DiamondBack, Cyclone 650watts and Dewalt A123 packs

[kfong]

Bummer, I had my first serious breakdown. I was out riding the trails the past two days. Spring has started early this year and the trails are already very ridable. Near the end of my second lap, the aluminum bracket supplied by cyclone fatigue and tore. Fortunately I was about a mile out and could coast half of the way back.

I’m actually surprised it lasted this long now that I look at it, since it’s really not well supported. The motor is held on by two bolts and the cantilever action eventually stress cracked the aluminum. I don’t think this would have broken if I used it only for normal street riding. I did so much trail riding last year and some the year before that it has taken its toll on the bike, with all the jumps and logs I had to go over. I will now have to rebuild the motor mount. Unfortunately, I don’t have spare working ebike and even if I did I would still want to use this one for groceries and errands. I will have to get it fixed over the weekend. I also need to make a new chain cover, the one supplied by cyclone broke on me yesterday while trail riding.

[kfong]

Started thinking of how I wanted to redo the motor mount. I could have moved the motor to the front tube, but decide it would be a lot of work and wanted to keep it simple. So I'm just going to keep the same setup. Here is the improved motor mount. I will have to start on the machining. Here is another view of the broken one.

During the inspection I noticed the bottom bracket bearings were loose. I had replaced them last year, looks like I will need to replaced again. Here was a good tip from the bike shop. Just put in more bearings without the retainer, more surface area. I ended up putting in 11 new bearings held in by grease. It should be better than the original setup now.

[amberwolf]

Another thing I have found helps bearing life in BBs is to totally clean out the whole BB, really scrub it down with degreaser and wash it out, including the crankshaft and all the retainers/etc., till they're shiny new looking.

Get high-temperature grease like for car wheel bearings, differentials or similar; I use a tube of red grease called "Mystik JT-6", by CITGO. I know what I have is old so I don't know if the identical one is still available anywhere, but something similar should be. It's listed as an NLGI #2 grease, for wheel bearings, chassis, etc. It's "dropping point" is listed as 550F, so it *never* gets gooey or runs or leaks on any bicycle stuff I've used it on. It's way overkill, but it works.

Coat a paper towel with the grease, and stuff it up into the seat tube (from inside the BB) a little ways, basically to plug the tube from leaking anything down into the BB. Do the same with the chainstays and the downtube (or any tubes connecting to the BB). If you like, you can also do this at the other ends of those same tubes, to prevent anything from getting inside them in the first place.

Fill the whole BB with the grease, as you install the bearings (packed with the grease) and crankshaft (coated with the grease), so you have essentially a solid BB with nowhere for dust, dirt, or mud or water to get in there to deposit stuff onto the bearings in the first place. Then the only wear will be from stress grinding away bearing or race surfaces, and leaving metal deposits in the grease. Can't change that.

I do the same thing with my wheel axles/hubs.

It adds some friction, but it keeps wear to a minimum, and given the flinty dirt we have around here in Phoenix, keeping the dirt out of the bearings is necessary.

[kfong]

Amberwolf, I did pack it in with lots of bearing grease. I also slipped on some o-rings on the outside to see if that helps to keep the dirt from entering. It probably has no effect since there isn't anything to keep it pressed to the sides, but I had them laying around so it was worth a try.

Now that I have the bike torn down, I thought it would be a good time look at the motor. I have never taken apart this motor. It has over 2000 miles on it and still running strong. The grease looks like it’s doing its job. I’m tempted to just close it up again and leave it be. The grease is quite black though but very sticky stuff and was difficult to wash off my hands. I have some high temp automotive bearing grease I can use but perhaps it’s best to leave it alone since I don’t see much wear?

[amberwolf]

Black grease is probably fine, because it might be black originally. If it appears to be a different color in areas where it is never moved around by the motion inside (There are usually a few little spots like that), then there are contaminants in it in the rest of where it *is* being moved around, probably ground off the mating surfaces.

If you see metallic particles in it, then changing it might be helpful to prevent further wear by the particles against the mating surfaces.

If it's steel mating surfaces but you don't see actual particles, yet suspect the blackness is from the surfaces, then theoretically you could take a tiny pinch of grease and dissolve it in a clear degreaser in a clear container, tape a magnet on the outside and see if the area near the magnet discolors while the rest gets clearer, and then you'll know if it's got worn-off metal in the grease, in which case changing it may slow further wear.

