[Wa-Aw]

Question here:

The Yeti 303DH. I don't know about the new one and I've only parking lot tested the older one but reviews generally came to the consensus that it was exceptionally good at plowing at eating the rough stuff. Yet Yeti claim it has an almost vertical axle path.

Could our resident e-experts explain?

 

[Udi]

I don't know anything about it, but I did think it was hilarious that they claimed a vertical axle path on the latest iteration when the original benefit of the rail was supposed to be a rearward path.

I think it's safe to assume that Yeti don't have a clue, but they have pretty paintjobs and awesome WC videos.

 

[Steve M]

Question here:

The Yeti 303DH. I don't know about the new one and I've only parking lot tested the older one but reviews generally came to the consensus that it was exceptionally good at plowing at eating the rough stuff. Yet Yeti claim it has an almost vertical axle path.

Could our resident e-experts explain?

I've actually gotten a couple of runs in on a mate's one (same weight as me), they are pretty good smash and bash bikes. IMO the reason is less to do with the axle path and more to do with the slack angles, long wheelbase and lightly progressive suspension - but they still don't have that feeling that you just can't hang the rear wheel up like really high pivot bikes do. Due to the high rate of chain extension at the end of the travel though, pedalling through the rough isn't all that amazing, and if you lock the rear wheel under brakes, you sometimes notice significant pedal kickback over braking bumps.

Yeti's marketeering team seem to change their mind every 10 minutes as to what their axle path is and what it's doing though...

 

[no skid marks]

Due to the high rate of chain extension at the end of the travel though, pedalling through the rough isn't all that amazing, and if you lock the rear wheel under brakes, you sometimes notice significant pedal kickback over braking bumps.

So is its wheel path as if the pivot is behind the rear wheel at about axle height?
I'm confused on the locking the rear wheel comment. So does braking make it squat and added to the hits from the braking bumps, get it into it's rearward travel you mentioned towards the end of it's travel? Or am I missing something else? as I can't see the braking making a difference otherwise.

 

[Steve M]

So is its wheel path as if the pivot is behind the rear wheel at about axle height?
I'm confused on the locking the rear wheel comment. So does braking make it squat and added to the hits from the braking bumps, get it into it's rearward travel you mentioned towards the end of it's travel? Or am I missing something else? as I can't see the braking making a difference otherwise.

When the rear wheel is locked, the cassette can't be unloading chain (ie no freehub overrun), so when there is chain extension due to bumps compressing the suspension, it tugs on the pedals. With the Yeti it's more noticeable than any other bike I've ridden in recent years.

 

[no skid marks]

When the rear wheel is locked, the cassette can't be unloading chain (ie no freehub overrun), so when there is chain extension due to bumps compressing the suspension, it tugs on the pedals. With the Yeti it's more noticeable than any other bike I've ridden in recent years.

Yeah okay. Do you think bikes with chain growth would benefit from hubs with less clicks?

 

[Welshy.]

Yeah okay. Do you think bikes with chain growth would benefit from hubs with less clicks?

All DH bikes benefit from hubs with less clicks. More clicks = bad on DH bike. It interferes with all frames.

 

[fluider]

But that must be damaging the free-wheel mechanism, doesn't it?
So, you obviously have two options. Try to eliminate the chain-pull effect by having a few-clicks hub, but you'll have to replace the free-wheel twice a year . Or have some usual hub with more clicks that will last longer but will pull the chain more thus it'll effect your ride, and you'll have to replace the chain each season .

 

[Wa-Aw]

I've been running I9's on my bikes which I ride plenty of DH on for the past 4 years and have never noticed what you're talking about. All single pivots. ASX, Scythe and 575.

 

[fluider]

Those are "low-pivot" single-pivots. Main pivot being located at very similar point, somewhere at granny ring height. They have only short chain-extension period, maybe in 0-2/3 of travel, then it's shortening again. High pivots get longer throughout the full range of rear travel.

 

[Pslide]

All DH bikes benefit from hubs with less clicks. More clicks = bad on DH bike. It interferes with all frames.

Wut? News to me!

 

[dw]

The real question that you should be asking: "Why or when are either any good"?

Once you understand that, you should be a bit more clear on what the next question to ask is..

 

[no skid marks]

The real question that you should be asking: "Why or when are either any good"?

