Metaljockey
Race Dog
On this last Zambia trip, I had some reliability issues with my X-Challenge. Here's a rundown.
The rear shock absorber
The airshock on this bike has come in for a lot of criticism worldwide. I do not know much about the grey art of suspension, so I decided to give it a fair chance and make up my own mind. I actually liked the action of it which was different to conventional shocks in that, it damped from a fully extended position on the downward stroke. After this trip however, I have a deep loathing for this shock.
Well, the shock did not last my first trip. At about 3000km it started squeeking like a 1970's Suzuki. I took the shock and swingarm off and greased every possible friction surface. (another thing I do not want to be doing while on a trip) I must also add here that the guys at KTM Cape Town helped me with that at KTM RAW. I very seldom let other people work on my bikes, but Donald turned out to be one of the scarce macs that really care about what he is doing. Anyway, it turned out the squeeking came from inside the shock itself.
By the end of the trip the damping was absolutely up to shit, on cold mornings it was bottoming by just sitting on it. As it heated up, it got better but still went up and down like a pogo, no rebound damping to speak of. When I got back from the trip, I took it to BMW, who agreed that the shock was shocking and they replaced it under warranty. R16 000 nogal!
My second trip was a non starter as I fell my arse off on the first day. Zambia was next up.
The shock was too soft from day one. As the days went by it got worse, to the extent where I was slowing down and swerving around holes in order to avoid bottoming. The reason it was too soft turns out to be that my electric pump can only get up to about 6.5 bar. I never knew because the gauge on the pump was overreading. I never knew it overread because the valve of the shock is difficult to reach and my tyre gauge cannot fit in there. Luckily I was pumping and checking my tubliss with the gauge and pump and found them to give different readings. With my electric pump not being able to get to the required pressure, I had to persist with the shock being too soft. I did take a high pressure handpump as backup, but it is just unpractical to try and get another bar in a 6 bar shock, it's like a full day's work.
The other thing that became an issue on this trip is the long travel of the shock, when you take your weight off the seat and transfer it to your foot the shock extends fully, effectively working like an ejector seat if you are not on flat ground. I have reasonably long legs and did not think this issue would have much of an impact on me. But it did. The more I got tired the more I fucked up my riding and the more I had to put my foot out to keep from toppling over. The more I did that the more the bike went over the point where I could hold it and the more I fell over.
Realistically one probably has to say that the problem lies more with me not making sure that I can effectively inflate the shock, than with the shock itself. The point is however, I have done two trips on this bike and both were influenced by the shock. On conventionally sprung bikes, you set the thing once and then forget about it. One does not always want to have to cart a high pressure pump everywhere too.
Subframe
As we all know the subframe is all aluminium, and parts of it quite fragile. I was warned that if the bike falls over onto the passenger peg, the frame will snap. It duly did just that when I had an off on the second trip.
The second problem is that the thread for the carrier is for 6mm bolts. That is pathetically inadequate, several guys had the bolts snap. So I had them drilled out and retapped to 8mm. That still leaves you with a hard metal bolt screwing into soft aluminium. If your bolt loosens just a little, the movement will destroy your thread in the frame in no time. Mine did just that on day three.
Bushes & sprockets
Like I pointed out before, my first trip on this bike was 9000 km. In that period the following wore out to the point of having to replace them;
-bush on front wheel
-left bush on back wheel
-right bush on back wheel
-rear sprocket
-front sprocket
That is not my idae of quality parts, I have other bikes that have never had a bush replaced, ever.
With our dealer shutting down, I received only two out of the three bushes and went on the trip with the right rear bush being the old one. I believe it is this one that caused the kak.
This soft aluminium bush had worn away so that the bearing it was supposed to seat against was allowed to be loose. A third bush, seated inside the two bearings carrying the sprocket, also made of soft aluminium, now took the punishment of not only carrying the sprocket, but also the wheel. So that one wore out, allowing the sprocket to start running skew, thereby destroying the sprocket and the chain. Also the hub had started to touch the swingarm.
Check it out, my new custom stainless sprocket from Fidel finished after 3500km.
So after having shimmed up the inner bush with a can, we were able to do about 300km to where I was able to have a machine shop machine a new inner bush from bronze. This took the better portion of a day, and with the right rear bush worn to the extent that it could not be used as a template, I had to refit it. Thus we made another 800km, by which time the new bronze bush had also called it quits.
This had brought us back to Kasane, but scuppered my plans of riding back down to East London.
Handlebars
The second last day we spent on tar at mostly at 130 - 140km/h. Just after sunset we get to the turn off to the camp. I hit the brakes to haul the bike down from 140km/h and as I turn onto the gravel junction, my handle bar bolt breaks off and my bars swing loose on the one remaining bolt. Luckily I am virtually at standstill. Luckily I wasn't counter steering to pass another car at speed.
