Giant DH Team, Cromotor, 18fet Lyen, 111v Lipo

[GCinDC]

put some air in that tire! what psi it at, anyway?

what shock do you have? my swinger spv stock shock sagged a lot and, well i didn't like it. it has a bunch of adjustmentstho.

i decided to get a new used one, a fox dhx 4.0 w/ a 500lb coil and i'm very happy with it.

[zombiess]

Shock looks like it needs to have the rebound tightened up which would control the rear wheel better, right now it looks like a pogo stick with no dampening. Does your rear shock have any dampening adjustments, compression or rebound? What shock is it?

It could also be your spring preload set wrong. Typically you want about 25-33% of the shock travel to be use up when sitting static in your riding position. You'll probably need help from a friend to steady your bike while you get into riding position and check the shock sag.

1. start with preload adjustment first, go for a ride
2. if rebound is adjustable, start tightening it up as that rear wheel looks completely undampened, go for a ride
3. if compressions is adjustable, set it to the middle and start adjusting it either looser or firmer until it rides the way you like

Shocks with lots of adjust ability give you lots of options and ability to tune the suspension to how you like, but they are easy to configure wrong. I'm no expert, but I have solved several issues with cars and bikes through some trial/error + research.

[binlagin]

My tire is at about 45 PSI... I could probably put another 20 PSI in there and it'd be all good. I am running hookworms currently.

I will have to look at the suspension when I get home. There is a dial on it.. but I'm not sure if that effects dampening or rebound. I've done some minor adjustments on my motorcycle suspension last year once I began to race... even minor changes had HUGE differences, that is why I gotta figure out what is wrong with the suspension on my ebike!

I'm pretty sure the shock is leaking oil... I don't know if having it overhauled is worth it... or if I should just buy a new one. I will post some more details on the shock when I get home.

I also plan on installing Method's throttle retarder tonight... so THIS retard doesn't run his batteries into low voltages again

[oatnet]

My tire is at about 45 PSI... I could probably put another 20 PSI in there and it'd be all good. I am running hookworms currently.

I run hookworms at their rated 65 PSI - and sometimes much higher. 45 is way too low.

-JD

[chroot]

+1 I run at 65psi on all of my hookworms.

[binlagin]

So I've done some searching for a new shock and got some good/bad news.

The Giant Team/Comp DH bikes have very small areas for the rear shock and it's reservoir. There is very LIMITED selection of rear shocks that are supported. Because the bike is so old.. it's hard to find these shocks.

I've sent emails around to the various shock manufactures and only Avalanch has told me they build a shock that will fit. The reservoir is mounted on the frame of the bike. From what I've read, these socks are very high end and that is why they cost so much. I was quoted $648 plus shipping with a 10day build time

I also asked if I could have a longer cable to the reservoir so I could mount it like the image.

Hmmm 700$ is quite steep, especially considering I paid 500$ for the bike. I wonder if such an expensive shock would be worth it.

[zombiess]

$700 for a shock? I'd pass on that for sure. What's so different about your bike you can't find a reasonable replacement? Is there something wrong with the shock you have?

[GCinDC]

i got a used fox dhx 4.0 w/ 500lb coil for $90 off ebay. here are others, same size that fit.

call foxtho and ask them what fits. they know.

the fox shock i got off ebay need different bushings, and i told them the measurements and they sent them out. very low tech operation it seemed, but worked great.

[gensem]

Just get a custom made shock from yasusu, I dont think you ll expend over a hundred bucks.

[zombiess]

Just get a custom made shock from yasusu, I dont think you ll expend over a hundred bucks.

I'll second this, I think the one cheap shock I have is made by Yasusu and for the $45 I spent it has a great range of adjustment on the rebound. The more expensive models have remote reservoirs and adjustable compression and rebound.

[lostrack]

Dude, just get your current shock serviced. These were world cup winning frames & shocks. Chances are it just needs some TLC, and proper setting up.

My manitou 6 way swinger worked great with a new 450lb shock, and the right settings. If you want a firmer ride, add air. You can change high and low speed compression - your shock looks like they are fully backed off.

[gensem]

once again... YASUSU

[binlagin]

Bike Update - Newbies first bike, to much power!

So in the quest for more power, I bought a 36-fet greentime controller(100a). I kept blowing my 18-fet and I didn't want the controller to be the weakest link in my setup. Well unfortunately after I installed the MASSIVE controller... I found the next weakest link in my build:


Axle failure, Sorry for the HUGE image (right click - view image in new tab).

I had taken my bike out on a few test runs and was on my 3rd commute into work with the new controller. I grabbed a wrist full of throttle from a dead stop and put all my weight on the front wheel to keep it from flipping me off. Then all of a sudden I lost power and came to a stop. I figured I killed another controller because this was the exact same spot as where all my other controllers have failed. But upon further investigation, the broke axle actually shorted out my phase wires and blew the controller.

For everyones information, this motor was NOT from the Zombiess shipment and I had made some modifications to the axle for upgraded phase wires (i'm a noob, this was stupid).

