[Closed] uncommon SS question.

[url= http://www.sheldonbrown.com/biopace.html ]Here's[/url] what Sheldon says about Biopace. Is that the same thing? I tried it on a fixie and it worked, and the slack-tight-slack-tight thing was noticable.

How noticable is it simon? I am fairly interested...
One solution would be to use a chain tensionner, but I am tempted to use it on a fixie too.

In short, yes. The chain will effectively change length (from the chain tension point of view) and it's best to have something to take up the slack or you're more likely to lose the chain.

You can't use it on a fixie. You want as even chain tension as possible. I've seen several efforts at using Biopace rings on fixed wheel bikes. All were abandoned.

Sorry to be blunt!

: P

Singlespeed? In the mountains around you? Crikey, you riding god.

Pierre +1, it won't work properly. If you do try it, film it for us.

On my bmx my chainring (despite being ridiculously hench) is slightly bent. This gives the chain a slight tight spot, and it is noticeable. A Q ring would be horrible.

Crikey, you riding god.

If it is symmetrical, why would you need a chain tensioner?

LOL I love the irony of fitting a device for increased cycling efficiency (Q ring) on a singlespeed. Thus requiring a tensioner and loosing some of the advantages.

You know, there are other proven ways to increase efficiency. Shimano or SRAM might sell you some 😉

IA it's just on rocky and technical uphill. Apparently on the local forum, people have tested it and it appears that the 33 tooth allows smoother pedalling and suppresses the "dead point" of the pedal stroke.

Yes, but do you know what else allows smooth pedalling? The right gear 😉

Don't worry, I'm just teasing. Ride a SS myself most days (tho no Q-ring). As epicyclo says, I can see how it might not require a tensioner, depending I think what sort of shape it is (i.e. the symmetry).

I'd go for "try it and see" but budget for a tensioner.

well I already have a tensioner (and gears but I miss riding my HT and riding SS).

I'll see if I can buy one (I am skint at the moment) and will get back to this thread to see how it goes.

Got Q rings on my hardtail. They are ok but I don't find the difference earth shattering.

I have used the rotor cranks on a single speed. They make a huge difference, much more than so than the Q rings. Though they probably cost as much as the rest of a decent single speed bike.

I think epicyclo is right. The chain is on roughly half the chain ring at any given time - assuming the chain ring isn't massively bigger than the sprocket. Now that half varies as the ring turns but it's always half - and half the chain ring always has half the teeth on it. Yes it takes up more chain at certain points in its rotation but it also lets more out.

Get the tension good and tight when the long diameter of the chain ring is perpendicular to the bottom bracket to drop out line and it will probably be OK. It won't be perfect but it ought to be OK unless there is a big difference either in the two chain ring diameters or between the chain ring and sprocket (or your chain stays are really small - thinking about it it ought ot work better on a 29er).

Note: I could be wrong

igm - Member
...Note: I could be wrong

Only if the chainring is poorly manufactured.

The reason I'm not certain is that the chain is on ever so slightly more than half the chain ring because the sprocket is smaller than the chain ring.

I'm assuming it's not enough to matter.

cheers everyone...
I'll see when I'll need to change the ring (soon as they are made of cheese shimano)