Chain Started Dropping on Motobecane Adventure - Causes?

[Catalyzt]

Curious about this, because I had no chain drops at all for the first 200 miles or so.

I've had three in the last 100 miles, all in completely different situations. The first was when I ran over something at night-- no idea what it was, not something living, fortunately, a hard object. The second time was descending a hill on asphalt and pedaling hard at close to maximum speed, about 36 MPH. I've taken that hill before pedaling hard a couple of MPH faster with no incident. The third time was a completely different situation-- just made a wrong turn, and had to downshift when going very slowly uphill, the kind of standard shifting error we all try to avoid but that happens occasionally anyway.

Anything simple I could try without taking it in? I was hoping to get in one more big climb before it gets too hot, and I'm confined to shorter evening rides (and when bodyboarding season starts!)

Thanks...

 

[mjeds]

chain stretch, though 200 miles is a bit low, most chains are good for 800 or so .. I have replaced the chain on my e-bike 4 times in 6,500 miles, the first one was toast around 600 miles, I then opted for an e-bike specific high torque chain and am managing closer to 2,500 miles per chain.

get a chain stretch tool and measure it, or take it to a bike shop and have them do it, most will do the measure for free.

 

[mjeds]

you can also try removing a link or two if you have a chain tool

 

[Catalyzt]

Good ideas. Hadn't occurred to me, because the E5000 on my bike only puts out 40 Nm, so you wouldn't think it would be that hard on the chain.

On the other hand, I probably do 800 feet of vertical even on my shorter rides, and often 2,500 or even 3,000 feet, so whether it's me or the motor, something's putting a significant load on the chain or I wouldn't be getting up the hill!

 

[mjeds]

Good ideas. Hadn't occurred to me, because the E5000 on my bike only puts out 40 Nm, so you wouldn't think it would be that hard on the chain.

On the other hand, I probably do 800 feet of vertical even on my shorter rides, and often 2,500 or even 3,000 feet, so whether it's me or the motor, something's putting a significant load on the chain or I wouldn't be getting up the hill!

true, with that kind of torque I suspect the chain is stretched. I commute 50 miles round trip a day on mine but it is mostly flat, the rise is from sea level to 1,300 feet but over the course of 24.2 miles, so not a harsh incline. But I am moving at 27-30mph going and 32-35mph returning as it down hill

 

[steve mercier]

chain stretch, though 200 miles is a bit low, most chains are good for 800 or so .. I have replaced the chain on my e-bike 4 times in 6,500 miles, the first one was toast around 600 miles, I then opted for an e-bike specific high torque chain and am managing closer to 2,500 miles per chain.

get a chain stretch tool and measure it, or take it to a bike shop and have them do it, most will do the measure for free.

If you have an 11 speed I endorse trying a Sram XX1 chain.

 

[Stefan Mikes]

Was the drive-train inspected at least once after 200 miles by a trained bike mechanic? With the first e-bike I owned, I visited the mechanic only after the derailleur hanger got damaged as complicated outcome of badly adjusted derailleur...

 

[Lar]

The first was when I ran over something at night-- no idea what it was, not something living, fortunately, a hard object. The second time was descending a hill on asphalt and pedaling hard at close to maximum speed, about 36 MPH. I've taken that hill before pedaling hard a couple of MPH faster with no incident. The third time was a completely different situation-- just made a wrong turn, and had to downshift when going very slowly uphill, the kind of standard shifting error we all try to avoid but that happens occasionally anyway.

Anything simple I could try without taking it in? I was hoping to get in one more big climb before it gets too hot, and I'm confined to shorter evening rides (and when bodyboarding season starts!)

Thanks...

My guess would be a bent derailleur hanger or damaged derailleur since it started right after you hit something.

 

[Catalyzt]

My guess would be a bent derailleur hanger or damaged derailleur since it started right after you hit something.

Possible, Lar, but I would think that would cause shifting issues as well, and shifting is still slick as snot. I figured the rear suspension just did a big boing and that threw a loosened chain, but I'll be alert tonight and see if I notice any odd behavior.

