Worn cog-wheels...help

To replace everything is expensive. I recommend that you only do one thing at a time, and only the repairs that are needed.

First on the tools, cycling has some specialized tools and and you may to purchase a tool kit. Kits can be less expensive then buying the individual tools, and it sounds like you will be needing the tools. LBS shops have them, or you can do the Internet mail order thing. I recommend using the name brand tools, such as Park, they are better quality (but a little more expensive). Probably cost about $100 to $150 US (not sure of the Australian price).

Start with replacing the chain. If after replacing the chain it skips on the cogs in the back (you will feel it when you put a lot of pressure in specific gears), then the cassette (the cogs in back) will need to be replaced. To replace the cassette, you will need a chain whip and cassette removal tool (Lock ring tool)(which should be included in a tool kit).

Below is the link to Park tools. This web site can provide a lot of detail on the repairs:
parktool.cominstructions.aspOpen ↗

Good Luck!

buckybux said:

To replace everything is expensive. I recommend that you only do one thing at a time, and only the repairs that are needed.

First on the tools, cycling has some specialized tools and and you may to purchase a tool kit. Kits can be less expensive then buying the individual tools, and it sounds like you will be needing the tools. LBS shops have them, or you can do the Internet mail order thing. I recommend using the name brand tools, such as Park, they are better quality (but a little more expensive). Probably cost about $100 to $150 US (not sure of the Australian price).

Start with replacing the chain. If after replacing the chain it skips on the cogs in the back (you will feel it when you put a lot of pressure in specific gears), then the cassette (the cogs in back) will need to be replaced. To replace the cassette, you will need a chain whip and cassette removal tool (Lock ring tool)(which should be included in a tool kit).

Below is the link to Park tools. This web site can provide a lot of detail on the repairs:
parktool.cominstructions.aspOpen ↗

Good Luck!

Thankyou! Hadnt thought of doing it in stages.....just assumed everything was knackered. Thanks again.
Sam

goodreuben said:

Thankyou! Hadnt thought of doing it in stages.....just assumed everything was knackered. Thanks again.
Sam

PS.... Is it easy to replace the chain? Do I need any specialist tools?

goodreuben said:

Thankyou! Hadnt thought of doing it in stages.....just assumed everything was knackered. Thanks again.
Sam

PS...Is it easy to replace the chain? Do I need any secialist tools?

goodreuben said:

PS.... Is it easy to replace the chain? Do I need any specialist tools?

Probably will need to get a chain tool to remove the chain, and make sure the length of the new chain is the same as the old one. Again, buy a good one as the cheaper ones break easy.

buckybux said:

Probably will need to get a chain tool to remove the chain, and make sure the length of the new chain is the same as the old one. Again, buy a good one as the cheaper ones break easy.

Cool, thanks again 🙂

I can't definitively speak for bikes , but in motorcycles it is always best practice to replace chain and sprockets as a set, as mixing old and new will prematurely wear the new stuff.

goodreuben said:

Hey, I have never EVER done anything to do with my bike before, other than ride it. A LOT. As a result, the cog-wheels on the chainset are very worn, also on the 8speed cassette I have at the back, and the chain itself is also knackered.

I dont really understand a lot about wht I need to replace...I kinda want to do it myself instead of take it to a bike-shop.

The set-up I have is Shimano DH Suntour pff nex300 ....the deraileurs are Shimano Acera. Do I just buy a new set? What would be a good online retailer?

Would i have to buy each cogwheel separately and put it all together? On the 8speed cassette. the chain feeds through two flywheels....do I have to replace these too? And if so, would i have to replace the Acera set? Doesnt that get expensive?

I am SO confused. I have attached pictures of the offending set-up...

Thaks for anything anyone can offer, advice-wise.....
Sam
[email hidden]

The FIRST thing you need to do is to rinse the dirt off the bike's drivetrain ...

