Pros & Cons of High Pivot or Idler Equipped Bikes

Primoz
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5/23/2022 2:03pm
Ah, for some reason I though the Jedi is "older", so above 65deg of angle. Disregard that part of the comment then.
Edthorne
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5/24/2022 10:24am
AndehM wrote:
I recently got an O-Chain to put on my trail bike (GG Megatrail). That frame has a relatively high amount of pedal kick (~12 degrees IIRC)...
I recently got an O-Chain to put on my trail bike (GG Megatrail). That frame has a relatively high amount of pedal kick (~12 degrees IIRC), so the O-Chain has been really noticeable at smoothing out chatter. I've noticed that it calms down the rear so much that I brake less often and carry more speed.

I wasn't very interested in idler bikes before this since my local trails aren't very rocky, but my experience with the O-Chain leads me to think that a mid-height idler design could be really incredible on a trail bike (~140-150mm). Not so high as to cause the rear end to grow a ton and make the bike feel like a barge in berms and tight corners, but still decoupling the pedal kick. A good idler design would still be key for me though - I hate noisy bikes, and if the idler sounded like it was grinding all the time it'd drive me nuts.

The inevitable update to the Druid (the geometry is quite dated at this point) should be really interesting.
This is actually more or less what got me thinking about mid-pivot type bikes. It seemed like last season a lot of DH racers were using the O-Chain with their low pivot bikes.

On top of that, in the past when I've ridden high pivot bikes, the first thing that I noticed was the lack of feedback you get through your feet in chundery/pitter pattery sections. It seemed to me that this lets you carry more speed.

Then I started to wonder how much of the speed increase is from the axle actually moving rearwards, and how much of it was a subconscious confidence increase having to do with perceived stability you get from removing feedback through the pedals.
3
5/24/2022 10:36am Edited Date/Time 5/24/2022 10:39am
Having changed from a 2018 Scott Genius to a Deviate Highlander i'll chuck my 2 cents in, all my components stayed the same as i just swapped the frame, plus geometry is very similar (reach within 5mm, head angle, BB hieght and stack all very close, just chainstay length is longer) therefore variables outside of the suspension and idler should be minmised.

Idler drag - drag is so minimal i'd argue other factors like a clean drivetrain, aligned chainline and tyre pressures (or tyre choice) all make more differance yet people fixate on idler drag (most of us accept draggy tyres for grippy rubber no problems). I reckon the anti-squat created by the idler position improves the acceleration under power more than enough to negate any idler friction, only on a long consistant fireroad climb or road pedal where people have tested idler drag might it have a tiny impact but that's not how alot of climbing is done in reality, at least not in Scotland.

Jumping - I think others have summed this up well, hitting proper jumps is no problem as all, arguably more stable when compressing up a takeoff but it can be a little harder to pop of things mid trail, this could however be down to how extra supple the Deviate is with a coil shock making it track the ground better.

Rough stuff - definitely the positive that is advertised, point it at a rock garden and let off the brakes and it just gains and carries speed so well, the only complaint is the back eats it up so well you wonder if your forks need some improvement.

Cornering - The longer chainstays and expanding length with the travel is noticable when cornering, i found in tight corners it can take a bit more effort to bring the rear round or to slide the back end when steering with the rear but it somthing you get used to, however when it comes to fast more open corners and berms the stability generated especially when hitting a berm hard into the travel is really impressive.

Tried to be fair with pros and cons and not bias about my own bike (loved the low pivot genius too) but ultimately think theres alot more that goes into the overall ride of a bike than getting bogged down over idlers and pivot heights.
3
Edthorne
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5/24/2022 10:45am
Primoz wrote:
The Range and the Forbidden bikes have a pivot that is much higher than the Kavenz, therefore chainstay growth should be more substantial too.
I think the Range's RC does grow pretty substantially, but it's worth noting that it's axle path does go vertical deeper in the travel where Forbidden markets theirs as being completely rearward.

I guess that's not particularly relevant to the rear center growth on those bikes specifically, but is maybe worth noting now that more "high-horst-link" type bikes are starting to come out.
Primoz
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5/24/2022 11:20am Edited Date/Time 5/24/2022 11:30am
The Range is a 170 mm bike. The Dreadnought is a 158 mm, the Druid is... 135? If you have a similar height of the pivot and a similar chainstay/RC length, the more travel you have, the longer the arc will be (or the larger the angle of rotation). With a similar starting point, the longer travel variant will get closer to vertical or maybe even go past that point. That's only natural.

