Been given a broken bike, worth fixing?

PiKe · 22 Nov 2019 at 18:39

Chain is hanging off, looks like the link is ok, just the rivet has got pushed out?

Also twist gears don't seem to work but cables are loose so I assume they just need the slack taking up, derailer and front one both freely move, rear tyre is missing an inner tube and front one might need replacing too.

The bike is a silver fox fx one.

Jonny ///M · 23 Nov 2019 at 21:25

Depends on a few things. If the chain has snapped because it's overly worn then it's probabaly not worth replacing it and thr cog st the back which will have worn along with it/possibly front rings of they appear spikey.

If it has just snapped under a bad gear change then a few quid on a quick link/chain tool to remove the damaged link would be worth it.

Tube is an easy fix and is part of cycling. Front one is probabaly soft from being unloved for so long.

Gear cables will need tughtnend yup, check for damage to the outer cables that could have caused it to go slack.

mattyfez · 24 Nov 2019 at 16:11

New chain approx a tenner.
New gear cable set about a tenner.
2 new tubes £6-10.
Some chain lube approx £6

So if you know what you're doing then about £36 in parts.

You might need a new cassette too, if it's worn.

Saytan · 25 Nov 2019 at 20:27

mattyfez said:
New chain approx a tenner.
New gear cable set about a tenner.
2 new tubes £6-10.
Some chain lube approx £6

So if you know what you're doing then about £36 in parts.

You might need a new cassette too, if it's worn.

Puncture repair kit £3....

PiKe · 25 Nov 2019 at 21:16

Saytan said:
Puncture repair kit £3....

New tube cost me £3.

Got it up and running now, but have an issue with the front derailleur twist shift, it's fallen apart and a piece of metal fell out, up until then I couldn't get it to work anyway, seemed overly tight?

PiKe · 25 Nov 2019 at 22:19

Managed to put the twist grip back together but still unable to get the front derailleur to move, what am I doing wrong? Cable tension is set with the adjustment on the handle bars screwed all the way in. Seems to move freely by hand.

Saytan · 26 Nov 2019 at 08:26

Disconnect the cable from the derailleur, hold the end in your hand and twist the shifter. Does it move?

Those cheap twist grip shifters are famously a bit rubbish....

mattyfez · 26 Nov 2019 at 08:47

Check the derailleur moves freely too whilst the cable is disconnected, it might be seized up, if you can't move it by hand a cable isn't going to move it.

PiKe · 26 Nov 2019 at 08:51

I can move it but it is stiff, not sure what tension these things should be...

Jonny ///M · 26 Nov 2019 at 09:15

Make sure the cable goes over the top of the nut and the wee tab that stick out. Under the tab will make it tighter to change.

Saytan · 26 Nov 2019 at 09:49

slather the deraileur pivots in GT85 too

PiKe · 26 Nov 2019 at 14:21

Jonny ///M said:
Make sure the cable goes over the top of the nut and the wee tab that stick out. Under the tab will make it tighter to change.

It pulls from above, its just between the washer and deraileur, it's not tucked under the 'ear'.

I think it's just stiff, I checked a deraileur in LBS and although stiff, it didnt seem as bad as mine.

mattyfez · 26 Nov 2019 at 19:33

Front dérailleurs can be a bit agricultural in operation, it might just be gunked up and or oxidised a bit, causing excessive stiffness.
As above give it a good scrub with GT85 or WD40 and a stiff brush, should free it up a bit.

PiKe · 28 Nov 2019 at 19:19

How can I tell if my gears are compatible with Shimano thumb shifters? Or which other brands would work?

Jonny ///M · 28 Nov 2019 at 20:10

Generally they will be compatible with them.

Sram are the only brand to change pull ratio in this market.