Gruber Assist: 100W in the seat tube

VSkudarnov

VSkudarnov

10 W
Joined
Nov 26, 2010
Messages
66
Location
Lausanne, CH
First, good news (for me:)...
On the local auction I managed to buy a Gruber-assist... for $1,000 :shock: ... including XC full suspension bike of my size (52cm) :shock: :shock: on TOP components :shock: :shock: :shock: in mint condition... :roll:

Some info on Gruber can be found here - http://www.gruberassist.com/english/product/technology/

First impressions:
- very smart Austrian design.
- very light - the bike is 12.5kg with motor. That's a large full suspension bike! Battery (30V 4.5ah) is +1 kilo
- smart controller interface - 1 button. Starts slowly, if it feels any conterforce - cuts off.

I will post more feedback and pics, when I ride it a little.

Future mods:
- Cycle Analyst, stand-alone model (already ordered) - want to see the watt consumption
- more battery!
- maybe slick tires for alsphalt trips.

Bad news: both batteries are almost dead. What are the best suggestions? I am a complete Lipo noob.

Gruber charge E300 for 4.5ah battery. No way I am going to pay that!!

I plan to go with HK Lipos. The voltage is 30V (8S) but 8S batteries are bulky and rare.
I plan to buy 6 (or better 8 ) x5000mah 4s ($30) and fit them into the saddle bag. 30V 20ah to be used at 100W should give me a plenty of range for mountain passes (Switzerland :roll: )
How do I charge so many batteries? I have a Gruber Lipo charger (33.6V, 1.5A) - can I use that?
Or do I need 3-4 Turnigy 8S chargers for balanced charging?

Many thanks, will post some feedback once I do more kms!
 
A true cheaters ebike...cool. Pics please. BTW, I was able to score 4s5ah Lipo in the hard cases for just over $.25/wh plus shipping. Series connect 2 and you have your 8s 30V.
 
That is quite cool. Heard about those - thanks for sharing. John's Lipo suggestion would be spot on IMO.
 
can't wait to hear your feedback. They're really in quite a different class than the low power ebikes that were all used to.
 
I will be interested to see the feedback on this drive.
Personally, i cannot see a 100W drive being worth carrying a battery pack for ! :shock:
.. but i am willing to learn otherwise.
!00W extra in a road race would be a game changer to a top level rider ( but cheating) , but doesnt take enough load off for me !
 
You would be surprised, 100w through the gears will easily carry you on flat ground with only slight pedaling at lower speeds, its just not enough for us power hungry folks!
 
Crap, that's a steal! I would of grabbed it at that price with a full susp frame. Nice buy.

Sounds closer to 600watts, looking forward to the field reports. You can't get more stealthier than this setup. I wonder if the controller current limits. Will you be using it for the streets or offroad? Is it really silent? Looking forward to hearing how efficient it is as well. How about pics!
 
BRIEF UPDATE:

* both batteries (LiIon, approx. 2 years old) are dead, do not hold charge. Gruber batteres are made from cyllindric cells by http://www.rkb-ag.de in Germany, really nice German quality (I have opened one of these). 4.5ah was 1.2kg - heavy and small.

* I have ordered 8 (!) 5ah 4S Zippy "bricks" from HK / Battery Medic / some cables/connectors. Can't wait to build a 20ah 8S battery that should fit into the large saddle bag (should be 3.6kg). Should give me 6 hours of countinious use in the mountains (the whole day). Or I will just take 4bricks (10ah) in a small bag for some easy trips. How much range in km/vertical meters? Will find out with Cycle Analyst :)
The charger is still Gruber 1.7A LiIon charger (but I am not in a hurry, should charge overnight).

Right now I am using it without batteries as a normal bike (12.5kg) - full suspension handles really well. But despite clip pedals, gear and locking front/rear susp (from the handlebar!) - I do not mind some assistance to tackle those steep mountain hills.

If it works - I will keep it. If not - will sell it to buy a BH Emotions Carbon road bike (with Panasonic drive) - these are also around 16kg with 10ah battery.
 
kfong said:
Sounds closer to 600watts, looking forward to the field reports. You can't get more stealthier than this setup. I wonder if the controller current limits. Will you be using it for the streets or offroad? Is it really silent? Looking forward to hearing how efficient it is as well. How about pics!
Click to expand...

Gruber does not give a lot of tech info (motor/gearhead type etc.). What I know is that optimal consumption shall be 3A, with peaks up to 6A. The controller probably limits to 6A, the wires are very thin. That's 90-180W applied directly to the crank - noticable assistance. Try to pedal in the gym at 100W and 200W - completely different levels.

I do not need an electric motorcycle to carry me - I like to pedal, can do 80-100kms on flats with my road bike. But I hate being breathless in the mountains at 10-15% hills. Let's see if 100W geared is enough for assist.
 
That thing is dope...some of my favorite youtube footage ever came from tour de france footage and obviously "doped bike"

http://www.youtube.com/watch?v=8Nd13ARuvVE&feature=related

You know you could just run a wire down the seattube and then have a more substantial battery mounted inside a small bag on the back of the seat....would make more sense unless you plan to enter some races.
 
Hey Miles...dont you think its good for the whole ebike community that an ebike may have won four prologues of the Tour de France.? Good for us i think...ebike winning multiple stages of tourdefrance and all.