@Maglor idler losses are a fact of life/design. Can't get around them. You're "almost doubling" the chain losses as the highest losses are when you are articulating a taught chain. With a normal drivetrain that happens going off the cassette and going onto the chainring. With an idler you add going on and off the idler. And worse still, with idlers being fairly small (in the 20-ish T range), the amount of articulation going on and off is larger than on most of the cassette and on the front chainring, adding to the losses (roadies hate Sram's 10spd groups due to the supposed additional losses from chain articulation).

There is the articulation at the bottom of the chain loop (off the chainring, derailleur and onto the cassette), but the chain is not as taught and thus the losses are lower. Don't have any number related to this, so I'm only guessing the lower loop of the chain gives substantially lower losses than the top loop.

Dirty chain? See above. Whatever the effect on a standard bike is, it's "doubled" on an idler bike due to articulation of the chain.

The comment about tyre pressures and compounds is totally on point though, no argument there, that's for sure. So the question is how much drag does the idler (in numbers) add compared to grippy and low pressure tyres for example. Based on your experience not a lot.
Edthorne
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5/24/2022 1:59pm
Primoz wrote:
The Range is a 170 mm bike. The Dreadnought is a 158 mm, the Druid is... 135? If you have a similar height of the pivot...
The Range is a 170 mm bike. The Dreadnought is a 158 mm, the Druid is... 135? If you have a similar height of the pivot and a similar chainstay/RC length, the more travel you have, the longer the arc will be (or the larger the angle of rotation). With a similar starting point, the longer travel variant will get closer to vertical or maybe even go past that point. That's only natural.

@Maglor idler losses are a fact of life/design. Can't get around them. You're "almost doubling" the chain losses as the highest losses are when you are articulating a taught chain. With a normal drivetrain that happens going off the cassette and going onto the chainring. With an idler you add going on and off the idler. And worse still, with idlers being fairly small (in the 20-ish T range), the amount of articulation going on and off is larger than on most of the cassette and on the front chainring, adding to the losses (roadies hate Sram's 10spd groups due to the supposed additional losses from chain articulation).

There is the articulation at the bottom of the chain loop (off the chainring, derailleur and onto the cassette), but the chain is not as taught and thus the losses are lower. Don't have any number related to this, so I'm only guessing the lower loop of the chain gives substantially lower losses than the top loop.

Dirty chain? See above. Whatever the effect on a standard bike is, it's "doubled" on an idler bike due to articulation of the chain.

The comment about tyre pressures and compounds is totally on point though, no argument there, that's for sure. So the question is how much drag does the idler (in numbers) add compared to grippy and low pressure tyres for example. Based on your experience not a lot.
I was fairly sure I'd seen the axle path listed somewhere when the bike was first released that showed it turning vertical quite suddenly near the end of the travel, but I can't seem to find it anywhere now. I'll post it here if I end up finding it.
yzedf
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5/25/2022 7:02am
smelly wrote:
Someone explain to me how gearing works on an idler bike? How come the gear ratio doesn’t think you got like a 100t front ring? And...
Someone explain to me how gearing works on an idler bike? How come the gear ratio doesn’t think you got like a 100t front ring? And what role does idler size play in it anyway?
All the idler does is modify the path of the chain, it doesn’t multiply anything.
1
6/15/2022 3:28am
I just got a new Commencal Supreme last week so I can compare with my previous DH bike that I raced until 2 weeks ago (a Czech Author Ninja DHT) which has a low pivot. I am still getting used to the Commencal as I only rode it for a day and a half thus far.

The main differences I noticed:

Positives:
The Commencal is incredibly planted in banked turns, I feel so much confidence and I am noticeably faster on the same tracks. Going over roots and rocks the bike also feels much more stable and planted though this might also be in part due to the fact that it is a mullet setup compared to 27.5 for both wheels on the old bike. The new bike is considerably faster and I feel more confident and in control.