I was very near to being upset about this, very near.
We cable tied the bar back on to do the last two kms. The next day I had to weld a nut onto the thread stump that luckily protruded a couple of mm from the handlebar mounting, in order to remove the stump. As I refitted the bar I tightened the remaining bolt, and it promptly sheared too, it was well on it's way to join it's mate already.
The bars have been giving me grief for the whole trip. They are rubber mounted, and something somewhere is not working like it should. The handlebars would go off-centre quite easily, with normal riding. It got progressively worse to the point where it could be turned up to 30 degrees while the front wheel stays stationary. this means little inputs on the bars have no effect, and I spent days riding very technical terrain with skew bars that will change it's angle every time I hit hard obstacles.
What I did before the trip is to tighten it as much as I can, this did not seem to help. At Sandy Bay Resort I stripped the whole lot apart to see how I could better the situation, and finally ground about 2mm off the spacer, to enable the bolts to compress the rubber grommets more. The spacer is no 5 in the schematic.
This helped a bit but not enough, the next day I had to tighten the bolts again and every other day thereafter.
I do not know why these bolts sheared, it may be because when I shortened the spacer, the bolts turned into the end of the blind thread recess. I doubt it though, I did check the ends of the bolts for marks indicating seating, and there was none. In any event, the socket I used for tightening is not strong enough to shear an 8mm bolt.
It may be that the bolts were damaged by the off I had two days earlier.
In closing
I had issues with the handlebars, I still do not know why.
I do know what caused the other issues though. I believe that BMW had been trying to make a light bike and that in chasing this goal they lost sight of quality.
The aluminium subframe, the aluminium bushes, the aluminium sprocket, the aluminium air shock - all of these are components that owe their weaknesses to being designed to be light, in stead of long lasting.
To be fair, this bike was probably not designed as a full on adventure bike, more of a play bike. But still, to have to replace all bushes and sprockets in less than 10 000km is not something BMW can be proud of.
Do I still like the bike?
Yes. It is not good enough as is and I will have to do the job that BMW should have done by having proper components made up by an engineering shop, and I'll have to fork out some dosh for a proper shock, but then I will have the bike I wanted.
[Edit] I forgot to add the fact that the alternator is of a lower spec than the Dakar's, again chasing weight loss. This led to my battery getting drained by the radiator fan. Pathetic.
The rear shock absorber
The airshock on this bike has come in for a lot of criticism worldwide. I do not know much about the grey art of suspension, so I decided to give it a fair chance and make up my own mind. I actually liked the action of it which was different to conventional shocks in that, it damped from a fully extended position on the downward stroke. After this trip however, I have a deep loathing for this shock.
Well, the shock did not last my first trip. At about 3000km it started squeeking like a 1970's Suzuki. I took the shock and swingarm off and greased every possible friction surface. (another thing I do not want to be doing while on a trip) I must also add here that the guys at KTM Cape Town helped me with that at KTM RAW. I very seldom let other people work on my bikes, but Donald turned out to be one of the scarce macs that really care about what he is doing. Anyway, it turned out the squeeking came from inside the shock itself.
By the end of the trip the damping was absolutely up to shit, on cold mornings it was bottoming by just sitting on it. As it heated up, it got better but still went up and down like a pogo, no rebound damping to speak of. When I got back from the trip, I took it to BMW, who agreed that the shock was shocking and they replaced it under warranty. R16 000 nogal!
My second trip was a non starter as I fell my arse off on the first day. Zambia was next up.
The shock was too soft from day one. As the days went by it got worse, to the extent where I was slowing down and swerving around holes in order to avoid bottoming. The reason it was too soft turns out to be that my electric pump can only get up to about 6.5 bar. I never knew because the gauge on the pump was overreading. I never knew it overread because the valve of the shock is difficult to reach and my tyre gauge cannot fit in there. Luckily I was pumping and checking my tubliss with the gauge and pump and found them to give different readings. With my electric pump not being able to get to the required pressure, I had to persist with the shock being too soft. I did take a high pressure handpump as backup, but it is just unpractical to try and get another bar in a 6 bar shock, it's like a full day's work.
The other thing that became an issue on this trip is the long travel of the shock, when you take your weight off the seat and transfer it to your foot the shock extends fully, effectively working like an ejector seat if you are not on flat ground. I have reasonably long legs and did not think this issue would have much of an impact on me. But it did. The more I got tired the more I fucked up my riding and the more I had to put my foot out to keep from toppling over. The more I did that the more the bike went over the point where I could hold it and the more I fell over.