Was the drive-train inspected at least once after 200 miles by a trained bike mechanic? With the first e-bike I owned, I visited the mechanic only after the derailleur hanger got damaged as complicated outcome of badly adjusted derailleur...

Stefan, no, but the bike was assembled by my LBS, and I have not made any adjustments since then.

true, with that kind of torque I suspect the chain is stretched. I commute 50 miles round trip a day on mine but it is mostly flat, the rise is from sea level to 1,300 feet but over the course of 24.2 miles, so not a harsh incline. But I am moving at 27-30mph going and 32-35mph returning as it down hill

My speeds are much lower, only 9-14 MPH average speeds, with top speeds of 36-38 MPH, which is very brief. But yes, I'm doing a bit more vertical... 1,300 feet for me is usually more like a 10-13 mile ride. Sounds like you have a fun commute!

All good thoughts, folks. I think I'll take the Moto for a shakedown medium-short run tonight and see if I have any problems. My hope is that I won't have to go to the shop before Monday, when I have planned my... (*ahem*) 'assault' on Mt. Verdugo. Later in the week, it will probably be too hot for long rides, and I can have the Moto checked out at the LBS. The replacement controller for the Trek kit bike should have arrived by then, too.

Dang, the Trek is gonna need some work, too, after I get the controller back, and I can't put that off too long either. Rear break just sucks-- it shrieks and has no stopping power even though I just replaced it. And that drive train really is showing its age... will need some attention over the summer, hopefully just a new chain, cleaning, and adjustment. It's always had problems shifting into the largest gear on the crank, but the new shifter for the rear derailleur has never been right in the middle gears.

 

[Stefan Mikes]

Stefan, no, but the bike was assembled by my LBS, and I have not made any adjustments since then.

Cat: The standard procedure is you get your e-bike assembled by the shop and then you shall visit them after, say, 150 miles ridden for checkup. The 150 miles mean "running-in of the bike" because many parts can get loose or misaligned in the first phase. Not sure how it looks in your area but big brands here in Europe require you come up for the "obligatory 1st service" to have your warranty honoured.

It could be a bent derailleur hanger in your case indeed.

 

[steve mercier]

Possible, Lar, but I would think that would cause shifting issues as well, and shifting is still slick as snot. I figured the rear suspension just did a big boing and that threw a loosened chain, but I'll be alert tonight and see if I notice any odd behavior.

Stefan, no, but the bike was assembled by my LBS, and I have not made any adjustments since then.

My speeds are much lower, only 9-14 MPH average speeds, with top speeds of 36-38 MPH, which is very brief. But yes, I'm doing a bit more vertical... 1,300 feet for me is usually more like a 10-13 mile ride. Sounds like you have a fun commute!

All good thoughts, folks. I think I'll take the Moto for a shakedown medium-short run tonight and see if I have any problems. My hope is that I won't have to go to the shop before Monday, when I have planned my... (*ahem*) 'assault' on Mt. Verdugo. Later in the week, it will probably be too hot for long rides, and I can have the Moto checked out at the LBS. The replacement controller for the Trek kit bike should have arrived by then, too.

Dang, the Trek is gonna need some work, too, after I get the controller back, and I can't put that off too long either. Rear break just sucks-- it shrieks and has no stopping power even though I just replaced it. And that drive train really is showing its age... will need some attention over the summer, hopefully just a new chain, cleaning, and adjustment. It's always had problems shifting into the largest gear on the crank, but the new shifter for the rear derailleur has never been right in the middle gears.

I would be curious to hear what you discover about the brake problem.

 

[Lar]

Possible, Lar, but I would think that would cause shifting issues as well, and shifting is still slick as snot. I figured the rear suspension just did a big boing and that threw a loosened chain, but I'll be alert tonight and see if I notice any odd behavior.

Stefan, no, but the bike was assembled by my LBS, and I have not made any adjustments since then.

My speeds are much lower, only 9-14 MPH average speeds, with top speeds of 36-38 MPH, which is very brief. But yes, I'm doing a bit more vertical... 1,300 feet for me is usually more like a 10-13 mile ride. Sounds like you have a fun commute!

