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DomP
11-02-18, 07:44 PM
Can't decide whether to change this sprocket on my Daytona or whether it's got some life left. What do you think?https://uploads.tapatalk-cdn.com/20180211/bca6fc46d92768e623834ae762a52851.jpg

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Red ones
11-02-18, 07:55 PM
Does the chain need replacing?

DomP
11-02-18, 07:56 PM
Does the chain need replacing?No the chains good, bikes only done 8973miles

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Red ones
11-02-18, 08:04 PM
Tbh I'd leave it until the chain needs doing, and then do both

DomP
11-02-18, 08:39 PM
Tbh I'd leave it until the chain needs doing, and then do bothThat's exactly what I wanted to hear!

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andy650
11-02-18, 08:48 PM
Ditto, it'll last until chain needs doing.

embee
11-02-18, 10:08 PM
Maybe a different approach.....
How much does a front sprocket cost and can you do it yourself? If it's maybe £15/20 for a JT or similar and it increases the life of the chain significantly it might be cost effective to change it. If you need to pay to have it done then probably not cost effective.
It's visibly worn, and it tends to give the chain a harder time once it gets significantly out of shape. The refinement also tends to start suffering.
Just a thought.

DomP
11-02-18, 10:23 PM
Maybe a different approach.....
How much does a front sprocket cost and can you do it yourself? If it's maybe £15/20 for a JT or similar and it increases the life of the chain significantly it might be cost effective to change it. If you need to pay to have it done then probably not cost effective.
It's visibly worn, and it tends to give the chain a harder time once it gets significantly out of shape. The refinement also tends to start suffering.
Just a thought.Yeah worth considering I suppose, I hate cracking front sprocket nuts off!

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glang
11-02-18, 11:27 PM
I always think that chain and sprockets wear as a set (logical when you consider that as one item wears the load is transferred onto the next so that wears faster and so on) so if any one component is changed its replacement will just wear rapidly until equilibrium is reached again....

DomP
11-02-18, 11:32 PM
I always think that chain and sprockets wear as a set (logical when you consider that as one item wears the load is transferred onto the next so that wears faster and so on) so if any one component is changed its replacement will just wear rapidly until equilibrium is reached again....Surely a front sprocket wears around 3 times faster as it has for example 16 teeth as opposed to the rears 40 odd so it each tooth contacts the chain three times for every one of the rears.

Just my take on it.

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glang
12-02-18, 09:34 AM
I think everything wears together so if you put a new sprocket on the teeth spacing will be slightly closer than the original so the old chain will only really be in contact with one tooth at a time. Then instead of the load being shared by all the teeth it will be concentrated on each one individually so wearing them rapidly until they reach the same spacing as the chain (and old sprocket) when the load will once again be shared and the wear rate slows. Unfortunately I think that during this process the chain is also temporarily more stressed so increasing its wear rate until it all settles down again.

Heorot
12-02-18, 11:15 AM
After getting a puncture in the back tyre repaired I noticed that the chain was too slack so I took the bike back to get it fixed. The mechanic (who is a biker himself) pointed out that the sprockets were wearing and that I should always replace both sprockets and the chain at the same time. So next time it is serviced it will get done. As the bike is on the original set and has done nearly 20,000 miles I don't think I have done too bad.

glang
12-02-18, 12:25 PM
Fortunately the sprockets are the cheap bits (unless you go for something fancy of course) however I think the quality of the chain can make a difference on lifespan. 20k is pretty good and apparently with auto lubricators that can be stretched (pun intended) up to 40k.

R1ffR4ff
12-02-18, 12:31 PM
I agree with the,"Leave it until you need to replace the chain" posts.A JT kit for my 1999 Curvy is only around £66 quid.I fitted a DID kit last year but might go with the JT next time as they seem just as good for less and the sprockets that came with the DID chain were JT anyway :)

embee
12-02-18, 02:56 PM
As the chain wears the pitch gets bigger (clearances in the pins/bushes increases). As the sprockets wear the tooth pitch hardly changes, or with the front if anything the pitch gets smaller as the root of the tooth profile where the roller seats wears and the effective diameter gets slightly smaller. The net result whatever condition is that the loading gets concentrated on the take-up tooth. A new tooth profile is designed to meet the chain roller at an ideal angle, a worn tooth means the contact happens at a different angle so results in greater impact, making it less refined.
The bigger problem is often the hooking and the drag which can happen as the chain leaves the tooth on exit.
I tend to work on the principle that front sprockets get the hardest time and are usually the least expensive, so fitting a new one roughly halfway through the chain life can be effective and certainly gives a better condition than a worn one. I know it isn't an ideal or perfect situation, but only a complete new set of bits will give you that.
Entirely up to the individual, I certainly wouldn't suggest either as necessarily better.

