Author Topic: Grasshopper FX  (Read 1336 times)

Socks

  • FFCT rally, France 2012
Grasshopper FX
« on: July 26, 2017, 11:49:29 am »
I know it's a bit early for the C word, however I've started thinking about a possible christmas present.  Or at least an excuse to buy yet another bike.  The Grasshopper FX looks good for me - I already have a Kingcycle, which I'm finding a joy to ride.

If I go for the ergomesh seat and aero bars it looks like I will have a similar set up but with the advantage of suspension.  20" wheels also an advantage, as I have several conventional 20" wheel bikes (Moulton spaceframes and a Dahon)

Does anyone have any experience of riding this bike and feedback that could be shared?

And any suggestions on how to go about buying a frameset / suitable dealers?

thanks in advance.

Charlotte

  • Dissolute libertine
  • Here's to ol' D.H. Lawrence...
    • charlottebarnes.co.uk
Re: Grasshopper FX
« Reply #1 on: July 26, 2017, 01:17:10 pm »
I have a 20" wheeled Challenge recumbent (non-folding, USS) and it's lovely.  Lower and faster than a full-on 26"/20" machine like a Streetmachine, but quite capable for touring.  I@d definitely buy a Grasshopper if I was to be doing more solo touring.

I'd give Ben at Kinetics in Scotland a call.  Or maybe call into Bikefix if you're in London.
Commercial, Editorial and PR Photographer - www.charlottebarnes.co.uk

Kim

  • Timelord
Re: Grasshopper FX
« Reply #2 on: July 26, 2017, 02:21:44 pm »
Paging rower40.  Rower40 to the diagonally striped courtesy phone please...


In my experience[1] the Grasshopper is a slightly more nimble, slightly less good for carrying luggage version of the Streetmachine, with the advantages (more aero, same tyre front and back) and disadvantages (exotic gearing) inherent in a 20:20 format.  They're the sort of bikes that you can ride all day, which makes them awesome for touring, good into the wind, and wide tyres and suspension mean you can go bombing down hills with impunity.

HPVelotechnik know how to do suspension, and they know how to do reliable.  They don't know how to do lightweight.  If it's hilly you won't be setting any speed records, other than on the way down.  They don't really know how to do cheap, either.

As with ICE trikes and the like, it's a pack it up and fit in a car easily fold.  You won't be hopping on and off the tube with it, but it might get you past some overly restrictive bike rules on an intercity service.  (That said, I've yet to meet a train I couldn't fit my Streetmachine on, but it often helps that I've got the boom set to about -1cm of extension.)


[1] I've had a go on a couple, and ridden many thousands of miles on its older sibling the Streetmachine.
To ride the Windcheetah, first, you must embrace the cantilever...

Socks

  • FFCT rally, France 2012
Re: Grasshopper FX
« Reply #3 on: July 26, 2017, 02:28:03 pm »
Charlotte / Kim - that's useful, thanks.  I did look at either Bacchetta or Lighting carbon framesets for the lighter weight but they would be beyond my budget.


Re: Grasshopper FX
« Reply #4 on: July 27, 2017, 08:06:56 am »
I briefly had a non-FX hopper with the BodyLink seat. At the time I found it too reclined and didn't get on with the seat. I traded it in for an ICE trike with D-Tek (who may well still have it). I've progressed since then and have wondered about the FX model which apparently has a longer wheelbase and is more stable. Also I'm in need of a 'bent which fits in the car.

I think 20/20 fully suspended SWBs are quite possibly the most versatile and easiest to live with of 'bents. They can do light trails and are train and bike rack friendly etc. The 'hopper is a well made, durable and reliable bike. I don't think the "no-squat" suspension is as efficient as HPV pretend, and the 1" steerer is perhaps an oddity. To be honest, I'd say the design is showing its age. The AZUB Bufo is probably cheaper, and the AZUB Mini is probably a better ride but neither fold. The Hopper is a fine machine and has good dealer support but I'd go with an Azub if the folding wasn't important.

Socks

  • FFCT rally, France 2012
Re: Grasshopper FX
« Reply #5 on: July 27, 2017, 10:10:32 am »
thanks Paul - while the fold would be handy it isn't essential for me, I'll have a look at those Azub models as well.

Kim

  • Timelord
Re: Grasshopper FX
« Reply #6 on: July 27, 2017, 01:27:09 pm »
I don't think the "no-squat" suspension is as efficient as HPV pretend

I think it's a case of pretty much everyone does rear suspension recumbents that way now, so there's nothing special about HPVelotechnik's design (which was presumably innovative when they first came up with it).  It avoids the chain tension compressing the suspension (as it does on most rear-suspension mountain bikes, hence the desirability of shocks with a lock-out), but you still get some bounce from the mass of the rider's legs flying around.

Its also one of those things that depends on your pedalling style, and how you've tweaked the suspension.  But it's not in the same league as, say, the Brompton's pogo-stick effect.
To ride the Windcheetah, first, you must embrace the cantilever...

Re: Grasshopper FX
« Reply #7 on: July 27, 2017, 03:17:15 pm »
There are technical reasons why the HPV design is probably infererior to a suspension system which allows the chain line to better oscillate around the swing arm pivot centre, or arguably slightly below centre. I suspect the Nazca system is better, and the ICE trikes and Azub trikes systems too. Then there's the multi-linkage system of the Catrike Road.

Kim

  • Timelord
Re: Grasshopper FX
« Reply #8 on: July 27, 2017, 04:23:10 pm »
Surely the chain should be as close to (or as you say, below) the centre of the pivot point as possible?  What else am I missing?

The Streetmachine has the chain slightly (how lightly depends on selected gear and suspension loading, but a couple of centimetres) above the pivot, and IIRC the Grasshopper is similar.  As that 1" steerer shows, it's an old design by today's standards.  (I kind of get the impression that HPVelotechnik are tired of the Streetmachine, but it remains popular because it's such a good bike for fully-loaded touring.)

One thing I do like about the Streetmachine geometry is the extremely straight drive-side chainline.  Depending on boom extension and gearing, the idler practically disengages in some combinations (which is presumably why they don't use a toothed idler).  IIRC the idler does a bit more work on the Grasshopper, and certainly the Speedmachine.

The ICE suspension allows the chain to move freely beside the pivot, but with derailleur gears the exact position is quite sensitive to which gear is selected, it being worst in the lowest gear, where efficiency matters most.  It's spot-on in the middle of the cassette, which is about the same as you'd get with a gear hub.  Of course it's quite a firm elastomer suspension, and I've certainly never thought of the Sprint RS as bouncy while climbing on it (indeed, it could do with a bit more bounce at the front end, but that's another matter).

Nazca seem to have the right idea, with the drive-side idler enforcing a chainline right alongside the centre of the pivot.

*googles*

I hadn't seen that catrike system before (I've only met rigid ones in the flesh), but for these purposes isn't it only the first linkage (which seems to be alongside the chainline) that counts?  The rest are just levers acting on the shock unit to move it out of the way and probably do something to the travel.


ETA: Just thought to check, and there appears to be some variation between ICE models.  Their newer 26" Adventure FS design has a second drive-side idler keeping the chainline right through the middle of the pivot, Nazca-style.
To ride the Windcheetah, first, you must embrace the cantilever...

Re: Grasshopper FX
« Reply #9 on: July 28, 2017, 11:23:47 am »
On the HPV machines, the chain can't pass below the pivot bearing  - it's constrained to be above it at ALL times even when actively in use. Contrast this with single idler ICE rear suspension. Arguably the chain should pass slighlty below the pivot when the machine is statically loaded so that it can best react to the chain tension in response to pedalling force.