Author Topic: DT-100 Bucket Racer (Read 30936 times)

jamoni · « **on:** March 17, 2012, 05:35:24 PM »

Hey, guys, it's been a while!
Anyway, I finally got my shop sort of together, and now I have a project. I had an old Yamaha DT-100 motorcycle. It's an enduro:a street legal dirt bike. It's a two stroke, and has a lot of torque but a limited top speed. 60 mph is about maxed out.
Here it is last year:
(It's the little green one in the background)

This is it right now:

So far the only thing I've bought for the project was the fairing. Everything else was done out of scraps and bits floating around the garage. I'm a full time student, so this is being done on a budget of free dollars. I decided not to even try to approximate a cafe racer, and instead went for a street legal bucket racer.
I welded up the handlebars out of plumbing pipe and some scrap steel. The seat is a pine board padded with an old bathmat and some scrap vinyl. The rear fender is bent out of some steel sheet I bought for another project.
Currently working on rear-sets:

SOkhA&index=1&feature=plcp

The aluminum I'm using is from some old radio equipment that was being scrapped at work.
Okay, I DID buy some allthread and a couple of bolts.
Anyway, it's not for everybody, but I like it just fine. It's a LOT more responsive and fun to ride now. It was already a wheelie machine, now it's moreso. The rear sets will really make it more comfortable. Skinny tires are also on the list. Eventually I'll be looking at some repro CR110 body work, regearing, and some engine work.
Here's some progress on the rearsets:

It took forever to do it this way. For the next one I'm going to drill a pilot hole, and rough cut the hole with the jigsaw before I mill. Easiest way would have been to put the piece on a lathe and bore it, but the swing on my lathe is about 1/3 what I would need to do this.

Then it's just a matter of milling the edges to shape, adding a pedal, and maybe drilling some lightening holes.
Stay tuned, cause there's a lot more work to be done!

nel2lar · « **Reply #1 on:** March 17, 2012, 07:18:02 PM »

Can you use a angle plate and bolt the part to it and use a boring bar?
Nelson Collar

nel2lar · « **Reply #2 on:** March 17, 2012, 07:22:13 PM »

jamoni
I caught my eye what you call it "DT 100". What does the DT stand for? I hope not Death Trap.

Nelson Collar

jamoni · « **Reply #3 on:** March 17, 2012, 11:11:08 PM »

Not sure what you mean. Do you mean bolt the part to the angle one the slide, and use a boring head chucked up in the lathe? If I had a boring head I could.

This way works fine, it's just a little slow. Actually, I did the shift lever today, and it went a lot faster. I used the jigsaw to rough cut, and that saved a lot of time.
Unfortunately, I got distracted and went a hair to big on my press fit. It's in there, but not as tight as I want, and it'll work loose eventually. I got to make a new lever, but I'll use this one while prototyping:

So I got the rear brake linkage squared away, and rode the bike around. Brake works great. Needs a slight adjustment, but no biggie. However I found out that the kick start doesn't clear the rear peg.

No big deal, as I was planning to replace those pegs with beefier versions anyway. I'll need to modify the kickstart, but for now it's popstart only.
There's a lot left to do, but it's coming along nicely.

jamoni · « **Reply #4 on:** March 17, 2012, 11:20:41 PM »

Quote from: nel2lar on March 17, 2012, 07:22:13 PM

jamoni
I caught my eye what you call it "DT 100". What does the DT stand for? I hope not Death Trap.
Nelson Collar

I'm not sure what the DT means. I think the "T" means trail, and the "D" is just a model designator, but I could be wrong.

Kjelle · « **Reply #5 on:** March 18, 2012, 12:58:25 AM »

Nice thing!
But please, make those foot-pegs folding! For safety, and for looks. And knurl them, or get some foot-peg rubbers, so your feet don't slide off...

