Chainset wear advice

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jon.mithe

New Member
Hi,

Fairly new to cycling I've been having some trouble with my bike, took it to a bike shop (fairly big one in city centre) and what they want to do seems a little extreme.

Trouble stared with my front gear (chainset one) cable snapping so I needed to get that fixed. I've also been having a little trouble with my rear gears, it only goes down to about 2 or 3 (1 being easiest, 8 hardest) and it becomes too hard to move the lever to get them any lower.

Anyhows, the man at the shop (who seemed to know his stuff) basically said my chainset and chain things at the back were all worn and is the source of my problems. So he wants to replace them all (comes to ~£50).

The bike itself is a cross between a hybrid and a racer (straight handle bars but thinner than hybrid typers but larger than racer tyres 700x28C) and is only 8 months old.

I cycle to work ~5 days a week and the round trip is ~7 miles. So 8 months is about 32 weeks give or take. 5 days a week tops = 160 trips, so thats a total of ~1100 miles. It is in the city, so I'm changing gears a little more often than if I were to cycle that many miles along contry roads.

8 months / 1100 miles just seems quite a short amount to replace the chainset and the rear chainset (not too sure what thats called). Although I'm new to cycling so I dont really know what I am talking about.

My gears sometimes use to skip, I played with the fine tuners next to the gear levers and managed to settle that down. Hasnt skipped for a while. Only problem was gears were becomming a little hard to change.

Can these sort of things were out with that amount of use / in that time? He didnt really take a look at my rear chainset but he seems to know his stuff well and doesnt come across untrustworthy (he swaped my brakes on warrenty with no trouble when one of the back levers broke)

Here are some pictures

Front chainset with flash

Front chainset no flash

Rear chainset flash

Rear chainset no flash

EDIT: I can definitly see on the front one there is a couple of spiky cog bits on the outside cog that are a little short (comparing to inner cog). Worn enought?

Any help would be great thanks, I'm taking my bike in tomorrow.
Jon.
 
A chain and rear cassette could easily wear out in this time if they've not been looked after, cleaned/ oiled. I'm a little surprised that the chain set would need replaced.
 
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J

jon.mithe

New Member
Yeah I have not cleaned it very much, just gets so dirty after a couple of days. But I have kept my cogs + chain oiled with some proper chain lube stuff I was advised at the bike store. You can probably see in the pictures I need to probably clean it :wacko: and put some lube stuff on. Thanks for your help.
 

cadseen

Veteran
Location
Hampshire UK
well if its not changing into the bottom 7 gears, it will not be the chainset or rear cassette, but cleaning them will help. yuo need to look at the rear changer and cables may be stiff. Or it could be the gear lever or STI lever sticking.

Basically the lower sprockets are selected by releasing the cable and the spring in the rear mech will force it to move out selecting the smaller sprockets. Make sure the rear mech moves freely, check someone hasnt screwed the adjusters preventing it moving fully. Start by cleaning it all and work the mech with your hand forcing it to move towards the lower sprockets.

It maybe you need to replace some parts, but you wont know till its clean, ooiled and running on all the gears.
 

gbb

Legendary Member
Location
Peterborough
The front teeth do look a bit worn, but you dont have to change the whole chainset...just do the chainrings themselves.
The rear doesnt look that bad...
But if you do the two front chainrings..say £15 each tops , a new chain which as HLaB says really should be changed...say £10, and some time setting it all up....perhaps £50 doesnt sound OTT
 

swee'pea99

Legendary Member
porkypete said:
Plenty of broken teeth visible in photop of front chain-ring (the largest cog) That certainly needs replacing.
Where? I can't see a single one. This bike shop guy's diagnosis sounds like complete cobblers to me. Or rather, it sounds to me like a bike shop owner who may indeed know his stuff but like every other small business in the country is strapped for cash, trying to rip you off.

There's no way worn chainsets/cassettes (that's the rear cogs) have anything whatsoever to do with your problems with snapping cables or changing gear. Worn chainsets/cassettes can cause problems, but not those problems. And as I say, yours aren't that worn. I've ridden bikes for hundreds of miles with chainsets/cassettes way more worn than those, with no problems.

Checkout that bicycletutor link. Also, two immediate things to do: lubricate your cables, and lubricate the point under your bottom bracket where the cables run. The latter is easy - just turn the bike upside down, look to see where the cable rubs, and oil with a basic oil like 3-in-1.

