Chain Guide or not to chain guide

Oppa

New Member
Mar 22, 2024
23
17
Rhode Island
So Orbea 2023 Rise M10. Looks to be ISCG standard on the EP801 motor bracket mountings. Challenge is I bought a bash guard Funn for the lower sprocket. Will not work with the existing chain guide. I could remove the upper guide and put on the lower bash guard or buy a new set up which includes both. If I had to choose where I am most likely to see a failure it will be on the bottom of the sprocket going over rocks and walls. Now depending on which article you read there is no definitive answer to either run with or without the top guide. Curious as to opinions here.
 

ari

New Member
Mar 1, 2024
23
9
Australia
Depends on the bike, i have one that will drop its chain jumping up or off a street gutter , its problem is the tension or lack of it in the derailuer , other bikes may drop the chain for other reasons [alignment issues etc].
 

Oppa

New Member
Mar 22, 2024
23
17
Rhode Island
Depends on the bike, i have one that will drop its chain jumping up or off a street gutter , its problem is the tension or lack of it in the derailuer , other bikes may drop the chain for other reasons [alignment issues etc].
I go over a lot of rough terrain in New England, rocky climbs, lots of tree roots, stone walls. They say with the new sprocket and cassett tech it’s more peace of mind. Guess I will give it a roll and see what happens.
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,204
4,709
Weymouth
I have 2 bikes neither of which have chain guides fitted as standard and never had any issues. They are both Sram Eagle transmissions using steel narrow wide chainrings and the chainline is standard 52mm/ boost. I wonder if the situation most likely to cause a chain to come off the chainring is fast descending over rough ground whilst the bike is in one of the highest gears (smallest cassette cogs)....something I avoid.
 

Oppa

New Member
Mar 22, 2024
23
17
Rhode Island
I have 2 bikes neither of which have chain guides fitted as standard and never had any issues. They are both Sram Eagle transmissions using steel narrow wide chainrings and the chainline is standard 52mm/ boost. I wonder if the situation most likely to cause a chain to come off the chainring is fast descending over rough ground whilst the bike is in one of the highest gears (smallest cassette cogs)....something I avoid.
Thank you for your perspective. Going for a ride today to give it a whirl
 

ebsocalmtb

Active member
Sep 29, 2021
220
231
Southern-Cal
I removed my chain guide and changed my chainring to the shimano 104bcd spider and 34t ring about 200 miles into owning my rise. I now have 3,700 miles, I just put on my second steel chainring and I have never once dropped a chain riding my rise extremely hard, in rocky/technical terrain in california, nevada, arizona and utah.
 

irie

E*POWAH Elite World Champion
Subscriber
May 2, 2022
2,103
2,044
Chichester, W.Sussex, UK
I only have a chain guard as insurance against the day that the chain might jump and break miles from anywhere. Pushing a broken eMTB cross country isn't my bag.

Have got away with destroying a rear wheel and a derailleur in 2 years/3,000 miles without having to walk home. Result.
 

Peaky Rider

E*POWAH Master
Feb 9, 2019
828
528
Derbyshire Dales
In the past years I've had a Jam 2, a Spectral on, a Rail 7 and a Rail 9.8 xt. I have taken the chain guide off all of them as all they do for me is collect mud.
I am no flying squirrel but I ride in the Derbyshire Peak District, which is very rough and rocky and all is well for me.
 
Last edited:

irie

E*POWAH Elite World Champion
Subscriber
May 2, 2022
2,103
2,044
Chichester, W.Sussex, UK
In the past years I've had a Jam 2, a Spectral on, a Rail 7 and a Rail 9.8 xt. I have taken the chain guide off all of them as all they do for me is collect mud.
I am no flying squirrel but I ride in the Derbyshire Peak District, which is very rough and rocky and all is well for me.
Wife and I have Reverse Components chain guides on our Rails and when it's super muddy we just flip them up. Also flip them when want to move the chain off the chainring.

 

Peaky Rider

E*POWAH Master
Feb 9, 2019
828
528
Derbyshire Dales
Wife and I have Reverse Components chain guides on our Rails and when it's super muddy we just flip them up. Also flip them when want to move the chain off the chainring.

