Clanking, Rattling and Skipping – mountain bike gears are a good reason to leave your bike in the garage. Lots of folks in this disposable world we live in just toss out their bike when the gears stop working and buy another.
I did some dumpster diving and found a Huffy Mountain Bike to repair. The cool thing is I get to documenting the repairs and adjustments for the folks reading this blog. The front and rear gears did not work at all. The twist shifters were broken and the cables were rusted and kinked.
With some added knowledge, odds are you can adjust the gears and get the bike rolling again.
BEFORE Adjusting Anything
A couple things to look at before digging into that might mean you need to buy some parts before attempting to adjust your Huffy gears.
- Bent derailleur hanger. Easily straighten or replaced this little bracket is should be straight.
- Kinked or damaged cables. Unfortunately, no repair for this, if the cable doesn’t move smoothly it won’t shift. Buy a new cable or housing. Here’s a link to a “universal kit” I bought on Amazon and used on my Huffy.
- Rusted or frozen chain. Most times you can repair this enough to get the bike shifting again. But if the chain is severely rusted it might be time to replace. I have a simple video HERE to clean a rusted chain.
- Broken Shifter. If the shifter doesn’t “twist” easily you’ll never be able to adjust it to work.
Tools Needed for Adjusting Rear Gears
- Screw Drivers straight and cross (Phillips) heads
- Pliers for grabbing cable
- 9mm wrench for tightening cable locking nut
Adjusting the Rear Derailleur/GEARS on a Huffy Mountain Bike
If your Huffy has a “twist” shifter the gears are shifted by pulling a cable that is under tension. The adjustments we’ll make change the cable position and tension.
We can adjust four spots on the rear shifting mechanism.
- Rough adjustment at cable attachment. (rough cable tension)
- Hi and Lo stop screws (stops derailleur movement)
- Barrel adjuster at derailleur (adds or removes cable tension)
- Barrel adjuster at twist shifter. (adds or removes cable tension for fine adjustments)
- Shift the FRONT gear into the middle gear. This is a good general starting point.
- Shift the REAR gear into the smallest gear. For my Huffy this is gear position 7.
- Screw the barrel nuts at the twist shifter and derailleur all the way in and back out a half turn.
- In this position the cable leading to the rear gears/derailleur should have slight tension. It shouldn’t be so loose you can pull it more than 25mm (about an inch) without changing gears.
- If it’s sloppy loose you’ll need to loosen the locking nut and pull it tight.
6. If the cable is tight, but won’t move into the gear. You’ll need to adjust the stop position. This is the small screw labeled H in the derailleur. Backing this screw out allows the derailleur to move outboard (away from the bike) and into position.
7. With the derailleur centered at the smallest gear, cycle to the bigger gears on the gear set. The rear gears are called a cassette. Shifting to larger gears corresponds to LOWER gears at the twist shifter.
8. Cycle up and down gears two or three times ending in the small gear (Gear 7)
9. If the gears aren’t shifting into the small gear smoothly, it’s time to turn the barrel adjuster at the derailleur.
10. Twisting the barrel out adds tension, this will pull the gear into the second gear position (6th gear) In most cases you’ll need to remove tension to allow the gear to move into gear 7.
11. With the small gear tuned in, it’s time to cycle the derailleur into the biggest gear (#1 on twist shifter)
12. The screw on the derailleur labeled L is the STOP for the big gear. If the derailleur extends to far it will pull the chain into the spokes.
13. If you’re unable to “pull” the cable into the biggest gear start screwing the barrel adjuster out to increase tension on the cable.
14. With the derailleur shifting into the big gear cycle the derailleur up and down the gears a couple times
DIY MTB Tip: Having a bike repair stand makes all the difference performing maintenance on your bike. I seriously love my Bikehand repair stand. As an alternate you can flip the bike upside down or prop it up by hanging it from the seat.
15. At this point you should take the bike out for a test ride and “fine tune” the shifting with the barrel adjuster on the twist shifter.
Get the Owners Manual for Your Huffy MTB
Having the owners manual is a great reference. The link below gets you to it FAST. Download to your phone and reference it while tuning up your HUFFY Mountain Bike.
Adjusting the Front Derailleur/Shifter on a Huffy MTB
The front derailleur is easier to adjust as compared to the rear. We’ve got three ways to adjust the gears. Stop screws, the barrel nut and how tighten the cable is at the attachment. I’m assuming that everything functions and the cable is attached correctly.
Adjusting the Front Derailleur aka Front Gears
- Twist the REAR derailleur/shifter into a middle gear. This is the back gears! This is a good starting point.
- Turn the FRONT gear twist shifter into #1 gear. The smallest front gear. These gears are called chain rings.
- Turn the front twist shifter barrel adjuster all the way in and then back out ½ a turn.
- The derailleur should be in the smallest gear. If not adjust the L screw by backing it out until the guide is centered over the small gear.
- Cycle the front shifter a couple times verifying it shifts into the smallest gear (twist shifter position # 1)
- With the small gear correctly positioned cycle the shifter into the big chain ring. (gear #3)
- If the guide is advancing to far outboard turn the H screw in until centered over the big gear.
- Cycle through gears again. Usually this will complete the adjustments.
- If the chain still won’t advance outboard into the big ring, turn the barrel adjuster at the twist shifter counter clockwise. This will “pull” the guide more.
- With the big and small stops set. Cycle through all gears front and rear confirming function.
- Test ride, sometimes I’ll bring a screw driver to fine tune stops. Most times I can complete adjustments with the barrel screw.
- GET OUT AND RIDE😎
With a basic understanding of how the gears work and some simple tools like a screw driver your Huffy can be back up and riding. If you toss your bike into the trash, just know somebody like me might grab it and quickly adjust it into working condition.
What Parts Do You Need to REPLACE the CABLES and TWIST SHIFTER?
My Huffy is a 3 X 7 which is sold as a 21-speed mountain bike. When buying twist shifters and derailleurs you need to understand what you have. The “3” on my bike describes the number of front gears or chain rings at the pedals. The “7” describes the number of gears at the rear wheel. (called the cassette)
Mountain Bike Cable Set I Used
I bought a universal brake and shifter cable set called YAKAMOZ 2-in-1 Cable Set. (Amazon link to check prices) The kit has been great. It contains both brake and shifter cables and the little cable ends and caps.
Which Twist Shifter?
Count the number of rear gears, then look for a brand name. Mine was scrapped off so I assumed it was the most popular brand SRAM. Like I said mine is a 7 speed so I purchased a SRAM MRX Comp Bicycle Twist Shifter Set. (Link to Amazon for current prices)
What Did It All Cost?
My total was less than $37 usd. This doesn’t count labor, which I can say I’m not cheap….😉. Given the price of the bike FREE, I’m super happy about how this turned out. I wrote this article – How Much Does It Cost To replace and Gears on a MTB.
I’m going to use my Huffy as a library bike. I like writing at the “brary” and it gets me out of the house. I’ll probably put a rear rack on – instructions for rear rack install HERE.
WORST CASE – Most bike shops will help you out if needed. If you show up with your bike, the guys might show you how.
Get Out and Pedal!
David Humphries is the creator of DIY Mountain Bike. For me a relaxing day involves riding my mountain bike to decompress after a long day. When not on my bike I can be found wrenching on it or casting a fly on a small mountain stream. Read more about David HERE.