Tag: SPD

November 25th – Another good one for Bob’s big book of bizarre mechanical failures. A few weeks ago I bought new cycling shoes and fitted new SPD cleats – the small pieces of metal that lock into the pedals for better engagement in place of toe clips – as is normal. I nipped up the screws, and gradually adjusted them for best cleat position.

Riding to work this morning, it felt like my left side cleat was clogged with mud or debris, and I had difficulty engaging and disengaging. As I went on it became more and more tricky. Arriving, I inspected the leat and found it had come loose and was rattling freely.

I have never had this happen before and am very surprised.Potentially very dangerous, I’m glad I found it trying to clip in and not out.

If you use lipless pedals, check your cleats for tightness today.

January 21st – another one for Bob’s big book of bicycle breakdowns. These are a pair of Shimano SPD XTR clipless pedals – the mechanism on them engages with a metal piece on the bottom of special shoes that means I ‘click in’ to them and can pull the pedals up as well as push down. 

These are considered a fairly high-end pedal, and have a platform – the black grooved frame – around them for additional foot support. They cost about £70 a pair, I guess and are generally good quality. This pair had done about 10,000 miles.

They are built around a cylindrical bearing held together internally by two nuts – an adjuster and a locknut, and this keeps everything adjusted and spinning without play.

Except when the threaded part snaps from fatigue, the bearing falls apart and the pedal tries to come off the spindle. The one on the right is normal, the one on the left, fatally broken.

Thankfully, it wasn’t far from home and was still ridable with care. That’s an unwanted expense in January…

May 21st – There’s a crucial bit of biking equipment I couldn’t live without – clipless pedals. Pedalling long distances on flat pedals is horrid, and your feet can slip in traffic. The old fashioned alternative was toe clips and straps, which were OK, but nasty if you had to get free quickly. In the 1980s, as a solution, Shimano developed the SPD clipless system.

I have sevral pairs of SPD compatible shoes, which have screw mountings on the sole under the ball of the foot. There is a metal plate embedded above which floats for adjustment. On to the plate is screwed a ‘cleat’ – a metal key block that engages smoothly with a spring-latched mechanism in the pedal. This provides a positive, hassle-free engagement which is predictable, adjustable and secure, yet twists free instantly when required. They ensure your feet are always in the best, comfiest position, and the pedals are double-sided, so you never have to think about clipping in. You just do it without looking.

Clipless allow you to ‘pull up’ with one foot while pushing down with the other, and even pedal one-legged while scooting through traffic. This small, drop-forged block of steel – about half the size and thickness of a small box of matches – transmits all your pedalling force in an absolutely tiny contact area, yet fits flush in your shoes in such a way that you can walk all day in a pair of SPD shoes and never feel the cleat.

The intense concentration of force in one small component and two 5mm screws is so great that it wears quite quickly. Tonight, my cleats had developed such a sloppy fit, I couldn’t put up with them anymore. After 5,000 miles, it was time for a change.

It’s easy to do; cleats come with pedals, or can be brought separately. You usually have to drill out one or two of the old screws due to the heads being fouled, but once you get them out, the cleat leaves an impression in the shoe that the new one locates in. A blob of grease on the screw threads, and crank them up. 

The fit is so good, it’s like riding a new bike.

My compliments to the inventors – these really are a great invention.