Belt phobia?

[Coyote Chris]

I have a phobia against belts. I think they are fine for drive applications such as the BMW F 800 GS. While expensive at $400, they are at least easy to replace on that bike, even though you need a special gage to align it.

But the new BMW 852cc engine uses a cam drive belt. (Chris starts to twitch). As you all remember, this was very popular in automotive engines of the last century. If the engine was non-interference, like some of the Ford Escorts, the belt broke and you had it replaced. One ruined day. If it broke on an interference engine, you had one ruined engine.

If I bought a BMW with the new engine, I would of course ask what the change interval is and what that would cost. If they or BMW USA wouldnt tell me, well, its off to the Triumph store....
Am I being unreaonable and too fearful? Those belts are no fun to change and with an interval on many of my past cars of 60K, I have done many.
Most cars today of course use chains.

 

[ARKNT]

My mind has a hard time trusting a belt but they have been used a lot with good results.
I would be open to a final drive belt. The simplicity and lighter weight compared to shaft would be plusses.
If changing a cam belt on a bike was simple, not likely, the cam belt may be OK but I would have to work into the idea and maybe let others test it for a few years.

Brad

 

[junglejim]

I don't blame you Chris. I had one real bad experience with a broken cam timing on an old 80-something subie. It was January, 20 below, 40 miles from anywhere, and only 30 hours to return from military leave and avoid an AWOL.

 

[Bear]

Chris, I'm with you. I don't trust belts.

 

[DirtFlier]

They've had belts snap when a rock got between the belt and the sprocket. With that being a reality, you'd think some of the ADV applications would have a complete plastic enclosure for the belt.

In the 60s and 70s serious enduro bikes used for the ISDT had fully enclosed chains and it really kept the drive chain clean but with a slight penalty of more unsprung weight that made life for the rear shocks more difficult.

 

[Coyote Chris]

They've had belts snap when a rock got between the belt and the sprocket. With that being a reality, you'd think some of the ADV applications would have a complete plastic enclosure for the belt.

In the 60s and 70s serious enduro bikes used for the ISDT had fully enclosed chains and it really kept the drive chain clean but with a slight penalty of more unsprung weight that made life for the rear shocks more difficult.

Yeah, a forum member has a hole in their F800 GS belt now due to a rock being between the sproket and the belt....he isnt too concerned...but thanks, I can see how getting a big rock in there could do damage. My exquisit Yamaha XV 920 RH sport tourer had a completely enclosed chain in a lithium grease bath. Once ajusted, I dont think I ever had to re-adjust it after breakin. I can see why off roaders would want that for the belts.

I suspect that the labor for changing the BMW cam drive belt could be very high....but I dont know that. If designed for maintenance, it actually could be quite easy....but I doubt that it is....I am going to take a WAG and say the drive chain and sprocket has to come off after the plastic....just like we had to take off the fan drive pulleys on the old cars.....
Chris the pulley puller.

 

[Coyote Chris]

Chris, I'm with you. I don't trust belts.

I am with you. While low reving family cars did well with them for decades, except for the wallet emptying procedure every 60k, I am not keen to be the first to own an engine with a belt cam drive. Maybe it is fine....the bikes come with three year warrentee. But we know what happens when BMW has made a mistake and grounds its bikes till they are fixed....

 

[Coyote Chris]

I don't blame you Chris. I had one real bad experience with a broken cam timing on an old 80-something subie. It was January, 20 below, 40 miles from anywhere, and only 30 hours to return from military leave and avoid an AWOL.

Yeah, I think many of us have those stories.....I am trying to think of a new car that still uses cam belt technology.....and I dont mean Mellow's Ferrari either....

 

[Brillot2000]

I think many of you have forgotten that the Gold Wings from the begin had belt driven camshafts as early as the 1975 GL1000s on beyond.

The recommended replacement intervals were at 80k. I had the ones of my GW rollover 100k on the original belts with no signs of wear.

 

[ARKNT]

Cam drives have been driven with chains and gears very reliably for a long time. I'm with the if it ain't broke, don't fix it bunch.
With that said I did have a CB350 twin that broke a cam chain and bent a couple valves. I think it was caused from lack of maint. I had just bought the bike and noticed a rattle inside the engine but I was too slow to diagnose and fix it. Oops.

Brad

 

[mikesim]

FWIW, I have yet to see a cam drive belt fail "before" the manufacturers recommended interval. I have seen numerous belts fail that were used over the recommended interval. The moral of the story is to perform "preventive" maintenance. If you choose to ignore the factory's recommendation, you do so at your own peril. The cost of replacement on the other hand is another story.

Mike

 

[Sojourner]

FWIW, I have yet to see a cam drive belt fail "before" the manufacturers recommended interval. I have seen numerous belts fail that were used over the recommended interval. The moral of the story is to performance "preventive" maintenance. If you choose to ignore the factory's recommendation, you do so at your own peril. The cost of replacement on the other hand is another story.

Mike

^
This.

