Chainring wear on a fixie

[classic33]

And too much time analysing things. Never had a frame break or chainrings or sprockets.

Had a brand new frame break riding it home from the shop.

 

[silva]

Which is easier and cheaper replace?
The frame(Isn't this the second frame that's failed/cracked on you?) or the drivetrain parts.
You're putting safety, not just yours, at risk to try and save a few pounds.

It becomes telegram style for you:
1) You're here claiming that the bicycle frame broke due to worn sprockets. Are you clowneske?
The frame likely broke due to stress cycles caused by a slot in it. A slot that allows belt drive configuration - a belt is continuous unlike a chain so it needs an opening in the frame to pass. That slot is fixed on the frame by 4 sunk head stainless steel bolts. I noticed its consequences and discovered these sat loose. Retensioning > back ok, but they kept again loosening. A possible explanation was galvanic reaction, stainless steel of the bolts that dissolves abit alu of the thread in the frame.
I decided to try abit silicone on the bolts thread, an after tensioning, silicone over the sunk bolt heads and as sealing elsewhere, as to keep electrolyte (water) out.
The bolts didn't came lose anymore.
Problem SOLVED.
But, since it took some time to notice something was wrong, and discover its cause, the frame tube part bottom bracket - slot could move a bit, stress at its fixed end (bottom bracket), and there it broke (most leverage point).
After receiving the replacement frame, I immidiately did that silicone job on the slot.
As to avoid a repeat.

2) You're minimalising avoided costs and work to "a few pounds", despite:
- it was the cost of 7 chainrings replaced by the cost of 1.
- the replacement and regular flipping work of 7 replaced by no work at all.
3) You're claiming my and other safeties at risk, without elaborating.

You refuse/ignore the beneficial points, the "why", I gave, without any argumentation.
I did the effort to describe my observations, testing and results of testing.

Same answer to fossyants parrot.
This is 7 years Captain Hindsight, yet you're both in a kinda permanent denial modus.
That's not my problem.
If you both were sprocket salesmen, I'd understood...

 

[mickle]

30 yo chainrings. Innumerable chains.

 

[classic33]

It becomes telegram style for you:
1) You're here claiming that the bicycle frame broke due to worn sprockets. Are you clowneske?
The frame likely broke due to stress cycles caused by a slot in it. A slot that allows belt drive configuration - a belt is continuous unlike a chain so it needs an opening in the frame to pass. That slot is fixed on the frame by 4 sunk head stainless steel bolts. I noticed its consequences and discovered these sat loose. Retensioning > back ok, but they kept again loosening. A possible explanation was galvanic reaction, stainless steel of the bolts that dissolves abit alu of the thread in the frame.
I decided to try abit silicone on the bolts thread, an after tensioning, silicone over the sunk bolt heads and as sealing elsewhere, as to keep electrolyte (water) out.
The bolts didn't came lose anymore.
Problem SOLVED.
But, since it took some time to notice something was wrong, and discover its cause, the frame tube part bottom bracket - slot could move a bit, stress at its fixed end (bottom bracket), and there it broke (most leverage point).
After receiving the replacement frame, I immidiately did that silicone job on the slot.
As to avoid a repeat.

2) You're minimalising avoided costs and work to "a few pounds", despite:
- it was the cost of 7 chainrings replaced by the cost of 1.
- the replacement and regular flipping work of 7 replaced by no work at all.
3) You're claiming my and other safeties at risk, without elaborating.

You refuse/ignore the beneficial points, the "why", I gave, without any argumentation.
I did the effort to describe my observations, testing and results of testing.

Same answer to fossyants parrot.
This is 7 years Captain Hindsight, yet you're both in a kinda permanent denial modus.
That's not my problem.
If you both were sprocket salesmen, I'd understood...

No such claim made by myself. But it is the second frame you've written off in your "experiment" in saving money. By your own admission.

 

[fossyant]

It's your teeth.

My commuter is maintained well as one fail could dump me into traffic - slipped chain etc. Road bikes, again well maintained - speed, climbing, etc. CX bike and MTB - extra attention - failed components could mean a very long walk home stuck in the middle of no-where or a very bad crash.

I mean, who puts a motorbike chain on a bicycle ?

