Some people like chain tubes and some don’t like them. Some people remove them, but I firmly believe the manufacturer knew what they were doing when they installed chain tubes. Chain tubes exist for a reason … a good reason. They help keep the chain cleaner. They help keep the chain from rubbing on the frame which protects the paint and the metal as the chain can actually cut thru the metal. This is important when the chain is positioned near the cross member or some other part of the frame. Chain tubes help protect the rider from contact with the chain and oil/dirt/grease off of the chain. However, that is not to say they are perfect and always trouble-free.

When my trike was fairly new I had it into the dealer to get some minor work done on it which should not have involved the removal or “breaking” of the chain. I picked up my trike at the dealer and started riding it. I only rode it about 3 blocks when I noticed something wasn’t right. I stopped and got off to look things over. I discovered that the dealer had rerouted the chain installing it wrong to where it was rubbing against the bottom of the cross member and cutting it in two. Needless to say I was not a happy camper. I installed the chain properly and went on my way. I contacted the dealer about it and they denied any responsibility. Never the less, they agreed to repair everything. The chain was suppose to go under the idler pulley but they had it on top of the pulley where the pulley did absolutely nothing. The chain was free to move upward when pedalling and make contact with the frame. DUH!!!

Most manufacturers do a pretty good job of aligning the chain tubes properly, but there are exceptions. The chain should never enter the chain tube at much of an angle like in the image above.That is just stupid … asking for the chain to cut thru the tubing splitting the end of it. Now that is made that way at the factory, but chain tubes oftentimes slip thru their holder and move out of position. They can relocate themselves right up against a sprocket or pulley and jam things up.

I have found it is best if the chain tubes are flared out on the ends. It makes a better path in and out of the tubes for the chain to move thru and causes less damage to the tube. I have flared my own chain tubes by heating the end of the tubes and then pushing the tube against a ball peen hammer held in a vice on a workbench.

Yes, those clamps holding the chain tube can be troublesome allowing the tube to move thru it. It can cause shifting problems as well as damage to the tubes if and when they move into the front sprockets (chainrings). The upper chain tube can move backwards and jam into the pulley. So it is a good idea to check all of this occasionally and do whatever is needed to prevent this from happening.

As to the angle of approach of the chain into the chain tube that can be more difficult to remedy and may require some ingenuity. I have had to remake the mount of more than one chain tube over the years. One aftermarket kit has solved the problem by making a sort of floating mount which easily and readily moves with the chain. In the image below this is a poor setup as far as the approach angle in and out of the tube. It will rub on the top of the tube and eventually cut thru it. And having the end of the tubing flared would also help a little bit.

Well, like ol Forest, that is about all I have to say about that.

KEEP ON TRIKIN”