Negatives:
It really does not want to pop or manual. The old bike was much more friendly in that it demanded less commitment to ride fast and have fun so the Commencal is better for racing, the old bike is better suited just to have in the bikepark and hit some jumps.

I am not sure how much of these are due to the high pivot or to other factors (different geometry, mullet setup etc.).
1
Edthorne
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6/16/2022 10:02am
I just got a new Commencal Supreme last week so I can compare with my previous DH bike that I raced until 2 weeks ago (a...
I just got a new Commencal Supreme last week so I can compare with my previous DH bike that I raced until 2 weeks ago (a Czech Author Ninja DHT) which has a low pivot. I am still getting used to the Commencal as I only rode it for a day and a half thus far.

The main differences I noticed:

Positives:
The Commencal is incredibly planted in banked turns, I feel so much confidence and I am noticeably faster on the same tracks. Going over roots and rocks the bike also feels much more stable and planted though this might also be in part due to the fact that it is a mullet setup compared to 27.5 for both wheels on the old bike. The new bike is considerably faster and I feel more confident and in control.

Negatives:
It really does not want to pop or manual. The old bike was much more friendly in that it demanded less commitment to ride fast and have fun so the Commencal is better for racing, the old bike is better suited just to have in the bikepark and hit some jumps.

I am not sure how much of these are due to the high pivot or to other factors (different geometry, mullet setup etc.).
That all makes sense to me, though I would also say that geometry might be half the difference there. The V4 Supreme is very slack, and pretty long by DH bike standards in terms of reach etc.
Kusa
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6/16/2022 12:10pm
I was on one of the first idler equipped bikes available (Appalache Real) and beside being it very smooth ride, the big cons was that the bike did not want to pop. Getting it into the air was simply a big pain. Luckily it snapped so many times that I get rid of it soon Smile

A friend of mine who bought Norco Aurum had the similar comments on the bike behavior and the hard time getting it into air. Which makes sense in a way how these bikes work.
lewzz10
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6/17/2022 12:37am
I ride a Deviate Highlander and find it actually jumps much better than my previous (non high pivot) bike. Manuals/wheelies are much harder though. I think maybe it carries so much more speed into the jumps that it counteracts the lack of 'pop'.
1
Edthorne
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6/17/2022 2:03pm
Kusa wrote:
I was on one of the first idler equipped bikes available (Appalache Real) and beside being it very smooth ride, the big cons was that the...
I was on one of the first idler equipped bikes available (Appalache Real) and beside being it very smooth ride, the big cons was that the bike did not want to pop. Getting it into the air was simply a big pain. Luckily it snapped so many times that I get rid of it soon Smile

A friend of mine who bought Norco Aurum had the similar comments on the bike behavior and the hard time getting it into air. Which makes sense in a way how these bikes work.
I had assumed that lack of pop would be an issue with my Range before I rode it, and I wouldn't say it has a poppy manner out on the trail at all, but the actual act of bunny hopping the bike is no more issue for me than any other bike I've had.
6/22/2022 1:29am
I Try to add my 5 cent to the discussion here.

I'm riding a Norco Range since November Last year (coming from a Yeti sb150).

The Range is a very interesting bike but presents many compromises.

The rear end is very very planted, offering undisputed traction and grip. The advantage in braking, off camber traction, stability, and comfort is very noticeable and it offers really something more than a traditional bike.

On the other side I found the bike to feel very "slow"*, it's difficult to generate speed through pumping or using natural features, the bike is very good at absorbing and disperse the ground inputs and the rider inputs, so it can be tiring to muscle the bike to maintain and generate speed. The bike really excel where it's steep, fast and rough.

*The bike does feel slow but as some testing (carried out with free lap) demonstrate that if the segment is sufficiently steep the bike is usually on par or faster than other bikes.

I recently got an Enduro by Specialized and we were able to carry out some back to back laps with the two bikes (both 170mm "enduro race bike") and the difference in approach it's very simple to detect.

Riding the Enduro it's generally easier to generate speed but offer way more feedback to the rider. The bike after the rear end is compressed wants to move forward and propels you to the next turn/obstacle ecc.
The Range erase the terrain and offer great stability but you have to relay more on your sheer force (by muscling the bike or pedalling) or gravity to gain speed.

