Preventative Maintenance: Transmission & Drive Train

This is the fourth of five articles in a series that address Preventative Maintenance for your tandem.

Drive Train & Transmission:

Shifters & Brifters:

Here’s my favorite rule of thumb when it comes to shifters of just about any type: if they ain’t broke, don’t try to fix ‘em! But, if they don’t seem to be working as well as they could, chances are it’s the cable, housing or adjustment of the derailleurs that need attention, not the “guts” of your shifters.
While there will come a time when Shimano’s STI shifters begin to falter and Campy Ergo’s don’t feel crisp, those tend to be after 10’s of thousands of miles. Bar-ends, downtube, triggers, twist grips and of course the new electronic shifters pretty much work until they get bashed or put away wet a few too many times.
Of all these, the bar-end and downtube shifters are pretty easy to disassemble, clean and then reassemble so long as you carefully take them apart and keep track of which part goes on first and in what direction. An “explosion drawing” from the manufacturer’s tech manuals can help here too.
Frankly, if shifter pods, STI Levers twist grips begin to act-up and it’s not the cables, housing or derailleurs think twice before tearing into them. I won’t pull apart a shifter unless I’ve read the tech data, studied the illustrations and checked a few cycling geek blogs to see if any mechanics have any tips to share… and I’m pretty darn sure it’s really the shifter that’s having issues. As many times as I’ve rebuilt Campy shifters over the years, I still pull up a YouTube video that shows me “how to” given I don’t do it often enough to be sure I’ve got every step down.
So, with all that said, this is about as far as I’ll go in describing shifter maintenance and service: there are just too many different brands and models of shifters to address. If you think you need to dive-in to a shifter, go download the manual, do your read-aheads and research before you pick-up any tools and start wrenching on that shifter. This goes double for the new electronic shifting systems; they are amazing once dialed-in, but you must follow the set-up instructions to the tee. Shimano developed a comprehensive Tutorial that every Di2 owner should go through; it helped me immensely when I demo’d a Di2 equipped Santana Beyond back in May 2011.

Derailleur Cables & Housings:

[media-credit id=67 align=”alignright” width=”223″]Similar to your brake cables and housing, when’s the last time you replaced those? In the old days of plain stainless steel the past I would replace cables about once a year on the tandems, but once “slick wire” and Teflon coated cables came on the market I found I could go at least two years or more and a quick inspection of the cables is all that it takes to confirm if you’re good for another season.
However, it does take some home mechanic skill to do this since the cable needs to be partially removed, i.e., disconnected at the derailleur and pushed back through the shifter to expose the hidden sections of the cable: easier said than done for some. This is really a must do for older versions of Shimano STI or Campy Ergo shifters where the cable ends buried in the shifter can start to become a maintenance problem as the cable begin to fray at tight bends in the shifter levers.
Your derailleur cable should slide back and forth in the housing without any effort. If that’s not the case, the cable and housing probably need to be replaced. Once again, if your shifters route the derailleur cables under your handlebar tape the best time to inspect the derailleur cables and housing is when you’re putting on fresh handlebar tape and already have the bar tape stripped off the bike. Be sure to pull off the ferrules to make sure your cable ends still have flush ends that seat tightly in the ferrules and that the ferrules aren’t cracked and still seat firmly in the cable stops. I can’t stress how important it is to use only the minimum lengths of cable housing needed to ensure bends aren’t too tight or bind when the handlebars are turned full right and full left lock. The cable housing ends should be filed or ground smooth after cutting and the Teflon liner ends should be opened up with a pick if they were pinched during cutting. A Dremel tool with a cut-off wheel is a great way to get nice clean and finished cable ends in a single step.
If you have in-line cable adjusters, make sure the parts that aren’t supposed to rotate don’t and the ones that are, do… just not on their own. I’ll leave it alone at that as I’ve had mixed results and enjoy a love-hate relationship with these things.
As noted before, there are some pretty good resources out on the Web that are worth a look-see for the do-it-yourself home mechanic that is just starting to work on their own bikes. Park Tools has a good article on brake and cable derailleurs and Bicycling magazine has a pretty rudimentary video on how to replace a derailleur cable & housing.

