For the sake of discussion, here is the baseline recommendation as posted earlier, but with the new eTrikeKit:
- (PT3CB-JR) with 3-speed, coaster brake, and front drum brake. with substituted front caliper - $555.
- Electric Trike Conversion Kit - FRONT 500W, Fwd/Rev, Speed Limiting, 'Fuel Gauge', 36v 12Ah SLA Battery - $696
Total = $555 + $636 = $1251. This is a pretty complete package that seems to address all the needs with the exception of ebrakes on the coaster brake which can be added as a DIY task - not too difficult.
JDPA wrote:Finally, I need a solution to add more/easier braking to the bike. The original Worksman had two hand brakes. One was a front caliper, the other was a front drum(?). So, now there is only the front caliper and there are two concerns. 1) it takes a LOT of effort to stop the bike 2) it's hard for her small hand to squeeze with any amount of pressure.
So, experts, what can I add? I believe the fittings are on the motor for a brake disk, but I don't think the fork has the needed clearance. Can I get a fork with the needed mounting points for the disk caliper that is wide enough for the wheel with the motor? I have an extra hand brake that is only serving as an e-brake. Should I change out the gear to a coaster brake? It's something she knows how to do, but would still take a heck of a lot of pressure to stop. And, I'd want to add the cutout components discussed before. What about rear disk brakes? Is that even possible (within reason)?
So - I'm a little confused about exactly what you have in hand - a little clarification will help. It's not clear to me what motor kit and Worksman trike were used to build your prototype - they do seem different than the recommendation above. This may be fine, but let's muddle through this just to be sure...
- You mention the Worksman Lightning which seems pretty close to what was discussed earlier except that it does not have the FWD/REV switch on the throttle and so is not really the new e-TrikeKit. It does have a front caliper and rear coaster but appears to be a single speed where a three speed may encourage more pedaling and make the bike more manageable if the battery runs down.
- You mention they showed you steps to modify the controller to limit the speed. This is surprising because they seemed in phone conversations to be adamant about modifications voiding the warrantee. Without more details, it's unclear that the dual speed 10mph-FWD/3mph-REV limiting of the new e-TrikeKit can be installed in your controller - typically such modifications yield only a single speed limitation that would apply to both Fwd and Rev.
- Similarly, it's unclear that Fwd/Rev can easily be retrofit to your controller or that the change will not void the warrantee.
- You describe the trike as having a front caliper brake and mention "Should I change out the gear to a coaster brake?". Does this mean it has no rear brakes at all? This does not sound like the Lightning (which seems to be based on the PTCB-Jr), but more like one of the first two single speed Port-o-Trikes above.
I may have misunderstood, so please help if this misrepresents the situation.
I'm guessing that you got a good price on the prototype, but stepping back, it seems there may be shortfalls in these areas: Fwd/Rev, coaster brake, 3-speed shifter, dual speed limiting (Fwd/Rev different). If you feel any of these are important, then you need to chase down how the vendors can help you achieve them ASAP. The problem that we struggled with in this project is that both vendors have pretty unusual custom products, and eBikeKit is (perhaps not unreasonably) unwilling to provide warrantee support for a modified system. This means that if they can't supply it, you can't have it - hence picking the right kit/trike to start is paramount. So here are some questions to clarify the situation:
- The questions you must answer yourself are:
- Is my daughter strong enough to back up the trike if it rolls against a curb, etc, or does she need Fwd/Rev?
- Can she handle the same speed limiting in Rev and in Fwd (10mph)?
- Can she stop this trike with/without a coaster brake?
- Can she handle a three speed shifter, and how important is the therapy/exercise component of the bike experience?
- The questions you must pose to Worksman are:
- Can I upgrade my trike with single speed or 3-speed coaster brake and how much will it cost?
- The questions you need to pose to eBikeKit are:
- Will modifications to the controller or motor wiring void the warrantee?
- Can they show you how to add a FWD/REV switch?
- Will the modification they outlined provide a single speed limiting for FWD+REV or the two different speeds of the new eTrikeKit?
- Will they swap out the throttle/controller with those from the eTrikeKit to obtain the standard out-of-box functionality that kit provides (assuming that only these parts need upgrade)?
- If you cannot swap the parts, how much will it cost to purchase the eTrikeKit throttle/controller outright or otherwise upgrade the kit to an eTrikeKit?
If the answers end up leaving you with missing features that you feel are important or with unmanageable costs to retrofit them, the best course may be backing up and exchanging your prototype for the motor kit and trike at the top of this post.
Apologies if all this was clear, but it seemed worth running over just to be sure something in all these many posts was not overlooked.
As far as switching to disc - this will improve the stopping power and you may be able to swap forks (a problem here is the short custom Worksman fork for 20" wheel) or get mounts welded to your current fork. However, you are not going to see a 5x reduction in effort to apply the brake. The required coordination to grab and squeeze the lever will be unchanged. Tuning up your calipers will probably improve what you have, but I personally believe that a coaster brake which uses major leg muscles and requires minimal coordination is the best choice (but that's just me).
Adding rear brakes is likely possible, but Worksman does not appear to provide the option so you are going down a path of re-engineering the rear end which will likely be more trouble and expense than it's worth. And as with the front, coordination to operate the lever will be a requirement.
As amberwolf points out, a kind of electrical braking effect can normally be had from the controller. This is often applied simply by pressing a button on the throttle. In this case, the controller does not appear to provide it (no regen switch visible, no regen switch wiring on the controller, and no mention in the doc). Although this might be wrangled by tinkering with the motor connections, we once again run into the warrantee issue when changing or modifying components.
The pulleys that amberwolf mentioned sound interesting - delicate brake modulation at only 10mph is probably not a huge consideration so this might be worth pursuing.