Have a nice day.
7
Edthorne
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6/22/2022 10:54am
I Try to add my 5 cent to the discussion here. I'm riding a Norco Range since November Last year (coming from a Yeti sb150). The...
I Try to add my 5 cent to the discussion here.

I'm riding a Norco Range since November Last year (coming from a Yeti sb150).

The Range is a very interesting bike but presents many compromises.

The rear end is very very planted, offering undisputed traction and grip. The advantage in braking, off camber traction, stability, and comfort is very noticeable and it offers really something more than a traditional bike.

On the other side I found the bike to feel very "slow"*, it's difficult to generate speed through pumping or using natural features, the bike is very good at absorbing and disperse the ground inputs and the rider inputs, so it can be tiring to muscle the bike to maintain and generate speed. The bike really excel where it's steep, fast and rough.

*The bike does feel slow but as some testing (carried out with free lap) demonstrate that if the segment is sufficiently steep the bike is usually on par or faster than other bikes.

I recently got an Enduro by Specialized and we were able to carry out some back to back laps with the two bikes (both 170mm "enduro race bike") and the difference in approach it's very simple to detect.

Riding the Enduro it's generally easier to generate speed but offer way more feedback to the rider. The bike after the rear end is compressed wants to move forward and propels you to the next turn/obstacle ecc.
The Range erase the terrain and offer great stability but you have to relay more on your sheer force (by muscling the bike or pedalling) or gravity to gain speed.

Have a nice day.
This is sort of unrelated to the high pivot conversation, but I would tend to say that the Range is actually not a very good enduro bike. It's a great bike for what I do (pedaling to DH trails & lift accessed riding), but it's not particularly nimble, and doesn't have the best pedaling efficiency.

I don't think that'll be an issue for most people, since that seems to be what most people are using 170mm bikes for, but it would be a bit confusing for someone who wants to race a bunch of enduro's. Particularly ones like the Wildside enduro's around Quebec, which almost always have a pedally slog of a stage hidden in there.
6/23/2022 6:25am
Don't know if has been discussed yet but, what do you think about installing a freecoaster like the freenightbmx, will it help with pedal kickback? Actually it could help with any bike isolating the pedaling forces I'm I right?
Edthorne
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6/23/2022 7:10am
Don't know if has been discussed yet but, what do you think about installing a freecoaster like the freenightbmx, will it help with pedal kickback? Actually...
Don't know if has been discussed yet but, what do you think about installing a freecoaster like the freenightbmx, will it help with pedal kickback? Actually it could help with any bike isolating the pedaling forces I'm I right?
I think a freecoaster would help to alleviate pedal kickback the same way things like the WRP center hub would.

https://www.williamsracingproducts.com/shop/p/centrehub-pre-order

Another option would be the O-Chain, which seems pretty popular on the WC circuit for riders with conventional suspension layouts.

The only thing is, I'm fairly sure all of these options would effectively (if not literally) reduce your hub engagement.
Primoz
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6/23/2022 7:42am
Effectively, as the freehub engagement stays the same, but you add slack at another location along the drivetrain, so the apparent (effective, not literal) engagement is bigger Wink

The whole idea about running an idler is to reduce pedal kickback, as it would be immense on a high pivot bike. You could, technically, do it without an idler, but that should be really noticeable. Another factor is the antisquat, as it would be way over 100 % without an idler - a high pivot adds a lot of geometric antisquat, then there is the chain component which can actually be negative in some cases, depending on the location of the idler.

Having an idler gives you total freedom on designing your axle path or the rearwardness of it (through pivot height) and tune the antisquat to your heart's content.
2
6/23/2022 8:56am
I had been riding a Forbidden Druid for the past two years, and recently switched to a 120mm travel Horst link suspension bike. Here are a few things I’ve noticed on my first few rides away from the high pivot and idler bike:
- square edge bumps and fast rough sections of trail. The high pivot feels like it float over, like a hovercraft, were the Horst link bike feels
Like it skitters across.
- poppy. I felt like the high pivot felt good off jumps and side hits, gaps and hops. The Horst link bike is much easier to get off the ground and feels more snappy.
- traction. The high pivot feels more stable and planted most of the time.
- noise. I didn’t pay attention to the noise of the idler much, but now not having it and riding with people on high pivots the idler does have some noise.

