Push Bike Backwards from shed, chain falls off

[Willieverlovemybike]

Hello - confused newbie seeking wisdom and happiness!

Background:
2017, as an overweight 60+ year old, I bought myself a pre-retirement ebike - Reiss & Muller R&M Delite GX Rohloff
The dealer I bought it from went bust early doors leaving me with no local dealership
I have done a small amount of miles since buying the bike (shuffles feet), maybe 500 or so.
Now, with 2021 retirement complete, I want to get out and about and fall in love with my bike
I am not clever or mechanically knowledgeable - hopefully I can describe my problem purposefully and reach out to you for help please...

Issue:
I have parked my bike in my shed since day 1 of purchase
I wheel the bike out (backwards), point it towards the gate and with some loss of dignity, wobble my way out onto the road
I have never had any issue with wheeling the bike out of the shed before
This week, I find my chain is repeatedly falling off

Closer inspection
As I push my bike out from the shed, I see the lower chain run (looping up and over the plastic roller guidance wheel) is travelling inwards slightly and pressing the inner edge of the plastic guidance wheel away from the frame
The plastic guidance wheel falls off and the chain falls off
A friend (non ebike), used his "chain measuring" tool and concluded there was minimal wear in my chain, the problem is with the plastic roller guidance wheel pulling away so easily from the frame

Help please?
1) Have I simply been lucky all these previous times pushing the ebike out of the shed, that the chain has never fallen off before?
2) Is it natural/normal for the plastic roller guidance wheel to be so easily pushed aside by the chain links so that the plastic roller wheel and the chain drop off?
3) Between 2017 and 2021, have there been any design improvements to the Delite Rohloff that I can upgrade to and provide better / more secure chain alignment?

Objective
To understand if the chain should so easily displace the plastic roller wheel so both fall off
To feel confident, once I have pushed the chain back on, I can (forwards) pedal and this chain displacement issue will not re-occur?

My thanks....

 

[JRA]

That lower roller should have a disc on the outside to stop the chain from jumping off. Looks like the right size fender washer might work there.

Sometimes if you have changed the shifting lever on a bike and roll it back the chain will jump around. Not sure if that is the case with a Rohloff however. Why it didn't do it before I don't know.

 

[Willieverlovemybike]

Hello - confused newbie seeking wisdom and happiness!

Background:
2017, as an overweight 60+ year old, I bought myself a pre-retirement ebike - Reiss & Muller R&M Delite GX Rohloff
The dealer I bought it from went bust early doors leaving me with no local dealership
I have done a small amount of miles since buying the bike (shuffles feet), maybe 500 or so.
Now, with 2021 retirement complete, I want to get out and about and fall in love with my bike
I am not clever or mechanically knowledgeable - hopefully I can describe my problem purposefully and reach out to you for help please...

Issue:
I have parked my bike in my shed since day 1 of purchase
I wheel the bike out (backwards), point it towards the gate and with some loss of dignity, wobble my way out onto the road
I have never had any issue with wheeling the bike out of the shed before
This week, I find my chain is repeatedly falling off

Closer inspection
As I push my bike out from the shed, I see the lower chain run (looping up and over the plastic roller guidance wheel) is travelling inwards slightly and pressing the inner edge of the plastic guidance wheel away from the frame
The plastic guidance wheel falls off and the chain falls off
A friend (non ebike), used his "chain measuring" tool and concluded there was minimal wear in my chain, the problem is with the plastic roller guidance wheel pulling away so easily from the frame

Help please?
1) Have I simply been lucky all these previous times pushing the ebike out of the shed, that the chain has never fallen off before?
2) Is it natural/normal for the plastic roller guidance wheel to be so easily pushed aside by the chain links so that the plastic roller wheel and the chain drop off?
3) Between 2017 and 2021, have there been any design improvements to the Delite Rohloff that I can upgrade to and provide better / more secure chain alignment?

Objective
To understand if the chain should so easily displace the plastic roller wheel so both fall off
To feel confident, once I have pushed the chain back on, I can (forwards) pedal and this chain displacement issue will not re-occur?

My thanks....

That lower roller should have a disc on the outside to stop the chain from jumping off. Looks like the right size fender washer might work there.

Sometimes if you have changed the shifting lever on a bike and roll it back the chain will jump around. Not sure if that is the case with a Rohloff however. Why it didn't do it before I don't know.

Thank you for the pick up JRA
I will research other 2017-2021 Delight gx Rohloff chain images and see if/how they may differ from mine.

 

[Alaskan]

If the roller is falling of because of chain pressure on the bolt or axle nut or whatever fastener that retains the roller on its shaft, has fallen out and needs replacement. Once the roller cannot move sideways of its axle or shaft the chain should stay in place without. The black plastic roller is supposed to be secured in place and should not be able to move off its shaft. You should not be able to take the roller off without removing a washer and nut that secure to threads on the outside end of the Axle/shaft or a smaller bolt and washer that threads into the shaft, or a possibly a snap-ring the sits in a groove at the end of the shaft with a washer and the roller inside of it.

