Honda Metropolitan / Reflex 250 swap

[furiousbob]

Alright so I picked up an 05 Reflex and 05 Metro for cheap.  Both were about $1k each.  The Metro wasn't running and the Reflex was in a front-end low-speed collision.

So I ripped the motor out!




Unfortunately, that's all I got for now.  I started tearing panels off the Metro.  It looks like the motors are pretty similarly sized.  The overall length is about 10" longer, though.  This will have a stretched look to it.  Some initial measuring tells me I MIGHT be able to use the metro motor mounting locations for the Reflex.  That or a simple cut/weld with some new tabs, perhaps?

A note about the Reflex motor.  It's got a LOT of vacuum hoses.  A bunch of them are emissions equipment, however.  There's an AIR system onboard (sorta like an EGR?), which can be deleted.  I believe there's also a charcoal canister system.  Same, delete!

I will re-use the overflow tank on the Metro for the 250cc.

The most complicated part is going to be figuring out wiring as I re-use the ECU from the Reflex.  I'm surprised these things have any sort of management, though.  They seem to be simple CDI systems.

Anyway, not sure when the next update will be but I'll post em here when I get em.

[brecken]

I have the exact same scooters outside. I started taking off all plastics and getting down to the the engine only on reflex. Came in to see what I could find on google. Will be following you closely.

[furiousbob]

Unfortunately not much progress on this since the last post. Going through some personal issues right around October of 2023 and I haven't had time to revisit my projects since.

It's still #1 on my radar though. I'll post updates here whenever they happen.

[furiousbob]

So one year after I picked up the scooters. We have progress.

It's been a heck of a year. Lots of ups and downs. Anyway, that's neither here nor there.

I bolted the front end to my welding table and started ripping in.



I tried getting the 250 motor as close to the front as possible.



There is definitely intake tube clearance issues.



I am planning on making the stretch arm first. The idea is to stretch it maybe 6 inches. The Reflex has dual shock mounts. I don't think I'll be able to use the Metro's shock mount since it's too far forward. Instead, the Metro's shock mount will be used as a mounting location for the left upright that triangulates the stretch arm. On the opposite side ( or right side ), I will need to make a new mounting hole for the right side upright. Not a huge deal.

The issue is how am I going to mount the single shock? Will a single shock suffice?



Worse comes to worst, I can just cut the panels. But I'm trying to avoid cutting anymore than I have to.

Anyway, this is just the beginning. It's taking up my primary workspace now so I need to keep rolling with this.

I'll start mocking up for the stretch arm tomorrow. So far, width spacing looks pretty doable. The mounts on the Reflex motor, at first glance, looks to be just narrow enough for the mounts on the Metro frame.

We'll see tomorrow.

[furiousbob]

Debated for a while on whether or not to butt the head of the motor up to the original location of the metro motor head. Having it in the same place as the metro's means only a 5" stretch and fabricating a shock extender would be much easier. Having it pushed further back would mean a 10" stretch and the shock extender would be sticking out well outside the rear fender. BUT a longer stretch means more room to work with for the intake tube but it would look ridiculous ( in a good way ).

I ended up opting for the shorter stretch. The intake tube will need to do a 180 and exit through the front panel so the carburetor would be between your feet. This makes boxing the stretch arm more difficult because of the lack of space but it makes making the shock extender much easier.

For the rear shock. AS IT TURNS OUT. The reflex has a separate mounting tab next to the original mounting tab that is further forward and fits the metro shock perfectly. It isn't rubber dampened, however. Not sure how significant a role that will play.



The shock extender will start with an eyelet at the original upper shock mount and run the length of the battery tray ( with a bolt or two to secure it to the tray. This step will come later after I figure out the stretch arms.

Speaking of..









I spoke about triangulating the stretch arms. I'm going to go another route. I'm going to use the original swing arm bump stop bracket and modify it to fit the new arms. I got the idea last night after I bumped into a generic Metro stretch kit on SmallFastThings:

www.smallfastthings.com/single-post/honda-metropolitan-stretch-kit-install



Or if I get frustrated with trying to cut off the original mount, I'll just do what SFT did and make a dowel with what appears to be an abrasion resistant UHMW sleeve. I also have some delrin lying around, I might just do that.

Anyway, tomorrow is my birthday and the missus insists that I celebrate it so I'll continue on this over the weekend. The next step is to box in the arms for rigidity. I may just opt for a hollow round tube instead of fussing with boxing it in. I'm also slightly concerned about the angles of the CVT case. As it sits now, the case is parallel with the ground. Once the suspension is loaded, I'm afraid it'll dive down towards the floor. But angling it up at static height means modify the arms I already made. I'll do some thinking.

[furiousbob]

I ended up redesigning the arm to add a large curve into it. The original straight arms had too many clearance issues with the Reflex case.

