Cecil's ride - 2017 Raleigh Kodiak 1 full suspension 27.5 plus bike with 750w TSDZ2 mid drive and rear rack dog carrier

Mostly thru breaking things and having to fix them in a way that won't next time.

I've been fixing badly-designed racks for a really really long time, and started building my own when I got sick of that, cuz there's not that much out there made to *actually* carry 30-50lb loads.

(they might be able to hold up a 50lb load just sitting there, but not with the bumps and potholes causing inertial "increase" of mass via acceleration, or the "wag" of pedalling/etc. causing cyclic stress on all the joints of the support structure, etc.)

Yes, you have me thinking now too. I will probably add the drawer sliders to the front because I think that those 8mm alum struts will be the next to break, and I will start working on a new design from scratch that has a better support structure and a carrier for Cecil that is not so heavy. I appreciate you sharing your wisdom!

Well I hopefully made the final revision to Cecil's carrier (aside from painting the new parts and adding a tail light and maybe a convertible sun shade. I removed the 8mm aluminum upper rack struts and replaced them with a pair of steel drawer sliders that I cut and drilled to fit. I think the steel will hold up better as steel will flex and bend rather than snapping like aluminum. It seems very sturdy and hopefully we can put a lot of miles on it until such time as I can design and build a lighter carrier (with better side to side triangular support as Amberwolf suggested).

I think you should add an extra set of struts that go from your forward mounts directly down to your lower attachment point near your axle. That will create a fully triangulated structure that will be very rigid and largely devoid of bending loads. Right now, that short strut is putting a substantial bending load on the upper portion of your rear strut. Take a look at the red arrow. Now imagine a large vertical load. Now imagine that your bolts are all just finger tight like they were hinges. Your front strut is going to want to pivot at bot of its attachment points.The same would be true of your rear struts except that you have those two small middle struts that attach to the rear struts. So as the whole assembly starts to pivot, a large bending load is applied to the attachment point of those rears struts. That makes the structure less rigid and that is the weak point of your structure.

If you add a long strut from the front mount to the lower attachment point (yellow line), all of the structural members will be in either compression or tension as far as vertical loads are concerned. Even if the bolts are just finger tight, the structure would be pretty rigid. The small middle struts would no longer be needed and could be removed. If you want to save weight, you might consider using 1/2" aluminum tubing rather than steel shelfing rails. That's what I'm using.

wturber said:

If you add a long strut from the front mount to the lower attachment point (yellow line), all of the structural members will be in either compression or tension as far as vertical loads are concerned. Even if the bolts are just finger tight, the structure would be pretty rigid. The small middle struts would no longer be needed and could be removed. If you want to save weight, you might consider using 1/2" aluminum tubing rather than steel shelfing rails. That's what I'm using.

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Thank you, I will give your suggestion some thought. I was hoping to build an entirely new setup but that may be a while. I have pretty much given up on saving weight, it is an exercise in futility at the moment.

I have a couple extra steel drawer sliders that I used for the upper and lower struts. I cannot mount them on top of each other though as you have suggested, well maybe with some sort of spacers. Perhaps I can mount a middle strut that bolts directly to the front strut (about 2-3" from where you suggest) and have it extend down to the bottom of the lower strut (again about 2" from where you suggest)? I would leave that small aluminum cross brace on as well, that is only part left over from the original rack.

Something like this maybe?

I'd mount them on the inside of the aluminum L bracket and the other side of your lower bracket so that the flat faces of each new strut is facing the flat face of the existing struts.

If there isn't room on the lower bracket, then mount it about an inch above the existing bolt. Get it close, but not so close that you don't have a good enough amount of material left between the two holes.

BTW, this will make the setup pretty rigid. It's possible that Cecil's current ride is being cushioned by the current setup's lack or rigidity. So make sure he has enough cushion. Maybe also consider lower tire pressure.

