2009 Mongoose Nugget - Proto shots

the new dh bike is nicely refined [HTML_REMOVED] looks light. i'd like to give one a try. i was initially skeptical, but i've heard several solid reviews (of the current chassis). as a (really) oldschool bmx'er, i'd kinda like to see mongoose turn things around. from what i see here, looks like they're on the right track.

yeah I was going to post that from littermag.. ps. littermag is awesome.

How does the suspension unload?

We're not talking about a rear wheel trajectory that sends the wheel straight back..it still travels in an upwards motion, its just that it is a "sweep" back. And it most certainly compresses in more of an upwards fashion rather than backwards.

So it's axle path is very similar to a high single pivot.

And to your point on the BB moving forwards and backwards under compression/decompression, you bring up a good point, if the bike was in a bike stand, yes that would be the case.
However you forgot to take into account that when your frame compresses under load while riding, its not just your rear triangle moving up, the front triangle also "squats" down and it's a combination of those two things, therefore relatively minimizing the movement of the BB.

Minimizing the mnovement of the BB relative to what ?

The idea is to isolate the BB from suspension compression, and as you can see from the Flash, the rear triangle and front triangle work around the BB piece. That animation is not taking into account the compression of the fork, so it looks like the frame gets really raked out, which exaggerates the BB movement. But if you use your imagination to picture the front triangle dropping down with the rear suspension in a similar fashion, I'm sure you'll be able to see what I'm trying to explain.

If you could see the fork compressing evenly with the rear suspension in the flash aninmation you would also be able to see the BB moving in a predominantly rearward arc relative to the bars ! The sprung mass (the rider) is connected to the rear axle via a short link that is at maximum extension -relative to the BB. The the effect of the link on suspension performance is minimal (I think it's main function is to allow for the location change between the BB section's pivot and the rear triangles upper pivot when the suspension is activated) so really it's a URT :agree:

So it's axle path is very similar to a high single pivot.

Minimizing the mnovement of the BB relative to what ?

If you could see the fork compressing evenly with the rear suspension in the flash aninmation you would also be able to see the BB moving in a predominantly rearward arc relative to the bars ! The sprung mass (the rider) is connected to the rear axle via a short link that is at maximum extension -relative to the BB. The the effect of the link on suspension performance is minimal (I think it's main function is to allow for the location change between the BB section's pivot and the rear triangles upper pivot when the suspension is activated) so really it's a URT :agree:

1. Axel Path of a Single Pivot Bike generally would come up vertically and then forward towards the bike as you complete your compression, this design would have nothing pushing the bottom of the swing arm out backwards. Trust me..if it was a single pivot, I'd tell you all about it.

If you look at the Flash Animation if you can see the dark grey line separating the rear wheel at the center (pre-compression) - on a URT design the wheel would begin moving vertically then curve to the right. You can see our axle path fades off to the left getting almost vertical near the top.

2. Minimizing the movement of the BB relative to the rear axle to minimizing chain growth, while having the axle path that we desire, which is to move back and up not forward and up.

3. The fork compression has relatively little effect on the bike - the flash demo would be a correct representation of the bike IF the front triangle pivoted at the head tube. In reality the front ends of bikes would pivot at the front wheel, thus the "rake" wouldnt be as severe. Also with the given head angle of the bike not only this bike but most bikes, compressing 7"-8" is really irrelevant.

I also didn't say that the BB doesn't move at all, infact it moves, but not to the extent that you have stated, it moves about 1" (+/-) depending on the frame..trust me, i have a few freedrive's sitting beside me here that I'm looking at. And for the record, you're not going to even notice your feet moving, its not like your feet are getting ripped out from under you! and plus your feet adjust all the time when you ride with out you even noticing.

If you're implying that the Freedom Link is in there for absolutely no cause …sorry to tell ya, but it serves a few purposes. If you study our bikes carefully, each bike has a different angle on the freedom link and the steeper the angle and the length of the freedom link - determines how "snappy" it is off the line and quicker the acceleration is. Thats obviously not the only reason. It obviously allows our axle to follow the axle path that we've designed it for and allows our bikes to have nearly no chain growth with a rearward axle path.

In conclusion…if Mongoose wanted to make a URT/Single Pivot…they would! and it's much easier to and if this bike was a Single Pivot bike I would have no problem telling you so.

But, I really don't know what else to tell you, I've laid out all the facts here and you keep telling me it's a URT/Single Pivot. It really isnt.

I have no problems with you having your own opinions about the design, all I'm doing is just laying out the facts so people can have better insight on the design as well as the purpose for the design and not quickly jump to conclusions.

that is seczy

scarface how can you say that bike is not a single pivot?

"Single pivot" are not dirty words, and yes that Mongoose is a single pivot. Just a different application.

Hokay. The wheel path is similar to the Balfa/Trek Session 10 or other high single pivot bikes. So, the wheel travels up and back as it goes through the travel. Where it differs from those bikes is the way that the BB is linked to the rear triangle. So there can be some chain tension anti-bobbing action tuned into it. It also means they don't have to use stupid idler pulleys to reduce the amount of chain-length growth and thus pedal feedback.

It is NOT a URT as the BB is not solidly fixed to the rear triangle.

Dave

Basically, the rear axle, sweeps up in a rearward and upward motion. This allows the wheel to clear free from anything activating the suspension design in a natural way. This is key to the FreeDrive design, and this will also help you maintain your forward momentum.