Cables are slightly trickier - you need to dribble oil into the end of the cable housing so that it runs down inside. It can be tricky to get access to the end - one end's in your shifter, t'others in the gear housing. But somehow you need to get oil to run thru' the 'tube' - preferably from one end to the other.

Prop your bike up somehow to get the cable as vertical as you can, to help the oil get down the 'tube'. Work the cable back and forth (using your shifters) to encourage the oil to move.

This may not completely solve your problem, but it's certainly the place to start.

Oh, and I'd certainly think about finding a different bike shop.
 
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J

jon.mithe

New Member
Hi,

Thanks for all the help! Especially for the video, he explains it well :smile:

From reading your replies and what my gut said, the rear cassettes (cheers) are ok enough, my outside front chainset may have a bit of wear on the outer cog but on the whole its good enough. So replacing it all does seem OTT. I've actually had no problems with my front chainset, except a little bit of stiffness which probably lead to the cable snapping.

I have played around with the trim on the gears (few months after buying the bike I had a problem with front gear chain falling off and the rear derailer skipped occasionally between 7th + 8th gear - trim fixed the problem but my gears were not as nice as before). After watching that video I shouldnt of done that and probably is why my gears are now in a bit of a state.

I will definitly clean it all up. I'm going to buy the gear cable and try and learn how to repair it myself, and setup my gears + lube the cables/derailer etc properly. I will also by a new chain. My brake pads also need changing, so I'm going to try and do that as well. You might see me write a couple more posts here if/when I get really stuck :biggrin: As soon as the front chainset gives me trouble I'll looking into swapping that.

Actually really getting into cycling so should be learning how to do this + maintain properly. The shop is in the centre of london so I reckon they just get alot of city folk who walk in with a problem and are just fine with thowing money at it and replacing everything thats not perfect without any thought.

Thanks again for all the help!
Cheers, Jon
 
Cripes Jon! how much time do you spend in the big ring? It's clear from your images that the teeth on the outer ring are much more worn than the inner. I suspect that you might be riding in too high a gear which accelerates chain wear due to the high loads involved.

Invest in a chain checker.

Research 'cadence'.
 
It's the best way in the long run, to repair it yourself. Your initial outlay maybe more as you buy the tools you need, but it will soon work out cheaper. And the ability to get your bike going again whilst out in the sticks is ...

priceless.

As others have said, regularly cleaning crud off your drive train and re-lubing can help. If you ride in all weathers, do you have any mudguards on your bike? As well as protecting you from road grim, they will help keep it off the bikes oily bits. A mudflap at the bottom of the front mudguard will stop road spray being flung upon to the front chainrings. That can where a chainrings out in double quick time.

Have a look here to see what I mean:
http://www.flickr.com/photos/ed_o_brain/3077487554/

The following bike had a mudflap finely crafted out of a plastic milk bottle and black duct tape:

http://www.flickr.com/photos/ed_o_brain/2301933727/

All the best
Ed
 
Forgot to say, one other option for reducing wear on the drive train and also making it cheaper to replace, is to go single speed.

If you live in a hilly area, I can see why you might be deterred from that.
 
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jon.mithe

New Member
Hi,

Yeah I was surprised at the difference between the inner and outer chainset ring. I usually start off in second gear on the small ring work it up to 4 or 5 then switch to the big gear and work it up to 8 (heard its not good to angle the chain, i.e. 1-3 on the big ring or 6-8 on the small ring angle the chain). I ride in / out of london city centre so I'm often on the big ring ~6th gear in the rear and have to floor it to pick up speed to safely mingle with traffic on the big roads or when busses ahead pull in. After I get out of the city centre I probably cruise at ~23-25mph and get up to 28-29mph when I push (busses are annoying, speeds according to my bike computer).

I ride in all weather but my bike has no mudflaps. I bought one of the removable ones that clamp to the seat to protect you back, but nothing on the front / back wheels.

Single speed, I see all the couriers have them here. Very tempted by that, would save all the malarky with gears, not that many hills in london.

Cheers about the chain advice, the chain checker would seem a good investment.

I'll look into a new big ring, guessing my one would wear a new chain more.

Yeah I'm definitly thinking learning this is important.

Thanks again,
Jon
 
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