Well, a lot has happened since I've embarked on this GNG journey over a year ago.
I've gotten a few friends to join the GNG club:
Two other GNG 1.1's w/ Cyclone ISIS Bottom Bracket/Cranksets are yet to be put together.
Cyclone has changed their ISIS bottom brackets over the past year. Initially, they had a 140mm spindle in a 73mm housing which I'm using on my bike as well as the Kona Howler pictured above.
The newer 148mm w/ 73mm shell is much beefier and smoother. I think it has an extra row of the sealed bearings.
Anyhow, onto more bike related updates. When I had purchased the bike, I was told it was a medium, yet it had a 450lbs rear spring. I thought it was kind of weird since the Kona Stinky of this year was supposed to have a 500lbs rear spring for the medium size. Eventually, I measured the top tube, and it turns out that it is a small. It's not all that big of a deal, but me + pack w/ battery in it = 220lbs. That's way too much weight for that 450lbs spring, and I could bottom it out on the progressive frame mount setting by just pumping the suspension for a bunny hop. :?
This 600lbs spring was long over due. I wish I had changed it out much earlier, but I was just afraid to tinker with it. I'm definitely more confident bombing down stairs and doing bigger jumps/drops with this spring.
What my bike needed more than a heavier rear spring was a fork oil change. Ever since I purchased my bike, I knew the fork was overdue for some fresh oil. It took me a year of owning it and doing all sorts of other bike related maintenance to finally rebuild it.
It was good thing I decided to rebuild the fork myself. Aside from the oil desperately needing changing, I found out that one of the previous owners of the bike had assembled the fork incorrectly. The area where the lower crown was clamped was on the thinner upper portion of the sanction and wasn't really clamping onto anything. My upper crown was taking all the force. Also, the headtube angle was more slack.
The bike really does feel more like a small now, but the fork feels amazing with this 10wt Motul oil. Another one of those things I wish I had done sooner as the bike just feels so much better over any terrain or anything I throw at it.
Now that all the bike stuff was taken care of, I thought I'd send GNG Jon an email regarding those sealed Jackshafts on the GNG 1.1 for a friend. One thing led to another then led to this:
All GNG Jon had sent me was the sealed jackshaft. That alone wasn't enough to complete my install, but I did make note that I needed the proprietary lock rings. I asked to borrow one of my friend's uninstalled GNG 1.1 motors, so I could use their sealed jackshaft lock rings and shaft keys while waiting for mine to come. Due to Lunar New Year, Jon isn't able to send out the lock rings just yet.
After laboring away with only hand tools wishing I had an air compressor, I noticed a lot of differences. One was that the shaft keys are different from the GNG 1.0 and 1.1. Another difference I noticed is the jackshaft housing was also different:
I was afraid the lock rings wouldn't work, but they did.
I ended up not using the newer Cyclone ISIS Bottom Bracket. The shaft on my 140mm/73mm ISIS bottom bracket is easier to adjust the spindle position for the chainline from motor to chainring. It's also narrower, so I figure that'd make up for the lack of beefiness.
Installation of the adjustable sheets was pretty straight forward. The difficult part was taking the old stuff off and doing the final adjustments to the tension. :|
It's really important to note that the primary pulley freewheel does have some play as it is a freewheel. Putting too much tension on the belt will cause it not to rotate true, and the belt will want to walk off the large pulley.
Anyhow, after reducing the tension and fiddling with the alignment I was able to get everything just right.
If LightningRods does end up making a freewheel delete, I may go back to using a freewheel on the secondary side. The play in freewheels cause them to have tight spots, so finding the right amount of tension was more difficult than proper alignment. It's not a big deal though since everything is working as designed. :wink:
For the most part, I'm done with this project.
P.S.
There are a handful of things that still bother me about my build, but it's all battery related as in my previous post.
In the end, I think the GNG still reigns king of the cheap mid-drive kits for heavy off road use. What I mean by heavy is rough terrain and bigger jumps. Unfortunately, there are two weak links from the factory. It's debatable which one is the weaker of the two since it's more subjective to the rider. Plenty of people don't have problems with the belt drive or with the weak bottom bracket spindle. I'm one of those people who had only gone through two belts on my GNG 1.0 set up with my first belt surviving over 700 miles of riding. On the other hand, I was able to bend my bottom bracket spindle on my second real trail ride. For what ever type of rider you are, there are great options out there now that have addressed these weaknesses:
There are three places, I know of, that have ISIS bottom bracket / chainring set ups available that work for this system from the get go:
Cyclone Taiwan (Paco)
http://www.cyclone-tw.com/order-chainwheel.htm
Sick Bike Parts
http://www.sickbikeparts.com/catalo...ucts_id=190&osCsid=t9n1ophk7uqf2nq81pg8rhu9g2
http://www.sickbikeparts.com/catalo...ucts_id=192&osCsid=t9n1ophk7uqf2nq81pg8rhu9g2
LightningRods
http://www.backusstudio.com/gng/
http://endless-sphere.com/forums/memberlist.php?mode=viewprofile&u=30024
The chainring set ups are a bit more complicated. I'm not sure if anyone has used an ISIS BB/Crank arms with the stock GNG chainring set up yet. I don't think it would be that difficult so long as you pop out that support bearing. There is a lot of debate in other threads regarding the necessity of the support bearing, but I'm not going to get into too much detail. I've put on over 1000 miles on my White Industries ENO freewheel without a support bearing, and it's held up even though it has only one row of bearings. The ACS style 10 hole flanged freewheel is probably the better option for most users. All the vendors/developers I've mentioned above carry them. It also helps that it's much cheaper than the White Industries freewheel.
As for the belt issue... personally, I don't think there is a problem with GNG's belt design aside from people saying it robs power. Belt longevity is really determined by how abrupt power is put through the system. Regardless, LightningRods has developed a wider belt option that replaces that dinky 15mm pulley with a beefy 25mm one. Of course, it's designed around his adjustable sheets.
There's also GNG's own primary chain drive as an alternative to the belt. This is probably a great option for those who don't care a whole bunch about noise. There are fixes for that, but I'm not going to go there since there is a thread dedicated to that particular kit.
Another future option will be LightningRods' complete kits which will use the 25mm belt from the get go as well as the beefier 148mm ISIS BB/Cranks.
Well, that's pretty much it.
If you have any questions, feel free to PM me.