Front & Rear Derailleur Cleaning

Frankly, I like to stay ahead of my drive train cleaning so that I don’t end up with heavy grime that needs to be scrapped away with a flat blade before degreasers can be used. Yes, you need to clean more often, but ultimately it takes less time since periodic cleaning is pretty quick and easy.
You can clean your derailleurs right on the frame or, for the Mr. Clean types, you can remove them and give them a detailed cleaning in a parts washer / basin. You can clean them with or without the chain removed depending on how you go about cleaning your chain.
Either way, a stiff bristle brush and a mild degreaser or solvent will do wonders. As for which solvent or degreaser, there’s a wide selection so you’ll need to go with what you’re most comfortable with. For example:

Finish Line makes an aerosol spray cleaner that I suspect is simply carburetor cleaner for the twice the price. They do a great job of blasting away grime but it’s not exactly environmentally friendly.
There are also those chain-cleaning machines that you put solvent in and then run the chain through by pedaling the drive train. I’m not a big fan, but they end up throwing enough solvent on the derailleurs, cassette, chain rings and just about everything else that you can usually just brush the derailleurs, hit everything with a soapy sponge and then hose off with clear water and call it quits. It’s a so-so drive train cleaning that’s “good enough” for a lot of folks and it’s certainly better than not cleaning.
Years ago I bought a Finish Line “Easy Pro” HDPE bicycle parts cleaning solvent tank / reservoir that holds 2 gallons of solvent: I dilute a gallon of Zep citrus degreaser (cheap) that I sit under the derailleurs as a catch basin while I clean with a stiff bristle brush and then wash with soapy water and finish with a final clear water rinse.
Again, there are a plethora of videos out on the web that you can also look to for derailleur cleaning tips and tricks.

I also recommend that as part of your annual deep clean that the rear derailleur’s jockey & idler pulleys be removed cleaned and inspected. They are typically attached by an “axle screw” that passes through the dust covers, a bushing or sometimes a bearing and the pulley body. Note that the two pulleys are not typically interchangeable, so you’ll want to take note of which one goes where and make sure that you don’t unintentionally mix the bushings and dust covers, as they are sometimes not interchangeable either. If the teeth on the pulleys have started to chip or have worn-down significantly, you might want to consider replacing them.

Front & Rear Derailleur Adjustment

If you had to replace your cables you’ll want to adjust your front & rear derailleurs.
As always, consult the owner’s manual for your shifters and derailleurs as they’re the best source for step-by-step adjustments that take into consideration the often times unique features of each shifter or derailleur.
- There are definitely some subtle nuances that you’ll want to know about lest you find yourself struggling with getting those derailleurs dialed back in.
- And, let me also note that tandems are somewhat unique in that you won’t really be able to get your rear derailleur fully dialed-in until you hit the road with your stoker aboard.
- Tandems have very long cables and the frames tend to deflect a bit once they are fully loaded with both riders weight. That little bit of frame deflection can change the effective length of your rear derailleur cable enough to require a slight twist of the barrel adjuster to get that last little bit of chain chatter dialed-out. BTW, that same frame flex is why some tandem teams may experience an “auto shift” when they’re up and out of the saddle putting maximum effort into the cranks.
Once again, here are a couple sample videos that take you through the “generic” process for adjusting a front & rear derailleur.

Cranks, Rings and The Other Things Down There:

I’m a bit old school when it comes to cranks: I think they’re something that you should be able to pull off without a second thought as part of a deep-cleaning.
- It lets you inspect the bottom brackets and bearings and makes cleaning the chain rings a bit easier.
- It also ensures that you’ve cleaned-up the crank / bottom bracket interface, applied lubricants or grease where required by the manufacturer and re-torqued the crank bolts such that the likelihood of having a creaky drive train is minimized.
However, with as much trouble as some cranks and bottom bracket designs give owners when it comes to bearing life, installation and removal issues and those pesky creaks and squeaks, I’ve accepted the fact that some crank sets are best left alone until it clear that they need some attention.
- So, if you fall into the latter category, feel free to skip all of this or leave it to your mechanic to address.

