There can be a lot of problems that might be causing your chains to slip which intern causes the gears to auto-shift and they can be very annoying sometimes and destroy a perfectly normal day for you.
If you are facing chain skipping, jumping gears auto shifting, or chains coming off, two main causes can be chain misbehaving or derailers out of alignment. Another one could be the cassette teeth are too worn off here’s how to fix them.
These problems can be with the newly bought bikes as well it probably happens because when they are shipped or when you put them in your car/trailer hood you accidentally bend the derailleur hanger or the cage of the derailleur just miss moves that’s when the problem occurs. Here’s how to troubleshoot all the problems and get to the main cause of it happening and how to fix it.
Checking the chain :
Here are some simple checks to perform on the chain to get to the main problem faster
- rusty chain
- stuck chain links
- broken/bent chain links
- chain length
if the chain is rusted and you haven’t done anything or if the chain is too old and there are dirt particles in it it may very well be the reason for chain skipping and gears auto shifting to fic this all you need to do is to
- identify the stuck links
- oiling the stuck links
Oil the links move them backward and forward to keep the chain going once smooth try running your bike if the problem still persists check out other things on the article to troubleshoot the problem.
if the chain links are bent or a little out of shape then you can either change the chain or there’s a budget-friendly solution as well all you need to have/buy is a chain tool to pull off those links buy just a few new links and replace them with that.
It will probably cost you around 20$ all in all. while a new chain may cost you more and it’s good for future maintenance as well.
sometimes if you buy a new chain or adjust a new chain to the bike you don’t check its length if you had bought a new chain recently the chain length could be the problem as well.
To troubleshoot chain length all you need to do is to put the bike in the highest gear and try running it uphill the chain will start skipping uphill because of its length. if it’s too long just use the chain tool to remove some chain blocks if it’s too short add them simple as that.
fixing Bent/twisted derailer hanger :
Check if the derailer hanger is twisted if it is you need to manually put it into place by hand, I am saying by hands because derailer hangers are mostly made up of aluminum, and it’s most likely that if you use a tool on it you may break it so its best to use hands.
Now how a derailer hanger can cause the chain to skip is that the cage the lower part of the derailleur gets out of line with the cogs and its, not in line which causes the derailer to move on its own since it’s not aligned and gears start auto shifting here’s how to fix a derailer hanger.
if the problem was not here and you didn’t notice any abnormality here the next best thing to look at would be the cassette.
How to check if the cassette has worn out :
another issue that mostly comes into play is the cassette of the bikes if the cassette is too old then it will start causing problems.
How to check if the cassette is too old :
to check it out all you need to do is to check the teeth on the cassette if they are too worn out with naked eye you know whats the cause of it try looking from the lowest cog to the highest because lower cogs are more in contact with the chain than the higher cogs and its most likely they will be worn out at this point.
There are other causes of chain slipping as well if all of the above causes were not on your bike and the problem still persists then maybe the frame is moving too much that makes your chain go wobbly or in the worse case your derailer being cracked or broken.
If that happened then you might just need to change the whole derailleur altogether.
How to prevent the chain from being stuck/rusting?
To prevent these mishaps from happening again and finding this trouble every other day all you need to do is to just oil it every day if that seems hard you can oil them every other day to prevent the rusting and the chain from being stuck also increase the chain’s life as well.
if your chain already has rust and it’s getting stuck I already wrote an article on how to remove the rust from your chain you can check that for now if you are in a hurry you can make do with the oil better yet if the chain is too rusty to keep up with consider changing it soon since it might eat up your cassette as well.
How to prevent Cassette from wearing out too fast :
If your cassette is out too fast the problem lies with the chain most probably if the chains are too old or too much worn out it will defect your cassette or should I say eat it out far too fast its probably best to change than chain at this point and oil it every now and then to prevent it from wearing out too fast.
Why derailleur hanger bends :
Derailleur hangers are made up of aluminum and the reason that they bend fast is because of this as well they were added as an extension to prevent the stress being shifted to the frame of the bikes bodies its more like a sacrificial part you could say if you are riding hard and fast and constantly changing gears up and down this little guy is saving your frame from bending by absorbing all that stress.
How to avoid these problems :
Well if you are facing these problems now pray that these get solved asap and here are some tips to avoid these problems from happening ever again or at least to avoid them as much as possible.
- Cleaning with water/dry cloth
- daily checks
- avoiding high stress and understanding your bike
Cleaning :
Cleaning and daily checks are really really important unless you just don’t care what happens or you run your bike once every year, but cleaning once every day or at least every 3 days can really save you a lot of money and increase the life expectancy of gear on your bike as well.
Just give your bike a clean wash after you have been on a rough ride and it’s filled with dirt and mud it will save your bike from rusting, losing paint and help you avoid problems like chain slipping.
Most mountain bikers including myself do it every day but if you cant be that punctual with it at least try it every 2 to 3 days and do not prolong because losing chain was just the iceberg of problems there will be a lot more like cassettes being worn out really really fast or brakes starting to fail early on.
Daily checks :
Before going out or hauling your bike on the back of your truck consider doing a quick check just run your bike on the road to quickly see if everything is in the order it can save you a lot of time and energy.
Avoiding high stresses :
If your chain is making noises or just yelling out on a very steep climb just get off it’s better to hike. I see people hiking all the time and its no big deal even I do it my self-understanding that your bike is just a mechanical tool in the end to help you and it has its limitations as well, yes the chain or gears may not be functioning well and even after fixing those you still hear creeks its best to try a higher or lower gear if it doesn’t stop there then it’s probably telling you that its the limit.
What I am trying to say is putting in a little effort yourself is better than coming home with bits of your bike.
do some maintenance on it perform some checks do some upgrades and see if those are working for you or just keep tweaking little things until you figure out a way for it to work rather than putting everything on the bike.
If you have problems with the scratches as well here’s how to remove deep scratches from your bike
There’s also another helpful article that I wrote on mountain bike gears if you had like you can check that out as well.
Let me know if this article was helpful to you and what method worked for you.