I know your bike is a utility thing, but pay a little more attention to the parts. Part of the experience of riding a bike is it's simplicity, and there is nothing better when it's working perfectly. The sign of chainring wear, mine goes in the bin. You can feel roughness when pedalling, and the shifting goes on geared bikes. On a fixed, if you end up changing a flat, and pop the chain back on and it feels rough, you know the sprocket is worn. Fixed gear chains/sprockets wear together, especially if running 'evens' sprockets - so you occasionally need to advance the chain one tooth if you've not taken the wheel out in ages.

You carry on riding a bike with worn/broken teeth. That's not for me. I like to have a reliable bike that's not going to fail at 40 mph, or dump me on the ground when out of the saddle climbing.

And how are you getting galvanic corrosion, do you not apply a bit of grease, or occasionally inspect the bike/wash it. Here in may be the issue.

 

[silva]

View attachment 797605
30 yo chainrings. Innumerable chains.

My avatar bikes chain tensioning mechanism is clamp welded in the frame at the bottom bracket location. It clamps a cilinder with a hole out of center, so by turning the cilinder, the hole moves up or down and forth or back, which provides the variable position needed to compensate for chain wear.
The position of the hole (where the axle for the chainset goes through, provides a -7 / +7 mm variation towards the centre, so a 14 mm variation.
So, in a drivetrain configuration #teeth front/#teeth back where a new chain results in a position at the "beginning" of this range (= most backwards), there is 14 mm chain wear compensation available. If it results in the "middle" of this range, it's 7 mm.
My longtime 47/16T results in an estimated 10 mm.

All above without having to remove a link pair in order to "use" the available tensioning range, as was the case with the original 48/16 - the eccenter position sat near its end, meaning I first had to make a chain of length 108, (otherwise too short to place) to then just weeks upto a month later redo the job by another on length = unacceptable extra work/hassle.

Of course, in this scenario, I could also just throw the month old chain in the bin, and make a new.
That way, you can keep a chainring looking like yours for a gazillion miles.
Every year 12 new chains, 12 times the cost+work.
That way just shifts the cost+work from sprockets to chain.

While on the other hand, my case, I allow the sprockets to wear to such wide and low valleys, that the chain can stay on for its entire recommended wear life.
= no shuffle of cost+work, but an elimination of it.
Instead, I spend the bucks on boxes potato and corn chips.
Instead, I work in the garden of or watch the Simpsons.
Just a choice.
To illustrate this: I could say, I don't want to put my hand that deep in my bag of chips, instead I bin the bag with its remainder and grab a new....

 

[silva]

No such claim made by myself. But it is the second frame you've written off in your "experiment" in saving money. By your own admission.

You lie 3 times.
My avatar bike was bought in 2017.
It's frame broke and was replaced in 2024.
Both old and replacement frames have nothing to do with my "experiment".

 

[silva]

It's your teeth.

My commuter is maintained well as one fail could dump me into traffic - slipped chain etc. Road bikes, again well maintained - speed, climbing, etc. CX bike and MTB - extra attention - failed components could mean a very long walk home stuck in the middle of no-where or a very bad crash.

I mean, who puts a motorbike chain on a bicycle ?

I know your bike is a utility thing, but pay a little more attention to the parts. Part of the experience of riding a bike is it's simplicity, and there is nothing better when it's working perfectly. The sign of chainring wear, mine goes in the bin. You can feel roughness when pedalling, and the shifting goes on geared bikes. On a fixed, if you end up changing a flat, and pop the chain back on and it feels rough, you know the sprocket is worn. Fixed gear chains/sprockets wear together, especially if running 'evens' sprockets - so you occasionally need to advance the chain one tooth if you've not taken the wheel out in ages.

You carry on riding a bike with worn/broken teeth. That's not for me. I like to have a reliable bike that's not going to fail at 40 mph, or dump me on the ground when out of the saddle climbing.

And how are you getting galvanic corrosion, do you not apply a bit of grease, or occasionally inspect the bike/wash it. Here in may be the issue.