[center]DIRT CAUSES PREMATURE AND/OR EXCESSIVE WEAR![/center]

AND THEN, lube the chain ... household oil (3-in-1, or equivalent) will do ...

Consider keeping the chain cleaner in the future ... having a dirty chain is like rubbing sandpaper against the parts that come in contact with it.

Your middle chainring should be replaced ... I must be the ONLY person who seeks out steel chainrings for replacing the middle/inner chainring, BTW -- steel IS heavier, but so durable that it's worth considering for the middle ring ...

Finding a 13t replacement pulley wheel is problematical, BTW ... the Dura Ace triple derailleur had them ... it would probably be less expensive to buy a replacement rear derailleur if/when you do get around to thinking about replacing the pulley wheels. 11t pulley wheels may be suitable ...

FWIW. I'm NOT a big fan of PARK tools ... yes, I have PARK tools (heck, I have one of those ~40 lb. Park workstands) and other brands. Unfortunately, PARK often uses the cheapest quality metal for their diecast tools (most of the "black" tools except for their cone wrenches) -- what used to be referred to as "pot metal" ... the steel on many of their OTHER tools is often on the "soft" side, IMO. Their HIGH QUALITY tools are generally SHOP tools which cost well over $100US, each ...

IF you get a toolkit, I would recommend you just consider getting the $50(US)[mail order price] kit that comes in a plastic shell case. I've looke at one, and it is suitable for the occasional mechanic. Some of the tools ARE use-once type (okay, you CAN use them more than once), some are BETTER than PARK's tools -- e.g., the Shimano bottom bracket tool is forged CroMo, AFAIK, instead of diecast. The cone wrenches in the cheap kit are barely useable, but most wheels now have sealed cartridge bearings rather than adjustable cones. The $100(US) difference can be used on the bike-specific tools you decide you need at a later date.

alfeng said:

The FIRST thing you need to do is to rinse the dirt off the bike's drivetrain ...

[center]DIRT CAUSES PREMATURE AND/OR EXCESSIVE WEAR![/center]

AND THEN, lube the chain ... household oil (3-in-1, or equivalent) will do ...

Consider keeping the chain cleaner in the future ... having a dirty chain is like rubbing sandpaper against the parts that come in contact with it.

Your middle chainring should be replaced ... I must be the ONLY person who seeks out steel chainrings for replacing the middle/inner chainring, BTW -- steel IS heavier, but so durable that it's worth considering for the middle ring ...

Finding a 13t replacement pulley wheel is problematical, BTW ... the Dura Ace triple derailleur had them ... it would probably be less expensive to buy a replacement rear derailleur if/when you do get around to thinking about replacing the pulley wheels. 11t pulley wheels may be suitable ...

FWIW. I'm NOT a big fan of PARK tools ... yes, I have PARK tools (heck, I have one of those ~40 lb. Park workstands) and other brands. Unfortunately, PARK often uses the cheapest quality metal for their diecast tools (most of the "black" tools except for their cone wrenches) -- what used to be referred to as "pot metal" ... the steel on many of their OTHER tools is often on the "soft" side, IMO. Their HIGH QUALITY tools are generally SHOP tools which cost well over $100US, each ...

IF you get a toolkit, I would recommend you just consider getting the $50(US)[mail order price] kit that comes in a plastic shell case. I've looke at one, and it is suitable for the occasional mechanic. Some of the tools ARE use-once type (okay, you CAN use them more than once), some are BETTER than PARK's tools -- e.g., the Shimano bottom bracket tool is forged CroMo, AFAIK, instead of diecast. The cone wrenches in the cheap kit are barely useable, but most wheels now have sealed cartridge bearings rather than adjustable cones. The $100(US) difference can be used on the bike-specific tools you decide you need at a later date.

