

With a brilliant companion phone app connected via bluetooth, you set various measurements and chose what kind of profile you want, and over successive rides, the app will make recommendations on adjustments to make, and request you ride certain surfaces – like bumpy trails or whatever.

You adjust, then restart the process.

Within a few rides you get a fantastic ride that really is what you’re looking for – often by telling you to make adjustments that are counter-intuitive.

Shockwiz is very expensive, but if you can borrow or hire one like I did, it’s a godsend. A month or more long process sorted in a few days. And probably far better.

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#365daysofbiking Gearing up

January 3rd – One of my bikes uses a Shimano Di2 hub gear – an Alfine 705. This is the original Di2 11 speed hub and has its own pros and cons, but on the whole it’s reliable and workmanlike, and apart from a somewhat fiddly oil change when the shifting gets lumpy, requires little in the way of mechanical attention during it’s lifetime.

Generally, the life I’ve found is about 15-25,000 miles. This hub has been through a lot, and more than 3 wheel builds, but I’m happy with the wheel it’s in now, which was why it was so annoying when it suffered a serious failure on Christmas Day. I lost about half the gears which just spun out when selected – 3,4,5, 9 and 11 I think. An oil change and filling with cleaning oil hadn’t helped at all. The hub was knackered.

There’s not much I don’t know about this system; I’ve been using it in different iterations for over a decade and I’ve got to know the tricks and fiddles and advanced maintenance procedures – both by reading manufacturer documentation and by trial and error. The internal mechanism of the hub is easy to remove and change for another – you remove the wheel, take off the changer mechanism, sprocket and disk brake. You then remove the non drive side cone and locknut, then unscrew the plastic retainer and oil seal on the drive side – I have the right tool for this but a strap wrench will do it fine too, but the key bit is it’s a left hand thread. Once it’s off, the whole gubbins will come out, the oil can be cleaned out and a new mechanism can be put back, or the old one repaired and refitted.

There was a snag. The 705 is no longer available, but there is a new version, the 7051. I didn’t want to rebuild the wheel. I scoured fleabay and the web for a 705. No dice. I found a brand new 7051 in Germany for about £250, which is a great price. I poured over Shimano drawings of the two hubs. I decided to risk ordering the 7051 and trying to swap the innards. If they didn’t fit I could always reassemble it and build a new wheel.

In time the hub arrived, and the good news is it fitted exactly the same. On the rare chance that anyone ever reads this wondering if it’s possible to swap the two, yes it is. I swapped the guts, but also the non drive side bearing and oil seal too – be careful popping that out as they’re easy to damage and if no longer flat, oil will leak from the cone.

The 7051 hub has an upgraded clutch, smother shifting and performs better changing under loading. I have to say, fitting it back was a dream, and it runs well. Once the factory stiffness had gone, changes are much smoother and there’s far less clatter when doing so.

The old hub mechanism I plan to dismantle to see what’s gone. Looks like I’ll be spending some time in the garage with the tools…

This post has been created on the off change anyone ever wonders the same thing: I would say this also applies to the non-Di2 cable variants too.

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#365daysofbiking Springtime:

November 30th – I wondered how long it would be before this set of Rockshox forks suffered the notorious ‘sticky lockout’ problem. A year, they’ve been fine, the control on my bars reliably allowing be to make the suspension solid on road, then active on rough terrain at the flick of a lever.

Usually, it’s as simple as a corroded cable. Not this time. The damper gate appears to be failing.

Spares on order, and for now, a spring and a cable tie to assist the mechanism over it’s reluctance.

This must be the fourth iteration of these forks, all excellent on the whole, but all suffering lockout issues.

Time for a redesign, SRAM…

#365daysofbiking The daily grind:

25th November – A mechanical job that should have been easy was far from it. Replacing brake discs resulted in a struggle with seized fasteners, the failure of a brake calliper and the discovery that the parts I thought I had in the spares box brand new for this eventually were in fact the wrong ones.

The front disc was so badly worn it was starting to warp.

For a job I thought would take 15 minutes and leave me bags of time to get out turned into hours and I was lucky to get time for tea…

Perhaps I shouldn’t leave it so long next time.

#365daysofbiking Rime and season:

November 22nd – First really cold morning of the year I think, with lurking black ice and hedgerows and verges adorned with a hoar frost. It was the kind of penetrating cold that hurts your throat and forehead, and even though I was wrapped up, on the morning trail, towpaths and cycleways the -2.5 degree temperatures were still a little raw for me.

Every year it takes time to re-adjust.

I was certainly glad of the ice tyres this morning.