Which brands/models chainsets / chainrings have perfect centering?

[silva]

I assume the spindle he's talking about is the bottom bracket axle, and the only way that can be off centre is if the bottom bracket is very badly worn with movement in the axle.

Upon asking, another explanation I've been given is that a square axle can be offcenter, causing the center of the spider of the crankset to rotate in a circle.

 

[Milkfloat]

I do think you over think things. Just ride it, maintain it and replace stuff that breaks.

 

[Grant Fondo]

I do think you over think things.

Very good, that made me larf.

 

[Deleted member 1258]

I do think you over think things. Just ride it, maintain it and replace stuff that breaks.

Thats spot on, just ride it.

 

[silva]

I do think you over think things. Just ride it, maintain it and replace stuff that breaks.

It's a fixed gear, I have to retension the chain regularly, a chain tension variation makes that harder, is a wear concentration cause, and is annoyant when pushing back due to the "dead" gap brought by the tension variation.
Is thinking of a solution, then overthinking?

 

[Deleted member 1258]

It's a fixed gear, I have to retension the chain regularly, a chain tension variation makes that harder, is a wear concentration cause, and is annoyant when pushing back due to the "dead" gap brought by the tension variation.
Is thinking of a solution, then overthinking?

Yes

 

[silva]

Yes

Your refusal to recognize a problem as such is not my problem, chain tension variation is.

 

[Milkfloat]

Yes

I agree. I ride thousands of miles per year fixed on a cheap non-centred chainring with a cheap chain. I replace the chain about every 2k miles, mainly because it is cheap. I don’t rotate the chain, unless it happens to do it on its own when the wheel is out, I rarely bother to region either. I just ride it.

 

[silva]

I agree. I ride thousands of miles per year fixed on a cheap non-centred chainring with a cheap chain. I replace the chain about every 2k miles, mainly because it is cheap. I don’t rotate the chain, unless it happens to do it on its own when the wheel is out, I rarely bother to region either. I just ride it.

Chain: 13.95 €
Front sprocket: 32.95 £
Rear sprocket: 16.95 £
I replace the chain about every 20k miles, mainly (sole reason...) because it's... worn.
I rotate/flip the chain when I notice wear differences between the drivetrain parts.
I find every work on a bike too much work, so I try to decrease it towards zero, and a centered chainring is just another step on that road.
I don't want a bicycle that inflicts me work every evening. Because I just wanna use it to go from A to B.

Same for that stupid hydraulic brake system on my 62 mm tyres bike. If I have to take out / put in a wheel brake modules on both sides need to be unmounted OR I have to deflate>reinflate the tyre. I wasn't warned about it and when I started to suspect it when seeing pics but a "no ofcourse not that would be silly" was the answer. Recently I decided enough crap and went for mechanical brakes like on my previous bike. Then the crap gets reduced to a simple hooking out a V brake.

You say every 2k miles you replace a chain, lol, did you order plastic ones?

If I find a well-centered chainring then wear differences will decrease and then I have to mess 'round with the bike less and have more time and money to do the things I want to do. Ofcourse. Imagine you carry a backpack that every return home requires sewing. What would you do, everytime sewing or a new same one? I'd choose a better quality backpack brand instead lol.

 

[Milkfloat]

I bought a pack of 10 chains costs less than £3 each. They are very much disposable items for me. My sprockets are about £5 but so far seem fine.

 

[silva]

I find it crap to have to replace a chain every 2000 miles. I'd go for a better quality and if it lasts 3 times the miles at 3 times the price I'd go for it, because that's still a win (no replacement work).

 

[rogerzilla]

It's only an issue if the chain, when set to avoid binding at the tighest point, is slack enough to derail elsewhere. I've only ever seen that on kids' bikes with stamped steel chainrings. Buf they're s/s so an unshipped chain is not as dangerous.

NJS keirin kit tends to be very round and expensive. The irony is that most keirin riders, for reasons unknown, run super-slack chains.

 

[silva]

It's only an issue if the chain, when set to avoid binding at the tighest point, is slack enough to derail elsewhere. I've only ever seen that on kids' bikes with stamped steel chainrings. Buf they're s/s so an unshipped chain is not as dangerous.