Once you understand that, you should be a bit more clear on what the next question to ask is..

Are you talking axle paths, or high or low click hubs?
Axle paths I prefer rearward for DH.
High click hubs I prefer for low chain growth bikes, but would imagine low click hubs are better for bikes with chain growth.
Good to see you chime in Yoda Don't be shy now, your thoughts are appreciated.

 

[eatmyshorts]

run chainless for a week then you many notice a difference...

 

[Wa-Aw]

If the ratchet mechanism of a hub can take the full force of what my leg can dish out, wouldn't that mean that in the case that a rearward axle bath + braking situation would simple just tug the pedals back? I doubt I could break my freehub if I jumped up and down on the pedals. And unless I were to start pedaling in a rock garden while I was braking, wouldn't there be more than enough time for the chain to retension?

The ASX and Scythe have pivots that I would say are mid-high, but I would think that having a very clickity hub would bring out any of this stuff. I will report when I get a full on DH bike!

 

[Steve M]

Yeah okay. Do you think bikes with chain growth would benefit from hubs with less clicks?

Not really. Since I've only ever noticed that effect on bikes with large chaingrowth at the end of their travel (eg the Yeti) and only under brakes where the cassette can't release chain tension, I think it's reasonable to suggest that the number of clicks in the freehub isn't going to play any major or consistent role in how much tugging you're getting at the pedals, because the ratchet is always going to be held hard against the stop anyway.

I think what DW was referring to was that people should look at the characteristics (positive and negative) of any given axle path in the various situations that a DH bike sees before asking which is "better". Every axle path you can imagine involves some form of compromise.

 

[toodles]

Which one does better skids?

 

[xy9ine]

^indeed! just pick something that looks cool & ride the crap out of it.

#itdoesntreallymatter

 

[toodles]

Blanket categorisation of a frames handling and suspension characteristics based on wheel path mapping is about as accurate as relying on the frame brand name IMO.

 

[kidwoo]

Seeing I just got lambasted by NSM for my "childish dribble" in the post above, I'll clarify for those people who are slightly retarded.

Really? I would have lambasted you for it not being dribbly enough.

Like this

Axle paths I prefer rearward for DH..

Well in terms of farting while you ride, the more rearward your wheel moves the less internal stress the rider/bike system experiences. As that wheel moves to escape the burrito product, it acts itself as a suspension system with a linear component in relation to the jet stream.

High click hubs I prefer for low chain growth bikes, but would imagine low click hubs are better for bikes with chain growth.

Suspension design, bar width, fast tires......all insignificant without first addressing the MASSIVE amount of friction induced on a suspension system by a coasting cassette and how many monumental barriers face a pawl with its high load spring sliding over a mm of aluminum in the fashion for which it was designed.

I mean I can't tell you how many times I've gone to buy a frame and then had to walk away after realizing the axle path and the sound of my coasting would be utterly incompatible.


Edit: aw man come on put that back up!

 

[toodles]

Edit: aw man come on put that back up!

Nah probably would just get another burst haha.

I liked the discussion on the performance benefits of more vs less hub clicks.

 

[Pslide]

Certainly if you could master this pedal jack phenomenon due to the more clicky hubs, by jumping on the pedals at the right time deep in the travel you get a turbo boost effect to launch you out of corners, kind of like nitrous. I imagine you'd have trouble keeping it between the tape.

 

[kidwoo]

Nah probably would just get another burst haha.

I liked the discussion on the performance benefits of more vs less hub clicks.

Just imagine the effect on suspension of derailleurs with larger pulley cogs!


Moar levrige, moar clix, moar awesome threadz!!!!

 

[no skid marks]

moar yaw-nin

 

[toodles]

Running a 38T front ring on a 11T rear cog comparing a 36 spline ratchet to a 72 position ratchet would equate to a difference of 1.44º of rotation at the pedals. And even then that is only if the freehub is at the furtherest from engaged, rather than the more likely scenario of being nearly fully engaged.

So I'd say the number of engagement points on the rear hub would make a negligble difference.

I'm embarrassed I even gave the matter any thought.

