worst designed bike ever?

[Kell]

I think as mentioned above, it's more about where the pivot point is. The nearer to the BB it is, the less pronounced the effect is of standing on the pedals stopping the suspension working.

So, it was probably incorrect of me to suggest that all URTs are useless, but the Mantra in particular was bad.

Also, I'm not sure the writer is young... to have used those elastomer pedals in anger would suggest they were there at the time and are speaking from experience.

 

[Johnsqual]

I haven't got a clue what URT is to be honest... thought it was a type of milk,

https://www.youtube.com/watch?v=pBwwcU2c3u4

 

[mattr]

Re: Re:

pretty sure i read somewhere that the mantis was originally conceived to have rigid forks.

I think I must have read the same Gary Klein interview, marketing insisted on suspension forks. Think it was during or immediately after the trek buy out, so there were a lot of things going on!

speaking of pedal bob and rigidity issues, i vote for the trek 9000 suspension design. you can almost hear the engineer saying "that'll do"

You can't have much faith in them then! All I can hear is marketing screaming down the phone and the designer biting through their pencil...... and weeping gently.......

 

[mattr]

I keep looking at this thread and thinking back to my first FS frame, a 2002 Specialized Enduro.

Crap at going up, crap at going along and crap at going down. Put me off FS for ages.

 

[velomaniac]

Re:

IF you have actually ridden a Giant Revive and then think they are the worst design ever then fair do's, your entitled to an opinion based on real experience.

I HAVE had a go on a Giant Revive and I thought it was great for its intended purpose, urban commuting. It was very comfortable, it had very good low speed poise and balance, simple but effective gearing. You still had good all round visibility and didn't get a crick in you neck. I'd have owned one if I had any spare cash which unfortunately I did not.

 

[Thias]

The nearer to the BB it is, the less pronounced the effect is of standing on the pedals stopping the suspension working.

Think again
Imagine a long wooden plank and you are standing in the middle of it. Your weight makes it flex downward. Would it flex less, if you take stool and stand on it?
It would flex less if you move more to the front or to the back

Now take that thought and look at the Mantra:
The "plank" is the line between the 2 wheels axes. The pivot point is quite nearly above the middle. Nearer than it would be in the middle of the bb

(Yea, I know this quick drawing does not include all possible weight distributions and leverages. But you get the idea.)

The 4-Link Systems want to have their point of rotation as near as possible to the bb because it reduces the influence to the drivetrain. Witch is obviously not necessary for a URT-Bike.

But the URTs have the effect of the bb not being at a constant distance to the seat. I think this is why Klein did not move the pivot further to the front.

 

[catf]

no fair enough it does do the job its meant to, kind of a bike for ppl that dont want a bike. i had a go on one once and i didnt really get on with the small wheel, high centre of gravity combo. have the same problem with most folders. mainly though i just think they look silly.

they come up on ebay quite regularly if you are that keen, wont cost you much now

 

[Kell]

The nearer to the BB it is, the less pronounced the effect is of standing on the pedals stopping the suspension working.

Think again
Imagine a long wooden plank and you are standing in the middle of it. Your weight makes it flex downward. Would it flex less, if you take stool and stand on it?
It would flex less if you move more to the front or to the back

Now take that thought and look at the Mantra:
The "plank" is the line between the 2 wheels axes. The pivot point is quite nearly above the middle. Nearer than it would be in the middle of the bb

(Yea, I know this quick drawing does not include all possible weight distributions and leverages. But you get the idea.)

The 4-Link Systems want to have their point of rotation as near as possible to the bb because it reduces the influence to the drivetrain. Witch is obviously not necessary for a URT-Bike.

But the URTs have the effect of the bb not being at a constant distance to the seat. I think this is why Klein did not move the pivot further to the front.

I think you're missing the point. For the rear wheel to travel (for the sake of argument) 15cm then the bottom bracket has to travel (again for sake of argument) 5cm. It may not travel directly upwards, but the swing of that arm produces a lot of travel.

With a design where the pivot is located near to the bottom bracket the movement of the bottom bracket is greatly reduced to the region of mm.

In fairness, I've only ridden a Mantra once - and it was nowhere near a trail, but having lusted after the design for years, it was a huge disappoint to find out that it was form over function.

 

[Kell]

In fact, I think the ratio is even greater than that.

Using your image above, and drawing a circle from the pivot point to the rear drop out and a circle from the pivot point through the bb, you can see the relationship between how far the rear wheel would move and how far the bb would have to.

 

[Thias]

And you say, the suspension is working less the more the bb is traveling? (has to travel)