Mid drive cassettte zip tie mod.

[AZguy]

Ok so I'm thinking this might be a way to make the bike even stealthier at night by silencing the rear hub freewheel and it does a good job of that since the pedal freewheel is nearly silent... cool

The only other advantage I found for my riding (yes! we have very different riding terrains and styles ) is that it eliminates the only thing I ever found brake sensors even remotely useful for (we already know what I think of them lol) which is downshifting while slowing since you can downshift while not pedaling which I have to admit is a *very* hard thing for me to get used to....

[Retrorockit]

As usual we are running opposite setups. You don't like brake switches. I didn't like the shift sensor.. This let me do away with the fixed delay, and long delay on multi gear shifts.You might try unplugging the shift sensor and see how that works for you.

[AZguy]

Decades of pedaling (without pressure) while shifting is pretty much too ingrained - I don't think I'll ever break that habit and stop pedaling while shifting and not sure I'd want to since it would typically not be ideal on most derailleur bikes

[Retrorockit]

When I'm in the higher power settings not cutting power to shift becomes an issue in itself, and I also probably want the power interrupted for as short a time as possible ( no shift sensor due to this). This allows both to happen for me at once.
The minute you zip tie the cassette "most derailer bikes" no longer applies.

[Retrorockit]

I've done some more work on this today. I bought a selection of recumbent trike chain management parts. tried a few things and found a setup that seems to be working.
bear in mind none of this is being sold as chin guides for chainrings. They're idlers for long chain runs. But the zip tie mod is off label also.
The one I ended up uisng is the 15t cog drive side idler. 2x 608 bearings and mounts on an 8mmm Allen bolt for a shaft.
https://t-cycle.com/collections/idle...power-idler-15
The thing I like about this is it's kind of like having a top derailer wheel to guide the chain onto the chain ring. The smooth rollers bump around on the back of the chain when engaged., and don't really keep it centered. This one turns all the time and is smooth and quiet. With my 50t ring it needs to sit pretty far back so the teeth don't meet.
I tried using my existing 8mm mounting clamp. But it ran into an old water bottle mount, and my torque arm on the other side of the seatpost. It wouldn't have been long enough anyway.
T Cyle had what I needed. Note, this was great for test fitting and worked for a while but the BBSHD broke it. ai now use one fo their battery hanger clamps.
https://t-cycle.com/collections/chai...on-idler-mount
5 mounting holes, and slotted so actually 6 adjustable positions. It can also be mounted 4 ways. front or rear, and up or down offset. I ended up using it Mine ende up offset up, and the rear most hole slid forward to clear the fender. So I needed every feature it had.
Be warned this is a machined product by precision type guys. It has 36mm hole but clamps onto a 34.9mm seatpost. That's a paint allowance. If it's loose just stick some metal duct tape in. Mine fit just fine. Also if you drop the washer they send, the one in your tool box may not fit in the precision slot they machined to fit the one they provide. The bolt won't tighten w/o it. no extra threads.
If you use a generic bolt with an extra thread or 2...... It works great the way they send it. But it can be fussy if you change ANYTHING.
Things that didn't work.
The mini roller to replace my generic urethane DH part I've been running. It has a deeper narrower slot, and an O ring in the middle to center the chain. One bearing lets it flop around. didn't work out.
https://t-cycle.com/collections/idle...ner-mini-idler I also had to change the bearing to 8mm. Don't bother.
I tried the sport return side idler. One bearing, slots too wide, and still bumpy on the back of the chain. It's machined for 2 bearing so that can be fixed.
https://t-cycle.com/collections/idle...t-return-idler
I tried this nice little chain keeper too. Clamps onto the head of the Allen bolt/shaft. The minute the chain started to drag against it all kinds of slack showed up. So no friction type chain devices for this mod. I actually pressed one of the 8mm rollers onto the pin on this for an offset adjustable roller bracket. Might come in handy one day.
https://t-cycle.com/collections/chai...d-chain-keeper.
I put about 50 miles on it today. So far so good.
Like most of my stuff file this under" the right way to do it wrong."
50t zero offset chain ring, not Wide/Narrow, bad chainline, 20 year old Rapid Rise derailer, and matching twist shifter. cassette zip tied to the spokes. Now a chain guide lashed up out of trike parts.
Still running cable brakes on a 35mph E bike too.
Here's the clamp I ended up using to hang the 15t idler.

