Hi Big wheels are better
I have seen in some of your other threads, that you are considering using your BCS 735 for some really hard work, making your question here a very valid one, but also a rather big one to comment on.
In the summer of 2011, I got a BCS 740, which I believe was a new model from BCS that year. It has the PowerSafe clutch, which was new at the time in Europe, and introduced in North America a year later. My experience is based on almost 500 working hours with this tractor, and with the 5 implements that I have gathered over the years.
In an electrical circuit, the designed failure point is a cheap fuse that will protect expensive components, should a malfunction occur. In a 2-wheel tractor, I’m only aware of the clutch to protect the engine and drivetrain, should something unpleasant happen. Some implements have shear pins or an overrunning clutch, that might/might not protect expensive components, depending on the type of mishap that you have.
I will list my implements, and try my best to comment on them in regard to your question:
My BCS Power Sweeper which I use primarily for snow removal in winter, has no build-in protection on its own, so working with this implement, the clutch is the „failure point“. I have never had a mishap with my Sweeper, but I feel that both tractor and implement are adequate protected this way.
My Berta 2-stage snowblower on the other hand, is protected by 3 shear pins! 1 for each half of the front auger, and 1 for the impeller. This makes sense, I think, as it sometimes is very difficult for the operator to see and avoid obstacles hidden in the snow in front of the implement. I also never had any issues with this implement.
My Berta flail mower does not have any protection on its own, so again here the clutch is the „failure point“. I have had a few incidents, where the rotor got jammed by fence wire and stopped almost instantly, but the clutch slipped for a second or two, until I could grab the handle and release it. No harm done to either tractor or flail mower
My Zanon ZCR lawn mower has an overrunning clutch, which prevents the mower from powering the tractor through the PTO-shaft, in case the mower spins faster than the PTO. This has happened once for me, when a bolt came loose on the PTO-shaft, and it got jammed and stopped in an instant. The overrunning clutch allowed the spinning blades to slowly wind down, and at the same time, the clutch slipped, protecting the drivetrain and engine from a shock load
My Zanon ZRF drum mower has a similar overrunning clutch as mentioned above. Once while mowing, one of the drums got jammed by a stone, and in that case, the overrunning clutch doesn’t help you at all, but again the clutch slipped, preventing further damage
So to summarize, I have been saved a few times by the clutch, and it has probably also saved me a lot of trouble and costs. I am very happy with the way this clutch works, and it seems to protect the drivetrain and engine when needed.
Once the overrunning clutch on my lawn mower also did its job, and prevented an extreme torque load on the PTO-shaft, by allowing the heavy drums to spin slowly to a stop. The Zanon company probably hasn’t installed overrunning clutches on their mowers by accident, but because they are useful on „high-torque“ implements.
I would call my Sweeper and my snowblower „low-torque“ implements, which you can easily get up to speed, simply by applying a little throttle, and engage the clutch. The flail mower is sort of a „medium-torque“ implement, where you need a little more throttle, and you need to „feather“ the clutch a little, in order not to stall the engine. These implements are well protected by the clutch, I think.
„High-torque“ implements on the other hand, carry so much rotational inertia due to their fast spinning and heavy blades, that they might cause a lot of damage, when brought to an instant stop. The overrunning clutch allows the mower to dissipate the stored energy over perhaps 10-15 seconds, avoiding damaged parts and bent metal
Sorry that this post got as long as it did, but I hope it helped answering an important question?
Best regards
Jens
