Mountain bike repair questions

[DouglasR]

Hey guys, hope everyone’s having a great summer.
I’ve noticed several of you talking about bikes on here and I’m hoping I can get some help figuring out what’s wrong with mine.

I’ve got like a 5 year old $500 trek that’s prob got somewhere between 4-5k mostly road miles on it.
During this time I’ve done pretty much 0 maintenance so that’s prob not a good start...
Anyways

I feel like it’s never really shifted through all the gears on the cassette properly but I’ve always just dealt with it because I’m usually on the road.
However, last weekend while I was riding on our local course it kept switching between gears while I was climbing hills to the point that I just had to give up and walk it.
I went home and tried indexing the gears using the barrel adjustment as explained in several YouTube videos but I could never get it to consistently shift through all the gears.

As of now I plan on swapping out the shift cable because it’s pretty worn and frayed and I’m wondering if it’s catching on the inside of the housing and changing the derailleur hanger to see if that does anything.

Anybody got any other ideas about what might be causing this issue?
What other maintenance should I be performing while I’ve got it tore apart?

It’s a 3 ring on the front 8 in the back, I think... if that makes any difference.

Bike shops booked till August 6th...

Thanks!

 

[Deleted member 28227]

When was the last time you replaced the chain.

 

[DouglasR]

Never... but maybe I should?

 

[nrpate05]

Hard to say but yea Im sure the cables and housing need to be replaced. Some of the tensioning screws in the rear derailleur may need to be adjusted as well. A new chain is probably a good idea too, they're pretty cheap I think. Sometimes the teeth on the rings (I think it's called a cassette?) can get worn down over time and they have a hard time holding the chain in the correct gear, especially if the derailleur is off a little bit. Crazy to think bike shops are booked out that long!

 

[Ajax2744]

Sounds like your derailleur is not adjusted properly. When it's not adjusted right it'll push the chain between 2 gears and it'll jump back and forth. Or it could be your shift cable isn't tensioned correctly so it doesn't index properly. Flip your bike over on the seat and handle bars and push the peddles and shift through gears. Your derailleur should push your chain onto each gear and once on the gear should not touch the chain. It's pretty easy to see if your derailleur is off (especially on your highest or lowest gear) or if it's cable problems.

 

[LuketheDog]

Just hose that sucker down with a can of WD-40 and keep mashing the pedals man


...maybe a little maintenance wouldn't hurt though. Start with a new chain and cable, those are easy, and see what happens. It also seems like bikes in that price range actually take more maintenance to operate properly because the components are cheaper and more finicky, I have this problem with my father-in-law, who has never maintained a bike in his life.

 

[Irrelevant]

My limited experience during COVID is that I simply am not capable of the black magic that a bike shop has. But outside of witchcraft tuning, new cables/housings, and a new chain are pretty easy fixes.

 

[Deleted member 20812]

Agreed on a new chain and shifter cable. Make sure you grease the new cable. Adjusting a derailleur isn’t that hard. Might not be a bad idea to change the crank and cassette out too while you’re at it. Wear items like that are sometimes better replaced all at once.

Check your brakes. Some good MTB maintenance videos on YouTube.

 

[Deleted member 20812]

It’s a 3 ring on the front 8 in the back, I think... if that makes any difference.

One thought on the gear jumping issue, if you are in the big ring and running at the low end of your cassette, or vice versa on the small ring and running all the way at the top end of the cassette your bike won’t like this much and it can wreak havoc with gear jumping.

 

[rwc101]

 

[Deleted member 20812]

I’m with @rwc101 on a new bike, but I can’t in good faith tell you to do it right now. The used bike market is absolutely stupid.

 

[Wrong Burgundy]

Hey guys, hope everyone’s having a great summer.
I’ve noticed several of you talking about bikes on here and I’m hoping I can get some help figuring out what’s wrong with mine.

I’ve got like a 5 year old $500 trek that’s prob got somewhere between 4-5k mostly road miles on it.
During this time I’ve done pretty much 0 maintenance so that’s prob not a good start...
Anyways

I feel like it’s never really shifted through all the gears on the cassette properly but I’ve always just dealt with it because I’m usually on the road.
However, last weekend while I was riding on our local course it kept switching between gears while I was climbing hills to the point that I just had to give up and walk it.
I went home and tried indexing the gears using the barrel adjustment as explained in several YouTube videos but I could never get it to consistently shift through all the gears.

As of now I plan on swapping out the shift cable because it’s pretty worn and frayed and I’m wondering if it’s catching on the inside of the housing and changing the derailleur hanger to see if that does anything.

Anybody got any other ideas about what might be causing this issue?
What other maintenance should I be performing while I’ve got it tore apart?

It’s a 3 ring on the front 8 in the back, I think... if that makes any difference.

