Why is an Eccentric...
 

[Closed] Why is an Eccentric BB Good?

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Thinking about a SBC Chameleon. Rumours suggest the eccentric BB is a bit of a groaner. Anyone got anything good to say about having an Eccentric BB given that chain could be tensioned from an E13 or similar.

 
Posted : 09/01/2012 2:44 pm
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had an EBB on my Fisher Ferrous - once I'd got it greased up and worked out how to adjust the tension it was great. Far easier than having a tensioner or funny dropouts.

You can use it to adjust BB height/front centre as well if you like to fiddle...

 
Posted : 09/01/2012 2:47 pm
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My mate's eccentric BB on his Niner ahrdtail is a proper PITA. Strip adn regrease every couple of rides

 
Posted : 09/01/2012 2:48 pm
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Eccentric BB on the tandem is great and simple - no creaks or groans and on a solo an ebb means no sliding bits at the rear wheel for chain tension.

 
Posted : 09/01/2012 2:50 pm
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So does anyone reckon that for example if you set them at 9 O'clock they're less hassle.
Is there a good time?

 
Posted : 09/01/2012 2:51 pm
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The one on my Swift works fine, never squeeked or slipped and takes seconds to adjust for a new sprocket.

chain could be tensioned from an E13 or similar.

It could be, or be a rear mech style tensioner, or track ends, or magic ratio. If I was designing a bike it'd be EBB based on my experience with the Swift. Probelem with chain devices is you cant get at the bolts once the chainsets on so how do you tension the chain?

Never thought about deliberately using it to shorten stays, raise BB etc, mine spends most of its time in the highly unfassionable high bb/long stays area as thats how long the chain is!

 
Posted : 09/01/2012 2:53 pm
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Aye, never had a problem on the tandem either. Mind you there are several ways of doing an eccentric, is one means more likely to creak than another? Ours is Bushnell on the Ventana and never been an issue. Can't recall any issues with the expanding wedge jobbie on the old Cannondale Tandem either (Sticking yes, creaking no)

 
Posted : 09/01/2012 3:01 pm
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I've had them on a couple of bikes. The first, a GT peace which I used as a SS. Worked perfectly, never moved, never creaked. The second, my Singular Swift - ditto basically.

That said, I do like the sliding dropouts on my 853 inbred - just looks neater IMO.

 
Posted : 09/01/2012 3:04 pm
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Swift and pegasus here, full and 1/2 eccentric, adjust and forget has been my experience, makes dropping the back wheel out for changing tubes a doddle too

 
Posted : 09/01/2012 3:08 pm
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Had a noise/creak issue with the EBB on my chameleon until I replaced it. It had worn.

Now it's greased and causes no hassle, not used as a singlespeed though.

 
Posted : 09/01/2012 3:10 pm
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thisisnotaspoon - Member

Probelem with chain devices is you cant get at the bolts once the chainsets on so how do you tension the chain?

You usually can - no more difficult than getting at an EBB, to be honest.

 
Posted : 09/01/2012 3:11 pm
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I've got one on a Singular Peregrine. Quite like it. when I'm running gears on it, I move it back and up off road for higher BB and steeper seattube, and back and down for a lower bb and steeper seatube - seems to be kinder to my knees.

Even if it makes next to no difference, it makes sense to use adjustment if you've got it.

Works well. Doesn't slip, but I've had creaking from the BB which has been sorted by taking it all apart and regreasing, so I'm not sure whether the offending bit was the EBB shell or the cranks or the BB itself.

And I'm on the other side of the fence to clubber, I think it looks cleaner than sliding dropouts!

 
Posted : 09/01/2012 3:14 pm
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I'm all for a bit of fiddling anyway, beats Cooking programmes, so yep, I think it'll be great!

 
Posted : 09/01/2012 3:20 pm
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with EBBs, out of interest, how much adjustment can you actually make in chain length terms? how often do you need to recalibrate it to deal with chain stretch and is there a finite amount of stretch it can cope with?

 
Posted : 09/01/2012 3:22 pm
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A good EBB is no problem. An example is the one used on the Singulars.

I suspect a lot of the problem some people have with nutted EBBs is applying too much pressure on the nuts. If the bike has a thin BB shell it then gets ovalised and nothing you can do will make it better.

I prefer EBB to sliders. Much neater rear end and you can't position your wheel out of alignment in one of those braindead moments.

 
Posted : 09/01/2012 3:23 pm
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with EBBs, out of interest, how much adjustment can you actually make in chain length terms?

enough - you don't actually need much - two links of chain (eg the min amount you can lengthen/shorten without halflinks) = 1" so you only need to be able to account for that really.

I rarely bother recalibrating. I find that if your chainline's right you can run chains very loose and still not lose them.

 
Posted : 09/01/2012 3:26 pm
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it's a shame to hide this away somehow (standard with Singulars)
[url= http://farm4.staticflickr.com/3480/3785785221_3b07dbc3af_o.jp g" target="_blank">http://farm4.staticflickr.com/3480/3785785221_3b07dbc3af_o.jp g"/> [/img][/url]
[url= http://www.flickr.com/photos/rocketdog/3785785221/ ]August 3rd[/url] by [url= http://www.flickr.com/people/rocketdog/ ]rOcKeTdOgUk[/url], on Flickr

 
Posted : 09/01/2012 3:28 pm
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with EBBs, out of interest, how much adjustment can you actually make in chain length terms? how often do you need to recalibrate it to deal with chain stretch and is there a finite amount of stretch it can cope with?

1/2" maybe? i.e. given a perfect/rubbish example you could remove 1"(1 link) of chain and it'd still work, but only in the completely front/rear positions. In reality it's a choice of tensioning clockwise or anti-clockwise, anything else youd need a halflink chain to get more adjustment.

I've only had to adjuust mine when swapping gears

 
Posted : 09/01/2012 3:32 pm
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No issues at all with my Phil Woods one in my Love/Hate..

 
Posted : 09/01/2012 3:36 pm
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The bushnell one in my HX2 is great

 
Posted : 09/01/2012 3:45 pm
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if you're worried about slipping then put the bb axle at about 2 o'clock - when you;re putting maximum torque through it the chain tension will resist the EBB slipping in the shell (tip from tim@sideways).

 
Posted : 09/01/2012 4:01 pm
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2 oclock from which side 😉

 
Posted : 09/01/2012 5:12 pm