NJS keirin kit tends to be very round and expensive. The irony is that most keirin riders, for reasons unknown, run super-slack chains.

Reasons I consider it an issue is that it voids an even wear spread, that pedaling is less smooth/rougher, that when I switch from pushing forward to pushing back there's a dead gap and that when doing a standstill before a red light / whatever waiting cause, it's harder to maintain balance, due to that dead gap.
Keirin looks like the cyclists version of 100 m sprint. Wear/maintenance does not matter, and a very slack chain likely gives some speed benefit.
Fact is that my two other previous singlespeeds>fixed gear bicycles never had a noticeable chain tension variation. Shimano cranksets, couple weeks ago I took a look, the cranksets were Shimano though forgot the model, have to look again for it.
So apparently, precise (centering) manufacturing doesn't require big bucks, the bikes costed 1/3 down to 1/4 of my current problematic bike with its 1001 problems.
But the cranksets are of a different and unusable for the current bike type. Maybe Shimano has some compatible models that maybe are precise centered.
But more recently, according to a lbs dealer, a square taper kan also be a cause. So it's then still not sure that the crankset is the cause.
It's not a hell of a problem, but still inflicts me a recurring hassle, that's why I want to at least try to find a solution.
It's like my current chain with 3/16" plates. It took half a year to finally find it / know its availability. I bought 1, tried 1 and it proved itself. Then I bought a whole stock of it. Because you never know, if that single company ceases then I'm thrown back to the begin. Now I have a buffer. If I find a crankset (or spindle) then that's again such a reference, ofc less important since it's not like a crankset has to be replaced as much as a chain/cog...

 

[silva]

Followup, since some weeks I have an octalink bottom bracket and Shimano 105 crankset mounted.

Pity was that I had (according to dealer) to change the chainring due to octalink not available with the current chainsets 144 bcd. So I had to mount a new / unworn chainring so that a 1 on 1 comparison with isn't possible.

The chain tension variation is still present.

I just tensioned the chain once again.
Measured with the bike hanging with its horizontal tube on a stander, measuring the same in both up and down running parts.
The chain tension is:
- maximal (tightest, set to about 1 cm up and downwards moveability), seen from the driveside, when the right (driveside) crank arm is on the 1:30 clock position.
- and minimal at the 7:30 clock position.
I made a dozen chain rotations, and those two clock positions stayed.

I do not have this tension variation on my previous fixie, that I used in a same fashion.
Aside: during the crankset/axle replacement, about a month, I have used that previous fixie.

I've ran out of ideas of the cause of the tension variation.
The variation cyclus is 1 max/min per chain rotation, if pushing the pedals/cranks would be a cause then I'd have 2 maxes every chain rotation.
Chain replacements (so far 2 so 3 in total, 2 brands) didn't affect it
Chainring replacements (so far 3 so 4 in total - 2 due to bcd change, 2 brands) didn't affect it.
Crankset replacements (so far 2 so 3 in total, 3 brands) didn't affect it.
Axle replacement (square taper to octalink) didn't affect it.
What else can be out of center / causing this?
Remember, earlier this year I have replaced chainring, cog and chain in one time - simultaneous, to notice a 2 cm up and down pushing tension difference directly afterwards, without any riding yet.

I now ran out of ideas. Can't even think of any possible other than above listed cause.
How different is my previous fixie to the new? The previous bikes chain was tensioned by moving the rear wheel backwards in its mount. The new one has a bottom bracket eccenter. But that just fixes (along two bolts) the axle into a certain position inside the shell, a position that doesn't change during riding or whatever else rotates the chain.

 

[silva]

It's only an issue if the chain, when set to avoid binding at the tighest point, is slack enough to derail elsewhere. I've only ever seen that on kids' bikes with stamped steel chainrings. Buf they're s/s so an unshipped chain is not as dangerous.

NJS keirin kit tends to be very round and expensive. The irony is that most keirin riders, for reasons unknown, run super-slack chains.

Keirin riders do not care about wear, all they care is the max speed on the short distance they play their game over.
About the opposite of my case so not really a reference and any irony is thus 'foreign' too.