BikeManDan

Was shifting down the the granny ring and suddenly the drivetrain locked (at this point you get that "oh ****" feel)

One of the jockey wheels somehow got itself loose and removed itself forcing the derailleur to curl over itself and cease to function. Actually did a thorough search of the roadway and managed to find all the parts (amazingly enough). The derailleur was too messed up to fix though so we were forced to make a 5 mile walk home (I figure we were lucky we wren't farther)


My question, what can I do in the future to save myself from the dreaded walk back home. Do people carry a spare derailleur?

masiman

If you had a chain tool you could have shortened the chain and made a single speed out of it. Hopefully the walk with your stoker was just the ticket.

TandemGeek

As for alternatives to the long walk home, if you have a chain tool you can convert a multispeed bike into a single speed by removing the rear derailleur and shortening the chain to fit around the front middle ring and one of your mid-size rear cogs... which ever one provides the most direct chainline to the front chainring. If you go too big or too small with a crossed chainline the chain will try to jump up or down to the next cogs. Oh yeah, and DON'T shift the front derailleur: this ain't no three-speed.

As for preventing the failure in the first place, there are a couple things...

1. Be attentive to any new noise coming from any part of the bike or shifting issues and figure out the root cause as soon as you can, e.g., a poorly shifting front derailleur can be caused by poor derailleur alignment, a really dirty drive train, or loose chain ring bolts. Better to figure out the bolts are loose before they start falling off the bike.

2. Make a habit of doing a quick wipe down of the outer plates of your chains with a rag after your last ride of the weekend: takes about a minute but it reduces the amount of grime that will build up on your cassette sprockets and chainrings and puts your eyes on your drive train about once a week, making it easier to spot small problems before they become big ones, e.g., loose parts and whatnot.

3. Give your tandem a good going over about every 500 miles, usually in conjuction with a light cleaning. Check for chain wear, timing chain slack, cable fraying, tire wear, wheel trueness, brake pad wear, and the overall condition of the frame. If you're really anal, clean the drive train to include the jockey and idler wheels on the rear derailleur (at which point a loose bolt would be pretty obvious) and removal of the rear wheel for cassette cleaning. While doing so, check the tension of the chain ring bolts and the lockring on your rear cassette.

4. If you do your own maintenance, put a drop of Loctite 242 (blue) on all bolt threads during reassembly... and I mean all of them. This will eliminate about 80% of a bikes sqweaks and creaks as well as prevent bolts from coming loose.

5. As previously mentioned in another recent thread, do at least one major tune-up each year... to include pulling the major components off the frame and checking all of the hidden places where water and grime can collect. Clean and inspect everything and then reassemble using Loctite 242. Again, if you're really anal, consider changing derailleur cables during this annual tune up, brake cables perhaps every other year unless you use travel agents... in which case you'll want to keep an eye for cable fraying around the travel agent's cable pulley.

That's about the best you can do to avoid preventable maintenance problems.

Xanti Andia

A three speed rather, assuming you have a triple crank. I have a Alien tool made by TOPEAK which in one neat package has all the tools you would need, including a chain tool. Well all except for pliers which are sometimes needed, I had to pull a wire puncturing the tire and had to borrow the pliers, would not come out otherwise, and I would have had to walk otherwise.

TandemGeek

This only works when you have a broken rear derailleur cable or have simply damaged the derailleur / hanger to where it won't shift gears, but where the rear derailleur can still work as a chain tensioning device.

If the derailleur gets mangled, falls apart, or comes off the bike the best you can hope for is a single speed.

cornucopia72

We had a similar situation while using a cheap rental down in Mexico a few years back. Made it a single speed and adjusted the limit screws in the front der to avoid trying to shift out of habit.

geoffs

when the bolt came loose from the top jockey wheel on our dérailleur, the dérailleur went into the wheel and broke spokes on both sides as well as bending the rear dropout. All this fun on a rail trail 35km from anywhere.
I made a replacement bolt out of one of the broken spokes. I did have a Leatherman Supertool with me that I used to cut a spoke just a bit up from the thread and twisted it into a loop so it wouldn't pull back through, then tightened the nipple on the thread. Worked a treat.
I think the newer XTR dérailleurs have a cir clip to hold them in place rather than the threaded bolt that my model used. mmm, wonder why they changed the design??
I carry a Stein cassette remover, chain breaker, a few other tools and some spare bolts for when we are touring.

I took me nearly an hour to rebuild the wheel and straighten the dropout so the bike was ridable.
Tandemgeeks suggestions are all good but when you have a few 20% hills to ride up, a three speed bike ain't much fun.
Friends just broke the internals for their old Hugi hub again when they were out for a ride a couple of weeks ago. They were a 2 hour walk, roll to a train station.

Cheers

Geoff

cornucopia72

Hey! it beats walking...

TandemGeek

There are some things that duck tape and a Swiss army knife just can't address. However, this underscores my preventative maintenance suggestions which usually take care of most things that can fail short of crash damage.