Just get with an experienced mechanic to figure out how to secure the black plastic roller in place and all should be good.

 

[Willieverlovemybike]

Alaskan - that was informative and puts it into context for me.

interestingly, I did have pre build / delivery issues with the bike (right hydraulic brake leaking with loss of fluid/brakes)
Perhaps the chain guide roller was also in-expertly fitted and has taken this time to disengage.

My thanks.

 

[Merryweather]

Hello - confused newbie seeking wisdom and happiness!

Background:
2017, as an overweight 60+ year old, I bought myself a pre-retirement ebike - Reiss & Muller R&M Delite GX Rohloff
The dealer I bought it from went bust early doors leaving me with no local dealership
I have done a small amount of miles since buying the bike (shuffles feet), maybe 500 or so.
Now, with 2021 retirement complete, I want to get out and about and fall in love with my bike
I am not clever or mechanically knowledgeable - hopefully I can describe my problem purposefully and reach out to you for help please...

Issue:
I have parked my bike in my shed since day 1 of purchase
I wheel the bike out (backwards), point it towards the gate and with some loss of dignity, wobble my way out onto the road
I have never had any issue with wheeling the bike out of the shed before
This week, I find my chain is repeatedly falling off

Closer inspection
As I push my bike out from the shed, I see the lower chain run (looping up and over the plastic roller guidance wheel) is travelling inwards slightly and pressing the inner edge of the plastic guidance wheel away from the frame
The plastic guidance wheel falls off and the chain falls off
A friend (non ebike), used his "chain measuring" tool and concluded there was minimal wear in my chain, the problem is with the plastic roller guidance wheel pulling away so easily from the frame

Help please?
1) Have I simply been lucky all these previous times pushing the ebike out of the shed, that the chain has never fallen off before?
2) Is it natural/normal for the plastic roller guidance wheel to be so easily pushed aside by the chain links so that the plastic roller wheel and the chain drop off?
3) Between 2017 and 2021, have there been any design improvements to the Delite Rohloff that I can upgrade to and provide better / more secure chain alignment?

Objective
To understand if the chain should so easily displace the plastic roller wheel so both fall off
To feel confident, once I have pushed the chain back on, I can (forwards) pedal and this chain displacement issue will not re-occur?

My thanks....

Hello,
I have the same R&M Delite GX Rohloff with the same issue though my chain idler roller stays intact. Wheeling the bike backwards sends the chain out of alignment across the roller ending up with the chain coming off. It has mystified a good local bike repair shop (Exeter) whose only answer was to not wheel it backwards! I subsequently replaced both sprockets, chain and idler roller. The problem is still there! I have noticed the side the chain comes off the roller is determined by which way I lean the bike when wheeling it backwards. With a tightly adjusted chain it doesn't completely come off but still goes well out of alignment, creaking and crunching horribly. I bought the bike (2017 model) secondhand a year ago and other than this issue its been an amazing bike. Have you or anyone else found any workable fix, I wonder?

 

[AguassissiM]

You can always try to find a metal washer larger than the outermost diameter of the idler roller by say 1/4"and secure it to the outside of the roller creating collar that will keep the chain in place.
Yes I do realize that this is not an ideal or the best solution however it should fix the issue.
Using a black sharpie you can paint the metal washer with to make it blend in with the black roller.

 

[Merryweather]

You can always try to find a metal washer larger than the outermost diameter of the idler roller by say 1/4"and secure it to the outside of the roller creating collar that will keep the chain in place.
Yes I do realize that this is not an ideal or the best solution however it should fix the issue.
Using a black sharpie you can paint the metal washer with to make it blend in with the black roller.

Hi,
Thanks for the suggestion. Fitting a washer as you say would stop the chain coming completely off, but wouldn't stop the chain misaligning across the roller. I feel the problem could be connected to the surface of the roller 'grabbing' the chain and amplifying the slight gravitational movement of the chain when the bike leans slightly as it is wheeled backwards. How to get around this is a mystery and I wonder if R&M have an update. I notice the later Delite models have Gates belt drive.

 

[theemartymac]

Right off the bat, that is a flat guide wheel, and that is typically used for a belt, not a chain. Interesting for R&M to use that one, and not a traditional grooved or tapered MTB chain guide wheel like these:

You could likely swap one out with the model like the Blackspire at the top, as long as you could validate that the spindle diameter and any offset works.

And as for the backwards drop off in general (for all bikes), the main problem is that the derailleur tension is normally maintained in one direction and the system is designed to be tensioned across the top from back to front, and when you walk backwards, you tension it in reverse across the bottom and add a lot of slack to the chain. Since the offset from the centerline of the rear cassette to the front chainring (referred to as chain line or cross-chaining) is less dramatic on a big front chainring with mild radiuses, it seldom falls off in that direction unless the tension gets way to loose, or the cross-chain angle is far too steep. Mountain bikes use those grooved or tapered guides to prevent this. However, in reverse, the smaller rear cog and tighter radius is more prone to binding up and allowing it to pop off.