Actually it is pretty rigid now. I have those bolts tight and the drawer sliders are coated with enamel or something and they really grip well. I carried 40lbs of groceries home the other day without any problem, and I can push down on it with 50-60lbs of force and it does not budge at all. It is pretty strong side to side too, much stronger than it was with the aluminum rack underneath. I think the aluminum was the problem, the steel holds up much better since it will flex a bit. Cecil has lost 2 lbs over the past couple months too. If he can lose another 1-2 lbs it will be a huge help, plus I moved the tools, pump, etc up front. But the summer is coming and that means we will be carrying 5lbs of ice water back there too. If I can replace his wooden box with a plastic crate I can probably shave 5lbs off his carrier, but the wood box will withstand a fairly substantial impact.

The tire pressure needs to be quite high, otherwise it is brutal to keep it moving with the 3" tires. He has a nice camping mat under him though and he doesn't seem to have any comfort issues. I really need a mirror so I can see his face when we ride though, that is the only way I can see if the bumps bother him. I will probably get him another cushion eventually too, but we only ride about 2-6 miles at a time now. I know he would like an opening in the rear so his tail could hang out however there are too many asshats in the world and I am afraid someone will yank it from a car window or something.

Thank you for the advice, it is much appreciated. I will have to see how much clearance I have inside the aluminum brackets to the tires.

John and Cecil said:

Something like this maybe?

rack.JPG

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The closer the connection points are to each other, the better the triangulation and the less stress on every part.

It should be possible to flip the new diagonal slides over and file or cut (hacksaw) or grind away just enough of the "L" rail on each side of the main flat area at the mounting end point to allow it to fit under the existing rails and up against the dropout/frame.

Without the L portion all the way to the end it won't be as stiff at that end but since it's just triangulation tying two points together, it makes less difference than it would to the other (vertical and "horizontal") struts.

If it could be welded along the mating edges it'd be better, but bolting the flat part is good enough for this.




Regarding the mirror, if you have a celphone, you could temporarily mount it to the back fo the seat and leave it recording video while you ride, then watch it later to see how he behaves thru all of it. Since the phone is on hte seat and he's on the suspension, you 'll be able to see when you hit bumps cuz he'll move up in the vid, and when you hit holes he'll move down.

Thank you. I will see what I can do but my capacity to fabricate is severely limited at the moment. I have already sold 90% of my tools and most of my parts collection is gone. I don't even have any wrenches or sockets anymore. I only have a small set of crappy homeowner tools to be able to make some house repairs if needed until it is sold. I probably sold 1000 lbs of tools.

I don't have a cell phone either, but I do plan on getting a crappy burner phone when we leave California. We will need a new phone when we get to Europe anyway. I don't think he is uncomfortable though, he lets me know when he does not like something. He actually nudges me in the back with his nose when we go to slow The bike suspension does not do very much anyway, especially the way I have it pumped up as stiff as I can get it. He has 85,000 miles already in his box from the motorcycles!

Well it has been a long time since I updated this thread. We have left the US and we are in Europe. I was able to take the bike apart and pack it into 2 standard suitcases. The (3) 5p2s 20v5ah Hercules power tool batteries went through TSA without issue (they are 90wh each so legal in cabin on airplanes). It took us a few hours to put the bike back together in Rome but we were able to ride the bike straight from the airport.

We have about 3000 miles on the bike now. We are still on the ORIGINAL blue nylon drive gear and I do not notice any problems with it yet. Our (3) 5s2p powertool batteries connected to make one 56v 5ah battery are working great. We get about 15km on turbo and about 40km on eco mode with a full charge. My motor was originally the 48v 500w model but I uploaded the 52v firmware into the controller. The motor handles the 63v max charge from the 56v battery ok, although if I try to ride right after a charge I have to pedal for a couple of blocks with the lights on before it will kick on.

I have had some issues, when my display shuts off from inactivity it cannot be turned back on. I have to unplug the battery and plug it back in and that turns on the display without even pressing the on button. Also after the display shuts off for inactivity the motor still has minimal assist power. I think I can fix it with a replacement display but it is working ok so I continue to use it as it is. Also, after uploading the new firmware the motor developed a glitch with the throttle and using the throttle throws off the motor calibration. The throttle became unusable so it was removed. I am also having issues with the usb charging port on the display, it does not charge very well (perhaps 5% as fast as a normal usb charger) which is a real problem as I cannot maintain a charge on my cell phone converted to a gps mapper.