Hugi / Coda hub failure? Been there, done that and per Murphy's Law, of course it was pre-GPS and well out into the woods on technical single track. Worst of all, I'd just loaned our MT3000 to TandemRacer and his stoker for that ride and it was their awesome power that blew the guts out of the hub. We all had a nice walk to the closest road.

Turns out that those Hugi / Coda star-ratchet hubs needed A LOT more attention in terms of internal engagement parts cleaning and relubrication to survive the rigors of off-road use or prolonged road use.

JayB

I've been tempted to use Loctite blue - by your previous posts - but worry that I won't be able to undo nuts whose threads I have filled with it. On my tube of the stuff it says nothing about undoing. What is your experiance?

TandemGeek

If you use the general purpose "blue" 242 you should never have a problem. There is a lighter-duty 222 product that's intended for use on the smaller bolts (under 6mm) commonly found on bikes. However, the 242 has never proven to be a problem for me in over 30 some-odd years of its use on bicycles and is readily available. Loctite is also similar to grease in that it works as a rust and corrosion inhibitor. As for dealing with a bolt secured with Loctite 242, I would note that even the permanent Loctite products can usually be released by applying heat.

Here is the Technical Data Sheet for 242
https://tds.loctite.com/tds5/docs/242-EN.pdf

Just so you are aware, there is a complete family of Loctite products that include both non-permanent and permanent thread looking materials:

Non-permanent grade products include:
Permanent grade products include:
There is also a special grade for use on plastics, noting that Loctite 242 is not recommended for use on thermo-plastic parts.

mlwschultz

Keep a cell phone handy & put some Taxi # in your contacts.

cornucopia72

Out in the West cell phones do not work in half the places worth riding to. Taxi # ????

BikeManDan

Why I posed this question in the tandem forum specifically (besides the event happening on a tandem) was that the large bike makes it difficult in situations where you could otherwise attach it to a car.
How is a taxi supposed to take your tandem?

mlwschultz

We've had to do this when we got a flat & exhausted our onhand supply of tubes (problem was the tire & I don't care a spare with me!). Call a cab, one goes home & gets your own vehicle to transport, other one stays with the bike. Five miles away, one of you won't be gone long & it beats a 5 mile walk with a bike (especially if you aren't wearing bike shoes you can walk in - we always do, by the way).

BikeManDan

Unfortunate for us, not even our own car can carry a tandem

mlwschultz

Maybe you can pick up a bike rack to fit your car. How do you get it to the LBS for tune-ups, etc.?

BikeManDan

I do my own tune ups
Anywhere we need to go with it we ride it there

We have a bike rack but it doesn't work with wheelbases as long as a tandems.

TandemGeek

You mean you can't attach a standard, two-arm trunk mount bike rack to your car? That's really all it takes... that and perhaps taking the front & rear wheels off to reduce the width and/or increase stability if it's a really cheap rack. Here's a link to one at REI that costs $39 and has a 105lb capacity: https://www.rei.com/product/48019565.htm

For truly spartan cyclists, you can always lay the tandem across the roof of your car just as many do to transport their Chirstmas trees. However, a few extra steps are required if you want to protect the roof of your car from damage. You can use a piece of carpet (knapp side down), a heavy packing blanket, a large piece of foam sheeting, or even an inflated truck tire inner tube will work. Before hefting the bike onto the roof you'll also want to remove the pedals on the left side of the bike (requires a 14mm or 15mm box-end or cone wrench) and you'll also want to loosen the stem & turn the handlebars to run parallel with the top tube (usuaully requires a 5mm hex wrench). You now have a relatively "flat" side of the tandem to lay on top of the vehicle. Once it's up top, just tie it down just like the Christmas tree, taking care to protect the paint and rubber seals where the rope, straps, or twine wraps itself around the roof and tops of the door openings.

Of course, anymore, a lot of taxi firms are now using mini-vans so you can always make a special request for something a bit more accommodating than a sedan, at least here in the states. Again, once you take the front & rear wheels off of a tandem it becomes a bit more compact.

Fenlason

To second TG on this...We use loctite at the shop and have not had any problems "undoing" any hardware. I can't say that we../..I use it on all fasteners.. but I do not see anything for a problem in doing it. I would may unless there is a problem with the hardware.. most situations where something has come loose.. it is because it was not tighten properly to begin with... but loctite is a wonderful guarantee.

hmm I purchase my vehicles.. with the idea of being able to haul tandems. I myself prefer to haul them Inside the vehicle... out of the weather. I used to have a big 15 passanger van... for hauling our "toys" [mostly bikes and big tandem kayaks] Mostly because of gas prices.. I have switched now to a honda mini van.

I have rarely broken down... and not been able to get myself home.. but riding last year with another couple .. they had a flat.. and neither of us had a tube with a long enough valve to fit his new rims. With in a couple of minutes.. we had two different people stop.. to offer assistance. The first one we sent on their way.. [it was before we discovered we did not have the correct tubes] The second one gave them a ride home of about 12miles. Not that people here are not freindly but we were suprised [and lucky].

glenn

JayB

Thanks. Useful. Didn't realise there were so many different types.