Kjelle (it's too early to write a longer reply...)

jamoni · « **Reply #6 on:** March 18, 2012, 02:49:55 AM »

Kjelle, The pegs are going to be MUCH shorter and stouter. They won't be folding, but if it ever gets to the point that they hit pavement, it will mean my boots are nowhere near them. So I'll have bigger fish to fry.

MadNick · « **Reply #7 on:** March 18, 2012, 05:53:40 AM »

A good start and something a little different too.

As for your press fit cant you glue it in with some bearing glue or similar?

Nick

jamoni · « **Reply #8 on:** March 18, 2012, 11:12:45 AM »

Nick, bearing glue? Are you messing with me? That sounds like "a box of grid squares" or "500 yards of flight line", or "muffler bearings".

Anyway, I think I'm embarking on a major design change to reduce the bulk of these levers. I have a bunch of steel and a little AC welder. I think I'm going to weld up some simple lever/pedal assemblies. It would have a tubular part that goes around the peg bolt, a long 1/2" round armat a 90* to that, and then a 1/2" pedal at a 90* to the arm. The tubular part would be long enough to act as the foot peg, and would also stabilize the assembly, so I wouldn't need a bearing.

Simple, clean, a little heavier but much stronger, and it'll look far more like race equipment. But.... the others are already done.

MadNick · « **Reply #9 on:** March 18, 2012, 02:02:15 PM »

Personally I would stick with Ali - Its easier to work with than steel and looks so much nicer when polished up plus why start again, you are refining the design.

And no im not messing with the Bearing Glue. A few years ago I restored a Yamaha RD350B and one of the rear wheel bearings was very loose in the hub. I was a bit dubious on the glue at first but the supplier said 'I wouldnt sell it to you if it wouldnt work' and she was right! I glued the bearing in and it was still there when I sold the bike a few years later.

Nick

jamoni · « **Reply #10 on:** March 18, 2012, 06:07:55 PM »

Here's what I did today:

Hit the gym, levers! I'm putting you on a DIET! Cut the levers down to a more manageable shape. Other than final shaping and sorting the pedals/pegs, the right side is done. Works perfect!

The left side is still pretty rough. I'm prototyping at this point. The shifter clamp needs to be remade in steel. It stripped out, and the clamp broke. You can see the break right near the screw. I'm pretty sure it broke/stripped because the geometry is wrong.
I also need a longer piece of allthread so I can get the geometry worked out. Oh, and that big ass joint at the front end is going to be replaced. It's overkill. I can make it much smaller. I may see about modding the original shift lever to use, since it's obviously strong enough.
Still, until the shifter stripped out, I was hauling @$$ up and down the alley, so can't complain!
Nick, now that the levers are cut down, I think I like them. I still need to remake the left one. At the very least I need to press in a sleeve and redo the bearing, but I think the geometry of the lever needs adjustment, so I'll probably redo the whole thing. Hooray for free materials!

MadNick · « **Reply #11 on:** March 19, 2012, 07:14:51 AM »

A good start.

Would definitely consider nylock locking nuts or at least use of split pins, especially for the pivots on the gearchange lever. Also some kind of sleeve for the pivots would be a better idea - steel on ali is not a good idea.

Nick

jamoni · « **Reply #12 on:** March 19, 2012, 08:02:14 AM »

Nick, you're speaking my language! The pivot bolts will all be replaced with smooth rods and cotter pins. I'll press in a steel bearing (or a ball bearing if I'm feeling froggy) on the lever. That'll keep the steel threads from eating the aluminum.
All of the bolts will get locking hardware and liberal doses of threadlock compound. I don't want a pedal falling off at 60 mph.

