Sprockets Help

[Yorick]

Some teeth here are a bit naff. Can I just replace the biggest sprocket?
Or do I need to buy the whole thing?

And where do I go to get them?

I know fark all about bikes.

20250218_135246.jpg (841.54 KiB) Viewed 616 times

20250218_135237.jpg (1.81 MiB) Viewed 616 times

[Mr Moofo]

You can just replace the large chain ring. But you will need a crank extractor to access the mounting bolts (in some cases you can do it in situ).
But if you chain ring is worn, and you just replace that, you may find the chain jumping all over the place , especially under load.
You might find that you have to replace the cassette and the chain at the same time.
Why do you think the chain ring needs replacing?

[Ditchfinder]

All the cool kids have ditched 3 front rings, shifter and mech for 1 chainring up front and a wide range rear cassette.

What does the bike get used for?

[Yorick]

All the cool kids have ditched 3 front rings, shifter and mech for 1 chainring up front and a wide range rear cassette.

What does the bike get used for?

Usual route is 10 miles. Only 2 miles on gentle dirt paths.

It's got a few other problems and thinking of ditching it and spending 500€ - 750€ at Decathlon.

Are these old bikes worth chucking money at?

[Ditchfinder]

Depends how much you need to chuck at it. Is it a 9 or 10 speed rear shifter?

[Yorick]

Depends how much you need to chuck at it. Is it a 9 or 10 speed rear shifter?

7

[Ditchfinder]

Really? that model of rear mech looks way newer than 7 speed!

[Ditchfinder]

Pretty sure it's an rd m772 which is 9 speed. You can fit an 11- 40t cassette (I use ZTTO ones) to that. Change the front middle ring to a 32t (104 BCD) and discard the others. Ditch the front shifter. Throw a new chain on as you will need to shorten it anyway. Should be less than £100 easily.

You should just about be able to take the middle ring off which the chainset in situ on that chainset. Might have to remove the pedal though.

If you're not racing or winching up the sides of a mountain you will have plenty of range.

[Yorick]

Really? that model of rear mech looks way newer than 7 speed!

Oops. It's 9

[Ditchfinder]

https://www.aliexpress.com/item/1005006 ... ry_from%3A

https://www.aliexpress.com/item/3290076 ... ry_from%3A

[weeksy]

https://www.aliexpress.com/item/1005006 ... ry_from%3A

https://www.aliexpress.com/item/3290076 ... ry_from%3A

Lol I can't wait for this

[Ditchfinder]

https://www.aliexpress.com/item/1005006 ... ry_from%3A

https://www.aliexpress.com/item/3290076 ... ry_from%3A

Lol I can't wait for this

Care to expand......

(the 2nd link should be to a chainring but it seems to default to the chainring bolts )

[Yorick]

https://www.aliexpress.com/item/1005006 ... ry_from%3A

https://www.aliexpress.com/item/3290076 ... ry_from%3A

Lol I can't wait for this

I won't be attempting anything technical

Will need local shop to sort it. And with rear shock rebuild and a few other little jobs, gonna be around 300€

Reckon it's time to give in and buy summat else.

[Ditchfinder]

All you need is a chain splitter and a 5mm allen key

[Ditchfinder]

I tell a lie the old cassette needs to come off too doesn't it

[weeksy]

https://www.aliexpress.com/item/1005006 ... ry_from%3A

https://www.aliexpress.com/item/3290076 ... ry_from%3A

Lol I can't wait for this

I won't be attempting anything technical

Will need local shop to sort it. And with rear shock rebuild and a few other little jobs, gonna be around 300€

Reckon it's time to give in and buy summat else.

In truth, that bike has had it's day and i know it has a bit of nostalgia for you, but yeah really it's had a good innings.

Do cover any metal on the new bike in ACF50 though to see if you can keep the ravages of salt water at bay.

and CLEAN the chain just a bit of GT-85 is a good start

[Yorick]

Really? that model of rear mech looks way newer than 7 speed!

I may have been right. I'm sure I counted 7 when I bought it.
But when I had to change the set, I just bought whichever Shimano set that Decathlon had in.

But I just checked the sets on the spare wheel I got.
One is 7, one is 9.

Looks like the original Shimano was 7. Who knows ?

20250220_161319.jpg (825.43 KiB) Viewed 469 times

20250220_161555.jpg (1.83 MiB) Viewed 469 times

[Ditchfinder]

Orange 5's were never sold new with a 7 spd freewheel and that rear mech would only work with a 9 spd cassette

Or for that matter a bolted hub

[mangocrazy]

20250220_161319.jpg20250220_161555.jpg

Do you leave it in the ocean when it's not in use?