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Post by vance on Sept 25, 2022 16:21:10 GMT -8
So, although the tandem is running great, and all is good there, I'm working on another bike. Because the tandem project had a bunch of issues, that lead me on to another project using the left over parts. One problem was that I ordered the wrong kit for the tandem, and then had to get the right one. Return shipping was 2/3 of the purchase price, so I rebelled and ended up keeping it. The first kit didn't use an LCD, so its corresponding controller didn't have a connection for one and I had to order new parts to make up for that mistake. My fault, so all is good. Then, mistake #2, I thought I'd need another battery so we could go the distance on the Joshua Tree ride. So, I bought a second, very expensive battery as a back-up. We've ridden the tandem 25 miles and haven't dropped the battery charge indicator even one bar. So, now I have a motor kit and an extra battery. What will Vance do? You know.... I spent the afternoon mounting the extra stuff onto a mountain bike I had languishing in the basement. I'll post photos as I go! Here I go quoting myself again! Sorry! This is relevant to the above post, but I went to a mid drive for this one. There are issues with the extra kit I bought, so it needs some troubleshooting. So, I spent the day installing a mid drive motor on a VooDoo rigid mountain bike. This was my go-to bike for singletrack back in the day. I chose this one b/c it has 29" wheels and a disk brake steel frame. I put it together today, and took a ride. It isn't completely finished as I need to clean things up, but it works! Zoom! I wanted a bike that I could ride with my friends, and to do errands with. We live in a very hilly area, and a regular bike won't cut it for me, seein's how I'm old (how did that happen?) I'll post photos when I get them.
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Post by SeaRat on Sept 25, 2022 16:58:53 GMT -8
Phil, I've had bicycle troubles too. I've managed to wear out two bicycles this summer (not just the summer, but over the last 20 years). They just wore out at the same time. My son, Brian is a mechanical engineer in the high tech field, and he is also a bicyclist. He has been racing in the past, and has five bicycles. He also put together his own bicycle stand. It allows him to get the bicycle up so he can do maintenance. IMG_0862 by John Ratliff, on Flickr He says he put in about $30 to make this stand. My Rivendell Rambouillet is now fixed, as I wore out its middle chainring. It has a new cassette, new chain, newer middle chainring, and I replaced one of the shifting cables. So it's now good to go. My Rans Stratus recumbent bicycle still has a front tire problem. I wore out the rim, and got a newer wheel for it. But, in taking the tire off, I messed up the bead and it won't seat, so tomorrow (I hope) to get a new tire from recumbentpdx.com in downtown Portland. John
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Post by vance on Sept 26, 2022 15:35:47 GMT -8
I had some fun today taking the rear hub wheel apart. It is having problems, which I can't seem to figure out. Apparently, this motor/controller is giving other people the same grief as well. I took it apart to be sure that all the connections, wires, and hall sensors are working properly.
I bought an ebike motor analyzer which showed everything was kopacetic, but I wanted to test for intermittent shorts and the like. Using a multimeter, I checked all the connections inside. All good, even with tugging and wiggling.
Huh.
Next thing will be to hook up to my working system on the tandem. If the motor works, then there's a controller issue, even though the controller is new.
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Post by vance on Sept 29, 2022 14:58:15 GMT -8
The rear hub motor still doesn't turn. Just judders.
Huh. It's a mystery. On the back burner, for now.
I took the mid drive VooDoo out for a 25 mile ride. It works great! Again, I went too big with the motor and battery (it seems to be my nature), but it's nice to have power when you need/want it.
Now that I'm getting older, this bike is getting me back out there. I have been a road and mountain cyclist for 25 years, but recently stopped b/c it's just too hard to ride the hills and mountains around my home. With the ebike, I can do the kind of riding I want to do with my friends.
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Post by vance on Sept 30, 2022 15:24:26 GMT -8
Here are some photos of the new build. This is the mid-drive motor. BTW, that's not rust on the chain. It's red dirt from MTB riding. And here are the 203mm Bengal disk brakes I added. These are WAY bigger than the standard 160mms. I like the Bengal brakes because they have no plastic parts that can melt during hard descents, and the increased rotor size makes them more efficient with less heat.
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Post by vance on Nov 17, 2022 15:21:10 GMT -8
The saga continues!
As I am who I am, I have started a new tandem project, which is in aid of "going to school" on installing a mid drive motor on a tandem bike. This is with our Burley in mind, and the nay-sayers say it can't be done with "an acceptable result". Already been there, and the results are better than acceptable.
The Burley currently (heh!) has a rear hub motor, which works fine, but is old school. A mid drive assembly would be much more efficient, and would ride more like a normal bike with the center of gravity more... well...., centered! Weight distribution is fairly important, as I'm now adding an extra battery on a rear rack.
Anyway, we've had a classic Gary Fisher mountain tandem in the garage forever. It had an unfortunate garage accident (it fell from the hooks that suspended it when the rear wheel was removed) which rendered the rear derailleur hangar useless for its intended job (welded hangar, alloy frame).
I hate to junk a vintage anything, and I went to work on making it ridable again. So, I installed a 7 speed internal hub rear wheel with a chain tensioner to make it road worthy again. This got me thinking about installing a mid drive on it. The object is to sell it down the line.
I ordered the parts, and they should be here tomorrow or Saturday. This ought to be fun! The trickle-down effect (hub motor going begging) has begun!
