Tag: mechanical

March 26th – There’s times when you just have to give in. For several reasons I’ve recently converted from 28mm Schwalbe Marathon Plus tyres to 25mm. the ostensibly small, 3mm change has made a big difference to fitting the tyres, which has led to a couple of tubes being pinched on reassembly – notoriously during my ride around the Roaches a couple of weeks ago.

I’ve been looking for solutions. These tyres won’t be fitted by hand, the combination of Mavic rims and Schwalbe rubber is notoriously tough, so I’ve opted to try a new tool – this plastic hook device made by BBB and costing about £7 pivots like scissors, and you rest one arm on the opposite rim, and hook the tyre on with the other.

I’ve not tried it yet, but it has to be worth a shot. Never known tyres this tight before.

April 18th – A devil of a day beset by difficulties at work. I rode off early in the morning into an unpleasant headwind with a bad stomach and the day didn’t improve much. I was distracted on the way home by a mechanical issue, and just took these photos of the new pond at Clayhanger, which is greening up beautifully at the moment, but is suffering a little for being a hanging-out place for local kids who are littering a little. 

Hopefully in a few weeks the slopes around the pool will be alive with orchids again, as they were last year. Sadly, it’s a bit too wet down there at the moment to investigate.

Repairs carried out at home, I’m hoping for a better day tomorrow – it wouldn’t be hard to achieve.

March 11th – A nasty graunching from the rear brake on the way home was severe enough to have me check it out as soon as I got home. Much to my shock, I found the stock, soft resin-organic brake pads in my rear calliper were just a bit worn.

Ahem.

The new sintered metal ones are at the rear, the ones I took out in front. That’s bad. Should have spotted it sooner – luckily I don’t seem to have damaged the disc.

Never take your eyes of those essential maintenance tasks, people!

September 26th – Interested and fascinated to note that the restored windmill at Longdon that I photographed a week ago actually has a sailed that rotates with the wind as required – note the sails are on a different side of the building this week.

That mill has to be a tour de force of mechanical geekery… I love it.

June 17th – So help me god, I’ve been asked how you know if your bottom bracket needs replacing (see last entry, 16th June) – so I made a quick video. The old part is held in a vice over white paper for clarity. I’m wobbling the other end, out of shot. There should be no wobble at all.

Hope that helps!

(Source: https://player.vimeo.com/)

April 25th – A recovery day, mainly resting and pottering around attending to mechanical issues with the bikes. Long-term readers will remember my bizarre crank failure last spring, and at the time I suggested I’d never see it again: well, I was wrong. 

This is an identical Lasco crank from my other bike. There are clear cracks growing either side of the pedal mount bore. Thankfully, I had a spare so changed it over on discovery, hopefully forestalling an unexpected failure.

I‘m not sure if this is a poor design, manufacturing failure or a sign that I should lose some weight…

July 23rd – Riding back home this evening, something shiny in the road caught my eye – lying on the edge of Green Lane in Shelfield, the debris from something that really shouldn’t happen. It’s a shattered bicycle sprocket.

This would have been part of the cassette, or rear group of cogs an the back wheel  of a cheap bike. It’s been used, as the teeth are worn, and the chrome coating ground through. Decent sprockets are made from high-grade alloys or steel, with some flexibility. Generally, they’re pressed or forged. 

This one is low grade steel, and has been made from cast material, making it inflexible and weak. It’s a fair assumption that under load, it’s cracked, and at some point catastrophic failure has occurred, and other debris in the road suggested as much.

Cheap supermarket or discount store bikes are often fitted with this kind of cheap componentry and fail in this kind of manner. Deprending on when it failed, this kind of breakdown could be very serious, and cause the rider to be injured – imagine if this had happened when cycling up a steep hill, like Black Cock Bridge, further on?

If you need a decent bike, and haven’t got much cash, a better option is to look out for a decent secondhand steed. You’d be surprised what you can get from Gumtree or the small ads for the same money.

A very, very cheap bike really isn’t worth the risk or hassle. They’re cheap because they’re made out of cheese, bus tickets and spit…

Aprill 11th – Before I do the usual ones today, tonight I had a nightmare journey home after a less than wonderful day. A couple of consecutive punctures (with different causes) were bad enough. But then, not far from home (thankfully), I gained another entry for Bob’s Big Book of Bizarre Bicycling Mechanical Failures™ – my non drive side crank sheared at the pedal thread. Clean off.

I have never seen this before. Not once.

It felt bad for a couple of miles – I figured a pedal bearing was going south. It felt odd, eccentric. This prepared me for disaster, so when it happened it didn’t hurt or cause me to fall off, but it could have been quite bad. 

The crank is by Lasco, and has done 10,000 miles. From the dark patch on the break, I’d say it’s been cracked awhile. I’m no small fella and fatigue has clearly worked it’s magic.

Oh well. Time for a new chainset, then…