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New Idea, Not Sure If It Has Been Done Before.


planet x alan

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stock street riders that run singlespeed. i came up with this idea after i snapped 2 mech hangers in a few days. its designed to keep tension in the chain, i hope you all see where i am coming from, i havent seen anything like this before. maybe theres a reason for not having the tensioner on the top but hey... here it is

[attachmentid=5340]

it can be held onto the frame by a couple of jubilee clips.

advantages of it:

weight saving (i think)

no mech hanger to snap

able to pedal grind on the drive side without being scared of snapping a mech

tell me what you think and what sort of problems there are with something like this.

might start making one in a couple weeks after all the exams are out the way.

thanks

alan :shades:

post-8855-1150292363_thumb.jpg

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it will be VERY hard to make a tensioner work on the top of the chainstays, the forces put through when riding will either bend a fixed one, or force the spring down on a sprung one making the engament feel crap and letting the bottom of the chain droop down and make it noisy and possibly come off all together.

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The amount of power you put through your drive train when for example doing a gap, would make your chain (on the section with your proposed roller on it) go extremely taught, this would compress your tensioner completely and so the underside of the chain would go very loose, this could cause it to come off the sprocket or chainring.

I may be talking crap, i may not be. Wait for a second opinion ;)

Ian

Damn you Ali C!!!!

:P

Edited by flipkickbs
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it will be VERY hard to make a tensioner work on the top of the chainstays, the forces put through when riding will either bend a fixed one, or force the spring down on a sprung one making the engament feel crap and letting the bottom of the chain droop down and make it noisy and possibly come off all together.

oh dear :ermm: didnt think of that :( thanks for the advise (Y)

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Yeah unfortunatly the most effective place to have a tensioner wont work.

How about a similar spring loaded thing mounted to the underside pushing the chain down?

That should work.

that kinda defeats the object, might as well just have a normal one on a mech hanger. ah well, back to the drawing board :)

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mink (on the forum occasionally) had a phantom gear for a while when he snapped a hanger. They do actually work, and his didn't cause him any problems. It was sketchy as f**k though, every time you pedalled, the whole thing moved down about an inch and obviously that made the engagement feel really mushy. But he had it for a couple of weeks with no problems.

I always wondered why someone doesn't make a tensioner that attaches to the stays (on the bottom, obviously). I guess it would be pretty hard to make, though.

The Leeson KISSS is kinda like that and it works really nicely IMO, but it's still quite close to the back of the bike.

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nope, redcar. hoping to ride scarborough this summer though :)

I went a few days ago, let me know when you going. (Y)

Why not make a DCD kinda thing, but make it ajustable. :huh:

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Someone on OTN (JamesB) has a setup similar-ish to the top, but it's mounted on the underside of the stays so it acts like a regular tensioner. It's basically a long bar attached to a spring which goes nearer the BB, and it has a little piece of random material (can't remember what...) that the chain slides under, so it pushes the chain down, but with no use of the mech hanger area at all, and in a way that you'd have to fully twat your actual chainstay lengthways to damage. Works well for him, looks super clean, and it's really, really cheap to make. When OTN's up again I'll get the pics of it...

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I went a few days ago, let me know when you going. (Y)

Why not make a DCD kinda thing, but make it ajustable. :huh:

I think the front chainrings used in trials are too small to give enough adjustment for that to work i.e. you could only push the chain up a little bit before it hit the chainstay :( Good idea though.

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You knwo when you put the chain on, we always put it so its tight across the top anyway, so all the slack it at the bottom...what if you put the chain on, si it fitted across the underside of the chaoin stays with all the slack above...would it possibly work then?

Best thing to do is botch together a proto and play around (Y)

Please tell me you're being sarcastic!

I made one out of a cotton reel:

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And it worked!

Alun

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