Compared to a 4-bar, FSR, Horst or other linkages that send your wheel in a nearly vertical/vertical wheel path, those designs do not react as well to square edge bumps and have a tendency to hinder your forward momentum.

This rearward wheel path is beneficial as your front wheel holds a similar upward/rearward wheel path and as your suspension compresses, FreeDrive allows you to keep a more consistant wheel base, compared to the other designs, giving you a more stable platform.

The design also minimalizes Chain Growth, as the isolated BB swings in a rearward path; this contributes to a consistent feeling suspension system, no matter what gear you're in. As for the leverage ratio, we're able to maintain a consistent leverage ratio throughout the beginning to ending stroke of the shock. This makes it an ideal platform for using air shocks, giving it a predictable, bottom-less feel. As the air ramps up, the leverage ratio remains the same.

You will see the Black linkage connecting the Swing arm to the back of the BB, this is called the "freedom link". The length and angle of the freedomlink determines how "snappy" or quickly the bike accelerates. Short and angled down = quick acceleration. Flat and longer freedom link = more supple.

Under pedalling pressure, there is a force called the "anti-squat" and it is the force on a chain that restrains the shock from compresssing under initial pedalling pressure. Obviously this does not "lock out" your rear suspension, but when you get started on your bike and you take those first few cranks or when you're sprinting, which places the most stress on your chain. This is when the anti-squat force will be most helpful in firming up your suspension enough to transfer as much of your pedalling force straight to your wheels.

thats exactly what a FSR design does… I'd be skeptical if that design does it better in all aspects.

1. Axel Path of a Single Pivot Bike generally would come up vertically and then forward towards the bike as you complete your compression, this design would have nothing pushing the bottom of the swing arm out backwards. Trust me..if it was a single pivot, I'd tell you all about it.

On a low single pivot that would be the case. However on an Orange or other (relatively) high single pivot where the main pivot is higher than the rear axle the initial part of the travel is slightly rearward. Most VPP's and DW's also have an initial rearward axle path, without coupling the rider to the rear axle.

2. Minimizing the movement of the BB relative to the rear axle to minimizing chain growth, while having the axle path that we desire, which is to move back and up not forward and up.

This I'll agree the design does reduce the effect of chain growth but the degree of it's effectiveness will depend on the length and angle of the 'Freedom Link'.

3. The fork compression has relatively little effect on the bike - the flash demo would be a correct representation of the bike IF the front triangle pivoted at the head tube. In reality the front ends of bikes would pivot at the front wheel, thus the "rake" wouldnt be as severe. Also with the given head angle of the bike not only this bike but most bikes, compressing 7"-8" is really irrelevant.

I also didn't say that the BB doesn't move at all, infact it moves, but not to the extent that you have stated, it moves about 1" (+/-) depending on the frame..trust me, i have a few freedrive's sitting beside me here that I'm looking at. And for the record, you're not going to even notice your feet moving, its not like your feet are getting ripped out from under you! and plus your feet adjust all the time when you ride with out you even noticing.

If you're implying that the Freedom Link is in there for absolutely no cause …sorry to tell ya, but it serves a few purposes. If you study our bikes carefully, each bike has a different angle on the freedom link and the steeper the angle and the length of the freedom link - determines how "snappy" it is off the line and quicker the acceleration is. Thats obviously not the only reason. It obviously allows our axle to follow the axle path that we've designed it for and allows our bikes to have nearly no chain growth with a rearward axle path.

In conclusion…if Mongoose wanted to make a URT/Single Pivot…they would! and it's much easier to and if this bike was a Single Pivot bike I would have no problem telling you so.

But, I really don't know what else to tell you, I've laid out all the facts here and you keep telling me it's a URT/Single Pivot. It really isnt.

I have no problems with you having your own opinions about the design, all I'm doing is just laying out the facts so people can have better insight on the design as well as the purpose for the design and not quickly jump to conclusions.

OK, I think the design has a fundamental flaw. In simple terms the riders weight is isolated from the main triangle and is coupled to the rear axle. Therefore impacts on the rear wheel (that have less effect on the front) will cause the main front triangle to pivot around the BB section and rear triangle. The only real independently suspended component in the design is the front triangle, which unless your seated, has no weight on it ! In every other suspended mechanical system that I can think of the main mass is independent of the unsprung suspension components.

the bike looks sweet and the linkage looks pro-quality, not like it was made in buddy's machine shop after work.

20 years into the future bikes will no longer have wheels. we'll ride hover bikes instead and have the ultimate in plush travel.

what's wrong with having to work a little for your ride? imo if it's too easy you're just wasting your time.

It is NOT a URT as the BB is not solidly fixed to the rear triangle.

Dave

By definition I agree. However the lower 'Freedom' link's range of motion is quite limited (it has to be to avoid excess chain growth) in linear extension so the design will IMO work in a similar way to a URT.

By definition I agree. However the lower 'Freedom' link's range of motion is quite limited (it has to be to avoid excess chain growth) in linear extension so the design will IMO work in a similar way to a URT.

What? "the range of motion" is that of the travel, and is therefore not limited at all….

It may not be 100% independent but it certainly is NOT the same in principle.

What? "the range of motion" is that of the travel, and is therefore not limited at all….

I don't get ya ?

well i couldn't care less how the suspension works or how the bike rides…

it just looks damn ugly….and wrong