Anyone know how to fix a bicycle?

MadPlumbarian · **on:** May 08, 2020, 01:54:22 AM

For some reason the kids bike is acting a little

If he’s pedaling forward the bike seems fine, but the second he stops and glides the bottom pushes forward, then if he turns the pedals backwards you can see in the pic, the top part drops, and the bottom does the same by pulling?
I cleaned the chain down and oiled it, then also the gears but that didn’t do anything, I also tried adjusting they hi/low but I think I kinda screwed that up cause it’s not going down to the smallest gear, maybe I pulled the cable too tight? Idk this is soo not my subject, give me a old school single speed fine, but a 21 mountain bike no clue.. I watched a few videos but that’s what’s got me to the point where it’s not even going into the smallest gear, so if anyone knows anything as to what I’m doing wrong please let me know,, thanks..
JR

SteveC · **Reply #1 on:** May 08, 2020, 01:56:45 AM

Not seeing a pic JR

MadPlumbarian · **Reply #2 on:** May 08, 2020, 02:05:37 AM

Oops,, rough day..
JR

MadPlumbarian · **Reply #3 on:** May 08, 2020, 02:08:54 AM

The Mrs said something and I had a brain fart, thought maybe the rear gears aren't free, need a good oil job to get them to turn freely to allow the chain to keep up?
JR

MadPlumbarian · **Reply #4 on:** May 08, 2020, 02:57:45 AM

Well, I had some time, I went out re adjusted it and it shifts 1-7, doesnt over shift, it’s spot on, and I lubed the crap out of the back bearings but nothing changed,, I’m stumped!
JR

nate j · **Reply #5 on:** May 08, 2020, 04:47:23 AM

Sounds to me like there is a problem with the freewheel/freehub. This may be fixed by oiling it, but if not I think it would need to be replaced.

MadPlumbarian · **Reply #6 on:** May 08, 2020, 06:53:54 AM

Quote from: nate j on May 08, 2020, 04:47:23 AM

Sounds to me like there is a problem with the freewheel/freehub. This may be fixed by oiling it, but if not I think it would need to be replaced.

I lubed that thing so much but it still sticks, I’m guessing I can take that off idk if I need a special tool? But if not I’ll take it apart clean it and re lube it to see if we can get this thing going, I do have a stare rear wheel, idk if that mechanism will fit if the other is bad? Guess we’ll have to wait to fin out..
JR

pomsbz · **Reply #7 on:** May 08, 2020, 07:18:17 AM

The Gear Cassette at the rear should rotate back without affecting the rear wheel when pedalling backwards. The fact that it isn't seems to point to the bearings or freehub being shot. If there are any open still around you it's easier simply to take it to the bike store.

This might help but you're going to need some speSmurfpillsed tools to remove the cassette.

https://www.parktool.com/blog/repair-help/freehub-service

MadPlumbarian · **Reply #8 on:** May 08, 2020, 07:24:40 AM

Thanks, I’ll have to look it over and go from there, he should get a new bike but no point of getting one now if we might move in a few months,
JR

Sea Monster · **Reply #9 on:** May 08, 2020, 09:30:34 AM

Been a long time since I pulled a bike apart, and I imagine there's more than a few ways they are put together.

I vaguely remember something about pawls sticking or jamming - bit of a clean, maybe replace a pawl or spring...

you might find a left handed thread in there somewhere, perhaps some circlips.

Nowhere near knowledgeable enough to prescribe any advice

If it were me, I'd go as far as I could until I didn't have the right tool (or a close enough tool

) to keep going then throw in the towel and take it to a speSmurfpillst....

If you've got the time, space, and enough tools, it could be a fun activity. Go slow, don't force anything, take pictures so you can check the sequence for reassembly.

MadPlumbarian · **Reply #10 on:** May 08, 2020, 05:03:11 PM

Quote from: Sea Monster on May 08, 2020, 09:30:34 AM

If it were me, I'd go as far as I could until I didn't have the right tool (or a close enough tool ) to keep going then throw in the towel and take it to a speSmurfpillst....

If you've got the time, space, and enough tools, it could be a fun activity. Go slow, don't force anything, take pictures so you can check the sequence for reassembly.

You read my mind, but it’s just a cheesy bike, and by the time if I could take it to a speSmurfpillst the cost for the repair is going to be close enough to just getting him a new bike, which he should have,
JR

hiraethus · **Reply #11 on:** May 08, 2020, 08:10:18 PM

Quote from: nate j on May 08, 2020, 04:47:23 AM

Sounds to me like there is a problem with the freewheel/freehub. This may be fixed by oiling it, but if not I think it would need to be replaced.

If it's not the freewheel then it might be the jockey wheels (the two small cogs) on the rear derailleur.

The Park Tool website has loads of good info about bike servicing: https://www.parktool.com/

MadPlumbarian · **Reply #12 on:** May 08, 2020, 08:57:47 PM

Ok, I watched a video and it pretty much broke it down for me,
I got the back wheel off and sure enough the set of gears aren’t spinning freely, there pretty stiff, unlike a casino roulette where you give it a spin and it just keeps spinning, this thing was tough and would stop on a pin!
I couldn’t get the set of gears off in order to clean them but I prayed them down then oiled the crap out of them, it did take some of the stiffness away but, still not great, I remounted the wheel, hooked everything up, then spun the crap out of it while hanging from the rafters, and of course it did the same but then after a few it seemed a little better.. so we’ll see..
JR

McStitchy · **Reply #13 on:** May 08, 2020, 09:14:55 PM

Being late to the party here.... but i agree with hiraethus. It seems that the chain is not going through the derailleur without hinder.

Otherwise it could also be the chain as that part with the two small wheels causes narrow bends.

Good luck JR

Sea Monster · **Reply #14 on:** May 09, 2020, 12:15:25 AM

Quote from: MadPlumbarian on May 08, 2020, 05:03:11 PM

You read my mind, but it’s just a cheesy bike, and by the time if I could take it to a speSmurfpillst the cost for the repair is going to be close enough to just getting him a new bike, which he should have,
JR

There you have it, if you're resigned to a new bike anyway- you've nothing to lose with a little playing around on this one.

It's just like student doctors digging up a corpse to learn on...