A Couple of Bosch Drive System Issues

[opimax]

replied via PM ,taking it off the thread

 

[Mike leroy]

I found a lot of info that might help explain chain stuck by mud :

http://electricbikereview.com/commu...mparison-electric-bike-chains-and-belts.1839/

 

[Mike leroy]

Yes, I have suffered from chain suck very many times and have replaced two SRAM XX0 derailleurs, one cassette, one chain ring, one SES sprocket and one chain and needed two of the Crank Bros Iodine wheel rebuilds. I sometimes have used my derailleur alignment gauge after every ride to get it straight. Looking at the Rotwild, that bike has a much more robust derailleur hanger than the one on my Haibike AMT Pro. Bosch are aware of the problem as they are seeing a significant number of motors coming back for replacement. I too am confident that they will upgrade the seal on the bearing. The plastic actually does have a large square hole in the bottom and that is where all the dirty water gets in.

I found technical details that you might find helpful. http://electricbikereview.com/community/posts/20517/

 

[jorge cunha]

A friend was recently talking about the Bosch drive system with me (he rides a lot of off-road terrain) and we were discussing the smaller front sprocket that the system uses (apparently this part gets built by the bike manufacturer but Bosch specs three sizes... all relatively small, ideal for higher speed racing, normal city riding and off road climbing). These smaller chain ring sizes (verses traditional larger sized front rings) seems to create mechanical advantage for their centerdrive motor, allowing it to spin at higher RPMs and achieve better torque and power as a result.

Instead of repositioning pivot points on frames to deal with the pedal kickback issues (which would make frames longer and change their handling dynamic) some full suspension ebikes like the Haibike FS 27.5" have introduced a chain routing system called a Sprocket Equalizing System (S.E.S.) that's basically a pulley wheel which link the chain up and around the pivot point. This seems pretty reasonable to me, here's a picture of the SES system from Haibike which also seems to double as a guide to reduce chain drops in rough terrain:

View attachment 1996

Okay, so this discussion is just setting the stage for one issue that my friend has experienced. Apparently in muddy situations he has found that the smaller chain ring and associated guide don't provide the necessary space or separation to avoid chain suck (which is when the bottom portion of the chain sticks to the sprocket and gets pulled up... possibly back into the top of the cog where the top portion of the chain is feeding in). He shared a picture with me recently and to be fair, since the sprockets are all made by the manufacturer and not Bosch, this may be a result of both the smaller mountain bike speck that Bosch recommends in their sizing guideline or simply the way the sprocket was made or possibly the addition of the small chain guide that hugs the front sprocket? Maybe the teeth on this particular sprocket were tighter than necessary? I discovered recently that Haibike actually uses a pattern of narrow to wide teeth that match the same pattern on the chain (it has narrow and wide slots from one link to the next) designed to reduce slipping and possibly avoid this type of issue. Here's the picture he shared from a Bosch powered electric bike that was being tested off-road along with another shot of the battery interface where some mud was leaking in.

View attachment 1997 View attachment 2000 View attachment 1999

The outcome of chain suck like that shown above is that the chain gets locked and the cranks stop turning and the rider is forced to stop pedaling at short notice. I'm sharing this because it's interesting and might be good feedback for Bosch on future design considerations or individual riders who go into mud and might encounter a similar outcome. In my opinion, rigorous terrain is bound to impact ride quality and I'm not surprised that something like this could happen but I can see how it might adversely impact a rider (they could bump their knee or have a foot slip off the pedal and scrape a shin).

Thankfully, the second issue I've heard about recently has less impact on ride quality. Apparently the Bosch Nyon display panel has a plastic bevel which gets narrow along the top and the plastic has cracked for some people (and not on impact... just as the result of being brittle or expanding and contracting due to temperature). The details on how this happens are sparse, one person said they just left the display on their counter over night and in the morning it was cracked like this:

View attachment 1998

That's about it, I'm just sharing these independently and opening up for discussion from Bosch, individuals or manufacturers that use Bosch so the product can get better or people can learn how to maintain it more effectively to avoid issues. I still thing it's an amazing system and have not had any issues with the Intuvia display that's sold in the US (apparently the Nyon is coming in 2016). Maybe there will be some updates to the design before we get it.

