|Professional Tweaks, Tips & Reviews By "AJ" Picarello
|I hope you find my Tweaks and Tips section helpful. If there is something you want to know about, send me an email and I will try to add that to one of my upcoming articles.
Once again, another tweak and tip. Shifting problems!! They suck!! You think your bike is perfect and "wham" your bike skips a gear. What do you do? Here's a few idea's.
Common Problems: Have you recently upgraded your bike to a 9-speed and all of a sudden you're getting terrible "chain suck" problems. (When you're chain jams between the small chain ring and you're frames chain stay). Not only must you purchase a new rear cassette, chain and shifter, you need to buy new front chain rings. Since the 9-speed chain is narrower than your old chain, it sticks to your front chain rings. You also need to purchase 9 speed compatible derailleurs, both front and rear. I notice this problem on a lot on downhill bikes. Many companies now have 9 speed DH chain rings.
Are you running too many or too few links in your chain? If your bike has full suspension, you have to run a couple of extra links in the chain, unless the main pivot pivots around the bottom bracket shell. For both suspension bikes and rigid bikes, try shifting into the smallest sprockets front and rear. If the chain has slack, and almost drags on the chain stay, remove a few links. Try and get away with removing as many links as possible without putting too much stress on your drive train. Every bike will differ. Be very careful with long travel, single pivot, downhill bikes. They need maybe one or two extra links in the chain.
Test out your DH bike by riding in your easiest gear and pushing up and down on the suspension. Check out how much slack your rear derailleur is taking up. The derailleur cage should still have some swing as you use up all of your bike's travel. A more professional way of checking this is by removing the rear shocks coil over spring and cycling the rear suspension. Keep in mind that the shock has a bottom out bumper installed on the shaft. Under extreme bottom outs, this bumper compresses giving your bike even more travel, sometimes up to an inch. Compensate for this by adding another link.
Figuring out proper chain lengths on XC bikes is a bit easier, especially if it's a hard tail. Shift into your largest sprocket in the rear and your largest chain ring in the front. The derailleur cage should point forward and should be under a full load, almost so tight that you can hardly get your bike into that gear. You should never ride your bike in this gear, or in the smallest front chain ring and the smallest sprocket on the rear cassette. This causes chain line problems. Try shifting your bike into these two gears and look at your chain line to see the amount of stress the chain and sprockets are under.
When you check your gears on the bike stand do they shift perfectly, but when you ride in the trails the gears skip miserably? You just installed all new drive train components and the bike still shifts badly. Solution: You need a longer section of outer derailleur housing located near the bikes main pivot. Because this section of housing is too small the inner cable pulls and tugs on the derailer as your bike suspension goes through its motions.
Do you check your bike out before you go riding? Buy a bike stand if you don't already have one. Shift through the gears and make sure everything is OK. Make sure the cranks are tight. If you're running Profile or other BMX style cranks, make sure there is no side to side play. Check this by grabbing each crank arm and pull them back and forth laterally. Snug down on XC cranks with either an 8mm allen wrench or a 14mm socket. Don't over tighten XC cranks. Just check to see if they're tight.
Next check all the front chain ring bolts. Don't forget the inner bolts. These bolts can become loose after one ride, especially if you're running a bash ring or hit your sprocket on logs. If you ride trails with log sections do yourself a favor and use steel chain ring bolts.
Lubricate your chain before every ride. Occasionally remove the chain and degrease it. Use only dry wax lubricants. Like Finishlines Krytech or White Lightening. Park tools makes a tool to clean your rear cassette. It has a thin brush on one side and a plastic pick on the other side. Clean the rear cassette and front chain rings every time you lube your chain. Use the Park tool to remove any bark or mud trapped between your sprockets. Also don't forget to clean the derailleurs pulley wheels.
Extend the life of your sprockets by changing your chain once every two months.
Is your bike skipping in only one gear? Try pedaling up a steep hill in the smallest front chain ring, then, pedal up in the middle chain ring. Does it skip in only one or both gears? If it only skips in your middle ring, you probably need a new middle ring and I bet you ride the middle ring all the time. I'd bet you're even running a 9-speed. The 9-speed chain rings are thinner than the old 8-speed rings. This causes them to wear out quickly. Check for a stiff link in the chain, as well as for a bent chain. Also check if your rear cassette is bent. Again this is a common 9-speed problem. Usually one of the top two gears on the rear cassette is bent. These gears bend if you're a heavy rider with a lot of power.
If you don't hear any clicking and you don't have a silent hub, then you probably have a freewheel problem. Shift your bike into its easiest gear. Step on your cranks with all your strength. If you have a freewheel problem, the chain and cassette will jump forward. Another way to check your freewheel is to try another wheel. Remove your cassette and install it on a friend's wheel, and go for a ride. No skipping? You need to either repair your rear hub or it's time to buy a new one.
