Red Rider

Background: We've been a tandem team since Oct. '06, and upgraded to our current tandem in July '07 (it's a custom Co-Motions Roadster; we've posted pics in this forum. Had ~100 miles and was a year old when we bought it. We've put nearly 10K mi. on it, according to my Garmin).

Sunday we were climbing a 7% grade between Loomis and Penryn, both standing, in the middle chainring and about the middle of our 11-30 cassette. Not a hard grind but stressful on the drivetrain. Suddenly there was a "kapow!" sound and as I looked down the chain jumped to the granny and then off completely. We clipped out simultaneously and marveled at what we observed: 4 of 5 chainring bolts were gone. Completely gone. We took a few minutes to digest that.

We still had hill to climb and at 31 miles into the ride, about 30-ish miles to finish. Fortunately we were a couple miles from a LBS, so we hamster-wheeled in (really, we could coast in the drops faster than we could pedal; how pathetic). In 20 min. the proprietor fixed us up, so we could finish in fine fashion.

My captain has owned that he hadn't checked those bolts in a while. I don't want him to beat up on himself too badly. So I pose this question: Has this happened to you? If so, please expound.

TIA.

B. Carfree

I've had chain ring bolts come loose on my half-bike, but that was many years ago and it only involved two of the five. Now I better head on down to the bike room and check on mine.

Mr. Beanz

I put aluminum red chainring bolts on our tandem cause they looked cool! Sheared 2 of them off about 200 miles later riding on the flats.

I replace the original brass bolts back and and haven't had a problem since. No more light weight cool looking stuff for our tandem.

rdtompki

We've been their hamster-wheel wise. I broke the left campy shifter and wound up in our granny (24t chain ring. In retrospect I should have disconnect the FD cable and used the L-limit to at least get to our 36. But the brain-dead captain and whiny stoker soldiered on at a max speed of 12 mph. The daVinci, of course, has no chain ring bolts so we are immune to the OP's particular calamity. By way of clarification, our mini-chain rings are hyperglide cogs and are stacked on a shaft similar to a freehub.

WheelsNT

When we were relatively new tandem owners, we had a creaking noise for a couple of rides and I was less than prompt in trying to track it down. Afterwards we realized that the creak was the chainring bolts on the captain's timing crank coming loose. We hit a bump while I was in the middle of a front derailer shift, so I was momentarily easing off on the pedals for the shift while the stoker's weight landed on the front pedal due to the bump. There was a moderately loud "bang" and some "dink dink dink" sounds as the fragments of the chainring bolts skittered away into the underbrush. Like the OP, there was one bolt left attached. The chainring was forced from its place, left held by the one remaining bolt and jammed between the crank arm and the spyder. We were only a few miles from the end of the ride and it was mostly downhill, so I removed the remaining bolt, the chainring, and the timing chain, and the stoker pedaled us home. I didn't bother looking for the broken bolts, although now I kind of wish I had -- I wonder if they sheared or if they just stripped out. The bolts were steel. I bought new steel bolts and now place much more importance on seeing that they are tight.

ksisler

Thinking back now; would not a set of spare bolts and a wrench have been a wise couple of ounces in your kit? It is a good lesson learned for anyone touring on a single or a tandem...preventive maintenance plus take a set of spares for the little breaky things unique to the components on you bike and include a minimal tool set in your kit. Walking home sucks!

ksisler

+10; Absolutely right on! Solid and reliable is the right press release!

rdtompki

A "better" solution can be found on eBay if you're concerned about the weight of steel.

zonatandem

Seems eons ago, but we did end up with disappearing couple chainring bolts on a new tandem we were test riding.
It pays do double check somebody else's assembly . . .

PMK

I don't recall ever having them fall out per say.

Have had the inexpensive aluminum fasteners fail during install.

Also exploded 2 of the 4 bolts by jumping the MTB single in to a rock garden section. Actually it bent the large chainring over enough to blow the bolts apart. Few miles to get home with a loose middle ring. Luckily it didn't bend the crank arms.

PK

Red Rider

Thanks for the feedback, folks.

We carry a trunk bag on a rack that's full of things like chain links, chain breaking tool, etc. -- stuff we've had to fix before. I think a better pre-ride inspection is in order, as in more thorough than that which we've been doing. And although the likelihood of this happening again are, I hope, slim, I guess we'll be adding a new tool & some bolts will find their way into that bag.

B. Carfree

If I put all the parts that I have ever broken while riding into my saddle bag, I'd have an entire bike minus the handlebars and seat post.

Red Rider

I hear you. As semi-weight-weenies we want to carry as little as possible. I doubt that we'll try to stuff spokes, downtubes or Thudbusters in our trunk.

Bill G

It does pay and I take it one step further myself, that is exactly why I build my tandems from the frame up myself. I order them new and specify they are to be un-assembled for a reason, again so I can build them myself. Most bike shops do not do tandem work well,: ( there are a few that do but not many. I just prefer to do the work right from the get go myself.

Ride Safe All,
Bill G

Red Rider

Our LBS does a great job on tandems. We have MTB, CX, as well as road tandems in there, and the wrenches do a great job.

Chris does most of our tandem work. He likes to do his own work, however, and he's beating himself up about the popped chainring bolts. I get it; I wouldn't check them before every ride either.

I can guarantee that this won't ever happen again.

Chris_W

An emergency solution that I've heard of being used before but have not had the misfortune to need myself yet is to use a cable tie (aka zip tie) instead of a chainring bolt to get you home. Cable ties are a lot lighter to carry than bolts, and have many other uses, but this would probably only work to replace one or two bolts, not four.

I've also had some aluminum bolts work loose over time, although I've always noticed the problem (the symptom being poor front shifting) before any of them fell out. I tried locktite, but then one of the bolts broke when I removed it. I now use only steel chainring bolts, which can be obtained in black as well as silver if you search hard enough (or steal them from donor cranksets).

In my spares kit for extended touring, I have a couple of spare chainring bolts, which I would highly recommend, but in an emergency spares kit you should definitely have some multi-purpose cable ties.

Bill G

Chris, like I said there are a few that do...Glad you got a shop that does, that's a good thing. I still don't let anyone work on my tandems but that is my preffrence, I am just to picky.

Ride Safe,
Bill G

chojn1

Something similar happened to us last month. Coming around a corner while both standing on our pedals, we heard a loud pop followed by rattling sounds. Apparently the drive chain had broke and wrapped itself around the cassette. The rear derailleur hanger was completely bent, and the derailleur was lodged in the spokes of the back wheel. Had I had a chain breaker, I could have used the timing chain to make my wife pedal us back home on a single gear. But as this was our short daily rides, I didn't carry any tools other than for tire repairs.

Question is what should I carry in my saddle bag? Never thought about the chain ring bolts, but I guess that has to go in there now along with the zip ties and chain breaker. I build my own bikes also, but I honestly don't check anything other than tire pressure on a routine basis. Do you go over a check list before every ride?

Bill G

(Quote) from post above = I honestly don't check anything other than tire pressure on a routine basis. Do you go over a check list before every ride?


For me I keep our tandems spotless and clean at all times to the exstreme. This allows me to check them out and give things a look over on a regular Daily/weekly basis. During the wipe down and cleaning I can catch any issues before there a problem. I am also looking for any problems during this process and this has kept any major issues from happening so far with our tandems for over 13 years now. I have always caught an issue before it was a problem by being this way, knock on wood. Also knowing what to look for and being a perfectionest to a fault bike mechanic helps..

And our tandems always look there best..

Ride Safe All,
Bill G