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A motorbike clutch replacement was supposed to be so easy. But after several days...

On the ride home from a job in Devon, my motorcycle’s clutch slips. This is annoying. I am busy and its MOT is soon due.

But “if you can’t change the situation, change your mind”, my friend Fletcher used to say, so I decide to be positive. It’s a chance to learn a new skill. I’ve written ‘clutch’ in a thousand car reviews without ever taking one apart.

Today, that changes.

A garage would want a couple of hours to do this. Owners’ forums say it is relatively simple, except for undoing one big nut, for which I’ll need an impact driver. I have one. So I give myself a day to do it.

First I need to remove the bash plate, which being aluminium is simple, and the exhaust, which containing 24-year-old iron is not.

I immediately shear two bolts and disintegrate a bracket around a crumbling intersection. Regardless of my mindset, this is definitely annoying.

The clutch cover is removed easily and I find what’s meant to be the hard bit: the nut.

This is ‘staked’: part of a flange around the nut is bashed into a notch on the shaft. It’s a crude and rudimentary method of preventing it working loose but, given it hasn’t budged in 75,000 miles, clearly works.

I’m told to prise out the stake with a screwdriver but can’t. I could chisel it off, I’m told, or grind it, but either may leave metal shards in the engine.

Simply, the impact driver may do the job, I read. But my battery-powered one isn’t up to it.

I once vowed that if I didn’t have the right tool for a job, I would either buy it or get a mechanic to do the work instead. The bike is already in pieces, so I go shopping. The day passes.

I like my new air impact driver, which arrives a day or two later. The thread on the bottom looks big, though, and my UK-spec air hose connectors won’t quite fit its American-spec threads.

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I’m sure I or a nearby shop have something to convert one to the other. I don’t. The shops don’t. So I go online.

A few days pass. Then everything connects. Within three seconds the nut is undone. Per hour of operation, the air gun is currently costing £180,000.

The clutch pack itself comes apart and goes back together relatively easily, although I don’t remember thinking so at the time.

And so to reassemble everything. I have apparently neglected to realise that something so difficult to undo will also want re-tightening, to a hefty 94lb ft.

I read that I should have left the bike in top gear (I didn’t and it now won’t leave first), so no matter how hard I wedge the rear brake, the back wheel turns instead of the nut torquing. If I use the air gun, I won’t know if I’ve torqued the nut correctly. If I block the back wheel, I risk bending a spoke. And a wedged-on back brake isn’t holding it. The day passes.

The next morning, I’m scratching my head when a friend arrives. I ask them to sit on the bike. I wedge the brake on and have lodged a piece of wood in the wheel. I apply the wrench and… click. As with the undoing, after several days of annoyance, within three seconds the job is done.

Now just to fit a new gasket, then sort the exhaust, then adjust the clutch.

I inspect the edges of the engine case and clutch cover. There is a lot of original gasket applied to both, a baffling substance with the relative hardness of granite and yet the clingy qualities of brie, gecko’s foot and wet shower curtain. It will have to be scraped off, a millimetre at a time.

A day passes. My bike still doesn’t work. The exhaust still looms. Soon, though, I’ll know how to replace a clutch, a skill I’ll have clean forgotten when it next needs changing, in 12 years’ time.

Matt Prior

Matt Prior
Title: Editor-at-large

Matt is Autocar’s lead features writer and presenter, is the main face of Autocar’s YouTube channel, presents the My Week In Cars podcast and has written his weekly column, Tester’s Notes, since 2013.

Matt is an automotive engineer who has been writing and talking about cars since 1997. He joined Autocar in 2005 as deputy road test editor, prior to which he was road test editor and world rally editor for Channel 4’s automotive website, 4Car. 

Into all things engineering and automotive from any era, Matt is as comfortable regularly contributing to sibling titles Move Electric and Classic & Sports Car as he is writing for Autocar. He has a racing licence, and some malfunctioning classic cars and motorbikes. 

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xxxx 17 June 2024

Couple of points, you never know what's possible till you try, I managed to replace a KTM clutch in 1 hour.   I'd also be amazed Honda don't sell a locking tool. Why not make the story complete by stateing how much a Honda dealer charge, plus what they'd charge to fix that exhaust.  

Bit weird you've an air compressor but no impact driver, they're really not that expensive. You may well of saved yourself some money plus have another tool.