I put 287,000 miles on a 2000 VW Golf TDI (that's a diesel) and 197,000 miles on a 2010 VW Jetta Sportwagen TDI, and have been very involved with TDI forums. As noted above, the belts themselves are extremely reliable. I've never heard of a factory-installed timing belt breaking before the replacement interval. Timing belts break due to extreme negligence -- not changing them when you should -- or more commonly, improper replacement by the mechanic -- things like not tensioning the tension roller properly, or torquing fasteners. In 2000, the timing belt interval for TDIs was 60k miles, by ~2005 they'd up'd it to 80k miles, and at last recollection it was 100k if not 120k miles. Belts were preferred for the TDI because they are quieter than chains, and the diesel already had a bit of clatter, so they didn't want to add more noise. Cost of a VW timing belt change is ~$900 and is about a 6-hour job; it involves having to support the motor because a motor mount is right in the middle of where the timing belt is, the water pump is driven by the belt so it's also part of a standard timing belt change, and there are other pulleys and hardware that are also changed. Yes, you have to do this a few times over the life of a car, but with proper maintenance, those motors can go a million miles. A friend of mine still has my 2000 Golf with 500,000 miles on it now.

I now drive a 2016 VW GTI. Traded in the TDI when the 'scandal' (sic) happened. Not because I felt VW was guilty of much of anything (kind of a joke, really), but they offered a great buy-back deal. The GTI has a timing chain, but I'd be ok with a belt again.

Timing chains last longer, but are more expensive to change than a timing belt. However, if you don't have a maintenance interval on a chain, then "when it goes, it goes", and you mangle valves.

That said, unless you put a ton of miles on your motorcycle, you will probably never need to change a timing chain.

My biggest concern with a motorcycle timing belt is, what does it take to change the belt? Can it be done on the bike, or would it involve removal of the engine?

 

[bicyclist]

Let's step back a moment. No BMW F800GS nor any BMW ADV bike has ever had a belt final drive. I'm not aware of any other brand of ADV bike using a belt final drive.

With respect to a cam drive belt, as has been already been stated, routine maintenance should obviate any issues. Having said that, experience tells us that BMW uses its customers as beta testers. It's a good idea to wait until the fourth year of production for them to fix their problems.

 

[Frosty]

Let's step back a moment. No BMW F800GS nor any BMW ADV bike has ever had a belt final drive. I'm not aware of any other brand of ADV bike using a belt final drive.

With respect to a cam drive belt, as has been already been stated, routine maintenance should obviate any issues. Having said that, experience tells us that BMW uses its customers as beta testers. It's a good idea to wait until the fourth year of production for them to fix their problems.

Chris meant a BMW F800GT, which has a drive belt. I found a 3/16" granite cube stuck in center of the belt when I returned from the Rally last Summer. I popped the stone out and bought a new belt which I still carry in the side case. I really like the drive belt system so far.

 

[bicyclist]

During the time I owned my F800ST, BMW was the single source for the Conti belt and it cost about twice as much as a Harley belt. BMW specified a 24K mile replacement interval for the belt. Most people just ran them til failure. I heard of only a few that actually broke; the usual failure mode was stripped teeth. If you kept an eye on it, you could see cracks develop at the root of teeth and you'd know it was about time to replace the belt. Most dealers didn't keep them in stock and there aren't many BMW dealers, anyway, so it behooved the long distance rider to carry a spare. My original belt was showing cracks at 30K, so I put on one I got from a low mileage wreck and carried the original as a spare.

I think a belt drive is generally superior to a chain drive. It's clean, quiet and doesn't require adjustment. Except for BMW's implementation, it's less expensive to run. Manufacturers could eliminate lots of drive problems if they would enclose the drive.

 

[DirtFlier]

[...I popped the stone out and bought a new belt which I still carry in the side case...Frosty]

Is that a swap you can make at roadside with tools carried on the bike?

In the latest issue of Rider magazine, they tested 3 large V-twin tourers (H-D, Indian, and Yamaha) and all weighed north of 900 lbs wet and all had belt drive so obviously drive belts have proven their worth. I'm not familiar with H-D models but I'd guess that most of them are belt drive and have been that way for more than a few years.

My other bike (NC700X/w DCT) is chain drive and I sometimes wish it had a belt; especially when I have to clean/lube the chain on a multi-day trip.

 

[ARKNT]

I have never replaced a drive belt and I'm sure some are easier than others. Some (HD) require primary drive disassembly, and I think many require swingarm removal.
For many roadside repair may be rough or not feasible. If purchasing a new belt drive machine it may be something to add to the list of things to consider. Good thing those belts are very reliable.

Brad

 

[Warren]

My next two wheeled vehicle is going to be a Honda Forza scooter so I hope the belts in those are reliable and long lasting.

 

[Brillot2000]

I have never replaced a drive belt and I'm sure some are easier than others. Some (HD) require primary drive disassembly, and I think many require swingarm removal.
For many roadside repair may be rough or not feasible. If purchasing a new belt drive machine it may be something to add to the list of things to consider. Good thing those belts are very reliable.

Brad

My Zero SR was belt driven. The belt outlasted the bike, the batteries went south and away it went.

 

[Sojourner]

My next two wheeled vehicle is going to be a Honda Forza scooter so I hope the belts in those are reliable and long lasting.

Reliable, yes. Long-lasting is relative. There is a service life to V-belts.....a quick google seems to show ~15k miles? It's not a bad do-it-yourselfer. I helped a guy put new variator weights in his Suzuki Burgman 400 drive. Need a torque wrench and a big socket, and a few standard tools.