Bicycle Question for someone who works on them...

[DGS49]

I recently bought a MTB to ride alternately with my E-bike. I got a mountain bike due to the hilly terrain that I have to deal with.

The bike is one level up from a "WalMart special," bought at Dick's for about $600.

When I'm in the lowest gear pumping up a steep hill, the chain jumps the rear sprocket. This is no fun.

What is the problem and what is the remedy? Is it cheap components or an adjustment.

That is the only time when it happens. Maximum effort, lowest gear.

 

[1srelluc]

Ask Mortimer. He's a budding bike fixer.

 

[odanny]

I'd recommend you buy a bike stand where you can have it up off the floor and you can figure out what is wrong while turning the pedals. Is your rear wheel seated all the way back in the dropout? Your chain should be taut and if you see obvious slack in the chain than that's a problem.

Your rear sprocket, or as it is usually called a rear cassette, will drop the chain when the gears are worn, they look like sharks teeth when worn out, but this bike is new, so that should not be a problem.

 

[Kruska]

I recently bought a MTB to ride alternately with my E-bike. I got a mountain bike due to the hilly terrain that I have to deal with.

The bike is one level up from a "WalMart special," bought at Dick's for about $600.

When I'm in the lowest gear pumping up a steep hill, the chain jumps the rear sprocket. This is no fun.

What is the problem and what is the remedy? Is it cheap components or an adjustment.

That is the only time when it happens. Maximum effort, lowest gear.

When your bike chain skips, especially under load like going uphill on rough terrain, it can be due to wear or misalignment in the drivetrain components. Here’s how to differentiate whether the issue is with the freewheel (or freehub) or the chainring (chainwheel):


Signs of Wear and Diagnosis

1. Chain Wear:
   - Check the Chain: Use a chain checker tool to see if the chain has stretched beyond the recommended limit (typically 0.5% or 0.75% for most chains). If the chain is worn, it can cause skipping regardless of the condition of the chainring or freewheel.
2. Chainring (Chainwheel) Wear:
   - Inspect Teeth: Look for shark fin-shaped teeth or a significant amount of wear on the chainring. If the teeth are worn down or damaged, it can lead to poor engagement with the chain, causing skipping.
   - Feel: If the chainring is worn, it may feel rough or not have a consistent engagement when you shift through the gears.
3. Freewheel/Freehub Wear:
   - Check for Slippage: When pedaling, if you feel the pedals move without the bike moving (like a slipping sensation), it could indicate a problem with the freewheel or freehub.
   - Inspect Engagement: Remove the rear wheel and spin the freewheel by hand. It should engage smoothly and not make any grinding noises. If it feels gritty or has noticeable resistance, it could be worn.

Testing for the Issue

1. Check with a New Chain: If you suspect the chain is worn, try replacing it with a new one. If the skipping stops, the issue was likely with the chain.
2. Inspect Gear Combinations: Sometimes the issue arises only in certain gear combinations. Pay attention to which gears cause the skipping. If it only happens in certain gears, it may point to wear on the chainring or freewheel.
3. Check Alignment: Ensure that the derailleur is properly aligned and adjusted. Misalignment can cause the chain to skip, especially under load.

Since you mentioned US$600 - I wouldn't be surprised about a lack of enough cable tension to properly regulate your derailleur and having a low quality chain as such. (US$ 600 retail price - means they bought that bike for around US$ 150.

 

[Meathead]

When your bike chain skips, especially under load like going uphill on rough terrain, it can be due to wear or misalignment in the drivetrain components. Here’s how to differentiate whether the issue is with the freewheel (or freehub) or the chainring (chainwheel):


Signs of Wear and Diagnosis

1. Chain Wear:
   - Check the Chain: Use a chain checker tool to see if the chain has stretched beyond the recommended limit (typically 0.5% or 0.75% for most chains). If the chain is worn, it can cause skipping regardless of the condition of the chainring or freewheel.
2. Chainring (Chainwheel) Wear:
   - Inspect Teeth: Look for shark fin-shaped teeth or a significant amount of wear on the chainring. If the teeth are worn down or damaged, it can lead to poor engagement with the chain, causing skipping.
   - Feel: If the chainring is worn, it may feel rough or not have a consistent engagement when you shift through the gears.
3. Freewheel/Freehub Wear:
   - Check for Slippage: When pedaling, if you feel the pedals move without the bike moving (like a slipping sensation), it could indicate a problem with the freewheel or freehub.
   - Inspect Engagement: Remove the rear wheel and spin the freewheel by hand. It should engage smoothly and not make any grinding noises. If it feels gritty or has noticeable resistance, it could be worn.

Testing for the Issue

1. Check with a New Chain: If you suspect the chain is worn, try replacing it with a new one. If the skipping stops, the issue was likely with the chain.
2. Inspect Gear Combinations: Sometimes the issue arises only in certain gear combinations. Pay attention to which gears cause the skipping. If it only happens in certain gears, it may point to wear on the chainring or freewheel.
3. Check Alignment: Ensure that the derailleur is properly aligned and adjusted. Misalignment can cause the chain to skip, especially under load.

Since you mentioned US$600 - I wouldn't be surprised about a lack of enough cable tension to properly regulate your derailleur and having a low quality chain as such. (US$ 600 retail price - means they bought that bike for around US$ 150.

There are usually three screws on the derailer. They just need to be adjusted but I'll be damned if I know how.

 

[Kruska]

There are usually three screws on the derailer. They just need to be adjusted but I'll be damned if I know how.

Just assembled my bike and that of my wife and daughter two weeks ago - tell me all about it

 

[DGS49]

It's a new bike, therefore a new chain. Maybe 100 miles on it. It can't be work out, nor can the gears.

Can that one gear be mis-aligned when everything else is cool?

I will check for some tension adjustment.

 

[yidnar]

I recently bought a MTB to ride alternately with my E-bike. I got a mountain bike due to the hilly terrain that I have to deal with.

The bike is one level up from a "WalMart special," bought at Dick's for about $600.

When I'm in the lowest gear pumping up a steep hill, the chain jumps the rear sprocket. This is no fun.

What is the problem and what is the remedy? Is it cheap components or an adjustment.

That is the only time when it happens. Maximum effort, lowest gear.

not enough tension on the chain .. try tightening the chain by adjusting the rear wheel .

 

[The Duke]

Turn it upside down and shift through the gears and pedal it.
If it won't go on the top sprocket (lowest) (biggest) it's either the screw or the cable needs tightened.
You want to lock it out so it (the chain) doesn't get behind there (the biggest sprocket) with the screw but the cable has to be tight enough to make it up to there.
The high and low screws are limiters. You want range to all cogs and no more than that.
Screwing out=more range, screwing in=less range.
Sometimes there's a derailleur cable adjuster to tighten or loosen the cable.
Sometimes there's a screw to keep the closest derailleur sprocket off the cluster some.
That screws off the frame and is next to the bolt the derailleur attaches with.

 

[log cabin republican]

Dicks is just another box store for sporting goods. Take the piece of shit bike back.

 

[The Duke]

I adjusted a derailleur yesterday, I had to bend the frame and the cage and all kinds of stuff.
That's in addition to normal derailleur things. Metal is malleable to an extent.
It works good now, think I wanna rip it around.