[kfong]

I ended up just putting the motor back together, seems like the original grease has been doing its job. Finally finished getting the bike repaired and rode it around today doing some errands. It’s good to have this bike running again since it’s the only one I want to use for shopping. I’m very happy with the new setup. It’s a bit over built but I wanted the bottom of the motor protected from logs and rocks. I also needed the thick spacing to provide clearance. I don’t think this motor mount will move around or break now. I also replaced the chain guard with a polycarbonate plate. It should be good weather tomorrow, so I’ll be able to test it out on the trails. I’ll probably anodize the aluminum black so it doesn’t stand out so much. I’m also in the process of adding more packs in the triangle.

[LI-ghtcycle]

Looks good Kin!

Glad to hear it's still going strong (even though you had to replace the motor bracket), I wonder how many of us put as much abuse on their E-Bikes as you and have had as little trouble. I'd like to take mine off-road too, but I'm still torn as how to set-up the tires.

I think I should get some good schwalbe tires and that they would pay for themselves in longevity, but I'm realizing that I first need to fill my triangle with adequate amount of batteries to power my bike AND lights and not stress them.

Once I have my battery situation resolved, then I will worry about better tires, and I'd still really like to go with a custom BMS & charger to charge the pack rather than my current set-up where it takes several hours to charge up since I have only a couple chargers and lots of batteries. I thought about just buying more Dewalt chargers, but the same money would buy me a custom charger to my specs.

[kfong]

I rode my bike to the post office this morning, got back and charged the 3 packs I used. I had a quick lunch and headed out to the trails with 6 packs. I had a great session, bike felt really solid, must have gained a little bit of efficiency since my distance was a little farther and I’m just starting the biking season. The new setup has the chains lined up better and its smoother all around. Even the throttle response feels more crisp. Not bad for a beater bike that I can run errands with and then take it out to the trails to bash on. I did some small jumps with the bike but did not see any big logs that would have tested the motor guard.

LI-ghtcycle, I’m just using standard mountain bike tires, but I see your point if it’s a hub motor. The part that’s not lasting on me are the rims and spokes. Broke some last year riding and bent the rims several times, the last straw was when I actually bent the axial. Currently riding the rear tire off my old Mongoose mountain bike, already had to adjust it from my last ride where I had the breakdown, must of hit something harder than I thought. With my BMC motor build, I hope the spoke and rim hold since it would really be a pain to repair.

[kfong]

The weather has been great the last few days for riding, over 70deg today. I went out for another trail ride. I’ve been riding the bike rather hard thinking that it can take the abuse. Did a bunch of small jumps, but since it was single track; one jump in particular didn’t have much room for error. Unfortunately, I erred. The handle bar hit the tree and I did a quick bail. I actually went over the handle bar, but luckily the ground was sloping down. I would have liked to have seen it on video since I was still standing when I hit the ground running. Not sure how I accomplished this feat. I only had a scrape when my left leg went past the offending tree. Even the bike was ok, so I kept making small jumps when I could.

Unfortunately this is the result of all the jumping. The rear steel rack broke at the anchor points during one jump. I really thought this new rack would hold up. It looks like I’ll have to look for a stronger one, but don’t like the fact that I would have to create new mounts for it. I might see if I can repair it some how with a new steel plate and some carbon fiber and Kevlar. I don’t have a welder so I would have to go this route. Not happy with the amount of breakdowns I’ve been getting lately.

[amberwolf]

I might see if I can repair it some how with a new steel plate and some carbon fiber and Kevlar. I don’t have a welder so I would have to go this route. Not happy with the amount of breakdowns I’ve been getting lately.

That's this rack, right?
download/file.php?id=24277
which replaced this one?
download/file.php?id=24276

Do you have an old steel bike U-fork or 10-speed style "aero" fork laying around, with pinched-style dropouts? If so, you can cut just a few inches of the very end of the fork off, at the dropouts end, slit them lengthwise with a hacksaw (you may need multiple slits to take out enough material to allow proper clamping, or very wide slits), and hose clamp that in at least two places along the length onto your rack's existing ends. Then use the old dropouts to bolt back to the seatclamp bolts as before.

It's nowhere near as good as welding but it will work, as long as the forks you use aren't hugely different in diameter than the rack's tubing.

[kfong]

Thanks Amberwolf, that is the rack I broke. I was thinking along the same lines last night. This is what I came up with. I’m pretty sure this will hold up. I’m going to fasten it to the seat post and use setscrews to lock the rack down.

