Is there any option to disassemble the gearbox with the motor inside od did you try this? My motor or gearbox stopped working after a crash. I suspect that the axle of the transmission bent after the impact. I have an RD-R9150 which is similar.
The whole unit is sealed and globally not made to be taken apart. From what I remember you’ll need to break the thing which then renders it useless anyway..
Thank you for the detailed explanation. Can you say what is the purpose of the spring that is adjusted with a 1.5 mm allen? My RD-6870 is not getting to the smallest cog after a crash, i can persuade it to get there if i gently move it with my hand, but i can feel that there is a spring like resistance that prevent it from staying exactly under the cog. I suspect that if I loosen this spring a bit, i would get less resistance, but not sure if this will degrade the shifting performance.
Yeh that spring does indeed seem to help move the derailleur towards the smallest sprocket. Maybe tightening down the screw will increase the spring tension load for the derailleur to shift to the lower gear. Of course, if you’ve had a crash, other parts could have misaligned. I doubt turning the screw a quarter turn each time will affect shifting. Best to try. You can always reverse it after.
Mine will shift if i extend derrailler down. Then it will only shift 3'4 shifts then stop working. Are there wires insides motor that may have broken? would a cleaning fix my issue?
Hi, never got to that stage of opening the motor itself. Maybe I should have. My guess would be a used/worn out gear inside the motor. They’re such tiny motors, that working on them will likely require some expertise. The motor is sealed and then the rotor part is stamped meaning it will likely not work properly once put back together again. There’s a video of a front derailleur motor being opened, to have an idea.
@@atboy4342 hi, I've recently opened some dura ace and grx derailleurs, since they were broken. It is harder to get in thease, since shimano doesn't want us to look inside, but I managed to 1 working one out of 3. I was opening the motor compartment, and I still need to seal it.
yep, i have the exact same issue. apparently there is a 'known' motor issue which causes it. I would have thought that maybe the motor or bushes could be the source of the problem but never quite wanted to waste time opening one up
@@SMarkGee I ended up buying a takeoff from a new bike that had been sitting in bike shop for a long time . Glad they had one. The other was just shot.
![[UNCUT] The Loyal Pin ปิ่นภักดิ์ EP.15 (2/4)](http://i.ytimg.com/vi/qbHbshrA1f0/mqdefault.jpg)
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dingue reparer c' est bien , mais pourquoi ne pas nettoyer l' ensemble ?
Do you recall what model of RD you used as the donor for the cage replacement? Looking to do the same for my RD-6770. Love your videos!
Is there any option to disassemble the gearbox with the motor inside od did you try this? My motor or gearbox stopped working after a crash. I suspect that the axle of the transmission bent after the impact. I have an RD-R9150 which is similar.
The whole unit is sealed and globally not made to be taken apart. From what I remember you’ll need to break the thing which then renders it useless anyway..
@@atboy4342 Thanks i thought so as well. I'll try spraying it with WD40 some more and if that doesn't help I'll have to buy a new unit.
Thank you for the detailed explanation. Can you say what is the purpose of the spring that is adjusted with a 1.5 mm allen? My RD-6870 is not getting to the smallest cog after a crash, i can persuade it to get there if i gently move it with my hand, but i can feel that there is a spring like resistance that prevent it from staying exactly under the cog. I suspect that if I loosen this spring a bit, i would get less resistance, but not sure if this will degrade the shifting performance.
Hi at what point in the video? (Time). I’ve done a hundred at least videos on derailleurs, I simply can’t retain all the info..
@@atboy4342 You start disassembling it at 3:55 and put back together at 17:15
Yeh that spring does indeed seem to help move the derailleur towards the smallest sprocket. Maybe tightening down the screw will increase the spring tension load for the derailleur to shift to the lower gear. Of course, if you’ve had a crash, other parts could have misaligned. I doubt turning the screw a quarter turn each time will affect shifting. Best to try. You can always reverse it after.
Thank you for the video, do you put grease or oil inside ?
Good afternoon, could you tell me what model is the screwdriver bit that you use to disassemble the gearbox? I can't find it in any store. Thank you.
Trigram Triwing Security Screwdriver Bit - aka Y screwdriver bit
Wondering still worth to purchase a 2013 bike with 6770di2 right now buy a mechanic ty
Mine will shift if i extend derrailler down. Then it will only shift 3'4 shifts then stop working. Are there wires insides motor that may have broken? would a cleaning fix my issue?
Hi, never got to that stage of opening the motor itself. Maybe I should have. My guess would be a used/worn out gear inside the motor. They’re such tiny motors, that working on them will likely require some expertise. The motor is sealed and then the rotor part is stamped meaning it will likely not work properly once put back together again. There’s a video of a front derailleur motor being opened, to have an idea.
@@atboy4342 I should send you mine . I got another one I was lucky enough to find . You could make a video !
@@atboy4342 hi, I've recently opened some dura ace and grx derailleurs, since they were broken. It is harder to get in thease, since shimano doesn't want us to look inside, but I managed to 1 working one out of 3. I was opening the motor compartment, and I still need to seal it.
yep, i have the exact same issue. apparently there is a 'known' motor issue which causes it. I would have thought that maybe the motor or bushes could be the source of the problem but never quite wanted to waste time opening one up
@@SMarkGee I ended up buying a takeoff from a new bike that had been sitting in bike shop for a long time . Glad they had one. The other was just shot.