https://t-cycle.com/collections/all-battery-mount-parts/products/heavy-duty-frame-clamp

[Retrorockit]

I didn't have the correct hardware for this, and the shops in my area were either out of stock or didn't carry what I wanted. So I rode into town yesterday and got what I needed. I put a hardened 8mmx50mm Allen bolt in for the shaft, a black nylon 8mm x 10mm long spacer which with a jam nut needed just 1 flat washer to line the idler up with the chainring. Using the slotted T-Cycle bracket I moved the idler so the tall flange was over both cogs. Running it up and down through the gears looked really good on the center stand. I decided while I was close to home to give it a test I never tried before. Full throttle takeoff in the very crosschained 1st gear. BBSHD, flat chainring, and 135mm MTB rear hub. Absolutely no problem except the front wheel coming off the ground. I couldn't provoke any issues there. I haven't tried the 8-3 downshift at 30mph yet. Not sure what I'm worried about. All that ever happened before was I needed new zip ties. I guess because IDK why it needed zip ties? It's not an actual problem to downshift at reasonable speeds anyway.

[Retrorockit]

I've got some miles on this chain guide upgrade. I can drop multiple gears down at speed w/o an issue. There is one place I can go 30mph and look down at my chain at the same time.
Hucked it off of a curb where I had my last chain idrop. No problem there. On the center stand at 35mph I can provoke some chain slap if I dump 5 gears at once. But rolling them down quickly no issues even at 24mph in 1st gear. But no sign of the chain coming out. I did learn that hitting the throttle on the center stand in Lo gear can still rock the bike back onto the rear tire. It was indoors on porcelain tiles so it just whizzed the tire some. On asphalt it may have gotten away from me.
Since zip ties were lasting 2 weeks already I won't know for a while if this will help or if they just wear out. With this level of chain control I might go up to the bigger zip tie.

[Retrorockit]

"Hucking it off a curb" may not sound like not mush to an offroader,. but the implication in street riding is that you're probably going form a sidewalk to a road. Not the best place to have a chain drop. I don't have any choppy trails nearby to try this out, and if I did the Ebike might not be welcome there. Equestrians keep bikes off a lot of the trails around here already.I'll be easing into this to see if it's real. The bike can take it no problem

[Retrorockit]

I never did the M900 derailer SRAM Gripshift mod.. This mod has saved the Rapid Rise/Revoshifter setup from the spare parts bin. If you already have a modern clutch type derailer, and a Wide/Narrow ring that may be all you need for this. Bur someone else will have to answer that question. Street and off road may differ also.

[Retrorockit]

If you NEED this you will know it.
Here is an example. On a few occasions my bike has spit the chain when making left turns under power. I don't mean a chain drop. I mean a broken Connex link, and me coasting to a stop, and running around in traffic trying to find out where the chain went. The problem was with the bike leaned over in the turn I couldn't pedal. But I needed an upshift to stay clear of following traffic (or oncoming traffic). When I cut the throttle to shift, the chain stopped moving due to the rear freewheel. That caused the blown shift, and split chain. Rapid Rise didn't help here. The zip tie mod (front freewheel) allows shifts under this condition. Like I said, if you NEED this you will know it.