The motor is quite powerful, we are probably putting out 1000w at full charge. My original rear rim developed hairline cracks from the power so I replaced it with a new wheel and I added a kill switch wired directly to the brake cutoff plugs to use as a "clutch" when shifting at high powered assist. We also broke a couple of rear cogs but otherwise everything is doing well. I re-geared the bike with a 38t front sprocket and a 40t-11t 8spd cassette which allows us to ride in 8th gear at 30 - 40kph at full assist while pedaling moderate to hard, but also to climb steep hills in 1st gear at 8-10kph.

The rear carrier has worked well with no issues. I have since upgraded the tires to 27.5 x 2.8 Super Moto-X and I like them a lot. I also added a front fender, motorcycle quality mirror, cell phone holder, tool bag, and front and rear lights. I just ordered a travel bag so I can take the bike apart to carry on a train for when we travel to other countries in Europe. I would like to get a larger battery but for now we need to travel light so we are sticking with our small battery.

Thanks for the update!

Possibly the power button is stuck on. Not sure if there is any option to replace just the button. A new display might fix that and the USB charger problem. Might not.

How does Cecil like the ride?

Thank you. I don't think it is the button since that button is also used to turn the lights off and on and that is still working. I am not sure if the usb charge issue is due to an error with the display or maybe the controller, or possibly it is a manufacturer defect. It is also possible that these problems arose from my overpowered battery as I am using mine at full 63v max charge which is not recommended by the manufacturer. I plan on eventually buying (2) 7s5p 17.5ah wheelchair batteries using the newer NCR18650GA 3.5ah cells to make one 8lb 52v 17.5ah battery for the bike, but I cannot carry the extra weight until we have a home. I will probably buy a new display at the same time as the new batteries and charger. I bought the 5s2p batteries I have now because they were $20 each and legal to fly, and they have quality Samsung high discharge cells.

Cecil really loves going for rides. If I say the word "ride" he races down the stairs to go, and if i say "ride for pizza" he will whine until we leave. He really misses the motorcycle though (he has 85k miles) but the bike is perfect for Europe. No license, no registration, no insurance, no parking issues, and no need to understand foreign street signs My only problem is it is difficult to travel by train and carry everything (65 lbs bike/battery/dog carrier + 30 lb backpack + 25 lb Cecil and his soft carrier). I cannot use a wheeled bike carrier as it needs to fold up so we can ride away from the station (we move to a new county every 3 months). I should probably buy a small aluminum lightweight folding bike and put the motor on that but I really like this bike as it is stable at 25mph and it hops up curbs easily. The only thing I would really like to change on my bike is the front end as I would prefer a triple tree front end like they have on downhill bikes.

I have been giving the bike some more thought. I tested it yesterday, in high gear it goes about 17-20mph on flat roads with only a very light effort on the pedals depending on battery charge. I believe I could probably ride quite a bit faster if I go back to the original 42t chainring and I replace the malfunctioning display with an aftermarket one so I can install the programmable aftermarket firmware into the motor. I would like to program the motor to allocate more power at lower torque sensor levels in the highest power level only for very easy pedal cruising at high power levels (rather than using a throttle). If not I am hopeful that the aftermarket firmware might correct the throttle malfunction but with a setting such as this the throttle will not be needed. I do not need a gear sensor or brake sensors as I love the clutch (kill) button. For someone who rode motorcycle my entire life the clutch button is very natural for me.

I also want to replace the battery with one with more range. I ride with a lot of weight on the back so I have unique needs. Right now I carry 4.5lbs of batteries on the handlebars and even that is too light, I really need to carry about 10lbs up front. I have yet to see a configuration like this but what I would like is a U-shaped battery that fits snug over and surrounding the headset between the fork and bar stem and extends maybe 6" back along the frame. This would be ideal for my situation, and then I can also mount a basket on the front for more cargo capacity. As it is now I am considering a couple 7s5p wheelchair batteries either hanging from the bars or mounted to the frame up near the headset. Either that or I may be able to relocate them under the shock inside the frame (if they fit) and then move the tools up front off the bars (I carry about 6lbs of tools and parts).

As for the rear rack I would eventually like to replace the wooden crate with a plastic one to reduce weight. I will also probably mount a piece of aluminum between the front and rear steel support struts and then mount the saddle bags below the crate next to the rear wheel. This will lower the weight on the rack and also add more structural integrity to the rack (as Amberwolf suggested).

