Chain keep falling off the crank - Giant Explore E3 - 2019

new_ebiker

Member
Glad the tune-up resolved your chain drop issue. How often had you been cleaning and lubricating your chain?

For mech bikes and hub motor drive ebikes, replacing the bottom bracket is fairly straight forward and a routine part of long term maintenance. With that said your bike has the Yamaha mid-drive motor, does it not? The function of the bottom bracket (connecting the cranks to the frame) is integrated into the motor bearings. A Giant dealer would be best suited to take a look at this to see if your motor needs any adjustments, but with your mileage I wouldn't expect anything major.

BTW - Other mid-drive ebike owners, like myself, are reporting that the extra strain on the chain is requiring chain replacements as often as every 1,000 miles depending on riding conditions. Something to think about...😎

I ride around 80km per week, and I usually clean it every 2 weeks. everything is original on my bike, as i only got it last September. I dunno the exactly km because it doesn’t have the lcd display. My battery has 26 cycles, so i think the lifetime mileage is around 2000KM (each cycle gets me 70KM, so 26 X 70 = 1820)
 

new_ebiker

Member
i wonder if any Giant ebike owner has replace their bottom bracket yet. Sounds like it’s something the dealer will charge you an arm and leg for it, given it’s not standardized parts.
 

Nova Haibike

Well-Known Member
i wonder if any Giant ebike owner has replace their bottom bracket yet. Sounds like it’s something the dealer will charge you an arm and leg for it, given it’s not standardized parts.

This would not be possible because motors and/or motor parts are not available for sale to consumers.
 

Sierratim

Well-Known Member
I ride around 80km per week, and I usually clean it every 2 weeks. everything is original on my bike, as i only got it last September. I dunno the exactly km because it doesn’t have the lcd display. My battery has 26 cycles, so i think the lifetime mileage is around 2000KM (each cycle gets me 70KM, so 26 X 70 = 1820)
Do you have a chain stretch gauge? Park Tool makes several versions. This one will work for your chain.

I admit that I change my chains early, but they are the least expensive drive train component. Early replacement saves other more expensive components for another day
 

Sierratim

Well-Known Member
I got 2,500 miles on each of my two Bosch powered Haibikes. One is at 4,200 now, may have to change that chain again before winter. Still on original cassettes. It's not a universal law that everyone destroys chains on their mid drives.
I should have said "some mid-drive ebike owners...are reporting". Didn't intend to imply all. But for example @Nxkharra had shifting issues at 2,000 miles and ended having to replace his chain and chain ring to get it fixed. YRMV...😎
 

Sierratim

Well-Known Member
i wonder if any Giant ebike owner has replace their bottom bracket yet. Sounds like it’s something the dealer will charge you an arm and leg for it, given it’s not standardized parts.
There really isn't a 'bottom bracket' in a mid-drive motor, at least in the classic sense. The bearings and mech connections to the cranks are an integral part of the motor.
 

Nxkharra

Well-Known Member
I should have said "some mid-drive ebike owners...are reporting". Didn't intend to imply all. But for example @Nxkharra had shifting issues at 2,000 miles and ended having to replace his chain and chain ring to get it fixed. YRMV...😎
To be exact there was no shifting issue. I periodically measure chain stretch using park tool. When the tool indicated that the chain was stretched more than .5 I took the bike to replace the chain. I had less than 2,000 miles and LBS informed me that I also needed chain ring. It was a challenge to get the new chain ring as the part was back ordered by Specialized and no third party offers chain ring for Vado.
I will try to be more vigilant about checking the chain stretch and don’t rely just on relying on the tool. @Sierratim has the practice of changing the chain each spring anyway. This inexpensive preventive maintenance prevents more expensive issues to follow.
I also have improved changing gears and not starting the ride on higher gear.
 

416dude

New Member
This happened to me again, the chain is keep falling off on the front crank... it turns out one of the links is bent, which explains the bike was skipping gear for the last little while...

Quick question, can I simply replace the bad link or I should just replace the whole chains? The chain is less than 2 months old with prob 400 on it, not sure why the link is broken.... maybe cuz it’s not a ebike optimized chain?
 

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Nxkharra

Well-Known Member
This happened to me again, the chain is keep falling off on the front crank... it turns out one of the links is bent, which explains the bike was skipping gear for the last little while...

Quick question, can I simply replace the bad link or I should just replace the whole chains? The chain is less than 2 months old with prob 400 on it, not sure why the link is broken.... maybe cuz it’s not a ebike optimized chain?
Have you made sure the teeth are in the right place. If not then the chain keeps coming off. Wide and narrow teeth in appropriate link.
 

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