Photos to follow!
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Post by vance on Nov 19, 2022 17:09:06 GMT -8
The kit was delivered today, too late (5PM) to start the install. I have a lot of things to figure out, but I'm confident I can make it work.
Chain line is a big issue, and I'm not sure if I will mount the motor fore or aft. My guess is fore, due to some perhaps insurmountable problems, which changes the synchronizing gear set to the other side. Bummer. This will initiate some new problems.
If I can get a workable chain line, somehow, with the motor mounted aft (shims? spacers?), I'd prefer aft. I have some wiggle room, I think, but when you start the process, things come up!
Tomorrow will tell! Photos to follow.
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Post by vance on Nov 20, 2022 16:00:37 GMT -8
So, I got to work today, but unfortunately my wife is sick. Not Covid, but she's not feeling good. I got to work on the bike a bit, but wasn't able to get all in. The motor has to be mounted in front on this one. I worked on mounting it in the rear for a while, but it just doesn't line up. This means that the synchronizing chain gets moved from the left side to the right. I didn't like this, until I thought it through. More to follow in another post. The problem that has been cited by everyone who has tried a front mount with an eccentric bottom bracket is that you will lose the ability to tension the synchronizing chain. That would be a problem, if it were true. Here is a photo of the eccentric. The way this works is, if you rotate the BB in the shell, you can tighten and loosen the chain that runs between the captain's and stoker's chain rings. Turns out, there's enough room to make some adjustment. It just isn't inches. Millimeters are enough what with 1/2 links and all!
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Post by vance on Nov 20, 2022 16:25:26 GMT -8
The kit for the mid drive motor can work with either a 68-73mm or 100mm bottom bracket. My vintage bracket shell is 80mm. I got the 100mm motor, and have to do some hoop-jumping to get it all installed.
There's a couple of machining jobs to do to get it installed. I think I need to make a couple of brass or delrin shims for the slightly bigger BB bore to OD of the motor shaft. That's not too difficult.
However, the length of the motor shaft is about 10mm longer than the BB shell. This will require a spacer. I made one that is the same diameter as the OD of the BB shell today. I haven't yet cut the hole for the motor shaft. It will be off center, same as the eccentric. The shim will allow the mount clamp to fix the motor in the BB shell.
Whew! Not easy to describe. I'll post photos of progress.
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Post by vance on Dec 14, 2022 16:12:46 GMT -8
This post comes much later than the above. Many hoops have been jumped, and a lot of problems solved. However, I still have a big problem that doesn't want to be solved.
The eccentric BB is needed to adjust chain tension. I made a spacer out of 1/4" aluminum, and drilled and tapped holes for the adjuster set screws. I fitted it all up, and went for a ride.
Torque is my enemy. After the ride, my chain was so tight, it caused shifting problems. The motor rotated up immediately under torque (tightening the chain).
I tried making a couple of torque arms to keep the motor assembly from twisting upwards, and both bent under load. @#$%&!!
The first was made out of 1/16" stainless steel, which crumpled like aluminum foil with the first application of power.
The second was a 1/8" steel strap that bent slightly under load, tightening the chain unacceptably. I need to figure this out. I could let the motor rotate upwards until the frame stops it, but then there's no way to achieve proper chain tension.
@#$%^!
The problem is there are multiple bends in the torque arm which buckle under the load.
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Post by SeaRat on Dec 14, 2022 17:31:46 GMT -8
Phil, I'm following this part of the thread with interest, but know that I"ll never have this problem, as I don't have the expertise to even attempt it. Best wishes. I had a 10 mile ride yesterday on my Rans Stratus recumbent ("Silent Wind"). John
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Post by vance on Dec 14, 2022 18:08:49 GMT -8
I don't know if anyone else is interested, but thanks for the comments, John.
This has been a very interesting build. There have been a lot of unique issues, mostly due to the damaged derailleur hanger, and having to use an internal hub wheel. Chainline has been driving me nuts!
I am getting closer, and all I need to do now is solve the eccentric BB/chain tension problem. I have no doubt it can be solved.
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Post by vance on Dec 18, 2022 15:27:09 GMT -8
I ordered a turnbuckle for sailing applications that might just work as a torque arm that will keep the motor in place, and have some adjustability when needed.
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Post by SeaRat on Dec 19, 2022 12:59:00 GMT -8
‘Just a thought, but is there any way to find the point it wants to rotate to, and use that as the defined point and work on the chain from there? It can only rotate so far, you know.
John
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Post by vance on Dec 19, 2022 15:40:12 GMT -8
The motor wants to rotate all the way up to contact the frame. Usually, this is the way these work. However, this is a special build. I need to utilize the eccentric BB in order to tension the chain that connects the two riders.
I need a way to hold the motor in place well below the contact point between the motor and the frame. Sucks that there's no rigid, adjustable mechanical stop for it that works, nor one I've come up with, yet. But this might work.
A wedge can be stuck in between the motor and the frame, which is a "Hail Mary", meaning that you're hoping the chain is tensioned correctly by it. Not easy to accomplish. The problem with this method is that proper chain tension is very difficult to achieve without blind luck .
Thing is, you want optimal chain tension so the components don't get ravaged by being too tight, or, if too loose, having the chain slip off.
So, you need a way to use the eccentric BB, which allows proper chain tensioning, but only if it won't move under load.
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