Bike shops booked till August 6th...

Thanks!

I have been there before. While at first glance the front and rear derailleur can seem complicated, give this a try:

Also, a new chain is always a good idea especially after that amount of time and miles. Minor chain 'stretch' can cause all sorts of issues while climbing in low gear or standing up out of the saddle and really grinding up a hill, etc. Also, yes, a new cable is good; things will shift more cleanly. And don't use WD-40, but go for a "dry" lube (insert 'that's what she said' joke here) as it doesn't attract as much dirt, grit, etc.

Lastly, give your tires and tubes a look (and have a spare), grease the bottom bracket (cranks) and you will likely get another pile of miles out of it.

 

[DouglasR]

Thanks for the help everyone.
Unfortunately a new bike isn’t in the cards for this summer so hopefully I can cobble this old one of mine back together.
I think I’m gonna start with a new chain and shift cable and go from there.
Worst case scenario I can probably go full millennial and get my dad to fix it.

What’s a good ball park figure of what you western adventure athlete types would spend on a bike?
Like a entry level cost vs. investment bike?
Some of the prices on those things make me wince.

 

[rwc101]

From a pure investment standpoint, I don't want to invest in something where I am spending 30% of the bike's MSRP doing routine maintenance like replacing cables, housing, and chains. If I were buying a new bike, I would look for something with a 1x crankset, good tire clearance for + tire options, hydraulic disc brakes, and rack/accessory attachment points. Preferably steel.

 

[Irrelevant]

Thanks for the help everyone.
Unfortunately a new bike isn’t in the cards for this summer so hopefully I can cobble this old one of mine back together.
I think I’m gonna start with a new chain and shift cable and go from there.
Worst case scenario I can probably go full millennial and get my dad to fix it.

What’s a good ball park figure of what you western adventure athlete types would spend on a bike?
Like a entry level cost vs. investment bike?
Some of the prices on those things make me wince.

I can't stomach new bike prices (though as JLS pointed out used prices are stupid high right now), I searched craigslist for a little over a year. I was looking for older quality lightweight full suspension. Forget the 29" or 27.5" wheels. I found an old yeti for $500, it was a real good deal and I jumped on it the first 2 hrs it had been posted. I think realistically, $1,500 should get you a nice all mountain bike that will last.

 

[Deleted member 20812]

What’s a good ball park figure of what you western adventure athlete types would spend on a bike?
Like a entry level cost vs. investment bike?

Like anything, the sky is the limit. The first really nice bike I bought was $1600 very lightly used. The last one I bought when I had to replace them on an insurance claim, I spent $4200 very lightly used. Both prices were about 1/2 of MSRP. The new one is a hell of a lot nicer, easier to ride, and so on. In all reality, I wouldn't spend that on a bike if it were coming directly out of my pocket.

I think for a utilitarian bike that is fun to ride anywhere, you could get a heck of a lot of bike for $1400 or so once the used market comes back to normal. A lot of it depends on what features are important to you. If you are willing to ride a hardtail, that expands your options a lot.

Look for 1x11 gearing, tubeless ready rims (I like the + size tires a LOT), good disc brakes, and compare components. Not all shifters are created equal.

 

[Irrelevant]

Not all shifters are created equal.

Truer words have ever been said.

 

[Deleted member 20812]

Forgot to add, my first bike was 26" rims. Second was 29", now I'm riding a 27.5". The latter two are huge upgrades over 26", and each has its advantages and disadvantages. You can read all day on the pros and cons of each, and there won't be definitive answer. My current bike will take up to 2.6" width tires. I think I have a 2.6 in front and 2.5 in back.

 

[Irrelevant]

Forgot to add, my first bike was 26" rims. Second was 29", now I'm riding a 27.5". The latter two are huge upgrades over 26", and each has its advantages and disadvantages. You can read all day on the pros and cons of each, and there won't be definitive answer. My current bike will take up to 2.6" width tires. I think I have a 2.6 in front and 2.5 in back.

NO way man! it's just the the 2nd and 3rd bikes were better bikes, not the wheel size. Besides another couple years and everyone will be raving about oldschool 26-ers just like they are about steel frames now. heck I have 2.4s on my 26er right now.

 

[LuketheDog]

What’s a good ball park figure of what you western adventure athlete types would spend on a bike?
Like a entry level cost vs. investment bike?
Some of the prices on those things make me wince.

I wouldn't go below $800-$1000 on a new bike, that will get into better components. And, if you do a hardtail instead of full suspension you'll get even better parts in that range...I just bought a new Salsa hardtail with 27.5x2.8" tires, and it was a very good decision over rebuilding my old 26" full-suspension rig. The hardest part for me was locating a large frame bike to buy as everybody has been buying up all the new bikes during the Covid stay-at-home baloney