Hi,
I think there are a few others on here with a Helios tandem so I’m hoping someone can check something for me. I think the wee wheel between the front and rear cranks is meant to act as a chain tensioner. However, my one springs against, rather than away from the frame, and doesn’t create much *tension* as such, just holds the chain up out of the way. Is it on upside-down or something or is that just how they are?
Thanks
G
CityCyclingEdinburgh Forum » Infrastructure
Circe Helios chain tensioner
(11 posts)-
Posted 6 years ago #
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I think that is just how they are. @Harts has some strong views on them as I have repeatedly taken mine in to him and shrugged that it isn't keeping the chain taught.
Posted 6 years ago # -
Mine rattled against the frame so I cable ties it in place. It does created a slight link in the chainline so presumably it is adding some tension.
I have wondered if I half link would work better.
Posted 6 years ago # -
It seems I was a few seconds too late to edit my phone typos in my last post. I hope someone manages to get some meaning from that.
Posted 6 years ago # -
Once chain is stretched too much it won't tension.
Our shop demo does tension fine.
How old is your Helios?
One other work round is to use a bigger idler wheel. Half link is one other possibility though get chain stretch measured first.Posted 6 years ago # -
Yes, I have strong views on these tensioners! They are rubbish. A tandem should have a eccentric bottom bracket on the front BB. The End.
As Laidback says, once the chain is worn to 1.0 or so, the tensioner won't take up the slack. This is slightly annoying because on a non-derailleur set-up you can run a worn chain way beyond 1.0 as long as you can eliminate the slack, so changing frequently is annoying.
I modded hankchief's tensioner with a 14t jockey wheel so he gets slightly more life out of his chains. Paired with steel 30T chainrings it increases the service interval and keeps the chain tighter when it's not worn.
I should say, the Circe is a great wee bike, it's just let down by not having an eccentric BB. It's not a show-stopper, just an irritation that could easily be solved by them..
Posted 6 years ago # -
Eliptical bottom brackets also have their problems. As they are in the spray zone they get wet and can seize as you know. I had these on two tandems previous to Helios and often had chains just dropping off once chain stretched. First one was a Thorn too.
As an item I've not had many problems with Helios. I've sold a few and people have toured on them. Many just hop on and off and just run them without doing much in way of fettling.
The tensioner used now is better than first example. That used an idler wheel without flanges.
I've no idea how old the model is under discussion.
I'm happy to get new tensioner from Circe if asked.Posted 6 years ago # -
Dave, yes, eccentric bottom brackets can be problematic if neglected. I've gotten out some pretty horrifically seized ones, though. Greased up and good to go again. They're still the best chain tensioning solution for a tandem!
Hankchief did have a flanged tensioner, but it's the the lack of tensioning available that's the issue, not so much the roller (although a bigger one would help). Again, great wee machines, just think you should tell them to make them with eccentric BBs :-)
Posted 6 years ago # -
Thanks for your help. The sync chain isn’t worn enough to merit replacement just yet. The helios tandem is great-we use it loads. I think, on balance, that I prefer the simplicity of the ‘normal’ chainset and the chain tensioner. It’s certainly standing up well to my relaxed approach to maintenance! I had a traditional tandem years ago which had a (seized) eccentric BB and needed a new chainset. I didn’t bother fixing it and put the money saved into a ‘new tandem fund’ with no regrets. The helios is much less cumbersome, feels faster and also stops thanks to the disc brake. Progress.
Posted 6 years ago # -
@Laidback.
Sent you a DM re: front chain on the Helios
Posted 1 year ago # -
Sorry just saw.
Posted 1 year ago #
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