I took some more pictures of the more recent addons. These were all very cheap additions, aside from the tires. The mirror and mount, front and rear lights, cell phone holder, kill (clutch) button, tool bag on frame, and fender probably cost about $50 total. Not including wearable parts replacements like tires/tubes/chain/etc I have about $1150 into the bike.

There is not much I can do now though as I sold all my tools and just about everything else to move to Europe. Hopefully this info is helpful to someone else with a similar project.

You might be able to mount batteries on the bottom side of the down tube. As long as you have clearance to the front tire it keeps the low but still forward.

fechter said:

You might be able to mount batteries on the bottom side of the down tube. As long as you have clearance to the front tire it keeps the low but still forward.

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If the tire would hit the top pack on full compression you could rotate your mid drive motor towards the rear as to make room to mount the packs lower.

The batteries I am looking at now are 10.5" x 3.8" x 1.6" x 3.75 lbs each (I would need 2 for 52v 17.5ah) so I could put one over and the other under the downtube and still clear the fork. I could also fit them both inline on the bottom of the downtube or both stacked at the bottom of the downtube near the bb. Another option is to mount them on the left and right side of the top tube all the way up by the headset. Also, they both might fit above the downtube inside the frame if I install the shock backwards. I should have ordered them a couple months ago when they were on sale for $85 each though, but carrying an extra 8lbs in my suitcases is not going to be possible. I have too much stuff already

Well we got another flat. I am not happy with the super moto x tire on the rear, the wire bead is shot as I can put the tire on the rim now without tools or even much effort. I probably killed it by walking the bike home with a flat. Even though it has most of the tread remaining I am going to have to replace it. I think a bike tire is fine on the front but we really need a heavy duty tire on the rear.

When I replaced my last tires (kenda hovak) I noticed that they were stamped like a motorcycle tire - I think they were 2.8 x 23. I am considering using a 23" motorcycle tire on the rear only. The Mitas SW12 motorcycle tire is 2.75" x 23" and weighs about 5.5 lbs (I think the super moto x tire is about 2lbs). I wonder if they would fit on a 27.5 x 50mm bike rim though.

Bike tires are crap, and also not cheap.

you might try a layered approach.

regular (or armored) bicycle tire on the outside, with the qualities you prefer for grip/etc.

slime (or similar) antipuncture strip inside of that, centered in the tread, preferably wide enough to cover the entire tread (some strips are narrower than others).

smooth-tread (non-knobby; slick works best) tire with the bead cut off inside of that.

optionally your old (as thickskinned as possible) innertube(s) with the valve stem removed, and circumferentially slit along that inner side, slipped over your actual innertube that will be inflated.

it'll probably still be lighter than a motorcycle tire, fit the rim bead better, and be about as puncture resistant.


unfortunately, depending on where you're riding, there are some things you may run over that nothing short of a car or truck tire could stop, because of the thickness of their treads and the steel belts inside, which you won't find in any tire that's likely to fit on the bike (even if you built a wheel with a motorcycle rim on a hub that would fit your frame).


regarding kenda tires, every single one i've ever had, over many years, has had sidewal problems, or outright failures, regardless of pressure run in them, etc. i think they just use a crappy way of bonding them together. none of the other brands i've used ever came apart like that.

my favorite brand is cst, cheng shin tire. the 26"x2.5" cst city is what i use on the front of the trikes and the bike, with no flats yet (excepting a valve stem separation from a crappy tube). it has knobs on the edges and slick in the center; don't want the knobs but haven't found a better tire that's all slick. i use the layered approach as noted above in those, except i'm not using a tire inside it, just the old thick tubes slit inside and fit over the real tube, with the slime strip between tire and old tube.

i liked the cst "the general" tire even better, because it was completely slick/round , no knobs, and slightly more air volume, but can't find it anymore (it was stickier for better traction/steering/braking but it wore out faster because of that).

on the rear of sb cruiser, i use a shinko moped tire, but those are 20" bike / 16" moped rims, and there's no other perfect crossover like that, except some 26" bike tires fit some 21" motorcycle rims. you may be lucky enough to find something that does crossover; if so please post it up in the sticky index thread in i think ebike general that talks about tires.

unfortunately i don't know any motorcycle or moped tires that fit 27" rims.