Cranks:

As with the other components on your tandem, cranks and bottom brackets vary from manufacturer to manufacturer and model to model. Therefore, always consult the owner’s manual for your cranks and bottom brackets to find out exactly how often they need to be serviced, to what extent, what torque values to use when installing them as they vary quite a bit:
- Bontrager® 310-380
- Campagnolo®312-324
- FSA® (M8 bolt) 304-347
- FSA® (M14 steel) 434-521
- Race Face® 480
- Syncros®240
- Truvativ® 384-420 ISIS Drive
- Truvativ® 336-372 square type White Ind® 240-300

Generally speaking, these are some things to consider on an annual basis:

Bottom Brackets:
- Like the cranks they’re connected to, you can either leave them alone and wait until you know they’re in need of maintenance or you can include them in your periodic maintenance plan.
- Again, you’ll need to check the owner’s manual for your particular bottom brackets to find out the particulars on how to service them. They vary quite a bit depending on what type of interface design is used, e.g., square taper, Octalink/Octalink II, ISIS/ISIS II, HollowTech, GigaPipe, MegaEXO, UltraTorque, BB-30/92, Pressfit, and well you get the idea.
  - Me, I recommend removing them from road tandems at least every two years as part of the frame inspection and to make sure that they don’t end-up becoming nearly impossible to remove. For tandems ridden off-road, every year.
  - If you opt to leave them on the bike, with the chains removed (oh, come on… you’ll need to get those chains off at some point) you’ll want to give the cranks a spin to make sure they rotate smoothly and aren’t binding or have a gritty feel. You’ll also want to grab both crank arms by the pedal axle and check for any side-to-side play by push/pulling the crank arms. If any of the undesirable conditions are present deeper investigation and maintenance is required.
  - If you pull the cranks but still leave the bottom brackets / bearing cups and bearings installed you’ll at least get a much better sense of the bearing condition. With the cranks out of the picture you’ll now be able to rotate the crank axles or, on integrated crank set bearings with your fingers. If they’re a little tight that’s OK (assuming they spun freely with the cranks attached); what you’re looking for is any gritty-ness or binding. The latter would suggest the bearings either need to be regreased or replaced.
  - Finally, if you pull the bottom brackets or bearing cups, be sure to keep track of any spacers that were installed and on what side of the frame; it varies. If you your bottom brackets don’t used a fixed cup on one end (Most Shimano BBs & SKF do, but Phil Wood and a couple others use two adjusting cups) you’ll want to record the number of exposed thread rows that are showing on both sides of the frame for reference when you reinstall: if you don’t you may have alignment issues with your front derailleur, any belt-drive sprockets or even crank/chain ring / frame interference.
  - With the bottom brackets removed you’ll be able to wire brush the rear bottom bracket shell to remove any rust or “crud” that’s collected in body or threads, make sure the bottom bracket, axle, etc. are in good shape and then do a fresh reinstallation per the owner’s manual / installation guide for a few more years of trouble-free, quiet service from your bottom brackets. If your bottom bracket bearings needed service or replacement, that’s also now quite easy to do. You’ll recall that bearing service was covered in the 2^nd Part of this Five Part Series.
Eccentrics: By the way, since we’re talking about bearings, let me mention the eccentrics.
- Your tandem’s eccentric(s) — a round alloy assembly that holds the bottom bracket and rotates to take the slack out of synchronization or in some cases the drive chain — is also something that needs at least annual attention to ensure it remains easy to adjust and remove.
- You can remove it from the frame with the bottom bracket still installed. Simply remove one of the crank arms, loosening the retention bolt(s) that hold it in place, then pull it out of the eccentric shell by the crank arm that’s still attached.
- Clean the shell, the eccentric body and its moving parts and give it a light coat of grease before reinserting it in the frame.
- Crank Arms, Spiders, Rings and Bolts
  - These are all pretty straight forward and you have two options when it comes to cleaning and inspecting them: you can clean them as a single unit or take them apart to get into all the nooks and crannies.
  - However, be forewarned, you’ll need to pay close attention to the chain ring bolts, sleeves and any spacers as you remove them so that your cranks will go back together with the same spacing they had when you took them off.