Fabian Cancellara should go down in ebike history as one of the heroes...one of the founders of the ebike movement...right up there with physics, drbass, and Hal. Does anyone know if he is a member here? Maybe he got some upgraded battery dope from someone here on the downlow or something? I have nothing against doping in cycling by the way...use whatever edge you get its good for the sport. Faster bikes are funner to watch.

Cancellara's message...even for in shape top athletes can use a pedal assist once in a while. No reason for us to be snobbed by roadbikers anymore.......cancellara if you happen to be reading...please back me up here. Electric motors are good addition for any bike...even a roady.
 
VSkudarnov said:
* I have ordered 8 (!) 5ah 4S Zippy "bricks" from HK / Battery Medic / some cables/connectors. Can't wait to build a 20ah 8S battery that should fit into the large saddle bag (should be 3.6kg). Should give me 6 hours of countinious use in the mountains (the whole day). Or I will just take 4bricks (10ah) in a small bag for some easy trips. .
Click to expand...

I was really happy with the large topeak wedge aero. I managed to fit 4x 5s5000mah batteries in it.
 
adrian_sm said:
I was really happy with the large topeak wedge aero. I managed to fit 4x 5s5000mah batteries in it.
Click to expand...

Thanks mate, I was thing exactly about this bag :)))))))
The size of my 8x4S batteries are 10cm x 13cm x 14 cm. The bag is 11 x 21 x 14 (probably outside) - should fit at least six 4S bricks . Worst case I will just use two interchanging bags (one in the backpack).

Currently, this one came with the bike, it should take at least 4 bricks.
 
The bag really narrows down at the front, so my batteries only just fit with 10 cells across the width. I don't think I could have fitted 4x 6s packs. But you might be lucky with the 4s packs. I went to a few bike shops and tried every saddle bag they had with my batteries. Might be worth doing the same if you can.

Good luck.
 
extremegreenmachine said:
Hey Miles...dont you think its good for the whole ebike community that an ebike may have won four prologues of the Tour de France.? Good for us i think...ebike winning multiple stages of tourdefrance and all.

Fabian Cancellara should go down in ebike history as one of the heroes...one of the founders of the ebike movement...right up there with physics, drbass, and Hal. Does anyone know if he is a member here? Maybe he got some upgraded battery dope from someone here on the downlow or something? I have nothing against doping in cycling by the way...use whatever edge you get its good for the sport. Faster bikes are funner to watch.

Cancellara's message...even for in shape top athletes can use a pedal assist once in a while. No reason for us to be snobbed by roadbikers anymore.......cancellara if you happen to be reading...please back me up here. Electric motors are good addition for any bike...even a roady.
Click to expand...
You have assumed it was a "doped bike".
 
It's not very likely, IMO.

Interesting analysis, here:
http://cozybeehive.blogspot.com/2010/06/anatomy-of-cancellara-attack.html

http://cozybeehive.blogspot.com/2010/05/did-cancellara-use-illegal-motor-power.html
 
I actually like how the Assist-control is done by Gruber: 1 button is used to turn on/of and to set the cadence frequency you need. I hate "gaz handles" - no good on pedal assist.
 
Miles said:
It's not very likely, IMO.

Interesting analysis, here:
http://cozybeehive.blogspot.com/2010/06/anatomy-of-cancellara-attack.html

http://cozybeehive.blogspot.com/2010/05/did-cancellara-use-illegal-motor-power.html
Click to expand...

Great stuff Miles...you are the best linker ever...i dont know where you come up with so many great links....you must have a gigabase of bookmarks.
 
VSkudarnov said:
I actually like how the Assist-control is done by Gruber: 1 button is used to turn on/of and to set the cadence frequency you need. I hate "gaz handles" - no good on pedal assist.
Click to expand...

Makes sense for a low power system without freewheeling cranks.
They can get away with a lot at such low power without endangering the rider.
On my 300W elation when the freewheel for the cranks jammed it certainly tried to push my feet off the pedals. Probably not so hazardous at 100W

I imagine that it must result in quite a natural bike riding experience rather than a half motorbike that the throttle setups give.
Hows it behave at say starting to pedal away from an intersection? is it a smooth application of assist power of jerky?
 
Ricky_nz said:
Makes sense for a low power system without freewheeling cranks.
They can get away with a lot at such low power without endangering the rider.
On my 300W elation when the freewheel for the cranks jammed it certainly tried to push my feet off the pedals.
Click to expand...

Ooh another seized FW crank victim :p . Ricky, did the ratchet assembly fail from overload like mine?
 
boostjuice said:
Ricky_nz said:
Makes sense for a low power system without freewheeling cranks.
They can get away with a lot at such low power without endangering the rider.
On my 300W elation when the freewheel for the cranks jammed it certainly tried to push my feet off the pedals.
Click to expand...

Ooh another seized FW crank victim :p . Ricky, did the ratchet assembly fail from overload like mine?
Click to expand...
That was the original dicta. It grabbed several times (fighing hard) before failing the other way. It was on the original 300W setup and I was pedaling mildely up a slight rise at fairly low speed/full throttle when it went.
Its still out the shed but I haven't opened it up. I'm running a SBP one now and I think its side play is getting worse slowly.
 
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