Chain covers

[il padrone]

I've had a reply from SJS to my query about using the Hebie Chainglider on the Rohloff. Whilst it has now been modified to suit Rohloff, they are still advising not to use it. Instead they are advocating the better option of using the Biologic FreeDrive Chain Wrap.




Does anyone have experience using this device, who could give some information on:

1. fitting it to a Thorn Nomad (47cm chainstays)
2. friction losses if any
3. lubrication, durability and the impacts of any water ingress.

Thanks very much.

[Danneaux]

Pete,

While I have no direct experience with this product, it appears nearly identical to a product that was available here in the States in the mid-late-1980s, and I did have experience installing that one on several friends' bikes.

It was a slotted tube much like the one shown, and it required super-gluing the overlapping ends together. The one you reference may attach differently, but the installed product looked the same. They came in the neon colors popular at the time, and it seemed all the ones sold as shop remainders were neon pink. Of course! For some reason, they seemed to end up on BMX bikes.

Here is what I recall about it:

1) It did a stellar job protecting the leading chain from dust, dirt, mud and water thrown up by the front wheel.

2) It did an equally wonderful job catching and holding rainwater when a bicycle was left parked outside on a rainy day, pretty much offsetting the benefits above. The lower run of chain sat in water all day, but most of it spun out on the first use, which also meant a lot of oily water was drained off as well.

3) It made wheel removal problematic in the extreme (glued joint; this one might be better).

4) With continued use in muddy conditions, an astonishing amount of dirty, muddy slop ended up cradled inside the protector with the chain,

5) The material eventually dried out and developed stress fractures at the ribs, such that it broke into several segments. Once it was no longer in a single piece, it got ejected in the run around the sprocket.

6) While they lasted, the earlier iterations I'm experienced with worked best at protecting clothing from oil stains.

7) The most successful installations were on a tandem timing chain and on the front-crossover drive on a recumbent with compound gearing, where the chain was elevated far above the road surface and wasn't exposed to much grit and dirt. In both cases, the primary purpose was to prevent getting oil stains on clothing.

Pete, I'm sorry my recollection is so negative, but keep in mind it is based on earlier examples that appeared identical but may not be comparable. Still, the design is similar enough for me to think it might trap about as much debris in with the chain as it deflected, as did the older version. I love the design and appearance, and it would be wonderful if it works to full potential.

Best,

Dan.

[il padrone]

Hi Dan

Thanks for that viewpoint. I was riding a lot in the 80s but must have missed this device. Not a BMX rider though.

Re. the water, I do use PE lube that is a rust-preventative, so maybe it will help the chain stay rust-free  
A video of the installation is shown here:

http://www.youtube.com/watch?v=rmcH2lBr2sI

If you go to part 2 you'll see, no clips nor glue involved. It's promising that Dahon use them on their folding bikes.
I'm hopeful of it being effective, and may soon get hold of one from SJS.

[edit] Dan, was your BMX chain cover like this one? Seems a much more basic type of thing, a rather large thin-walled plastic hose ?? But I could be wrong.

[Danneaux]

Dan, was your BMX chain cover like this one?

I don't recognize the name, but the execution is near-enough to be the same. On the other hand, the YouTube installation for the video shows the Biologic version going on just the way I remember. At the point where the ends overlap and lock-together is where I added the drop of glue as instructed. I do remember it took a couple tried to get the tubing tension optimal with the chain tension. Too loose, and it didn't travel at the same rate as the chain. Too tight, and it wanted to pop off as it rounded the sprocket. It wasn't too difficult to hit the happy medium.

I suspect the plastic on the ones I installed was not as robust as on the newer model; they were using a bit more force to pop it on the chain than I recall, and that would be consistent with thicker material.

I do remember it looked a lot like wire-loom tubing, but was translucent. Have you considered making your own from that material? It doesn't look as if it would be terribly difficult. Maybe the originals were just sunk by poor materials. I often wondered if the original product might have been greatly improved by drilling the occasional small drain hole at intervals to release any trapped water; small holes wouldn't have allowed much dirt to enter. I do recall the tubing caused some change in tone but nothing objectionable (then again, I didn't ride the bikes they were on). The installations I made used no chainring cover; they were simply a chainring and sprocket covered by the tubing. I suppose the tubing could cause some scuffing against the inside of the cover, making them a little but noisier.

Oh, Pete, I really hope this works out. The originals were such a great idea in concept, and I was hopeful then. It would really make me happy to see one of these things successfully performing its intended job.

If you have any questions or if I can offer any help, please give a shout.

Best,

Dan.

[Andre Jute]

I'm amazed to hear SJS recommends the Biologic FreeDrive Chain Wrap, and doubly amazed to hear they recommend it in preference to the Hebie Chainglider.

I have had a Hebie Chainglider on my bike for about 5000km now, and it is good as new.


Before that I had a Utopia Country chaincase, and before that I used Dutch plastic cases as seen on Dutch city bikes. Of all these the Hebie Chainglider is undoubtedly superior in every respect. The Utopia is about three times the prices of a Chainglider installation for a Rohloff.

The thing presently called a Biologic FreeDrive Chain Wrap has been around for a long time. Dahon supply it, or at least supplied it at one stage. I haven't tried it, and the reason I didn't try something so cheap is that a German engineer fitted it to his commuting/touring bike and published photographs of his trouser cuffs as the thing disintegrated over the next three months; he described it as not economically a good choice. You just have to look at it, and be told it rides around with the chain, and is so inflexible it needs a 17t sprocket minimum, to know the  links will break apart and let out whatever is inside, which is usually dirty water rather than oil, as the thing, when it is new, is a water trap.

It does have an advantage though. It is cheap on the surplus market, or was when I last looked at it, seven or eight years ago. But I worked  out that the four or five I could get for the landed cost of a Chainglider would just about last me a year.

***

It may be that Dan's wish will come true, that a theoretically good idea has been made to work. I don't recollect the rubbish product of a few years ago being white but rather glossy black.