This is the areas that I modified. I believe the metal i shaved down from the yellow areas had no effect on the failure but I did some light filing in the wire channel (in red). I believe this is the reason my axle failed. I didn't really feel like i removed much material in the wire channel... but when the axle isn't very big to start with... removing any is detrimental to it's life.



So now after this expensive lesson... I'm wondering where I should go next.

New Axle built by a local machinist?
- I have no idea how much this will cost. I dont' know where I can source an original Axle... Zombiess doesn't have any.

New Cromotor in 16/24 inch rims?

Mod a crystalyte HS and live with a 18fet controller and low settings?

I'm open to suggestions, because right now... I'm feeling pretty defeated!

[gensem]

Once you know the power you ll never come back!

get another cromotor in a 16-17" moped rim from zombies
get a 24fet hacked controller from methods
and you are set.

[binlagin]

get another cromotor in a 16-17" moped rim from zombies
get a 24fet hacked controller from methods

I like your thinking! But my wallet doesn't!

[hillzofvalp]

This kills me to look at the axle... *cringe* rethinking 9kw. I've been running It at 145A phase 90A battery (~5kW) in a ginormously stupid 28.8" wheel and I'm surprised this hasn't happened. What power level were you at again? Can we establish a safe power limit in a16-20" wheel?

Based on some calculations involving slope angle and full throttle torque , wheel size, etc., we may be able to get a ballpark torque rating

[GCinDC]

don't blame yourself so quick. most of us have filed our axles to upgrade the phase wires. take more pics. big moose (edit: found it->)identified the failure of another axle. i can't remember which now. but a 53xx xlyte. neils? anyway, if there's something inherently faulty with the axle, we all should know about it. of course it may have been your fault, but sometimes the true cause is elusive.

i wonder if these axles were properly hardened, cause they're not as strong as 9C's. i have no idea what the manufacture is like, but i noticed in the old Raleigh video how they hardened the bottom brackets..

[gensem]

This kills me to look at the axle... *cringe* rethinking 9kw. I've been running It at 145A phase 90A battery (~5kW) in a ginormously stupid 28.8" wheel and I'm surprised this hasn't happened. What power level were you at again? Can we establish a safe power limit in a16-20" wheel?

Based on some calculations involving slope angle and full throttle torque , wheel size, etc., we may be able to get a ballpark torque rating

Gimme sometime and we will find out if the axle (unmodded) snaps when launching with over 12kw of power

[GCinDC]

Duh, it's a cromotor... I was thinking it was an xlyte...

[zombiess]

That's the same axle that's on the original motors, like the one in my bicycle now. The new ones appear to be different material but I can't say for sure. I know the original stuff is pretty hard since I managed to strip the threads out of a nut and didn't hurt the threads at all.

Any idea how much material you think you removed? It looks like it broke at the thinnest area. I think the new axles are thicker in the area where yours broke but I'd have to take my wheel off and measure or find a picture to be sure.

The other question I have is how was your torque arm setup? A torque arm can could act as a shear if it's not on flat or frequent movement occurs. Is the break right at the torque arm edge or in a different location. I want to make sure I don't have to worry about mine at all when I pump lots of power into it, but being that I run a 20" OD tire I probably experience less stress since there is absolutely no way I can go WOT @ a 100A battery limit into it from a dead stop and expect to stay on it even if I'm leaned all the way over the handle bars, just not going to happen, maybe with my 12" longer swing arm I might be able to.

[binlagin]

I was running a 36fet Greentime controller(viewtopic.php?f=30&t=33636&hilit=greentime). It was configured to run at 100a battery. But it wasn't configurable past that. It's freaking HUGE! But I mounted it along my top tube between my legs.

Unfortunately my CA is not working (blew a cap), so I'm not sure how much power I was actually pulling. But I imagine it was above 5kw...

I was at a dead stop and hammered the throttle 100% on the "lowest" 3-way setting on a very slight uphill. Don't get me wrong this.. even on the "low" setting, the bike still wanted to take off like a bat out of hell. I have to move all my body weight over the front wheel to prevent a wheelie... but i kept it down, until the axle snapped

Thanks for those words GC, I'll just chalk this one as learning experience. I understand at these power levels... stuff happens... especially since this is my first bike.

I only took off a little bit in the wire channel... somewhere like 1mm? I've tried to illustrate where I've done that in the red in the image above.

I'm using the Kiwi dropouts... everything felt tight, but I'm not a dropout expert. The axle snapped on the edge of the dropout.

I'll inspect the other side of the axle and see if there is anything wrong with it as well.

But looking how thick the wire channel is and it just feels very small.

I think i'm going to go with a smaller wheel diameter. I'm getting tired of blowing everything up

[hillzofvalp]

It looks like there was a fair bit of twisting before it gave in.. It looks like the wheel became progressively looser...

[pchen92]

Hi,

Fortunately you don't get hurt
You can see my setup on my sign, I'm going to switch the crystalyte for a cromotor.
You should go with 17-18" motorcycle rim. The smaller diameter will put less stress on the axle and you could run less amp as said before.
I saw your video, your setup was freaking awesome

[GCinDC]

Fortunately you don't get hurt

+1!

[nechaus]

How did it fail? a jump with lots of poweer?