Tension Roller Tweaks

[etheric]

Ghost Ring Tension

Holy crap this ghost ring trick is cool. We just tried it out and it not only works really well, but looks very cool while in motion. If you've got an old cassette I'm sure you could find the right size to plop in somewhere. I think we used a 46t chainring so it would fit right in the middle.

augi am I being overly picky, or could the post subject spelling be corrected so that people in the future could use the search function to find this useful thread? Can the original poster edit the subject? Feel free to tell me that I am just being anal; I'm okay lettin 'er ride.

 

[gone_fishin]

done!

etheric, thank you very much for getting involved 8)

if anyone has a similar suggestion about any topic anywhere, just post your
thoughts at the end of the thread & we'll handle it

 

[Blaze]

Ghost ring chain tensioner

Wow, that ghost ring idea is great! I wish I would have known about that when I built my Nirve Switchblade chopper. I don't think I would have put it on the motor chain, but it sure looks cool.

I solved the problem by moving the wheel to adjust the proper motor chain tension, then for the pedal chain, I installed a one-speed spring-loaded chain tensioner (tension is pushing upwards on the chain). My bike didn't have a derailer mount, so I got one at a bicycle shop that bolted on to the axle.

I don't know if a ghost ring would have worked with the slack in such a long pedal chain, but it would have been cool to try it. Instead I went through the trouble of installing the tensioner to pick up the slack, and a 60t sprocket up front and a 30t pinion in the back to make room for the motor. A ghost ring might have been a lot cheaper and simpler, and soved both problems for me: chain tension, and getting the chain spread apart enough to clear the low motor placement. Looking back on it, I might have just left the 44t up front and added a 44t ghost ring at the back.

$18 at nycbikes.com

 

[Haggard]

would it not be easier to grad a rear derailer off any old mountain bike, lengthen your crank chain to suit? You'd never have to look at that chain again as far as tension and just having the one engine chain to adjust should be a breeze.
just a thought

 

[Blaze]

Unfortunately, most derailleurs you find are multi-speed, so they will be spring-loaded and cable-operated. What you need for this application is a single-speed derailleur, which are pretty rare. I couldn't find one at any local bike shops, so I had to order it online.

 

[psuggmog]

Here is a picture of an old tensioner. It clamped on the chainstay. This one is a cycle ace.

 

[etheric]

A derailleur needs multiple sprockets to exist as a DeR, otherwise it is a tensioner, like the Surly Singulator pictured above.
You can also take an old DeR and dial in both limit screws to your liking, then remove the upper jockey pulley and guide the chain around the backside of the lower tension pulley to create the same tensioning effect. A bolt through the hole of the where the upper pulley was will be required to keep the cage plates in place. This will still require a DeR mount however.
A tensioner will have a metal wheel in it, and a DeR will have some composite wheels though; may not matter much at all (especially if you keep the unused jockey wheel) but it may be worth considering in the long run.
I'd like to see a new chainstay mounted tensioner.
The cycle ace above looks like a spur.

 

[Proboscis]

I don't understand these tension roller tweaks, i took mind off the 2nd day and cut the chain to size (albeit i use the rear quick release to tweak it)

 

[psuggmog]

some times you can find old Huret or Cyclo derailleurs with metal idlers.

 

[etheric]

Here an example of the poorman's tensioner I desribed above. Not a close-up, but it may help seeing it.