 

[no skid marks]

Running a 38T front ring on a 11T rear cog comparing a 36 spline ratchet to a 72 position ratchet would equate to a difference of 1.44º of rotation at the pedals. And even then that is only if the freehub is at the furtherest from engaged, rather than the more likely scenario of being nearly fully engaged.

So I'd say the number of engagement points on the rear hub would make a negligble difference.

I'm embarrassed I even gave the matter any thought.

So would a 120 clicker compared to a 30 clicker have about 6degree?
So it'd reduce pedal kickback by less than 5% using a 30click hub compared to a 120click hub?

 

[toodles]

So would a 120 clicker compared to a 30 clicker have about 6degree?
So it'd reduce pedal kickback by less than 5% using a 30click hub compared to a 120click hub?

It would only affect the point at which the pedal feedback was discernible. Once the engagement point was reached, the feedback is the same.

Actually I think I worked out my previous example wrong, the gear ratio wouldn't make any difference to the equation, only the degrees of engagement at the wheel make a difference.

A 30 point hub engages every 12º of rotation, a 120 point every 3º of rotation.

Truth is, I'm not sure which would be worse - pedal feedback that occurs instantly or slightly delayed. When you think about it, the 12º of rotation would give the sensation of nothing for longer followed by a more sudden and abrupt snap back through the pedals. The 3º would be felt sooner but would have a smoother feel to it through choppy sections.

 

[squiby]

What about places where you can gain momentum? If the rearward axle path is faster through the rough by absorbing the square edges and lengthening the chainstay/constant wheel base, do you loose the ability to accelerate to a greater potential on the backside as it shortens? Is a vertical axle path faster on the backside (pumps/berms etc after compression) when the suspension extends to keep the chainstay constant/lengthening the wheel base? Will this change acceleration in certain situations depending on the axle path?

 

[Sandwich]

could you accelerate by only pumping the bike, if you had high chain growth?

excluding would you want to and no because of freehub overrun...

 

[squiby]

could you accelerate by only pumping the bike, if you had high chain growth?

excluding would you want to and no because of freehub overrun...

I was wondering that also. If so could that be an advantage of a design like the Lapeirre Pendbox? Especially considering Blenkinsop's riding style. That boy pumps the backside of everything. Must be a NZ thing... hence the scared sheep.

At first I thought it would be possible to accelerate by pumping with high chain growth. Wouldn't you have to be in a high enough gear that the speed of the pump/chain-growth engaged the freehub to push against and propel forward? Would that speed and gear be compatible with normal gearing for pedaling at a similar speed, meaning practical in application? Seems improbable that all of these elements could come together and create a distinct advantage, but maybe, as I am likely missing half of the equation.

The questions about the axle path combined with wheel base change effecting acceleration during the extension of the suspension is different. If it did have an effect it would not rely on gearing and could be separated from pedal forces. Could it be a big advantage considering pumping can provide a lot of speed when pedaling can not? Does that make any sense?

 

[tacubaya]

I think the performance and quality of a bicycle rear suspension is proportional to the number of fluid resistance disks used

 

[MrPlow]

Haven't totally read through every post here but here is my thoughts:
High pivots absorb bumps better and setup right a single high pivot can pedal and brake great too.
But a standard chainline plus high pivot = GT RTS
So you run dual chain or idler etc. at extra cost for the increased performance. OR: You make a sick marketing gimic that saves you cost and satisfies a placebo performance gain

High pivots "feel" slower in bermed corners (not in flat / off camber IMO) because a low pivot decreases wheelbase as it compresses through the berm, you get lower and are travelling a greater distance / higher velocity through the corner. A high pivots wheelbase can be equal at all times (like mine is) and as there is no change in wheelbase your not experiencing this compression sensation through the corner.
Make sense???

 

[Pslide]

High pivots "feel" slower in bermed corners (not in flat / off camber IMO) because a low pivot decreases wheelbase as it compresses through the berm, you get lower and are travelling a greater distance / higher velocity through the corner. A high pivots wheelbase can be equal at all times (like mine is) and as there is no change in wheelbase your not experiencing this compression sensation through the corner.
Make sense???

Um, not sure I followed. Perhaps you were getting at this:

shorter wheelbase = increased turn rate

 

[MrPlow]

Um, not sure I followed. Perhaps you were getting at this:

shorter wheelbase = increased turn rate

Yeh, excuse my lazy blabbering post.