I don't take mine off because they attract mud, I take them of because they are pointless, in my experience.
But then I've always been a bit of a rebel.
 

LeeS69

Member
Aug 27, 2022
96
105
Yorkshire
Binned my guide weeks ago, no issue (less crap collection though) then when doing the bearings a couple of weeks back I took the mount off too. Clattered down more than enough rough rocky stuff since taking it off and no drops at all....
 

Rod B.

Well-known member
Aug 18, 2021
510
869
USA, Orange County Ca.
So Orbea 2023 Rise M10. Looks to be ISCG standard on the EP801 motor bracket mountings. Challenge is I bought a bash guard Funn for the lower sprocket. Will not work with the existing chain guide. I could remove the upper guide and put on the lower bash guard or buy a new set up which includes both. If I had to choose where I am most likely to see a failure it will be on the bottom of the sprocket going over rocks and walls. Now depending on which article you read there is no definitive answer to either run with or without the top guide. Curious as to opinions here.
Oppa,

Manufactures put chain guides on eBikes because if you drop a chain under full boost conditions, bad things will happen. Your bike's motor and chain quickly become a chain saw. If the chain drops off the outside of the chainring it'll scratch your crank arms. No biggie....However, it the chain drops down between the chainring and motor shell/bottom bracket, it'll chew the living shit out of the frame before you can realize what has happened and can stop pedaling.

99% of the time, a chain guide isn't required due to modern chain tooth retention design. However, under the right conditions of uneven terrain, chain slapping, shifting and mode application, it's possible to drop a chain. Buy the bash guard and chain guide combo, it's cheap insurance.

Be safe,
Rod
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,204
4,709
Weymouth
rear mechs with clutches and chainrings with narrow/wide tooth profiles should make chainguards redundant. I understand the point that they can, nevertheless, provide some additional insurance, but for most chainguards I have seen, they have to be so wide to cater for the chainline difference between gear 1 and gear 12 that I doubt one would stop the chain skipping off the chainring. Maybe what would make more sense is a one sided chain guide designed only to help prevent the worst case scenario of the chain falling to the inside of the chainring.

I have mentioned previously that I avoid having the bike in the highest 2 or 3 gears when charging down a lumpy descent in order to prevent chain slap and I renew chains at 0.5%. ( no chainguards on either of my bikes as standard).
 

JayGoodrich

New Member
Aug 11, 2023
29
34
Alpine, Wyoming
So Orbea 2023 Rise M10. Looks to be ISCG standard on the EP801 motor bracket mountings. Challenge is I bought a bash guard Funn for the lower sprocket. Will not work with the existing chain guide. I could remove the upper guide and put on the lower bash guard or buy a new set up which includes both. If I had to choose where I am most likely to see a failure it will be on the bottom of the sprocket going over rocks and walls. Now depending on which article you read there is no definitive answer to either run with or without the top guide. Curious as to opinions here.
I took mine off 2000 miles ago and haven’t had any problems. The new chainrings are designed to hold on to the chain, which makes me question the chain guide altogether. I feel like chain guides are the “lawyer tabs” of the 2020s’.
 

emtbPhil

Well-known member
Jun 20, 2021
387
433
UK
Never had a chain fall off any bike - with a modern narrow-wide cassette and any half decent derailleur they seem pointless.
Both my last two bikes have chain guards, both have clogged completely full of mud/clay on rides.

Pointless things. At least the one on my new bike flips up quickly so I can get all the shit out of it - but very tempted to bin it.
 

Downhillr

Active member
Jul 2, 2021
233
111
SF Bay, California
Wife and I have Reverse Components chain guides on our Rails and when it's super muddy we just flip them up. Also flip them when want to move the chain off the chainring.

That guide’s just like the guide from OneUp Components… who copied who?
 

irie

E*POWAH Elite World Champion
Subscriber
May 2, 2022
2,103
2,044
Chichester, W.Sussex, UK
That guide’s just like the guide from OneUp Components… who copied who?
At first sight they look similar but having looked at the installation guide on the Oneup website they are in fact very different (the Oneup guide requires messing around with shims, for example).
 