  - Chain rings may or may not wear out depending on how attentive you are to chain replacement. I’m going to cut myself a break here and just link to another article I wrote on chain maintenance over on my own blog. In it you’ll find out how to check your chain for wear. In general, if you change out your chains before they wear too much your chain rings (and cassettes) will last a very long time / thousands & thousands of miles. If you don’t change your chains before they wear out, then the chain rings (and cassette) will need to be replaced when the chain is replaced.
  - If you opt to remove your chain rings for your annual deep cleaning, you’ll want to make sure you use the correct torque spec when you re-install those bolts, as they have a tendency to disappear if there not tight enough: somewhere between 40-80 in lbs.
Chains
- As mentioned above, I’ll take the easy way out here and link to another article I wrote on chain maintenance over on my own blog
Timing Rings & Sync Chain
- Timing rings are the chain rings that connect the cranks to each other, regardless of which side they’re on.
- However, unlike the drive-side chain rings I recommend that you leave the rings attached to the crank arms for cleaning for two reasons: (1) with just one ring it’s very easy to clean, and (2) If your rings are centered, you don’t want to mess that up! By centered, that means there are no significant “high” or “Low” spots that cause you chain to go extra tight or extra loose on each rotation of the cranks.
- The chain that connects the timing rings is properly called the synchronization chain, but timing ring chain works too. Like the drive chain, it will eventually wear out… just not nearly as quickly as the drive chain.
  - Because the sync chain is just a simple direct-drive and doesn’t need to be derailed to support gear changes, you can opt to wear the chain and rings out – we’re talking over 10k miles – and replace them as a system, or to replace the chain and preserve your rings.
- There are also some other tricks that you can use to extend chain ring life such as “rotating” the timing rings, i.e., moving the front ring to the back crank arm and the back ring to front crank to double their service life.
Pulleys & Belts
- [/media-credit]With the arrival of the Gates Carbon-Drive tandem sync belt comes a slightly different maintenance task. While the belts don’t need to be lubricated, they do need to have the valleys between the teeth washed-out and then be treated with a dry silicone spray to ensure quiet operation and minimize wear and tear on the pulleys.
- Early on, the belts seemed to be outliving the pulleys so long as the belts were not mis-handled and properly tensioned. Thankfully, the cost of the belts and sprockets came down significantly a few years ago to the point where they may be a little less expensive to own and operate than chains… but it’s a very narrow margin.
Pedals
- Yes, they need attention too. Check the owner’s manual for your particular brand/model of pedals and service as suggested.
Rear Hub & Cassette
- We briefly looked at hub service way back in the Frame, Fork & Bearings, but to get to those bearings you’ll need to pull-apart your freehub. Guess what? Yup, they’re all a little different.
- As before, you’ll want to follow your hub’s owner’s manual when it comes to how often they should be serviced and more importantly, how to service them. Some of the more popular hubs are covered briefly in the Park Tools freehub service summary.
- The cassette is like the chain rings in that you can either get it pretty clean still mounted to the hub or remove it and toss it into a parts cleaner / solvent bath to get it really clean.
  - As noted way back in my periodic cleaning run-down, I always opt to pull the cassette and soak it in a solvent bath before hitting it with a nailbrush and then rinsing with clear water.
  - Cassette removal and reinstallation requires a couple specialized tools, but they’re not expensive tools and will come in handy if you would like to change out cassettes for different gearing, to fix a broken spoke or… well, cleaning the cassette to extend its life.
  - To clean it on the bike, perhaps the easiest way I know of is running a terry cloth rag that’s been dipped in solvent between all of the cogs with a sawing motion. Follow that up with a clean edge of the same cloth and you’ll get most of the grime off the cogs.
  - As tempting as it may be, don’t spray or brush solvents onto your cassette while it’s mounted to the hub. Solvents have a habit of finding their way past the dust seals into cartridge bearings and there are a couple of pretty important bearings right there in the freehub that your cassette is attached to. Blasting a hub with a stream of water from a nozzle or pressure washer is also a pretty bad idea.