All good thoughts, folks. I think I'll take the Moto for a shakedown medium-short run tonight and see if I have any problems. My hope is that I won't have to go to the shop before Monday, when I have planned my... (*ahem*) 'assault' on Mt. Verdugo. Later in the week, it will probably be too hot for long rides, and I can have the Moto checked out at the LBS. The replacement controller for the Trek kit bike should have arrived by then, too.

Dang, the Trek is gonna need some work, too, after I get the controller back, and I can't put that off too long either. Rear break just sucks-- it shrieks and has no stopping power even though I just replaced it. And that drive train really is showing its age... will need some attention over the summer, hopefully just a new chain, cleaning, and adjustment. It's always had problems shifting into the largest gear on the crank, but the new shifter for the rear derailleur has never been right in the middle gears.

You may just need to adjust either the high or low screw on the derailleur then. Doing that will only change the overall travel range and not where it shifts in relation to being aligned with the gears if that makes sense.

 

[Catalyzt]

Just did 8.5 miles and 1,300 feet of vertical. (There are a million different routes from my house, but every 40 minute ride in any direction that avoids major surface streets seems to be 8.5 miles and 1,300 feet of vertical. I'm not complaining, it's just a little weird.)

No chain drops until the last block... and then that sudden feeling of no resistance when I'm pedaling. I wasn't shifting, wasn't taking any hits, seemed crazy...

Then I mentally replayed the last three seconds before the chain dropped while it was still fresh in my memory. There was a little tug from my right leg...

And now I'm feeling a little stupid, because I think I'm catching the corner of my PANT LEG under the chain. Just barely, though. On the Trek kit bike or my Raleigh Competition acoustic in New York, it would have grabbed the fabric and I'd have enough warning to stop pedaling before it dropped.

Was I wearing the same pair of pants for every ride? I think I was. This could also have happened the other times the chain dropped as well.

I'm not sure this negates the chain-stretch or derailleur adjustment theories, however. Maybe in the first 200 miles, the Moto would have also grabbed the fabric instead of throwing the chain.

It's got to be looked at. I'll see if I can get it done before Monday, but if not, I think I'll be fine for the big ride. One thing that's wonderful: The chain doesn't get stuck anywhere when it pops off, nothing jams.

Cat: The standard procedure is you get your e-bike assembled by the shop and then you shall visit them after, say, 150 miles ridden for checkup. The 150 miles mean "running-in of the bike" because many parts can get loose or misaligned in the first phase. Not sure how it looks in your area but big brands here in Europe require you come up for the "obligatory 1st service" to have your warranty honoured.

It could be a bent derailleur hanger in your case indeed.

Just checked the warranty, and there is no 200 mile requirement for the Motobecane. (Though I guess I should check Shimano's warranty.) And again, the shifting is smooth as silk up and down the cluster, so I don't think that's the problem.

I'm glad you posted, however, because after reading about all the symptoms of a bent hanger? Yeah, the Trek's hanger is probably bent! (If it has one? It's an older steel frame.)

Also going to carefully visually inspect both bikes tomorrow now that I have some vague idea what this is.

 

[Lar]

Maybe you just need to quit wearing bell-bottoms. Come on man the sixties are over.

 

[Mr. Coffee]

...
And now I'm feeling a little stupid, because I think I'm catching the corner of my PANT LEG under the chain. Just barely, though. On the Trek kit bike or my Raleigh Competition acoustic in New York, it would have grabbed the fabric and I'd have enough warning to stop pedaling before it dropped.

Was I wearing the same pair of pants for every ride? I think I was. This could also have happened the other times the chain dropped as well.

This is why I do not wear pants when I ride, or at least rarely.

You can get little reflective velcro straps at your bike shop to hold your pants out of the way if you choose to wear pants.

