Letters this month:
LETTER OF THE MONTH:
Service Costs on a BMW K 1600 GT
I’ve just been told the cost of a 30,000km service on my BMW K 1600 GT will be around $850 and possibly more if the valve clearances need adjusting. I noticed online that the same service in the US is $417, depending on the exchange rate. I can’t find what’s involved in the service but my workshop said it was an eight-hour job and it was only charging me for five or six. It all seems a bit expensive. I can’t fault the bike, though. It’s awesome. I expect some additional cost in the servicing of an engine like this but $850 seems a little rich.
Most of the cost is labour, Kevin. To check the valve clearances, all the fairing has to be removed along with the radiators. BMW says check clearances every 30,000km and since you now have access to the engine, the plugs are replaced at the same time. Six plugs, filters and various lubricants are included in the cost along with new coolant. Eight hours is about right to do this properly so your dealer is doing it cheap. The American price could be lower labour costs but it could also be a half-arsed job.
Vibrations on a 1989 Honda CD250U
A while back I got myself a 1989 Honda CD250U. I love the bike but it had sat outside in the weather for a couple of years before I picked her up for the princely sum of $250.
I got her to use as my first bike as I like the idea of not having huge power or great top speed while I’m learning. It’s on the road now and I’ve done about 1250km on it, but it has a problem.
At 100km/h, a terrible vibration occurs which goes right through me. If I pull the clutch in, the vibration stops. Any idea what’s going on?
What you have to work out, Andrew, is if the vibration is in the engine or the chassis. If you do the same revs in third gear that the engine is doing in top at 100km/h, do you get the same vibration? If the engine revs out cleanly in the lower gears without vibration, the problem isn’t with the engine. If the vibration is evident in the lower gears, it suggests the engine is worn and out of balance. If this is the case, you’ll get the most engine life from not riding in the vibration zone.
Your tactic of pulling the clutch in and the vibration disappearing points at the engine but the moment you do it, you also lose road speed which might disguise other reasons for the problem. These could include worn suspension, swingarm bushes, steering head bearings, bent wheels or bent frame.
Just out of interest, does the vibration go away when you go faster than 100km/h? Can you ride through it or does it just get worse?
Contrary to popular wisdom, you can wear a CD250U engine out and maybe yours is getting to that stage. You could prolong its life a little by fitting a countershaft sprocket with one extra tooth. This would move the vibration up the road speed range so you’d get less of it at 100km/h. Let me know how you get on.
I’m 76 years young. About 15 years ago I had an idea and sat on it until sometime in November, 2014 when I got around to doing something about it. This is my registered-copyright protected IP Service International idea: a hydraulically and/or battery assisted motorcycle centrestand.
My line of thought was that as motorcycles are being built heavier and more women are embracing riding, this could be the right time to introduce the idea to motorcycle manufacturers and see what develops. To me, it seems much easier and more sophisticated to just press a button than having to use brute force to get the bike on and off its stand.
I know this practice is easy for some but for oldies and those of a lighter build, it’s a problem that will keep getting worse.
I started riding in 1955 and it surprises me that with all the other changes in technology, motorcycle centrestands haven’t developed at all. What do you think of my idea?
Centrestands have an interesting position in the history of motorcycle design. You’ve probably noticed that they’re becoming increasingly rare on new bikes. This is partly to save weight but it’s also because they limit ground and cornering clearance.
There was a time when all bikes had them and they were part of the design exercise. If you were able to position them correctly under the bike, they were much easier to use. With technical developments including computer-assisted design and the practice of using the engine as a stressed member of the chassis, it became harder to physically locate them.
They make more sense, of course, on big tourers where saving weight isn’t as much of an issue. Some adventure bikes come with centrestands as standard equipment because they make maintenance easier. Mostly, though, if they’re actually available, they’re now an optional extra.
BMW introduced an electrohydraulic centrestand on its K1200LT where an electric pump built up pressure in an hydraulic system to extend the centrestand.
There are also aftermarket systems available to fit a variety of bikes so, John, unfortunately you aren’t the first one to stumble on the idea.
I’m curious that IP Service International issued a Notorial Escrow for you which would only seem appropriate if you sent them a particular design that was somehow original or distinctive. I hope whatever fee they charged you was modest…
Rims & Tubeless Tyres
I’m wondering if there’s a satisfactory way to seal the nipples on a spoked wheel with a view to running a tubeless tyre?
I noticed a spoked-wheel KTM recently with the tyre prominently marked in white ‘tubeless tyre’. Did it still run a tube?
Motorcycle rims could be made with a slightly deeper well and the rubber band that normally sits over the nipple head could be bonded in place.
I still have vivid memories of a puncture in the rear tyre of my Triumph Tiger 110 (1957). There was a garage open about a mile away and they lent me the tools necessary to remove the wheel.
When I returned I asked if they repaired punctures. “Yes, but not motorcycle wheels.”
I spent an hour on the garage floor wrestling with the bloody thing with an assortment of tyre levers and hammers. This was in 1959, long before tyre machines were invented. I’m 73, still riding and I wish I still had that Tiger 110.
There are all sorts of rim designs now, Ken, that allow for the use of tubeless tyres on spoked wheels. MT had a Yamaha XT250 for a while that had a rear wheel with a centre rib on the rim to which the spokes were attached. Other designs have the spokes running to the outer edges of the rim so no leaky nipples are located between the beads.
The reason you couldn’t use tubeless tyres on most older spoked rims is because the spokes allow the wheel to flex a little in use and this would allow air to escape. This flex is actually desirable in terms of suspension design and it’s why adventure and off-road bikes still proudly use spoked wheels. You can, by using a combination of silicone sealant, tape and a tubeless valve, make older wheels work with tubeless tyres but it’s not reliable.
I picked up from the situation you described that you might be thinking tubeless tyres don’t get punctures. They do, of course, and because they’re designed to hold air, it’s much harder to get them on and off rims. With respect, you could have fixed the puncture on your Tiger 110 with a bicycle repair kit and a couple of forks from the kitchen draw. Imagine a rear wheel puncture on something like a current Triumph Rocket Three!
Modern puncture repair kits for tubeless tyres are actually pretty good, allowing for repairs to the most common forms of punctures that occur. Cynics in the industry say the sole purpose of front tyres is to stand loose nails and screws on the road upright so they can enter the rear tyre at exactly the right angle.
I wish you still had your Tiger 110 as well, Ken – lovely bike.
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