I might see if I can repair it some how with a new steel plate and some carbon fiber and Kevlar. I don’t have a welder so I would have to go this route. Not happy with the amount of breakdowns I’ve been getting lately.

That's this rack, right?
download/file.php?id=24277
which replaced this one?
download/file.php?id=24276

Do you have an old steel bike U-fork or 10-speed style "aero" fork laying around, with pinched-style dropouts? If so, you can cut just a few inches of the very end of the fork off, at the dropouts end, slit them lengthwise with a hacksaw (you may need multiple slits to take out enough material to allow proper clamping, or very wide slits), and hose clamp that in at least two places along the length onto your rack's existing ends. Then use the old dropouts to bolt back to the seatclamp bolts as before.

It's nowhere near as good as welding but it will work, as long as the forks you use aren't hugely different in diameter than the rack's tubing.

[Kevinator]

Hey Kin, I've decided to travel back in time and pick up where you left off with your Motobecase/Cyclone build.

I have a black Motobecane Fantom Elite DS frame here waiting for cranks from sickbikeparts because I've misplaced the ones I had for my 900w Cyclone kit. I ordered the downtube mounts from Paco at cyclone-tw and test-fitted them yesterday. They fit surprising well but I might go with 2" u-bolts instead.

I haven't gotten around to putting together the dewalt interface boards yet, but plan on using dewalt packs and mounting a couple somewhere on the bike.

[mwkeefer]

kfong,

your rack broke because it was mounted to the bearing bolts of a suspension seat. Even strong (I doubt it's hardened) steel would break given any real weight because of jumping and more importantly landing on the bike...

It looks from the pics that your seat retain clamp is actually part of the seat downtube? If so, just move the clamping brace you designed above down below the seat clamping tube... this will position all the force on a fully stationary piece of steel from the frame instead of somthng which moves with your weight (just the seat post alone from that retaining clamp upwards moves as you ride).

If you relocate the attachment point either as I indicate or even down to the top trailing arms coming off that seat post mount down to the dropout (don't remember what those are called) it would be much more structurally rigid = )_

I must say all these bottom bracket drives are enticing... I would love to do somthing similar but using an Astro or similar RC inrunner with a low kV and high kT then reducing to perhaps 80RPM maximum cadence at the cranks... Speaking of which, do you have any idea what your maximum cadence at the cranks is now... can you pedal assist with the motor or is it useless to pedal?

One other idea for a Rack - grab a steel rack from a Bell or other Childs bike seat... those are heavy guage steel and designed for clamping to the tubes I mentioned above for frames without rack bosses... they are very sturdy when attached properly... I have 2 here and would offer one but the weight and shipping would be too much...

Hope it helps!

-Mike

[kfong]

Kevin, the Motobecane Fantom is a nice bike. I’m still working on mine with the BMC torque motor. http://www.endless-sphere.com/forums/vi ... =6&t=12654
Be careful with the u-bolts, if it was a steel tube it would be ok but with an aluminum one. I would worry about crushing it, add some backing material. As for the Dewalts, I recommend using 3 packs. This is what I use in the trails and only during steep hills and delayed pedaling do I get the bms to stutter. This means I’m drawing more than 60amps.

I ended up ordering a new rack from amazon.com http://www.amazon.com/Ventura-Universal ... _rhf_p_t_2 . It’s steel and looks fairly sturdy. The reviews were good and it looks similar to the one I have, so I expect it to be an easy swap. I was going to fix the old one, but it would have added more weight, and the new rack was cheap.

Mike thanks for the advice. It was the only place I could mount that particular rack. The new rack has a better setup. As for the cadence I do a lot of trail riding, so pedaling is important to me. It is very effective since I’m usually going less than 15mph through the single track while in low gear. I’m able to do useful work helping the motor on the steep inclines. For flat road riding I’m able to help out with pedaling all the way to 20mph easily by matching the gears. Above that, the cadence gets a little too high.

[kfong]

Got my new rack last week and have already been bashing on it. I’ve come the conclusion that bike racks aren’t really designed to take jumps. I’ve already broken the new rack. I plan to mill a new bracket for the repair this time. It needs to be a lot stronger than the original design. It didn’t help that I took a hard fall. Face plant on the ground, luckily it was only on leaves and a soft ground. I was so glad it wasn’t a rock or log. I should think about getting a full face helmet. I was a bit surprised that the bracket broke, it sheared off.

