Are my teeth getting old?
Moderators: Philip Whiteman, Andy Terry
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- Posts: 413
- Joined: 10 Oct 2009 13:12
- Real Name: Barry Evans
- Location: Birmingham
Are my teeth getting old?
Apologies upfront to the likes of Mr Weaver, who need to look away from the following photos. Hard to believe I know, but I did clean these bits up before photoing them
Do I need new chain rings? I'm not sure how many km they have done. Possibly 15 000 +. Its a compact DA 7800.
Thanks, and greetings from DownUnder
Do I need new chain rings? I'm not sure how many km they have done. Possibly 15 000 +. Its a compact DA 7800.
Thanks, and greetings from DownUnder
Belt up, we're going for a ride
- Philip Whiteman
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- Location: Drayton, Worcestershire
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- Posts: 413
- Joined: 10 Oct 2009 13:12
- Real Name: Barry Evans
- Location: Birmingham
- Philip Whiteman
- Posts: 2046
- Joined: 19 Nov 2006 16:17
- Real Name:
- Location: Drayton, Worcestershire
What I find curious about this is that, in the picture where you can see the whole chainring, the teeth at roughly 2 o'clock to 3 o'clock look quite worn, while the teeth around 6 o'clock don't look very worn at all.
I tend to run the chain rings on my winter bike until I can 'feel' the wear (chain gets a little loose on the ring and you can feel it as you pedal, particularly at a high-ish cadence). At that point, I bit them and fit the slightly worn rings off one of my good bikes, then buy new ones for that bike.
I tend to run the chain rings on my winter bike until I can 'feel' the wear (chain gets a little loose on the ring and you can feel it as you pedal, particularly at a high-ish cadence). At that point, I bit them and fit the slightly worn rings off one of my good bikes, then buy new ones for that bike.
Also, Barry, you are clearly not riding up enough hills (or you are riding up them Museeuw-style), since your little ring looks unused.
I think that it is down to the design to aid and assist in changing gear George.George wrote:What I find curious about this is that, in the picture where you can see the whole chainring, the teeth at roughly 2 o'clock to 3 o'clock look quite worn, while the teeth around 6 o'clock don't look very worn at all.
"You only need two tools: WD40 and duct tape. If it doesn't move and it should, use WD40. If it moves and it shouldn't, use duct tape"
So the 2 o'clock teeth aren't badly worn? That's how they start out?AlanW wrote:I think that it is down to the design to aid and assist in changing gear George.George wrote:What I find curious about this is that, in the picture where you can see the whole chainring, the teeth at roughly 2 o'clock to 3 o'clock look quite worn, while the teeth around 6 o'clock don't look very worn at all.
Its hard to say to be honest from the photo, but if you look at a new one you'll see that nearly every tooth will have a slightly different profile.George wrote: So the 2 o'clock teeth aren't badly worn? That's how they start out?
Gone of the days when every tooth was machined the same and you could tell straight away when they were worn coz they were clearly hooked over.
I had the same problem a few months ago, I had fitted a new chain and cassette but the gear changing still wasn't as sweet as I expected it to be. I honestly couldn't tell if the front chain ring was worn or not, despite knowing that it had done thousands of miles. So cutting a long story short, I bought a new chain ring (@ £80.....!!!) and it cured the "problem".
"You only need two tools: WD40 and duct tape. If it doesn't move and it should, use WD40. If it moves and it shouldn't, use duct tape"
- petemarshall
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- Real Name: Pete Marshall
- Location: Stourbridge
None of my recent Shimano rings have sharks fin profiles.
The teeth of Shimano outer rings are slightly off set from one another but not hooked like a sharks find, that is a sign of wear.
I would be very unhappy if a ring started to sharks fin at 15,000 usually a sign of inadequate maintenance although why they have only gone in one place is a little strange. Maybe to long a chain?
I think ultegra outer rings are forged alu rather than pressed, so they should wear better although I can't see much difference on the 105 over the ulegras I have (the ulegras do look better though ).
Replace the outers with stainless steel ones and they will last forever at a weight and small shifting penalty. Not for racing but good on touring bikes. I have an ancient Shimano 600 triple crankset on my tourer that has TA stainless rings throughout, still shiney and no sharks teeth after god knows how many kms in the last 20 years. Weighs a ton though
The teeth of Shimano outer rings are slightly off set from one another but not hooked like a sharks find, that is a sign of wear.
I would be very unhappy if a ring started to sharks fin at 15,000 usually a sign of inadequate maintenance although why they have only gone in one place is a little strange. Maybe to long a chain?
I think ultegra outer rings are forged alu rather than pressed, so they should wear better although I can't see much difference on the 105 over the ulegras I have (the ulegras do look better though ).
Replace the outers with stainless steel ones and they will last forever at a weight and small shifting penalty. Not for racing but good on touring bikes. I have an ancient Shimano 600 triple crankset on my tourer that has TA stainless rings throughout, still shiney and no sharks teeth after god knows how many kms in the last 20 years. Weighs a ton though
I nearly fell for that recently when deciding my middle ring needed changing and I noticed some odd looking teeth on the big ring. Luckily I spotted odd teeth on a photo of a brand new chainset. It is indeed meant to give the chain an easy route off the ring in question.
AlanW wrote:I think that it is down to the design to aid and assist in changing gear George.George wrote:What I find curious about this is that, in the picture where you can see the whole chainring, the teeth at roughly 2 o'clock to 3 o'clock look quite worn, while the teeth around 6 o'clock don't look very worn at all.
Eat cake before you're hungry
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- Posts: 413
- Joined: 10 Oct 2009 13:12
- Real Name: Barry Evans
- Location: Birmingham
Umm... confusing. Canvassed mates here DownUnder (by taking the rings down the local café!) and opinion was roughly 50:50! So then I took them to a couple of LBS and whadya know? One said change, the other said fine.
Seems to be a bit of a maintenance dark hole exasperated by the pre-cut unequal teeth.
And yes George, big ring only on anything less than 10%
Seems to be a bit of a maintenance dark hole exasperated by the pre-cut unequal teeth.
And yes George, big ring only on anything less than 10%
Belt up, we're going for a ride