DR650...something

[squarefour]

This is coming along. I still need to do cables, brake and oil lines, and electrics. I'm going to test ride it a bit, then tear it down for paint and plate. I'm thinking yellow cadmium for the frame, which looked good on a-arms for a 4-wheeled project.

Don't ask me what it is, street tracker, bobber, cafe, whatever, I dunno. At this point I'm just building what I feel compelled to build.

'99 Suzuki DR650 engine, wheels, forks, brakes.
Replica SonicWeld rigid flattrack frame. Came with footpegs, which I had to heavily modify to be symmetrical L/R.
Moped seat.
BSA Victor (?) tank.
1.9" coilover shock with 75# spring for seat suspension (4-wheeled project leftover).
TM40 pumper carb.
Flat tapered bar for freestyle snowmobiling.
Aftermarket billet top triple clamp with a bunch of brackets sawed off.
Vintage NOS J&R silencer.
Stock steering damper from GSXR600. (I was told this is going to be a wheely monster, so I thought a damper was prudent.)
2.50-21 cheap Chinese trailbike tire
Stock DR650 rear tire.
DR650 oil cooler (a bit ugly and a PITA).

[redsox716]

Love it! Totally new and different. Keep it goin!

[Sighless]

My oldest will be getting his learners permit next summer. Something like this would be perfect for him. I'd better get buildin.

[Twinkies]

I dig it.. how does it ride and stop with the stock dr650 forks and hardtail/ seat suspension combo?
Were the forks re-valved?

[squarefour]

As soon as it's running, I'll let you know how it rides The forks and springs were shortened about half a foot, but not revalved. I added air valves to the caps; some air pressure should soften bottoming. I'll start with ATF in the forks, but I may need to go to 15 or 20 wt. Oh, I shortened the forks by just adding a big aluminum spacer on the damping rod, above the topout spring.

The seat coilover actually has a damping adjuster, anywhere from zero to it-takes-5-minutes-to-rebound-fully. So I'm feeling pretty confident I can tune in an acceptable ride.

[Ember]

Nice bike. Are you going to use it strictly for dirt? I've been wanting to build a trail bike for some time.

[squarefour]

Oh it's meant for the street, but I live on a dirt road, so I guess a little of both.

[mcdowell72]

bad ass, totally bad ass.

[squarefour]

One of the downsides of the DR engine is the lack of kickstarter, and it is not easy to add one. So I needed to keep a battery. I decided on an unusual approach that may be of interest:

[earz]

What kind of cells are those?

[squarefour]

They are (4) LiFePO4 batteries, similar to the "DeWalt" or "A123" cells. I got them from from here:

http://www.batteryspace.com/lifepo432900pfsizecell32v45ah90arate144wh.aspx

Some sport bikers and WR450 guys are using them, but in a regular pack.

If you can't see in the crappy cell pics, the pack is slid up into the frame backbone, with a clamp at the bottom with terminals. As far as I know, this will be the first "BIF" motorcycle. Woohoo!

[earz]

That's kinda what they looked like, but I wasn't sure. I'd been doing some reading on those a while back. What's the deal with the equalizer or whatever to keep each cell charging at the same rate? I had read that the cells need to be balanced when charging otherwise they could wear out prematurely or possibly explode!!?!

I don't have any experience with them, it's just what I have read. If there are guys running them like this with no problems, I'd say rock the BIF. I'm curious to see how it works out.

[squarefour]

It's the LiPo cells that explode, not LiFePO4. The A123 type cells are pretty much explosion-proof. The one thing you have to do with these is do an initial charge on each cell individually, and make sure that they are fairly equal in capacity. After that they seem to live with alternator charging fairly well. I imagine if I ever run them dead even once they may be history. And I worry about shorts happening inside the tube, so I used a long of heat-shrink, etc. And the exhaust runs a little close to the bottom, so I'll have to wrap it (they don't like heat).

[earz]

Ok, cool. I wasn't aware there was a difference.

I'll have to keep this in mind in the future. I decided to go straight kicker with capacitor on my current build.

[squarefour]

Yay, it runs, finally. Toodled around all weekend, playing with the jetting.

It's been a bit of a struggle. First, I had trouble with the LiFePO4 pack, mainly due to QC on the cells being unacceptable. Coincidentally, right at this time I was given a new gel battery for free, so I accepted fate and installed it. I might try the LiFePO4 thing again later on, preferably from another vendor.

I was also not getting any spark. I checked the impedance of the stator and pickup coils, and the ignition coil, all ok. I checked the waveforms of the coil outputs with a digital scope, all ok. The pickup coil shape looked a little "sharp" to me, but I was assured that was normal. I bought an ebay ignition coil, no dice. I then bought another CDI on ebay ($275!), no dice. I brought the ignition coils and CDIs into work and had them fully bench tested with very sophisticated equipment that can synthesize the coil inputs. The coils worked fine but we couldn't get the CDIs to work. During this testing I was also spending hours poring over the schematics looking for a mistake in my wiring, even though it's pretty simple. I also spent months ignoring the bike's existence. Finally, since I couldn't think of anything else to do, I ordered a computer-programmable CDI from Ignitech in the Czech Republic. Once I installed the Czech CDI, it ran, sort of. It was backfiring like crazy and wouldn't idle or rev out. I programmed in a flat advance curve as an experiment, and then it idled at least. It was then that I noticed the RPM readout on the laptop (which reads from the pickup coil through the Czech software) was jumping around from 800 to 2000 RPM. The only thing that could POSSIBLY be is the pickup coil.

So despite the ohmmeter and scope telling me it's ok, I replaced the $40 pickup coil and it ran great. DOH!

Now, off to run the DMV gauntlet to get plated...

Oh yeah, it's amazingly comfortable and fun to ride. It is NOT prone to wheelies, to my relief (and a little disappointment).