People who ride in the winter sometimes have freewheel problems, generally due to water trapped in the rear hub. If this is the case, take apart the hub's internals and clean them and regrease them following the manufacture specifications.
Wow, bet you never guessed your bike could potentially have so many problems? I'm still not finished.
A branch got tangled in your wheel and chain, you just crashed and your bike tumbled for a ways, or your buddy purposely sabotaged your bike while you were taking a leak. If all of a sudden your bike starts to skip, most likely your derailleur hanger is bent. Before you try riding your bike, stand behind it and look at the derailleur to see if it is bent. Sometimes you can grab the derailleur and bend it back by hand. Usually it will bend towards the wheel. However, if you tried shifting into your easiest gear and the chain jumped over the cassette's largest cog and into the spokes, then grab the derailleur and pull it away from the wheel. If your bike has a replaceable derailleur you should always carry a spare to change it on the trail. Permanent derailleur hangers are usually stronger than replaceable hangers. Some manufacturers have designed machined aluminum replaceable hangers, which appear to be stronger than cast aluminum or steel.
Fancy high-end expensive cables may not cure shifting problems. Prevent cable friction by lubricating and changing your cables regularly. Purchase a roll of stainless inner cable, Teflon outer housing, slick honey (anti stiction lubricant), plastic or aluminum ferrules, and a special cable-cutting tool. After cutting your housing use a 1.5mm allen wrench to open up the ends. Make sure your ferrules and housing are the same size. Use only derailleur ferrules on derailleur housing. Never use brake housing for your derailleurs.
Always clean your cables after riding in sloppy weather. If you are running continuous cables then this next tip doesn't apply. Shift your bike in the smallest cog in the rear and the smallest chain ring in the front. To do this, you have to pedal the bike and shift at the same time. If you are working on your bike upside down, then ride the bike into this gear before you flip it over. Now, this is the tricky part. Pedal the cranks forward and shift the rear derailleur manually. Push the derailleur towards the spokes. It should have some tension, but will push over easily. Stop pedaling the cranks. The chain should stay in your largest sprocket on the rear cassette. The shifter cable should have a noticeable amount of slack. Pull your cable housing from the frames welded on fittings by pulling away from the fitting and sneaking the inner cable through the small slit provided. You now have access to the inner cable without removing it from the bike. Clean and lubricate the inner cable with a light coating of slick honey. Reinstall your outer housing into the frame's fittings. Make sure the fittings are in good shape. If you see any rust or water seeping from the cable, it's time to install a new one.
A simpler way to install your rear derailleur: Remove your chain. If you're on the trail this becomes difficult, unless you're running a Sachs with a master link. With your chain off, shift your rear into the smallest sprocket. If your upper pulley wheel is not lined up directly below the smallest sprocket then try this: loosen the 5mm allen bolt that pinches down on the inner cable. Leave it loose. You might as well tighten the barrel adjuster all the way in. If you're running Grip Shift, then your only barrel adjuster is on the shifter.
Where is your barrel adjuster? It hangs off the end of the derailleur. Your outer derailleur housing sits inside it. Sometimes it's covered with a protective boot. Sometimes this is the culprit of your shifting problems. If the adjuster is broken, buy a new one. If the barrel adjuster breaks on the trail, try removing the broken threads and rethread whatever is left on the adjuster back into the derailleur. You'll probably have to ditch the plastic gnarled piece and the spring. That's OK. You still have an adjuster on your shifter.
At this point, you can start messing with those scary little philips head adjuster screws. Don't know which one to adjust? Use your sense of sight and touch. You will see and feel the derailleur move when you turn the correct one. Line up your derailleur's upper pulley with your smallest sprocket. Manually push the derailleur over towards the spokes. Check if the upper derailleur pulley lines up with your biggest sprocket. If you are turning the correct adjuster, you will see and feel the derailleur move. This time you must keep pressure on the derailleur to line up the pulley. After reinstalling your chain and cable, you can make your final adjustments. Make sure your derailleur's pulley wheels spin freely, use Tri Flow if necessary. If they are seized, you should replace them.
Release pressure from the derailleur and secure the inner cable by lightly tugging on the cable and tightening the 5mm allen bolt. Pedal your bike and try shifting through the gears. If you still have a shifting problem, add more tension by turning the barrel adjuster counter clockwise. If this doesn't solve your problem, try realigning your upper pulley with the largest sprocket.
You should be getting the idea by now. If you don't, then go to your local bike shop. If you remember just one thing from this article that will help you with your shifting problems, then reading this tech tip was well worth it.
Next months tip: How to ride fast in mud and snow.
You are not authorized to write a update.