No, the rims aren't 27" they are really 23". They call them 27.5's but that is bike language. There are not many tires for a 27.5 plus bicycle. With 50mm wide rims I have to run at least a 27.5 x 2.5 tires and preferably a 2.8 or 3.0" width. There are very few tires in this size. Actually the kenda seemed to hold up better than the schwalbe super moto x except the kendas wore out quickly. The sidewalls on bike tires are very thin which is a problem as well as the bead not being tight against the rim. I think the wider plus tires may exaggerate this effect.

I have yet to get a flat from an object going through the tread, that is not a problem. One flat was from a rim strip that slipped because the shop did not glue it down, one was from a thorn in the sidewall when I parked near a tree, and the last two were from jumping curbs so I am guessing the tube pinched or something.

The problem is sidewalls are crap on bike tires and that is weakening the bead, at least with the super moto x tire on the back. I believe the tire needs to be thicker on the sidewalls to reinforce and support the rim bead and also to support side to side forces better. This is also useful when you get a flat and need to walk the bike home, the tire needs more support structure.

I did read that someone supposedly mounted a 22" motorcycle tire on a 26 bike rim (actually 22" rim), as well as 16" motorcycle tires mounted on 20 bike rims (actually 16"). I believe the 23" tire will fit (especially since my kenda was labeled like a 23" motorcycle tire) but I am concerned about being able to stretch the thick motorcycle bead enough to get it onto the lightweight flimsy bike rim. My rims have a 45mm internal width so I believe they are wide enough so that the extra thick tire bead can clear the tire valve.

I went through some of my bike pictures trying to see what is stamped on my old kenda tires. They were marker 27.5 x 2.8 and also something-23 M/C (I think I recall it being 2.80-23 M/C but that part of it is cut off in the photo). I think when they first started making 27.5 tires they stamped them with motorcycle sizing and then later changed them over to bike sizing. The newer kenda tires only seem to show the bike sizing. I am trying to find a picture online that shows the motorcycle sizing but so far I cannot find anything.

I found another bike tire that looked nice, the Duro Crux 27.5 x 3.25" although it is a knobby tire (I would prefer street tread). It weighs about 2.2lbs so I thought it might be better, but then I saw a picture of the tire on a bike when the air leaked out and I can see the "ripples" in the sidewall. It is another tire with paper thin sidewalls. Tire sidewalls should be thick enough so they fold over, not ripple I also found a Chaoyang Ebike slick tire in 27.5 x 2.8 and it weighs a whopping 2.65 lbs. I am looking for info now to see how sturdy the sidewalls are on that tire.

EDIT: Nevermind, Chaoyang's website states the tire is only 795g. Much too light to have any solid structure to the sidewalls.

I may have to buy another bike tire for now. If I was in the US it would be easy to get a tire and try it but on an island in Italy it is much more difficult. I can get another super moto x tire here pretty cheap, but Schwalbe's "snakeskin" sidewalls are absolute crap. I guess the tire is fine if you never get a flat but god forbid you have to walk the bike home with a flat and distort the sidewalls and ruin the tire bead.

amberwolf said:

my favorite brand is cst, cheng shin tire. the 26"x2.5" cst city is what i use on the front of the trikes and the bike, with no flats yet (excepting a valve stem separation from a crappy tube). it has knobs on the edges and slick in the center; don't want the knobs but haven't found a better tire that's all slick. i use the layered approach as noted above in those, except i'm not using a tire inside it, just the old thick tubes slit inside and fit over the real tube, with the slime strip between tire and old tube.

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I just saw a nice looking bike tire, unfortunately it is not available in 27.5. It seems a little heavier than most and it has a nice tread pattern. You might like it, perhaps you already saw it or tried it though. If it was available in 27.5 x 3 I would have given it a shot. The tire is Chaoyang Sandstorm and is available in 26 x 2.5 and 26 x 3, the 2.5" weighs 935g. It has a nice tread pattern for street riding, not a slick but it looks like a very good street tread.

http://www.chaoyangtire.com/index.php/pro/pro-details/6/336?type=PLUS&name=SANDSTORM

I hope your dogs are doing well!