A friend was recently talking about the Bosch drive system with me (he rides a lot of off-road terrain) and we were discussing the smaller front sprocket that the system uses (apparently this part gets built by the bike manufacturer but Bosch specs three sizes... all relatively small, ideal for higher speed racing, normal city riding and off road climbing). These smaller chain ring sizes (verses traditional larger sized front rings) seems to create mechanical advantage for their centerdrive motor, allowing it to spin at higher RPMs and achieve better torque and power as a result.

Instead of repositioning pivot points on frames to deal with the pedal kickback issues (which would make frames longer and change their handling dynamic) some full suspension ebikes like the Haibike FS 27.5" have introduced a chain routing system called a Sprocket Equalizing System (S.E.S.) that's basically a pulley wheel which link the chain up and around the pivot point. This seems pretty reasonable to me, here's a picture of the SES system from Haibike which also seems to double as a guide to reduce chain drops in rough terrain:

View attachment 1996

Okay, so this discussion is just setting the stage for one issue that my friend has experienced. Apparently in muddy situations he has found that the smaller chain ring and associated guide don't provide the necessary space or separation to avoid chain suck (which is when the bottom portion of the chain sticks to the sprocket and gets pulled up... possibly back into the top of the cog where the top portion of the chain is feeding in). He shared a picture with me recently and to be fair, since the sprockets are all made by the manufacturer and not Bosch, this may be a result of both the smaller mountain bike speck that Bosch recommends in their sizing guideline or simply the way the sprocket was made or possibly the addition of the small chain guide that hugs the front sprocket? Maybe the teeth on this particular sprocket were tighter than necessary? I discovered recently that Haibike actually uses a pattern of narrow to wide teeth that match the same pattern on the chain (it has narrow and wide slots from one link to the next) designed to reduce slipping and possibly avoid this type of issue. Here's the picture he shared from a Bosch powered electric bike that was being tested off-road along with another shot of the battery interface where some mud was leaking in.

View attachment 1997 View attachment 2000 View attachment 1999

The outcome of chain suck like that shown above is that the chain gets locked and the cranks stop turning and the rider is forced to stop pedaling at short notice. I'm sharing this because it's interesting and might be good feedback for Bosch on future design considerations or individual riders who go into mud and might encounter a similar outcome. In my opinion, rigorous terrain is bound to impact ride quality and I'm not surprised that something like this could happen but I can see how it might adversely impact a rider (they could bump their knee or have a foot slip off the pedal and scrape a shin).

Thankfully, the second issue I've heard about recently has less impact on ride quality. Apparently the Bosch Nyon display panel has a plastic bevel which gets narrow along the top and the plastic has cracked for some people (and not on impact... just as the result of being brittle or expanding and contracting due to temperature). The details on how this happens are sparse, one person said they just left the display on their counter over night and in the morning it was cracked like this:

View attachment 1998

That's about it, I'm just sharing these independently and opening up for discussion from Bosch, individuals or manufacturers that use Bosch so the product can get better or people can learn how to maintain it more effectively to avoid issues. I still thing it's an amazing system and have not had any issues with the Intuvia display that's sold in the US (apparently the Nyon is coming in 2016). Maybe there will be some updates to the design before we get it.

I have noticed this morning that the edge on my Nyon head unit has cracked on the top left corner for no reason? Will be contacting my supplier very shortly J

 

[J.R.]

I have noticed this morning that the edge on my Nyon head unit has cracked on the top left corner for no reason? Will be contacting my supplier very shortly J

Sorry to hear that.... Will be interested to hear how that goes and the outcome. Can your bike be ridden with the crack? It would be a shame if you are completely sidelined!

