View Full Version : chain tube

09-22-2009, 07:27 AM
Hi All

I have build the Maruder 1, just missing paint and finish.
I was test driving last night and I thought about using some chain tube under the seat, but I donīt know any thing about that.
So I am asking:

Is chain tube something special, or can any type of tube be used?
What do you use?


09-22-2009, 08:42 AM
I use half inch LDPE (low density polyethylene) irrigation tube, which is very cheap, low friction, and available at any place that sells garden supplies. It comes in a coil, so you will need to straighten it with heat. Use hot water, a heat gun, a sunny location on a hot day, etc. Then flare the ends of the tube so the chain doesn't drag. You can do that by dipping the end of the tube in boiling water and then pushing some tapered object into the end before it cools.

Radical Brad
09-22-2009, 09:00 AM
Garden hose and "heater hose" from the hardware store is my choice.


09-22-2009, 05:25 PM
Thanks a lot I will try that.


12-15-2009, 09:38 PM
This is a little late for Soren, but could be useful for anyone else interested in chain tubes. Check out this page in two places, about mid-way and closer to the bottom. http://forum.atomiczombie.com/showthread.php?t=2807&page=7

12-20-2009, 07:56 PM

This is the type of tube BC is referring to and it is a real good choice. It seems to wear like iron, it's rigid enough to need almost no support. I am using it on my old LWB to keep the chain from sawing the chain stay and I'm going to add it to the run up front now that I aquired a roll. Cheap too. I'll be using it on the drive and return run on my high roller with only one clamp in the middle of the tube, each of which will be around 4 feet long.

12-21-2009, 06:13 PM
Here's a photo of irrigation tube like badcheese mentioned, it's what I used too. I flared the ends a bit, though it's hard to tell in this photo. Then I fabbed a wire hanger to loop around the pulley bolt, so the tube floats freely and moves back and forth with the pulley as the chain changes rear sprockets.


01-29-2010, 11:54 AM
That's some nice looking work Danner, I like the sliding idler too!

03-17-2010, 03:41 PM
hey Danner, DaveC here. I like the idea of a sliding chain pulley. How much travel do you allow for on your set-up? I'm building a Marauder 2 and plan to use two 3.5 inch pulleys on my chain. Nice looking set-up. DaveC:sunny:

03-17-2010, 05:35 PM
Hey DaveC, I allowed for about 1-1/2 inches of travel, and the pulley was about 1" thick and the chain line was about an inch out from the frame where the bolt enters the nut. So it tool about 3-1/2 or 4" long bolt to get the pulley in the right range to align with the chainline. You can see more details at the New Quadster thread (http://forum.atomiczombie.com/showthread.php?t=2807&page=7).

03-18-2010, 02:54 PM
thanks Danner, I will definitely consider that mod for my Marauder. DaveC:sunny:

03-18-2010, 05:32 PM
I've only just noticed the use of "O" rings to keep the hanger in place. Neat idea.

John Lewis
03-19-2010, 08:15 AM
Hi likebikes,

I ended up changing the modified derailer for a chain tube on my Marauder. There are some pictures near the end of my build thread. I think it was a definite improvement. My idler pulley is pretty wide so I didn't make it slide. It was unnecessary really when you consider the chain length. Might be different if I had a 10 sprocket cluster of course.

John Lewis

05-26-2010, 06:26 AM

I ended up running my chain using wide belt pulleys from a garden tractor store. The results weren't quite what I was looking for as the chain doesn't slide across them as I'd hoped. The pulleys are made in two halves and joined in the center which leaves a groove in the middle of the pulley which the chain hangs up on and so never transitions across the full width of the pulley. I would like to try Savarins method and have a sliding narrow pully, maybe plastic to save weight. Can anyone suggest a source for the right hardware? I haven't seen one yet that had what I have in mind. I think the gears would shift much smoother if I could get the chain in line with them a little better.

John Lewis
05-26-2010, 08:02 AM
Hi likebikes,
Try cutting a wide band or two from inner tube and stretching onto the pulley. I don't know how it will last but worth a try. Need a small tube or perhaps bike tube. I've had good luck cutting a groove in a skate board or roller blade wheel. I think Savarin has done some like that too.

On the Wolf I got a pulley from a machine at the fitness store. The bearing was no good and failed quickly. I replaced the bearing and also fitted a circlip to stop it coming out.

Terracycle sell suitable pulleys as do Greenspeed. The Greenspeed one I have has teeth in the middle for the chain. Given the length of chain I don't think you need worry about having the pulley sliding.


05-26-2010, 08:07 AM
. I've had good luck cutting a groove in a skate board or roller blade wheel. I think Savarin has done some like that too.

yes, but make sure they are the hard wheels
The other thing I do on those this walled plastic pulleys is place an "O" ring in the middle of the pulley for the rollers of the chain to sit on. It seems to make it smoother, quieter and less wear on the sides of the pulley