[Retrorockit]

My first try at fixing this was to ditch the Connex link, and rivet the chain. I haven't snapped an actual Wippermann 8SE chain yet. Then a home made roller chain guide at TDC to keep the chain on. I was wondering why those shifts still crunched, and also why teeth in the mid gears would get bent on the cassette.But at least the bike didn't stop in the middle of the road. Then I read about the Magic Cranks/zip tie mod, and then the Shimano Front Freewheel System safety feature. Since it only took 2 zip ties to try this I went for it. I had to up my game on chain retention, but it's working great.

[Retrorockit]

While working on this and trying to provoke a problem on the center stand I figured out that the zip tie doesn't break until the derailer arm runs out of travel to take up the slack. It has nothing to do with chain suck in that situation. Dropping down a bunch of gears at 30mph speed puts it into the larger cogs, The overrun on the top of the chain makes the chain too short, and the zip tie pops.
I'm actually running a mid cage derailer to keep slack out. In low gear it's right at it's limit. A long cage derailer from the 3x8 MTB days might actually be better for this. Since more normal down shifting at 20mph doesn't cause any problems,I'm not going to backtrack on this theory and give up my mid cage Rapid Rise XTR derailer. When wiping the chain to lube it if the rag goes into the chain ring, the derailer arm winds up, and them the wheel turns bckwards to unwind it. As long as it doesn't run out of travel the zip tie is OK. So a long cage derailer will absorb more slack than a shorter one. It works OK with a proper sized arm if you don't buzz the downshifts. But bigger may be better here.

[Retrorockit]

Here is another guy doing this with a piece of foam behind the freewheel or cassette to provide clutch action instead of a breakaway solution. You could probably find an O ring that will fit for this purpose also. He's not doing mid drive E bikes so IDK what he's using in front.
https://www.instructables.com/Modern-po ... cycle-FFS/
I like the breakaway for testing because it keeps you honest about chain management issues. But perhaps another option might suit some riders better. You can always grab the cogs with a rag and test the force needed to release the chain. The breakaway does have the advantage of going to zero force immediately. It definitely works.If i dropped a chain when testing this it just sat there not moving.

So a little history on this.
50 years ago Shimano offered this, but chain management was just a 2 speed derailer cage. Youtube videos make fun of it, but they don't mention riding it. In the comments people who rode one liked it. I think Rapid Rise low normal derailers won out because they were interchangeable with existing bikes. I still use them for 1x8 bikes.

Magic Cranks still offers Front Freewheel with zip ties, and requires a chain guide, but they don't get specific about what's required there.
It very expensive and noisy also.

Mid rive E bikes make this an option again for anyone who is interested. Front Freewheel is already there. Modern MTB derailers, and recumbent/ trike chain management solutions didn't exist 50 years ago.

[Retrorockit]

The foam for a clutch mod does require a Dork Ring.

[pbreezy]

Tried this mod last night and the bike tried to fly away. It was all going just fine until I got off the bike and started to walk it back into my garage. I had forgotten to turn off the Eggrider and had Sport level 5 engaged. When I started walking the bike it started turning the cranks and the controller engaged the PAS. the bike did a flying wheelie and almost hit my car before I could get my hand to mash a brake lever.

I’ve removed the ties for now until I figure out how to not be a stupid head… but you know old habits die hard.

[Retrorockit]

Launches from stoplights with the front tire skimming the ground are normal for me.Throttle and any other advantage I can find are welcome. Shifting while leaned over on traffic circles without spitting the chain in traffic is a big plus.The 15t idler/chain guide is worth having on it's own.My brother commuted in Miami on an acoustic bike. He moved to NYC where it's safer.

[pbreezy]

That’s pretty smart! The cars can’t run you down if they’re all gridlocked.

[Retrorockit]

Getting sucker punched by pedestrians in the bike lane is an issue.

[Retrorockit]

I found another little tweak for this mod. I installed a smaller cassette and decided not to shorten the chain which was at the minimum length as advised. I realized that if you cut the chain to the minimum you no longer actually have the full travel your derailer cage can provide. Since the zip tie mod can create some slack in the top run of the chain it may be better to leave it a little longer and allow the chain guide, and derailer to deal with it instead of having it jerking on the chain. This mod is reliable enough now that it's hard to tell if this makes a difference or not. Especially since I spend very little time in the lowest gear.