SV650rules
12-02-18, 04:46 PM
Surely a front sprocket wears around 3 times faster as it has for example 16 teeth as opposed to the rears 40 odd so it each tooth contacts the chain three times for every one of the rears.

Just my take on it.

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+1

There is also more force on each front sprocket tooth as less teeth so less chain rollers in contact to spread the load over. Front sprockets don't normally cost too much.

glang
12-02-18, 05:41 PM
youre right its just that, as I say, Ive found the new sprocket has slightly different pitch compared to the partially worn chain so the load instead of being spread is taken on individual teeth. This drastically accelerates the wear on the new front sprocket (and maybe the chain) until its pitch matches the chain and then the wear rate returns to normal. Effectively you have gained very little and may even have reduced the life of the chain....

DomP
12-02-18, 05:43 PM
Can 'o' worms!

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Biker Biggles
12-02-18, 09:30 PM
If it aint broke------Fix it until it is broke.:D

Or just ride it until it wears out then buy another one.:thumleft:

shiftin_gear98
13-02-18, 08:42 AM
So yet another thread that concludes one thing.
We all do different things because we are all different people.


DomP - If you can be arsed to replace it and you want to, then the people have spoken - do it.
If you can't be fudged as other people have also spoken - leave it till it's all mullered.


I know which one I'd do.




(It is still cold in the garage and there are many other things that involve less swearing)

DomP
13-02-18, 11:06 AM
So, that's cleared up then [emoji14]

Shall we resolve oil or tyres next? Just kidding :smt018

I must admit, I looked at the sprocket made my opinion (which I'm keeping to myself) read other comments, thought "what?" and took another look and thought "well, ok, maybe", took another look and thought "nah".

Still, it keeps me occupied and stops me bothering other people (until I start thinking out aloud).For what it's worth its staying on!

I've moved on to shall I flush the coolant and brake fluid now, both of which I think are more urgent

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SV650rules
13-02-18, 12:49 PM
Yeah, replacing brake fluid regularly can prevent corrosion in the system and pay dividends in the longer term. Modern coolants are good for a least 5 years (10 years in a car) - how old is the Daytona ?

DomP
13-02-18, 12:50 PM
Yeah, replacing brake fluid regularly can prevent corrosion in the system and pay dividends in the longer term. Modern coolants are good for a least 5 years (10 years in a car) - how old is the Daytona ?2012

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SV650rules
13-02-18, 12:52 PM
Here is recent thread on coolant.. enjoy

http://forums.sv650.org/showthread.php?t=229185

Bibio
13-02-18, 04:05 PM
i can only see a pic of a front sprocket and to me it looks like new so no need to change it.

there is a simple test on rear sprockets/chains. if you can insert a pencil between the chain and sprocket tooth then your chain and sprockets need changed as they are fubar.

visual inspection, if the teeth on a sprocket are 'hooked' then they need changed.

i have said it before but a scottoiler is the key to chain & sprocket life. if you have OCD then use 'dry lube' and put up with shorter chain & sprocket life.

cracking the throttle open to get your kicks also reduces the life of tyres, chain & sprockets.

DomP
13-02-18, 04:08 PM
i can only see a pic of a front sprocket and to me it looks like new so no need to change it.

there is a simple test on rear sprockets/chains. if you can insert a pencil between the chain and sprocket tooth then your chain and sprockets need changed as they are fubar.

visual inspection, if the teeth on a sprocket are 'hooked' then they need changed.

i have said it before but a scottoiler is the key to chain & sprocket life. if you have OCD then use 'dry lube' and put up with shorter chain & sprocket life.

cracking the throttle open to get your kicks also reduces the life of tyres, chain & sprockets.I used a scottoiler on my sv but there is little to no room to fit one on a Daytona 675 without it looking ugly and let's face it it's half the reason I got a 675

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DomP
13-02-18, 05:21 PM
Here is recent thread on coolant.. enjoy

http://forums.sv650.org/showthread.php?t=229185Good lunchtime read that was, thanks!

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