1) No, it are the chainring and cog teeth.
2) It was you claiming risk, and me denying it, and also confirmed by Captain Hindsight.
3) Galvanic corrosion, what do you mean, that I should have unmounted the frames belt slot to put grease on the stainless steel bolts, then mount it back?
The bikes drivetrain was chosen, ordered and delivered with chain drive.
Why the hell would I unmount the frame slot?
Rather the contrary: don't touch it.
After discovering bolts loose, I tensioned them again. I didn't know why they came loose, and dealer didn't know either. Ofcourse, SINCE that discovery, I started to check, I found now and then one that could be retensioned abit.
THEN I came on the idea of galvanic corrosion. So, I did what I described in earlier post: silicone to prevent water coming in.
Captain Hindsight then informed me of Problem Solved.
Some years later, after frame broke, I didn't forget the problem, and I sealed with silicone directly.
I DID still check later on ofcourse.
But the bolts didn't came loose, I checked less, then I ceased checking.
Because Problem Avoided.

Your attempts to blame me whatever are becoming desperate, you realize?

 

[silva]

...
I mean, who puts a motorbike chain on a bicycle ?
...

Is that criticism?
What's wrong with it?
The avatar bike started in 2017 with a chain that lasted 1 month.
A contributing factor may have been the 5 mm wrong chainline the bike was delivered with.
I considered that unacceptable and searched for improvement. I discovered and fixed the 5 mm wrong, and after alternative chain findings and tryings I arrived at this motorcycle chain.
Captain Hindsight again speaking - since it proved lasting longest, since 6 years.

 

[silva]

I didn't bother a WHILE to count the chainrings (mounted januari 2019) broken off teeth, but just decided to do, instead of 12/47 broken, it became nearly its complement: 11/47 NOT broken.
So a further 25 broke without me noticing consequences.
The breaking likely happened in consecutive order like before, all remaining 11 sit on consecutive positions.

And I also noticed the same that I noticed at the rear cog: the valleys between the teeth got worn deeper, so the outer ring strength has been reduced abit, much like the rear cog, causing the links to grind off a part the circumference of its 6 mount bolts.
For the chainring, this can't happen since the mount holes sit on the inner circle.

Still, it's something to pay attention to (clean regularly and check for crack starts), since the ring is alu, alu is alot less tough than steel (rear cog), so any starting cyclic deformation due to outer rings weakening, soon ends in it breaking somewhere.
That's a drawback of the weight reducing (cosmetic is also a further possible reason) CNC'ing alike is done on Velosolo's own rings. For ex I saw models of brands MOJO and Origin 8 rings not having such CNC'ing so no such weaker sections.

The chain tensioner sits now near the end of its range, with the already second chain life cog with all its teeth broken off at middle height, already before placing this chain. So, it looks like that second chain life will be completed.
2 weeks ago the non driveside bearing of my rear wheel has been replaced, and the play it had before, caused the rear cogs teeth remainders to be grinded off more along one side than the other, and they showed some sharkfin shaping in it, so when I mounted it on my spare rear wheel, I did so the other way = flipped.

Due to being the other wheel, apparently different threading, because despite I put the bolts in the same position as original, the by the chain sideplates grinded flat sections on their circumference, came in other positions after tensioned, resulting in further flat sections.
Important to keep an eye on, a bolt head ripped off = hub loss, and since Velosolo ceased, no replacement.
So, when mounting the next new chain (already made on length and kept with the bike) I might decide to dig that rear cog.
If I had known this all on forehand, I'd bought a stock of 17T's instead of 16T's, it would accept more wear before reaching the bolt heads.

So, the test I decided, now has a proven result: that rear cog DID do the job for another chain.
The current situation became:
- a chainring mounted since begin 2019, 11 teeth NOT broken off in the middle, with 3 filed down to their base, by me, due to me wrongly thinking a broken off teeth would risk a roller skip - it didn't.
- a rear cog with all its 16 teeth broken off in the middle, and the middle of the valleys inbetween, worn 1 mm deeper, in effect, increasing the teeth height again, the same distance.

For Your Information.

 

[EckyH]

Dear kids,

this

11/47 NOT broken.
So a further 25 broke without me noticing consequences.
The breaking likely happened in consecutive order like before, all remaining 11 sit on consecutive positions.

has nothing to do with any kind of responsible bicycling.
Please don't try this at home.

This is an example of deliberate negligence of bicycle maintenance and a recipe to endanger the own health and if riding such a broken bicycle near other people also risking to hurt other people due to crash which is waiting to happen.

E.