russelleldridge

Hi, just canvassing opinion about a recent mechanical breakdown.

I have a new Cannondale Synapse Di2 disc road bike that I've owned/ridden for 2 months. Was out for a short ride pedalling at about 18mph in steady gear when suddenly heard clunk followed by completed loss of power to pedals. Looked down to my horror to find the rear mech on the other side of the road and chain snapped in half.

Further inspection of the chain showed that it seemed to have splayed at a link that was jammed into the rear mech. I think this has then been ripped from the frame - the rear mech hanger was ripped into two pieces, one part on the frame the other on the rear mech. I don't have any pictures as the bike is with Evans Cycles (with whom I ordered the bike from online), sorry!

I was hoping to get away with a new chain and rear mech hanger +/- jockey wheel but been told today that the rear mech has been damaged and wont shift to top or bottom 3 rings of rear cassette.

My question is this:
- have I just been (very) unlucky in having the chain snap after less than 500 miles of use, and will just have to accept forking out for repairs or
- does this indicate some fault with the chain, either mechanical or installation, and the repairs should be covered by the manufacturers warranty?

Any thoughts appreciated, thanks for reading!

To complicate matters I think i'm going to have to pay to get things fixed initially as taking the bike on holiday next week!

2manybikes

Did someone re-install the chain using the same pin over again? Shimano chains need a new pin each time.

russelleldridge

Its a brand new bike so would be the chain installed on the initial bike build

Homebrew01

Do you know what kind of chain. It could have been a bad initial pin-job. That's why so many prefer "quick-link" type connectors. Hard to make a mistake with them.

2manybikes

There still is a chance of using the wrong pin. Probably never know.

70sSanO

I have seen a chain link start to spread off a pin on a mountain bike. I think it is caused by forcing the chain to shift under a high load. When the chain widens it becomes weaker and can also catch as it goes through the derailleur.

When I first started mountain biking I needed to adjust how I unloaded the pedals and making sure I completing the shift when going to a large 34t cog heading into a steep section before applying power to the pedals. Unfortunately I occasionally got lazy and I tore my rear derailleur into pieces and snapped the chain. A nice 5 mile walk, fortuantely a lot downhill, reinforced the lesson, along with packing a chain tool from then on.

John

russelleldridge

I wasn't shifting gears at the time it snapped but wouldn't have put it past me to change gear under high load before and start the process of spread the link. One of the perils of Di2 is suddenly shifting gear by accidentally brushing the shifter - not great to suddenly swap the front chain-ring to the large one when stomping up a steep hill!

Marcus_Ti

Hehe, a few years ago I had a Connex 10s link snap on a tour. Gone. SAG patched me up in the field....it was then that I noticed that said shop didn't know how to properly re-pin Campag 10s chains together in the field (new replacement pin and the $200 campag chaintool)

russelleldridge

Its definitely a shimano as bike shop is dealing with Madison who supply shimano parts. Can't be certain of model but presumably would be Shimano HG700, 11-speed as stated on Cannondale website.

spdracr39

Should be under warranty.

CliffordK

My only quick link I've used in years blew up on me... so back to pinning.

I've been re-using my 9s pins, and mark where the link is... so I'll know if I caused a potential break. So far, about 4000 or so miles on several bikes without problems.

Assuming the chain was linked with the proper replacement pins, you should be able to recognise the replacement pin, and verify that it is in the chain, and whether it is the link that failed. That pin should look more solid than the rest of the pins.

obed7

I would think this should be a warranty issue.

Homebrew01

Probably. Chain installed improperly at the shop or assembly line.

jimc101

Really nothing to do with Shimano or Madison as the bike is 2 months old, any warranty issues (which covers everything on the bike due to the age) would be covered by the reseller, then the manufacture, in this case Cannondale.

fietsbob

I'd have to see it, in person..

yea shut off the computer and take the bike back to the Shoppe.


If you got the bike from a remote seller , the assembly of the bike from the shipping carton may be questioned..

russelleldridge

Finally have a resolution to this saga! Company that built the bike for Evans Cycles have inspected the parts and agreed to refund the cost of the parts to repair the bike as a "goodwill gesture". Result!

spdracr39

Should never have been a question. I'm glad they consider covering defects and premature failures a "goodwill" gesture. Bike warranties are a joke. You should almost just assume there isn't one.

rmfnla

russelleldridge

Chainring bolts have now fallen out and inner chain ring now bent...ffs

cny-bikeman

Wow - have never seen that occur on a newer bike. Would be extremely unusual on a stock crankset. Were there any changes made in chainring size when the bike was assembled?

reshp1

Check the rest of chain. If you can't find the special pin they used to install the pin (it's solid instead of hollow and a darker color) it's probably the one that let go and is now presumably missing. I would say that's an assembly issue and the shop should make it right for you.

jimc101

Why? what relevance does the chain have to the chainring bolts falling out?

For the OP, has it really taken almost 8 months to get the first issue resolved? If what your saying is correct, still not sure why you had to pay for the fix at the beginning, was this taken to another shop? as it was such a new bike, the original reseller (Evans) should have been the first and only contact, getting others involved will have limited/complicated your options for rejection/repair of the bike.