Both designs have good and bad traits. In the end modern bikes are amazing, and get us out into the woods, on amazing trails, so get whatever you want to try and be happy out there.
2
grambo
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6/28/2022 11:56am
I Try to add my 5 cent to the discussion here. I'm riding a Norco Range since November Last year (coming from a Yeti sb150). The...
I Try to add my 5 cent to the discussion here.

I'm riding a Norco Range since November Last year (coming from a Yeti sb150).

The Range is a very interesting bike but presents many compromises.

The rear end is very very planted, offering undisputed traction and grip. The advantage in braking, off camber traction, stability, and comfort is very noticeable and it offers really something more than a traditional bike.

On the other side I found the bike to feel very "slow"*, it's difficult to generate speed through pumping or using natural features, the bike is very good at absorbing and disperse the ground inputs and the rider inputs, so it can be tiring to muscle the bike to maintain and generate speed. The bike really excel where it's steep, fast and rough.

*The bike does feel slow but as some testing (carried out with free lap) demonstrate that if the segment is sufficiently steep the bike is usually on par or faster than other bikes.

I recently got an Enduro by Specialized and we were able to carry out some back to back laps with the two bikes (both 170mm "enduro race bike") and the difference in approach it's very simple to detect.

Riding the Enduro it's generally easier to generate speed but offer way more feedback to the rider. The bike after the rear end is compressed wants to move forward and propels you to the next turn/obstacle ecc.
The Range erase the terrain and offer great stability but you have to relay more on your sheer force (by muscling the bike or pedalling) or gravity to gain speed.

Have a nice day.
Edthorne wrote:
This is sort of unrelated to the high pivot conversation, but I would tend to say that the Range is actually not a very good enduro...
This is sort of unrelated to the high pivot conversation, but I would tend to say that the Range is actually not a very good enduro bike. It's a great bike for what I do (pedaling to DH trails & lift accessed riding), but it's not particularly nimble, and doesn't have the best pedaling efficiency.

I don't think that'll be an issue for most people, since that seems to be what most people are using 170mm bikes for, but it would be a bit confusing for someone who wants to race a bunch of enduro's. Particularly ones like the Wildside enduro's around Quebec, which almost always have a pedally slog of a stage hidden in there.
I know a few people riding Ranges on the Shore and they all have said the same thing. Amazing bike at steep rough gnarly terrain (the stuff they are using it for) but not something you'd want to be out pedaling all day or racing on tighter enduro tracks. They also like the bike for the big jump trails in Whistler. I really want to ride one and see how it feels.
2
Mtbbeta
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7/8/2024 9:34am

I have been watching Vital Raw Slo-Mo's and have started to see more and more High Pivot bikes with an O-Chain. Amaury was running one at Les Gets which surprised me. I have a V4.2 and have never thought that the bike would benefit from an O-Chain. I believe the V5 has more of Mid High Pivot but am wondering if anyone is running an O-Chain on their V4.5 Supreme? My last DH was a V10 and I hated the pedal kickback and brake jacking that bike has. An O-Chain there seems perfect. I have never felt the Supreme to have either if these issues. 

I did put an O-Chain on my Meta SX and think its a pretty significant improvement. The SX gets a fair amount of pedal kickback and a little bit of brake jacking. 

7/8/2024 10:47am
Mtbbeta wrote:
I have been watching Vital Raw Slo-Mo's and have started to see more and more High Pivot bikes with an O-Chain. Amaury was running one at...

I have been watching Vital Raw Slo-Mo's and have started to see more and more High Pivot bikes with an O-Chain. Amaury was running one at Les Gets which surprised me. I have a V4.2 and have never thought that the bike would benefit from an O-Chain. I believe the V5 has more of Mid High Pivot but am wondering if anyone is running an O-Chain on their V4.5 Supreme? My last DH was a V10 and I hated the pedal kickback and brake jacking that bike has. An O-Chain there seems perfect. I have never felt the Supreme to have either if these issues. 

I did put an O-Chain on my Meta SX and think its a pretty significant improvement. The SX gets a fair amount of pedal kickback and a little bit of brake jacking. 

I'm firmly of the belief that the main benefits of an o-chain are the result of damping inertial chain forces as opposed to pivot location dependent induced pedal kickback.

1

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