Jogalite Wide Leg Band 1.5 Inches | REI Co-op

Increase your visibility when walking, cycling, skating or jogging at night with a Jogalite Wide Leg Band. The 1.5-inch-wide reflective fabric will help you catch a driver's eye so you can stay safer.

www.rei.com

 

[mjeds]

Just did 8.5 miles and 1,300 feet of vertical. (There are a million different routes from my house, but every 40 minute ride in any direction that avoids major surface streets seems to be 8.5 miles and 1,300 feet of vertical. I'm not complaining, it's just a little weird.)

No chain drops until the last block... and then that sudden feeling of no resistance when I'm pedaling. I wasn't shifting, wasn't taking any hits, seemed crazy...

Then I mentally replayed the last three seconds before the chain dropped while it was still fresh in my memory. There was a little tug from my right leg...

And now I'm feeling a little stupid, because I think I'm catching the corner of my PANT LEG under the chain. Just barely, though. On the Trek kit bike or my Raleigh Competition acoustic in New York, it would have grabbed the fabric and I'd have enough warning to stop pedaling before it dropped.

Was I wearing the same pair of pants for every ride? I think I was. This could also have happened the other times the chain dropped as well.

I'm not sure this negates the chain-stretch or derailleur adjustment theories, however. Maybe in the first 200 miles, the Moto would have also grabbed the fabric instead of throwing the chain.

It's got to be looked at. I'll see if I can get it done before Monday, but if not, I think I'll be fine for the big ride. One thing that's wonderful: The chain doesn't get stuck anywhere when it pops off, nothing jams.



Just checked the warranty, and there is no 200 mile requirement for the Motobecane. (Though I guess I should check Shimano's warranty.) And again, the shifting is smooth as silk up and down the cluster, so I don't think that's the problem.

I'm glad you posted, however, because after reading about all the symptoms of a bent hanger? Yeah, the Trek's hanger is probably bent! (If it has one? It's an older steel frame.)

Also going to carefully visually inspect both bikes tomorrow now that I have some vague idea what this is.

Amazon.com : Leg Shield Reflective Ankle Bands - Very Large Reflective Surface Area - Bright, Comfortable, Neoprene - Straps for Biking, Running, Walking - Protects Cyclist's Pants from Chain (Silver - 4 Bands) : Sports & Outdoors

Amazon.com : Leg Shield Reflective Ankle Bands - Very Large Reflective Surface Area - Bright, Comfortable, Neoprene - Straps for Biking, Running, Walking - Protects Cyclist's Pants from Chain (Silver - 4 Bands) : Sports & Outdoors

www.amazon.com

I use these,

 

[Catalyzt]

Obviously the best solution-- since I live in Hollywood, and anything goes-- is simply to wear a skirt. However, then I suppose I'd have to get a matching top and flats, and my wife and friends would have to weigh in on all my fashion choices, so I'll probably stick with gender-confroming attire and go with the ankle bands.

Maybe you just need to quit wearing bell-bottoms. Come on man the sixties are over.

Ah, you are taking me back, Lar. I remember what a PITA bell bottoms were for bike riding. Once in the early '70s, I had a pair snag on my front derailleur and twist it about 30 degrees. We had metal pant clips in those days, and they were awful-- scratched the bike, cut off your circulation, etc. And with really big bell bottoms, you'd have to wrap the fabric around your leg a couple of times, and it always worked loose from the clip.

 

[RunForTheHills]

Obviously the best solution-- since I live in Hollywood, and anything goes-- is simply to wear a skirt. However, then I suppose I'd have to get a matching top and flats, and my wife and friends would have to weigh in on all my fashion choices, so I'll probably stick with gender-confroming attire and go with the ankle bands.



Ah, you are taking me back, Lar. I remember what a PITA bell bottoms were for bike riding. Once in the early '70s, I had a pair snag on my front derailleur and twist it about 30 degrees. We had metal pant clips in those days, and they were awful-- scratched the bike, cut off your circulation, etc. And with really big bell bottoms, you'd have to wrap the fabric around your leg a couple of times, and it always worked loose from the clip.

I use metal clips similar to what we used in the 70's. While I do have to wrap the fabric around before putting them on, I Haven't had any scratching of the bike or my pant leg working loose from the clip. I find they are easier to put on and take off than the velcro ones and mine have reflectorized tape on them for night riding.