Oliver likes the tread pattern of your tire photo, says “Arf arf” (hello) to Cecil.

John and Cecil said:

I just saw a nice looking bike tire, unfortunately it is not available in 27.5. It seems a little heavier than most and it has a nice tread pattern. You might like it, perhaps you already saw it or tried it though. If it was available in 27.5 x 3 I would have given it a shot. The tire is Chaoyang Sandstorm and is available in 26 x 2.5 and 26 x 3, the 2.5" weighs 935g. It has a nice tread pattern for street riding, not a slick but it looks like a very good street tread.

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i prefer "slicks", so that hte rubber is thick thru the entire surface, rather than "knobby" treads like that, which have thin areas between the thick knobs (even though this one is much closer together than most). "the general" tire was similar shape to the above tire, but was solid surface all over. i don't really need tread that allows for water channels, as it rains so little here, and when it does rain it is often so much that it doesn't matter what tread i have, it is so inundated there's really nowhere for the water to go anyway.

if it rained "normally" more here, then i'd probably prefer treads like the sandstorm's.

another problem with such treaded tires is they are usually harder compounds, and so they skid much easier on dry street and solid surfaces, which is a problem for a front wheel for steering and braking.

so while that tire might work, it's not my preference for center tread style. if it had center solid band like the cst city does, i'd probably like it better than the city (assuming it's a soft grippy compound).

I hope your dogs are doing well!

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three of them (yogi, kirin, jelly) are, but one (peanutbutter) isn't doing at all anymore.

amberwolf said:

three of them (yogi, kirin, jelly) are, but one (peanutbutter) isn't doing at all anymore.

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I am sorry about Peanutbutter, I guess he is getting old? Cecil is showing his age now too, he is 10+ years old. He sleeps a lot and I have him on glucosamine/chondroitin supplements for early stages of arthritis. He walks ok most of the time but he has some days where it appears he has a little joint pain. Thankfully he loves riding the bike and that does not affect his age issues. I have been thinking about it a lot lately and when he passes on I am going to be devastated, hopefully he has another 5 years but who knows. I am thinking about upgrading to a longtail cargo bike in the future, like the Mongoose Envoy. Then I can possibly adopt another rescue dog and ride with both of them simultaneously so when Cecil does leave me I won't feel so alone. Cecil really does not want another dog in our pack but I think it would be a good idea.

Thanks for the info about the hard tires. That is the thing I like most about the super moto x tires, they are great for traction and braking on the street but they also have noticeably more drag from the grip. I wish the sidewalls were thicker though. I did finally get the tire to seat better on the rim by inflating it less and riding it and over time raising the pressure until it was centered on the rim. The tire is wobbling about 1/2" from side to side even though the rim is straight. I was thinking about buying a WTB Bridger tire as they are on sale and weigh a whopping 1.2kg. The reviews state they have a more sturdy carcass / sidewalls which I like but the tire has small knobbies and the tire compound is hard. They have little rolling resistance which is nice but the ride won't be as smooth and the braking will not be as good. I wish I could get the motorcycle tire locally to try it but those 23" x 2.75" / 3" tires are rare. I used to ride an old Honda XL500s that used that same tire size up front, it is one of the only motorcycles that uses that size tire. I went up a a 6" curb once on a 30 degree angle at 25 mph to avoid getting t-boned by a car. The bike made it up after the rear tire slided along the curb for a bit and I was even able to ride next to the car while on the sidewalk screaming at them afterward. Bridgestone makes a trailwing 23 x 3" and Mitas makes a 23 x 2.75" knobbie and a 23 x 2.5" slick but it has the ability to mount ice cleats to the tire.

Now you have me thinking about the 23 x 2.5" Mitas SW-08 slick motorcycle tire on a 27.5 rim.

I think I just stumbled across a motorcycle tire that will actually fit a 26 bicycle rim if anyone is interested. Mitas SW-13 2.75" x 22 knobby tire. I believe the 26 bicycle rim is actually a 22" rim, as is this particular tire. I never saw a 22" motorcycle tire before.