[Retrorockit]

I had some concern about reduces range due to the chain turning all the time when coasting. The rear wheel does slow down sooner than before when spun. Due to constant strong winds here it's hard to tell what's really going on. Also this mod allows standing on the cranks and throttling around going up and down through the gears like a motorcycle. The winds were calmer yesterday so I did a range test. Literally a PITA with a 24Ah battery. I rode the 36 mile loop to my favorite LBS at the othre side of the county. I rode PAS1/5 on side streets about 15mph, and PAS2/5 on longer runs 20-22mph. Full throttle at all intersections. Short bursts of PAS3/5 on busier traffic sections into the lighter winds. Basically riding as if I cared about range. The battery showed full at the far end of the loop which my 18Ah battery couldn't do, and stayed full about 1/3 of the way back.( I just have the 4bars on the display). I got to within a 1/2 mile of home before the 3rd bar dropped. So I guess the reduction due to added drag is real but not large. I have flattened this battery completely on 30 mile rides. But 20-25mph headwinds, and hooning around on the throttle explain most of that. Running at 32mph makes a dfference too. if you're a Watt watcher this mod may not be for you. With a BBSHD I always advise getting the biggest battery possible. 24Ah is NOT too much. Maybe most of the time, but not always. I also have the huge roller chain guide that makes the zip tie mod work, so i wanted to see how it all adds up.

[Retrorockit]

I think I crushed the bearings on the first idler. Automotive idlers you just crank down the nounting bolt to hold them tight. This one you need jam nuts to set it up like a bicycle axle bearing set.For recumbents they actually let it float around on the shaft

[Retrorockit]

Here is the acoustic bike version of this.

https://bikerumor.com/intend-adds-a-freewheel-to-their-cranks-letting-you-shift-without-pedaling/

[Retrorockit]

Somebody asked for a photo of the recumbent toothed idler/ chain guide so here it is. It catches the chain in mid air and sticks it down on the chain ring. This is 15t, the bigger one is 23t. So you can play around with some cogs if your bike is different. I may have it further back, and further down since this photo.
You can see there's not much hope for an inset chain ring. So this is a flat 8 speed Surly SS 50t. Full power in all 8 gears with this crosschained beast.
Basically it's a jockey wheel like the derailer has to put the chain where you want it.
There's a right way, there's a wrong way, and there's a right way to do it wrong.

[Retrorockit]

Because the idler is moving with the chain it doesn't add friction to the system With the zip tie mod anything that rubs the chain makes things worse.

[Retrorockit]

Be sure and do the later version in the photo below. The 5 hole one shown here was a nice development tool, but not up to real world use.
T-Cycles battery mounting clamp is what's needed. That 5 hole plate made a nice tap starting guide for hand tapping M8 holes.
I'm too cheap and lazy to do stuff that isn't elegant.

[Retrorockit]

All the torque was pivoting around one M6 bolt. The tab to the other bolt was too thinned out for this purpose. It was good for proof of concept, and mock up duty. 2x M6 bolts seems like enough but they both need to be sharing the load.

[Retrorockit]

I'm sure you guys will be shocked to hear I broke something. I mean i tried to see if it would break during testing and nothing happened. But tonight the clamp section of the idler bracket broke off. It was a transition form a very thick section to a very thin one in the clamp area.. It would have been OK in the intended idler application, but right next to BBSHD with 95# of torque it wasn't enough. I rdoe home OK with no chain guide at all. I just stayed out of the 2 lowest cross chained gears and rode gently. T-cycle makes this bracket for some larger tubing sizes. I've asked if they could take one of the larger bracket and under bore it for Ebikes. A 2' bracket under bored to 1 3.8" should solve the problem

[Retrorockit]

The performance of this has been flawless. It's just under some big loads in directions it wasn't designed for. T- Cycle has gotten back to me already, Which from west coast to east coast is pretty good.