I also, had a flat yesterday in the trails for the first time, only bitten twice by mosquitoes. I was very glad they were not out in full force. I had forgotten my bike kits, was in such a hurry to ride again. Flat happened after a jump. Maybe I should lay off jumps for a while. They aren’t even big jumps, but the solid frame and extra weight is just brutal to equipment.

[amberwolf]

It's hard to tell without a high-res closeup of the break, but it looks like the bolt is pressing it around the curve and bending it there. That pre-stresses the whole thing, and the shear line is right across the weakest part, with the bolt holes.

It almost looks like it *tore*, rather than sheared, which suggests it is being wiggled back and forth, which will fatigue the metal and cause this, too. Is that attach point tab on the rack steel or aluminum? Look like steel, but hard to tell for sure.

One reason wiggle happens is because the rack is bolted to it's side supports, AFAICS, rather than welded to them, so it can move back and forth a bit more easily (even if only a teensy bit each time). Another reason is that the rack has nothing to keep it from swaying and twisting side to side at the rear end, which causes the front attach point to be twisted a teensy bit each time that happens. This will fatigue the front rack attach point.

To fix that, put an X brace across the vertical supports to the rear end of whatever rack you use, and it will stiffen it up at least a little. A second X across the vertical supports under the rack up to the front attach point might help too. Just make sure the X is fixed in it's center, so the whole thing can't pivot

It'd be interesting to see video from a camera securely mounted beside the seatpost so it can record along the rack's side as you ride. I bet it will show significant sway on the rear end.

[kfong]

Amberwolf, I had it bolted on rather tight, so I don’t think it had any movement. I also used a fiber lock nut to secure it. The plate is steel; the whole rear rack is steel. The fall that I had could have done most of the damage. In reality, most of my breakdowns have come about due to me jumping. I started to do this last year in the fall and the breakdowns have been coming on very frequently since. With all that dead battery weight coming down on the rack, it’s taking a lot of abuse. I should be able to come up with a more solid repair. I’ll try to see if I can beef up the rack even more. Since I don’t do any welding there might not be much that I can do for bracing. Once I get the rear rack issue solved, then I’m pretty sure this bike will once again be very reliable out in the trails. The new motor mounts have been holding up quite well, even going over log piles. Something I would not have done with the old motor mount setup.

[amberwolf]

Amberwolf, I had it bolted on rather tight, so I don’t think it had any movement.

I bet there is more movement than you think, although you might not notice it. Can you physically grab the rear end of the rack and make it sway even a tiny little bit side to side (vs the bike frame position)? I'd bet this is possible with almost any rack out there, even of welded construction.

In many cases I don't think it makes a great deal of difference, but in extreme-use cases like yours, it can't be helping any.

I'd love to see someone do that camera test with racks like this. I have two bolt-together premade racks I'll see if I can test, plus one crappy welded rack I made. I have to build a camera mount first, and see if I can borrow a camera that does not have any extendable mechanical-focus mechanism for the lens like mine does (otherwise the vibration I intend to force during the pothole tests might damage the camera).

Steel flexes; it's one reason why it doesn't just break like aluminum does, which tends not to flex as much. But repeated tiny flexings still induce fatigue and eventually cracking. Depending on the metal type and structure it can happen quickly, too.

I also used a fiber lock nut to secure it. The plate is steel; the whole rear rack is steel. The fall that I had could have done most of the damage. In reality, most of my breakdowns have come about due to me jumping.

I don't doubt that major failures can be caused by that kind of stress, but I do think that other stresses are contributing. I just see too many rack failures posted up on the web that don't look like they should be happening based on the rack design, unless there is some sort of sidesway that is causing fatigue--the rack should not move in order to break otherwise, based on the way they are made. I'm no materials guy or mechanical engineer, so I don't know any of this for sure--it's just an intuition thing, which is often wrong.

I’ll try to see if I can beef up the rack even more. Since I don’t do any welding there might not be much that I can do for bracing.

You can make a reasonably stiff bolt-on X-member, if you can take steel tubing and hammer down the ends flat, then bend them to conform to the shape of the tubes you're connecting to at the angle they'll be connected at. Then make a matching piece for the other side to clamp it with, or even a flat plate.

To connect them at the middle of the X, dent the tubing in where they meet so they'll be inset against each other and can't easily rotate when bolted together, then drill a hole thru both at that point and bolt them tightly.

You could also machine something out of a solid bar to do this, too.