Thanks again everyone....I did ring around my local bike shops to see what they could do, and they all qouted me about £30 for the front set of cogs, £30 for the back cassette, £10 for the chain and then £10 to fit it for me and set my gears up.....£80 total (I actually live in the UK, but have just returned from travelling for the last 6months, hence the email address...)...this would be about $220 Australian I guess. As the bike is my only form of transport at the mo, and I dont really have the time to sit down and learn a load of stuff about bikes (starting university in a week), Im considering putting into a bike shop as it would be done within the day providing they had the parts. Is the price quoted above a reasonable one?

I would charge you $15 just to clean the bike! 😠

For the rest, its OK.

goodreuben said:

Thanks again everyone....I did ring around my local bike shops to see what they could do, and they all qouted me about £30 for the front set of cogs, £30 for the back cassette, £10 for the chain and then £10 to fit it for me and set my gears up.....£80 total (I actually live in the UK, but have just returned from travelling for the last 6months, hence the email address...)...this would be about $220 Australian I guess. As the bike is my only form of transport at the mo, and I dont really have the time to sit down and learn a load of stuff about bikes (starting university in a week), Im considering putting into a bike shop as it would be done within the day providing they had the parts. Is the price quoted above a reasonable one?

George would know ...

BUT, I guess I'm so cheap that I would suggest that for the "dollar" amount in question, you could buy the parts PLUS the economy-toolkit AND do-it-yourself ... and, probably have money left over for at least one meal and a round for your Mates ... OR, buy books!

You probably don't need a new cassette UNLESS the chain is on-and-hiding the offending cog on the cassette ... again, without seeing the large chainring (which I presume is behind the "guard" wheel), it looks like the middle ring & derailleur pulley wheel are the offending culprits in your drivetrain which need to be addressed, first ... THOSE two (and, a dirty & probably un-lubed chain/etc.) may be the only problems.

NB. I've got an 11t cog that has at least ONE pointed tooth (from shifting), and the chain doesn't skip on/off it ... so, that's my reference point.

The chain price is "okay" ...

Replacing the middle chainring == $20AU ... tops ... eBay (~$15US, with shipping!) if you must. That crank can be bought for LESS THAN £30 ... heck, you could probably get a used XT (in good condition) & BB crank for that amount of money if you were patient & lucky.

A replacement rear derailleur (OR, spending a half hour cleaning & lubing your rear derailleur) + a new chain (if cleaning-and-lubing doesn't resolve skipping which you may be experiencing) would be less than £35 ... YOUR current rear derailleur is not an expensive rear derailleur ...

I think the "cheap" Deore rear derailleur mail orders for about $35US + shipping ... that's £20 + chain (I'm thinking $20AU could cover the chain).

You'll need a 5mm allen wrench (what, $2AU, tops, if bought separately ... an 8mm allen wrench, possibly a Shimano BB "tool" (~$15AU for the forged CroMo LIFU if you can find one & ~$30AU for the pot-metal PARK version) , a chain break/riveter ($20-to-$30AU) ... well, the cost of the stuff adds up quickly to the point where, as noted, those economy toolkits (probably $60AU ... frequently available for $40US when on sale) are at worst close to a break-even if you use them just once, IMO.

BTW. Lubing the cables (in their housings) could go a long way toward improving the performance of your shifting, too.

BTW2. The "how to" can be found on the Park Tool (!) website AND other places ...

I think there is a lot of over kill here. Be careful about spending more money on the replacements than the bike is worth.

Chains need to be replaced the most frequently. Books recommend they be replaced every 3000km or so, however, right now I am at about 6000km and the chain is still good. Cassettes according to the books say about three chain changes to a cassette change, I usually go about 5-6 chain changes. But then I clean and do frequent maintenance.

Rear derailers seem to last about 20,000-40,000 km, or longer (mine last 50,000 km). Cranks the same or longer. But if you are racing or riding really hard (ie, mountain single track), wear can be quicker.

From looking at your photos, I would say the most you need is a new chain and propably a new cassette (but the detail in the photos is not the best). It takes a lot of wear to go through a derailer and crank.