[Retrorockit]

T-Cycle was nice enough to replace the broken part. It was and still will be a useful fixture for fitting their idler to other bikes, and some light testing.
The band of the clamp is no bigger than any other similar seat post clamp with 2x5mm bolts. It lasted 2 weeks on my 1500W bike. On a 350W bike it might be OK, or you could drill it out for 6mm bolts. But it's the thin strap at the bracket that broke, not the strap across the back. The 15t idler is amazing. I really miss having it on the bike. I may take the broken bracket to a welder, and have some extra metal added. To be fair it wasn't made for this, but so far no simple off the shelf solution yet.
Getting back to DIY territory I ordered a T-Cycle battery support clamp in 1.375" (34.9mm) Thicker (5/8") material and bigger strap and M6 bolts. So they do know how to make Ebike parts when they want to.
t-cycle.com
Frame Clamp
The heaviest duty clamp we offer! It's the clamp that holds the Battery Mounts, the SPRING Mini Fairing Mount and the WINTR Fairing Mount in place! Sporting twin 6mm bolts, this 5/8" thick beast stays where you put it and holds what you need it to hold. Made in an ever-growing list of sizes...
t-cycle.com

https://t-cycle.com/collections/all-battery-mount-parts/products/heavy-duty-frame-clamp

You have to look in their a la carte section to find these. Some are for square tubing so don't let the illustration photo deceive you.
Now that I know where the 15t idler needs to be, a few minutes at the drill press to make an adapter plate should have this resolved.
Functionally this is doing everything I ask of it. Structurally it would be nice if it stayed on the bike a little longer.
So the update is.
The zip tie mod works but needs serious chain management to go with it.
The T-Cycle 15t idler handles all kind of chain issues. But the bracket to use it for an Ebike chain guide doesn't exist yet. At least not at BBSHD levels.

[Retrorockit]

A little progress while waiting for parts. I took some of the stuff that didn't work so well and installed 2 different small roller guides at once in tandem. Seems to be working at reasonable power levels. I know it won't stay adjusted under full power launches So the bikes not parked. The 2nd one is on an arm clamped to the head of the Allen bolt holding the first one. None of these parts were intended to be used together.
One of everything=one of "something".
Aaron at T-Cycle was kind enough to send me the dimensions of the HD Battery Bracket so I can make my chain guide conversion adapter plate while waiting for parts. 2xM6 bolts 1.97" apart. I like the wide spacing, good leverage on the bracket. I'm going to test it as sold to see if there is a one stop shopping solution for this.
But it could be drilled & tapped out to M8 for maybe a wider Fatbike installation if needed.
There is another version of this same clamp for attaching fairings to trikes. I didn't think to ask what the difference is. probably something to do with the bolts.
One other option for this 15t idler is a 10mm bearing. At the width I'm using the M8 bolt makes sense because I've bent them before, and it's a simple repair to just relalce an M8 Allen bolt (as opposed to breaking the clamp). Like the zip tie it's nice if nothing ever breaks. But it's also nice to be able to fix it easily if it does. But if you need to go wide it's an option.

[Retrorockit]

I got my parts. I tried the T-Cycle idler bracket again and watched it bend every time I got on the throttle. I hand made the adapter plate too long, so I fixed that and swapped the parts, it doesn't move now. The aluminum spacers are from T-Cycle too. The plate is 3/8"x1" 6061. It's not T6 like the T-cycle stuff but it's about 8x as bigger than the section that broke. The price is the same for the 2xm6 hole bracket and the battery hanger clamp. Wit the 5 hole plate it's actually about $20 more. So functionality is back to 100%, I think it's not going to break for a while this time.
I'm getting some bearing rumble. Most automotive idlers you can crank down the mounting bolt. I used a jam nut last time, and this time I didn't so I need to look into that. I did pick up a spare idler. T-Cycle likes to float the idlers on the shaft, so I may need to be a little more delicate with it. Their bolt kit comes with jam nuts, so maybe I didn't take the hint? I'll probably make another adapter plate with a 17* angle to match the 73* seatpost angle. I need wider material to do that. I'm a ham fisted truck mechanic, so if I can get it where it doesn't break for me, it's probably good to go.