I used 1/4" x 3" flat bar to cut these curves out of. They're not the best looking because my belt sander setup doesn't have the best radii. I had to do a lot of hand filing like a pleb.

Anyway, I gave up on cutting the factory bump stop thing out. I ended up just duplicating it. The original bump stop thing holder was 14ga or 0.090" thick, I bumped it to a .120".

I then turned down some tube sections to act as spacers for the rear long bolt. I used 3/4" OD 0.120" wall tubing. It had a 0.500" ID which worked decently well with the 12mm long-bolt.

I then used some 1" OD 0.090" round tube to brace the arms.

Here is the final product:









This will all get cleaned up and I will be sandblasting and powdercoating it in-house in matte black.

Next up is to start the rear shock relocation bracket.

And after that's sorted, it's on to the intake tube manifold thing.

It's coming along!

[furiousbob]

Only had a couple hours to work in the garage today.

Mocked up the rear shock. I don't want to spend money on additional parts yet so I tested the factory shocks. I've been having a week-long debate with my buddies about which shock to go with. The general consensus is to stick with a single Reflex shock. I'm adamant that a single Metro shock will suffice. Either way, here's the Metro shock mocked up:





And the Reflex shock:





The amount of lift provided by the Reflex shock is enough to steer me towards the Metro shock.

In any case, I did some measuring and I have about 4" of travel at the shock. I'm mounting the shock at around 2" so it's sorta static.

I've started making the plate that'll bolt onto the factory Metro upper shock mount. And I've opted to keep the upper shock mount rubber bushed. I scavenged the rubber bushing off of the old Reflex shock and I turned down some round stock to press it into. It needed a double taper, like an hourglass taper or whatever you call it.

Photos to follow soon.

[aeroxbud]

I think the metro shock might be too soft with the 250's power delivery. Worth a shot though.

[furiousbob]

I am considering swapping to a Ruckus shock. Not much better in terms of dampening but it'll at least have a rubber bushing built into the shock.

This might be a guess-and-check sorta deal. If it is too soft, I can just lop off the top mount and make a new one.

[jbjhillbilly]

Aftermarket Ruckus shock might do the work, but you’ll need an adapter to use a Ruck shock on a Met frame (or make one).

mnnthbx.com/product/honda-met-shock-mount-2/

And Forsa makes a more substantial shock

theruckshop.com/product/forsa-ruckus-performance-shock-252mm/

[furiousbob]

Thanks for that! I ordered a $25 ruckus shock off of Amazon. It's a no-frills factory replacement. I'll be basing my upper mount off of that. If it works, I'll probably keep it there. But chances are I'll need some suspension tuning down the road.

[furiousbob]

Been working on the rear upper mount the past couple days.

Basically made a plate that bolts to the underside of the rear deck where the ECM originally lived. Also bolts to the original upper mount. I extended the plate to the right too in case I need to mount a right side shock down the road.








With the cowls on:











It seems with the suspension loaded, there is ample space for a intake tube. Next question is where to go with it. Front exit will block the fuel filler door on the floorboard. Rear exit might be too long of an intake tube. I was thinking maybe out the driver's side fender cowl. I'll have to do some thinking.

Also, I mayyy have gotten a bit too careless with the shock placement. There's about 1/16" of clearance between the spring coils and the tire sidewall. It's currently got 130/70r12's on. I was debating on going with a 110/60r12 or something to mitigate this.






Anyway, next step it start building the intake manifold and tube. And after that, it's plugging it all back up and seeing if she runs!

Edit:  Forgot to mention, the rear shock is a cheapie $25 shock off of Amazon.  Designed for a ruckus, I believe.  My initial impression was not great:

[furiousbob]

A small update.

I was able to replicate the factory CN250 intake manifold ends. This way I can reuse the factory rubber carb connector instead of figuring that out later. These parts took me a solid 2 afternoons. I also have a intake tube made up but it's been challenging figuring out where to locate the carb.

[furiousbob]

Did some test fitting last night with the intake tube.

I could not find a good direction to go forward, up, left or right. Any of these directions from the head would mean I'd have to cut a lot of plastic out of the way. Normally that wouldn't be an issue BUT the storage box bin for the Metro acts as a support for the rider. So cutting into the bin would mean I'd have to reinforce it down the road.

Here's my solution:








The bin has a natural hump at the bottom. I think this was to facilitate the GET's carburetor placement. I used that hump to give me space for a long ( maybe 1 ft long ) tube to exit out the back. I'll be using an angle cone filter to get the cone facing the rear.

Next step is to assemble the bin and seat temporarily and get the scooter down on the floor for some suspension travel testing. I need to see how close the intake tube gets to the stretch arm.

[xdruck78]

I am very interested in seeing more of this build. I have a Ruckus and I am picking up a Reflex motor and suspension next weekend. I am curious what your plans are for the wiring harness to run the swap.