DugT

Active member
Sep 4, 2022
113
104
Truckee, CA
Oppa,

Manufactures put chain guides on eBikes because if you drop a chain under full boost conditions, bad things will happen. Your bike's motor and chain quickly become a chain saw. If the chain drops off the outside of the chainring it'll scratch your crank arms. No biggie....However, it the chain drops down between the chainring and motor shell/bottom bracket, it'll chew the living shit out of the frame before you can realize what has happened and can stop pedaling.

99% of the time, a chain guide isn't required due to modern chain tooth retention design. However, under the right conditions of uneven terrain, chain slapping, shifting and mode application, it's possible to drop a chain. Buy the bash guard and chain guide combo, it's cheap insurance.

Be safe,
Rod
I'm curious how this is possible. If the chain falls off the chainring and goes inside, there is nothing to keep the chain moving because the chainring is what propels the chain. Also, if there is no load on the chain, I think most motors stop or at least slow down. You mention, "Full boost conditions". Does that make a big difference in the rules of motor engagement? I'm relatively new to ebikes, 1.5 years with a Trek Evo, so I'm open to correction.
 

ari

New Member
Mar 1, 2024
23
9
Australia
I'm curious how this is possible. If the chain falls off the chainring and goes inside, there is nothing to keep the chain moving because the chainring is what propels the chain. Also, if there is no load on the chain, I think most motors stop or at least slow down. You mention, "Full boost conditions". Does that make a big difference in the rules of motor engagement? I'm relatively new to ebikes, 1.5 years with a Trek Evo, so I'm open to correction.
I dropped my chain last sunday in a race , the chain got dragged up and over the top of the chainring[from 6ocloct to one o clock] ,few weeks earlier it did something similar a wrecked everything, it is a hardtail so it needs a guide. Chains do some unexplainable things.

434602905_835368975296773_3817808351670595738_n.jpg
 

Rod B.

Well-known member
Aug 18, 2021
510
869
USA, Orange County Ca.
I'm curious how this is possible. If the chain falls off the chainring and goes inside, there is nothing to keep the chain moving because the chainring is what propels the chain. Also, if there is no load on the chain, I think most motors stop or at least slow down. You mention, "Full boost conditions". Does that make a big difference in the rules of motor engagement? I'm relatively new to ebikes, 1.5 years with a Trek Evo, so I'm open to correction.
DugT,

Your thoughts are mostly correct. The damage occurs during the brief moment the chain has partially dropped and begins to rotate against the frame before the chain fully drops and stops. Usually when this begins to happen you won’t immediately realize it. As you pedal the chain will wedge in between the chainring and frame and grind away a bit of paint and frame material. Carbon fiber is soft and can be easily marked up by the chain. The chain isn’t going to saw the bike in half, it’s going to mark up the bike and or remove a little bit of frame material.

Under full boost, a rider is typically pedaling very hard, i.e. max effort, usually say a punchy climb or flat out over flat terrain. The motor is putting out max power at max cadence. The damage from a dropped chain occurs quickly in full boost mode. On the other hand in Eco mode, the rider will likely be pedaling at a slower cadence, may hear the noise of the chain beginning to drop and stop pedaling. The damage is usually greater in full boost mode.

Regarding motor engagement. Every rider is different and has his/her motor settings set differently. As an example, I ride trails with lots of drops, rock gardens and ledgy rock step ups. Even though my derailleur clutch is in excellent condition, I still get chain slap when I slam into a series of rock step ups I’m trying to climb up. Momentum is your friend. I have my motor set so that the motor will briefly supply power even though I‘ve stopped pedaling. This allows me to take half strokes with my crank arms without needing to take a full crank. My bike still propels me forward and I can mostly avoid pedal striking on a rock or lip of a ledge I’m stepping up on. Even though you may not actually be pedaling, the motor is still cranking briefly and dropping a chain will cause some damage to the paint and or frame.

I rarely drop a chain, maybe once in the last 4,000 miles. But it has happened. When it’s happened, it’s because I screwed the pooch on a shift or took the wrong line and caused massive chain slap which derailed the chain. Shit happens…

Here’s the thing. Do I need a chain guide? Probably not, but it’s cheap insurance against being pissed off every time I look down and see the gouge in my frame where the paint has been removed by a dropped chain.

Here are a few pics from my afternoon ride, which featured a bit of chain slapping.


1717063887401.jpeg


1717064143655.jpeg
 

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