A clutched derailleur as found on many premium bikes and mountain bikes can help by reducing the amount of slack the derailleur can allow to be introduced, and dirty or stiff chain links can exacerbate the problem by reducing the chain's flexibility. A worn rear cassette can also allow more drops (in reverse) as the teeth might not be engaging as deeply. This is all just spit balling for discussion, but if after cleaning and lubing everything, and evaluating the chain line to make sure the front to back alignment is reasonable, there might not be a ton of options available other than trying a different chain and cassette combo?

 

[Merryweather]

Right off the bat, that is a flat guide wheel, and that is typically used for a belt, not a chain. Interesting for R&M to use that one, and not a traditional grooved or tapered MTB chain guide wheel like these:

You could likely swap one out with the model like the Blackspire at the top, as long as you could validate that the spindle diameter and any offset works.

And as for the backwards drop off in general (for all bikes), the main problem is that the derailleur tension is normally maintained in one direction and the system is designed to be tensioned across the top from back to front, and when you walk backwards, you tension it in reverse across the bottom and add a lot of slack to the chain. Since the offset from the centerline of the rear cassette to the front chainring (referred to as chain line or cross-chaining) is less dramatic on a big front chainring with mild radiuses, it seldom falls off in that direction unless the tension gets way to loose, or the cross-chain angle is far too steep. Mountain bikes use those grooved or tapered guides to prevent this. However, in reverse, the smaller rear cog and tighter radius is more prone to binding up and allowing it to pop off.

A clutched derailleur as found on many premium bikes and mountain bikes can help by reducing the amount of slack the derailleur can allow to be introduced, and dirty or stiff chain links can exacerbate the problem by reducing the chain's flexibility. A worn rear cassette can also allow more drops (in reverse) as the teeth might not be engaging as deeply. This is all just spit balling for discussion, but if after cleaning and lubing everything, and evaluating the chain line to make sure the front to back alignment is reasonable, there might not be a ton of options available other than trying a different chain and cassette combo?

Thanks, the Blackspire roller looks worth trying. I have Rohloff hub gears and by default the drive chain rotates when the bike is wheeled backwards. This wouldn't presumably be the case with derailleur systems. I rode 30 miles yesterday afternoon with no problems until reversing the bike out of a friend's gateway.

 

[theemartymac]

Thanks, the Blackspire roller looks worth trying. I have Rohloff hub gears and by default the drive chain rotates when the bike is wheeled backwards. This wouldn't presumably be the case with derailleur systems. I rode 30 miles yesterday afternoon with no problems until reversing the bike out of a friend's gateway.

Where is it popping off? Right at the guide wheel? Or the rear cog into the Rohloff hub?

I'd check the chainline first, looking carefully from the rear, make sure the rear cog and the front chainring are very much inline and no visible offset.

Then I'd check the tension. if you don't have a tensioner on the rear, as the chain and sprocket begin to wear you should be able to take up the introduced slack by moving the rear wheel slightly backwards? I'm not familiar enough with that model to tell you where that adjustment is, but there must be some kind of slack adjustment at the rear dropout or maybe the guide wheel?

 

[Merryweather]

Where is it popping off? Right at the guide wheel? Or the rear cog into the Rohloff hub?

I'd check the chainline first, looking carefully from the rear, make sure the rear cog and the front chainring are very much inline and no visible offset.

Then I'd check the tension. if you don't have a tensioner on the rear, as the chain and sprocket begin to wear you should be able to take up the introduced slack by moving the rear wheel slightly backwards? I'm not familiar enough with that model to tell you where that adjustment is, but there must be some kind of slack adjustment at the rear dropout or maybe the guide wheel?

Thanks for the advice. I have done what you suggested but while tightening the chain improves the situation and with meticulous adjustment I can almost trust the chain not to misalign on the roller. Over tightening the chain eliminates the misalignment but I fear that will lead to other problems. As a previous respondent suggested I have just ordered a channelled chain roller from Powerbikes to see if that will do the trick. Even with scrupulous adjustment the R&M chain roller tends to send the lower run of the chain to one side or the other when wheeling backwards.

 

[theemartymac]

Thanks for the advice. I have done what you suggested but while tightening the chain improves the situation and with meticulous adjustment I can almost trust the chain not to misalign on the roller. Over tightening the chain eliminates the misalignment but I fear that will lead to other problems. As a previous respondent suggested I have just ordered a channelled chain roller from Powerbikes to see if that will do the trick. Even with scrupulous adjustment the R&M chain roller tends to send the lower run of the chain to one side or the other when wheeling backwards.

I'd think standard 'fixie' chain tension would be appropriate, which would be roughly 1/4" to 1/2" deflection in the top chain either way from static, or 1/2" to 1" inch total travel (max). Slightly looser is always better than slightly tighter for longevity.

But your plan to drop in a channeled wheel should be perfect. Post pics after you get it installed!