Nearly 25’000 miles and a couple of things…

What is it they say? Bike issues are like busses; nothing happens for ages then three come along at once! Changed the fork oil for the first time, replaced the chain’s master link, which had decided to eat one of its o-rings and had to deal with a rather unique speedo issue…

With the fork oil, a few things were worth noting; the condition and, more importantly, amount of old oil that had been in the forks since the bike was built a few years ago in India. What came out could be described as some sort of radioactive grey/green sludge. And when I pumped out the first leg, a little alarm bell went off in my head as there didn’t seem to be much ‘oil’ coming out.

I decided to measure the amount in the second leg. Bear in mind the specification is 167mm of air from the top of the stanchion to the oil. Well, I measured a 225mm gap! I’m absolutely certain that no oil has ever been lost from either fork and the seals are immaculate as I fitted gaiters very early on in the bike’s life. The result is noticeable. A firmer feeling front end, which handles those bumps better with less jelly-like flappyness. And an annoying wobble in the handlebars when decelerating at around 40mph has drastically reduced. Well worth doing and I know of at least one other account of someone finding the same low amount of oil in their forks too, so you may want to check it out. It’s documented in the Haynes so I won’t go into details here…

And the speedo. Well, during a commute, I started to hear a squeal coming from the front of the bike. I immediately thought the worst and suspected wheel bearings starting to fail (they often ‘whistle’), but decided to check do easy things first, like oil the speedo cable in case it was the culprit. As I went to undo the top ring which holds it to the speedo itself, it just fell away. Not because it was loose, oh no… This is why:

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That thing in my hand is the part of the speedo where the end of the cable screws on, and it had somehow sheared off! Fortunately there was a set of clocks with broken glass for sale on eBay for £15! And it’s a good thing that the CBF’s clocks can be disassembled so I could set about harvesting…

It turns out that the speedo/odometer itself is a complete unit and you really can’t do much with it. It’s an old fashioned 100 year old technology eddy current device – look it up on Wikipedia if you’re interested. So I had to replace the entire thing. Here’s a shot of both units and you can clearly see the broken part:

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All I had to do was adjust the mileage to match my old one. Quite easily done – wedge a fingernail between the dials and push them towards the spring on the right, then you can turn them freely. Just keep moving your nail ‘up’ a dial to adjust the next one, and so on…

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Notice the magnet at the bottom which rotates inside an aluminium bowl which is connected to a spring and the speedo needle itself. When the magnet rotates, eddy currents try to turn the bowl around with it, but the spring resists and tries to turn the bowl back the other way, so the bowl only rotates by a fixed amount for a given rotational speed of the magnet. Interesting.

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4 thoughts on “Nearly 25’000 miles and a couple of things…

  1. Nice to hear the bike is still going strong now your mileage is creeping up, although there are many miles of life left in it im sure. Im going to change the fork oil on mine soon so i will measure the original level and post up what i get, as like you i know i havent lost any past the seals.

  2. Followed your guide for fitting the fork gaiters, perfect, you should write for Haynes manuals. At the same time I opened up my forks to change the oil. Having let the oil drain off the springs into the forks and fully compressed the legs each had a 250mm air gap!!!. No wonder they were so soft and almost bottoming out. Pulling away was like being on a rocking horse. I thought this was normal as the demo bike I took out was the same and no, they have not lost any oil through leaks. Anyway, changed the fork oil for Silkolene SAE 15. This was actually much thinner than the stuff that came out ?, don’t know why as Honda quote using 10w oil !. Having rebuilt the forks with the correct air gap I could not believe the difference. The bike now handles, less dive under braking, less dazzling oncoming motorists on acceleration, more feel of the road surface without being anywhere near what I would call firm.
    I cannot overstate what a difference this basic maintenance task made to the bike. Honda should be shot for their quality control of this essential part of the bike.
    Well worth the £10 for oil and 2 hours work ( taking it slowly and working methodically ) with only basic tools on the centre stand ( I put a bag of compost on the pillion set to prevent it tipping forwards ), Plus you can fit gaiters ( about £14 ) and lube up your axle which Honda seem to have forgotten to do.
    Top Tip – Remove the top fork bolt, loosen and slide the fork down about 3cm then retighten the bottom yolk pinch bolt to hold the stanchion tight whilst you initially loosen the top cap of the fork. Remove the fork and disassembled carefully. This will save using any grips or a vice on your forks.
    The spring is only under moderate pressure and can be removed and reassembled without special tools just a bit of downward pressure on your spanner or socket.

  3. The clock on me cbf 2010 has no rev counter on I have seen clocks with rev counters on,on eBay can I and is it easy enough to fit these on mine

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