 

[jorge cunha]

Sorry to hear that.... Will be interested to hear how that goes and the outcome. Can your bike be ridden with the crack? It would be a shame if you are completely sidelined!

yes can still ride it... but it will be in back of my mind.

 

[jorge cunha]

Just to put the cat amongst the pidgins,,, i have 4 Haibikes 1 Gen 1 and 3 gen 2's and have not experienced chain suck, although i have cleaned the front ring half way through a ride as it is easy to pop chain off and run water over ring. I clean/lube them after each ride and the oldest i have the Gen 1 just needs new bearings.Overall I'm impressed...

 

[jorge cunha]

*new head bearings

 

[Brambor]

nice work Jorge!

 

[stevenast]

nice work Jorge!

Agreed!

...and thanks for the chain ring care tips!

 

[jorge cunha]

Just received reply from supplier about Nyon Head unit and they are sending another no questions asked...

Ive been riding Haibike xduro's for nearly 5 years when they first arrived with the motor mounted inside the frame and have had no major issues i.e: motor or electric's.Don't think any of the systems mentioned (opti/funn) would last five minutes in the UK not to mention the legal restrictions,,,and IMO they are very ugly.
Ive used and abused All my Haibikes and use them just like any other manual bike...just a little care is need when washing down and i think there's something to be said about how people are "hosing it out".
As for the 11 speed...IMO overpriced junk... no need for it,bang for buck Shimano all the way. The tolerances on these 11's are too minute for UK mud and i see a pattern of chain suck on 11 speed set ups,,,chain width may be a factor??

 

[grench]

Nice Jorge thanks for sharing. Good to see people testing their bikes.

 

[stevenast]

Nice Jorge thanks for sharing. Good to see people testing their bikes.

I "test" my bike every time I sit on it!

 

[Bike_On]

Just received reply from supplier about Nyon Head unit and they are sending another no questions asked...

Ive been riding Haibike xduro's for nearly 5 years when they first arrived with the motor mounted inside the frame and have had no major issues i.e: motor or electric's.Don't think any of the systems mentioned (opti/funn) would last five minutes in the UK not to mention the legal restrictions,,,and IMO they are very ugly.
Ive used and abused All my Haibikes and use them just like any other manual bike...just a little care is need when washing down and i think there's something to be said about how people are "hosing it out".
As for the 11 speed...IMO overpriced junk... no need for it,bang for buck Shimano all the way. The tolerances on these 11's are too minute for UK mud and i see a pattern of chain suck on 11 speed set ups,,,chain width may be a factor??

Real world results...good stuff and thanks for the post.

4 Bosch bikes? What models?

What are funn bikes??

 

[stevenast]

He means

Real world results...good stuff and thanks for the post.

4 Bosch bikes? What models?

What are funn bikes??

He means 8fun.

Nice to hear more affirmation of the quality of Haibike/Bosch, not that there was ever any doubt!

 

[jorge cunha]

Real world results...good stuff and thanks for the post.

4 Bosch bikes? What models?

What are funn bikes??

8fun rubbish and optibike I'm taking about...Cannot talk about any other make really...as I've only had experience with Haibike. These machines are not TOYS they have more than enough of my capabilities to shred.
Its unfortunate that Lumos had had them problems i can only think that it has something to do with the 11s set up,and take for what it is...if you see a ton of crap in the chain line take a minute to move it.
The front chain ring on Haibikes use an X sync cross tooth milled out of one piece...its beautiful and I've had no problems with Shimano 10s kit,i think i read somewhere this has been patented and KTM, Lapiere and others that have Bosch drives use a normal narrow narrow tooth front ring.

 

[Scuff Wheels]

The chain lock-up problem, experienced by many riders in muddy conditions can be resolved by installing an ACS device on your Bosch Drive Motor Unit. The ACS (Anti Chain Suck Device) bolts on to the Bosch motor unit. It surrounds / protect the driver sprocket, preventing build-up of mud on the chain transmission system... Part available at following link: (Link Removed - No Longer Exists)