Realistically one probably has to say that the problem lies more with me not making sure that I can effectively inflate the shock, than with the shock itself. The point is however, I have done two trips on this bike and both were influenced by the shock. On conventionally sprung bikes, you set the thing once and then forget about it. One does not always want to have to cart a high pressure pump everywhere too.
Subframe
As we all know the subframe is all aluminium, and parts of it quite fragile. I was warned that if the bike falls over onto the passenger peg, the frame will snap. It duly did just that when I had an off on the second trip.
The second problem is that the thread for the carrier is for 6mm bolts. That is pathetically inadequate, several guys had the bolts snap. So I had them drilled out and retapped to 8mm. That still leaves you with a hard metal bolt screwing into soft aluminium. If your bolt loosens just a little, the movement will destroy your thread in the frame in no time. Mine did just that on day three.
Bushes & sprockets
Like I pointed out before, my first trip on this bike was 9000 km. In that period the following wore out to the point of having to replace them;
-bush on front wheel
-left bush on back wheel
-right bush on back wheel
-rear sprocket
-front sprocket
That is not my idae of quality parts, I have other bikes that have never had a bush replaced, ever.
With our dealer shutting down, I received only two out of the three bushes and went on the trip with the right rear bush being the old one. I believe it is this one that caused the kak.
This soft aluminium bush had worn away so that the bearing it was supposed to seat against was allowed to be loose. A third bush, seated inside the two bearings carrying the sprocket, also made of soft aluminium, now took the punishment of not only carrying the sprocket, but also the wheel. So that one wore out, allowing the sprocket to start running skew, thereby destroying the sprocket and the chain. Also the hub had started to touch the swingarm.
Check it out, my new custom stainless sprocket from Fidel finished after 3500km.
So after having shimmed up the inner bush with a can, we were able to do about 300km to where I was able to have a machine shop machine a new inner bush from bronze. This took the better portion of a day, and with the right rear bush worn to the extent that it could not be used as a template, I had to refit it. Thus we made another 800km, by which time the new bronze bush had also called it quits.
This had brought us back to Kasane, but scuppered my plans of riding back down to East London.
Handlebars
The second last day we spent on tar at mostly at 130 - 140km/h. Just after sunset we get to the turn off to the camp. I hit the brakes to haul the bike down from 140km/h and as I turn onto the gravel junction, my handle bar bolt breaks off and my bars swing loose on the one remaining bolt. Luckily I am virtually at standstill. Luckily I wasn't counter steering to pass another car at speed.
I was very near to being upset about this, very near.
We cable tied the bar back on to do the last two kms. The next day I had to weld a nut onto the thread stump that luckily protruded a couple of mm from the handlebar mounting, in order to remove the stump. As I refitted the bar I tightened the remaining bolt, and it promptly sheared too, it was well on it's way to join it's mate already.
The bars have been giving me grief for the whole trip. They are rubber mounted, and something somewhere is not working like it should. The handlebars would go off-centre quite easily, with normal riding. It got progressively worse to the point where it could be turned up to 30 degrees while the front wheel stays stationary. this means little inputs on the bars have no effect, and I spent days riding very technical terrain with skew bars that will change it's angle every time I hit hard obstacles.
What I did before the trip is to tighten it as much as I can, this did not seem to help. At Sandy Bay Resort I stripped the whole lot apart to see how I could better the situation, and finally ground about 2mm off the spacer, to enable the bolts to compress the rubber grommets more. The spacer is no 5 in the schematic.
This helped a bit but not enough, the next day I had to tighten the bolts again and every other day thereafter.
I do not know why these bolts sheared, it may be because when I shortened the spacer, the bolts turned into the end of the blind thread recess. I doubt it though, I did check the ends of the bolts for marks indicating seating, and there was none. In any event, the socket I used for tightening is not strong enough to shear an 8mm bolt.
It may be that the bolts were damaged by the off I had two days earlier.
In closing
I had issues with the handlebars, I still do not know why.
I do know what caused the other issues though. I believe that BMW had been trying to make a light bike and that in chasing this goal they lost sight of quality.
The aluminium subframe, the aluminium bushes, the aluminium sprocket, the aluminium air shock - all of these are components that owe their weaknesses to being designed to be light, in stead of long lasting.
To be fair, this bike was probably not designed as a full on adventure bike, more of a play bike. But still, to have to replace all bushes and sprockets in less than 10 000km is not something BMW can be proud of.
Do I still like the bike?
Yes. It is not good enough as is and I will have to do the job that BMW should have done by having proper components made up by an engineering shop, and I'll have to fork out some dosh for a proper shock, but then I will have the bike I wanted.
[Edit] I forgot to add the fact that the alternator is of a lower spec than the Dakar's, again chasing weight loss. This led to my battery getting drained by the radiator fan. Pathetic.