The broken bracket is on the left, (and the new one) the larger battery hanger bracket is on the right with the DIY BBSHD rated adapter plate for the idler.
The HD strap passes under the SS torque arm on the other side of the seat post. The M6 bolts match up nicely there.

[Retrorockit]

I looked up inside the idler. The inner bearing races don't meet in the center, so I definitely crushed the preload on them. I'll put the spare one in carefully this time, and get some new bearings for this one. So use jam nuts to fit the idler softly on the shaft. This makes it fussy to install the idler because it won't move sideways on the bolt when tightening it. But when I put it on this time I think it's going to stay there.I may switch to cap screws so I can remove the adapter with the idler as an assembly. It's a good thing I didn't counterbore the bolt holes yet.
This wouldn't have been an issue in it's original application hanging in the middle of a long chain run. It's only a problem here because the idler overlaps the chain ring and can't move sideways when being installed.

[Retrorockit]

I have a couple blank plates to make some more adapters. I'm going to try a couple things. Just small adjustments really. I think the bike is abcuk at the point where I can ride it around without any issues again. It was that way before until the clamp broke. I haven't quite got the shaft back exactly where it was before.. I put the hex head bolt behind the idler. Now it can swing up off of the chainring for maintenanece. Now I have an excuse to call it the Rockin' Roller.
Rode 25 miles today. the wind was 20mph and gusting higher. Shifting direction all over the place too. I let one poor guy on a pedal bike draft me for a couple miles. He was young and fit so 20mph into a 20mph wind he was keeping up pretty good.
Enough about the idler chain guide. the zip tie mod is still in there doing it's thing.Up and downshifts any time, any gear ( within any sort of actual reason) the Rapid Rise junk still pops several downshifts standing still. Don't need that as often anymore. I'll stick a new chain on it. This ones had 6 months of R&D done to it.

[Retrorockit]

I replaced the chain that's been on it through all the testing. Wippermann 8SE washed and waxed (Squirt) and riveted. I tried adding an extra link, but my mid cage derailer couldn't absorb it.
There is a formula 1 link (1 inch) equals 4t capacity. So dropping from an 11-40t cassette to an 11-36t got me where I needed to go. I've dropped the chain a few times during this (not with the 15t idler) and since I put the extra slack in there the zip ties haven't broken. 1 extra link seems to do it from the tight on the large cogs setup. I made another plate. The same thing but moved the 2xM6 holes so it's 1/4" longer. That lets me put it a little lower on the chain ring. In the big cog I can push the chain down to the chain stay and still have a little derailer travel left. That seems to be what this setup needs.

[Retrorockit]

I made my final plate. I used 3/8x1 1/4 6061. The extra width allowed me to drill the M6 pattern at a 17* angle to compensate for the 73* seat post angle. This did 2 things for me. The angle now provides the vertical offset to get the thicker clamp lower and away from things on the seat post.I moved the M6 holes 1/4" further forward. So the M8 hole is 1/16" from the fender, and so is the end of the 50mm bolt. I'n using all the available space to get my adjustment..The Rockin' Roller feature is working. I just loosen the 10mm head hex bolt behind the idler, and remove the M6 socket head front bolt and the idler swings up enough to clear the chain ring, and work on the chain, adjust the clamp height, or remove the idler/shaft as an assembly. The idler is as far back and as far down as it can go on this bike. So now there is no need to mess with the adjustment of the seatpost clamp, or bearing preload to work on anything. I'm having trouble getting photos from my phone to the computer so no pix for now. But the bracket is now parallel to the ground..