Neither of those is as sturdy as welding, but it might help if the X goes far enough down the rear brace to the dropout mounting point. That would mean an X that has short top arms and very long bottom arms, a little like a chromosome (but in a pure X shape rather than with any bends in the arms). The idea is to make as long a base for a triangle as possible, to give the stiffest shape over the longest possible portion of the frame.

[kfong]

The rear rack is now repaired; the metal on the original rack was actually softer than I had thought. I was able the tear off the rest of the broken plate with a pair of pliers. I road the bike yesterday with several jumps and did not see any problems, I think this setup should hold. I don’t expect any problems with the repair. Hopefully the rest of the rack holds up as well. I did have to tighten up the rear wheel spokes; they are taking a beating from the jumps and torque. I was planning to add more packs in the triangle and actually had the parts made, but in the end I didn’t want to give up the water bottle after riding one time with out it. I also didn’t want any more weight as well. The bike looks like it’s pretty much finalized for now until things break again. I would like to put back a mirror for riding the streets, but I have not found one that can outlast the trails.

[kfong]

I finally had to replace the freewheel a few days ago after a ride. The pawls on it finally gave out and only one was working making it difficult to pedal. Luckily I was able to get spare parts from an ES member. I was not able to get the freewheel off the crank. It was solidly fused to it. I ended up using the crank from the spares. I put anti-seize compound this time around.

All this recent effort was wasted. I finally thought I had all the bugs worked out on the bike and have broken everything that could break on it. Well I was wrong. Took the bike out to the trails today and rode it hard like I usually do. Did a jump off a tree root, landed and immediately thought my handle bars had dropped. I’m thinking no-way, since I knew it was tighten and had not given me problems. I look down and find the frame had broken. I was lucky that it didn’t snap in two. It wasn’t much longer that it broke off completely trying to walk it out of the woods. This is where the fun begins; try hauling a 62 lb. bike with no support out of the woods. I ended up sticking a wood branch into the top tube and hanging the front tire off it. Holding the branch while rolling the back tire all the way back to the car. The cables kept me from being able to separate the two. I’m glad I didn’t get hurt, but bummed that the bike is now trashed. It’s going to be hard to be without a good utility bike for errands. Time to build another.

You would think I would have stopped jumping. Oh well, next bike will just have to be tougher.

[jateureka]

Wow, I've seen the forks crack near the crown but nothing like that. You're very lucky you didn't get hurt.
Now you have an excuse to get that full suspension set up you obviously need to satisfy your desire to do jumps!

[kfong]

Yeah it could have been a lot worse. I was just lucky. I would have never expected it to break like that as well. I also discovered the bike is steel framed and not chrom-moly. I did find another donor bike locally that is out of chrom-moly, but has a cheap front suspension, hopefully it will hold up to my abuse. I really need to finish my full suspension BMC build, but I still have to have a utility bike for errands. So getting this bike repaired has priority.

[amberwolf]

WOW. I somehow missed the update to this thread on the 6th. I've never seen the whole headstock just snap off like that! That could have really sucked if it'd snapped all the way thru as you were landing.

Can you use the fork from this one on the other bike, instead of it's suspension fork? Assuming you think this fork is better than the cheap suspension one.

[kfong]

Amberwolf, unfortunately the new frame has a 1.25” head tube. The broken Diamondback is a 1”. Just as well since, I was never able to upgrade it due to the old style headset. I’m going to pick up the replacement bike later today. I’ll know more about the front shock once I have the bike. I don’t plan to put much into this, since it’s suppose to be just a utility bike for errands and shopping. The only reason I’ve been riding it so hard is because it’s my only ebike at this time. Once the other bikes get running. It will see a much easier life. The full suspension BMC build is coming along, but this weekend, my CNC computer crapped out. I need to fix it before I can move on. In the mean time I’m really missing my ride and the trails. I’m hoping I can just bolt on my cyclone tonight and be riding tomorrow.

WOW. I somehow missed the update to this thread on the 6th. I've never seen the whole headstock just snap off like that! That could have really sucked if it'd snapped all the way thru as you were landing.

Can you use the fork from this one on the other bike, instead of it's suspension fork? Assuming you think this fork is better than the cheap suspension one.

[kfong]

Well, when life gives you lemons. Here is my Diamondback with a new purpose in life. I needed a way to true my rims and it occurred to me that the old frame could still serve a purpose. I ended up cutting off the broken ends with a hacksaw.