All of that comes after I get the geometry dialed in.
I knew this side would be the hardest. It'll just take time.

jamoni · « **Reply #13 on:** March 19, 2012, 04:35:25 PM »

Much better! The geometry is perfect! This thing shifts nice and smooth.
Still need to finish boring the bearing seat. Then it's on to finishing up the pedals and pegs.
I'm thinking about chopping off the original folding pegs and using those on the rear sets. They'd stick out a little further than I want, but hey, they're folding!

jamoni · « **Reply #14 on:** March 25, 2012, 10:54:44 PM »

I haven't worked much on this bike lately. My homemade milling rig had some hiccups, and I had to fix those first.
Today I milled out the bearing seat on the shifter pedal and pressed in the bearing. No pics because it doesn't look much different.
This time I used a different method. I chain drilled the perimeter of the hole, used the jigsaw to connect the dots, and then just milled till I had a flat surface. Checked with the calipers, milled to press fit, done! So much faster, so much easier, so much more accurate!
Also, a decent bearing press is high on my list of things to acquire. I bent the handle on my vise. :/
So on the rear sets, the only thing left to do is square away the shift linkage pins and fab up pegs and pedals. I think I'm going to fab up some motocross pegs. We'll see.

jamoni · « **Reply #15 on:** March 26, 2012, 10:57:42 PM »

She's a goer! She goes! Know what I mean?

Shifter side mostly completed. Just need to clean a few things up and put some locking hardware on the push rod.

Brake side: I may need to rebuild this at a later date. It's too low. The pedal should be about 1 1/2" higher to make using the brake easier. It works fine, but I think it could be better.

As expected, the rear sets really add to the comfort and control of the bike. It's much more a part of you, if that makes sense.
Unexpectedly, it is no longer a wheelie monster. I'm guessing that having my legs tucked up that tight tended to force my weight up and back, whereas the new riding position keeps my weight forward and low.

Brass_Machine · « **Reply #16 on:** March 26, 2012, 11:31:19 PM »

Making rearsets is always an interesting job. I must have re-made my 1st set 3 or 4 times to get the positioning exact for me. Was constantly tinkering with them. It definitely is a better feeling making them rather than buying them.

Good job. What's next on the bike modification front for you?

Eric

jamoni · « **Reply #17 on:** March 26, 2012, 11:58:32 PM »

Well, on this one, not much. I'm not worrying about the bodywork too much because once I get a little cash it's getting some CR110 replica fiberglass. Tank, seat, full fairing. There's a bunch of cosmetic tidying up I can do in the meantime.
I just sorted out a taillight. I need to mount the license plate and a light for it. Then this guy is street legal. I'll invest in some skinny road tires in a little bit. I also need to check the brakes on this guy. You can hear them squealing off camera.
As for my other bike, a 75 CL360, I need to recover the seat. Dry rot is a PITA. It looked great when I bought the bike, but after a couple months of riding it's cracking in a hundred spots. I also may make some side covers and a skid plate (and maybe a flyscreen) out of diamond plate.

EDIT: I also need to make a support for the fairing.

jamoni · « **Reply #18 on:** March 27, 2012, 12:06:41 AM »

Brass Machine, got any pics of your DIY rearsets? I'm interested in the design.

Brass_Machine · « **Reply #19 on:** March 27, 2012, 12:36:40 PM »

Nope. All the pictures for that particular build got deleted. I have some CAD models of another set I was going to do for a different bike though.

The set I had built was for a Suzuki TL1000R. I used aftermarket pegs and levers for a GSXR1K. That way I only had to design the bracket. The other set I did never made it to manufacture. A company in asia started making a cheap set of rearsets that everyone gobbled up (The bike I was making parts for is no longer made in the states and has a cultish following) that up instead.

Was going to be the same thing. An adjustable set of brackets using aftermarket pegs and levers.

I still do the kickstands and other parts...

jamoni · « **Reply #20 on:** March 28, 2012, 12:03:35 AM »

Kickstand! I knew there was something I forgot!

Brass_Machine · « **Reply #21 on:** March 28, 2012, 12:21:03 AM »

Here ya go...

One billet/CF stand I did for a custom RZ350

Eric

MadNick · « **Reply #22 on:** March 28, 2012, 12:26:16 AM »

Nice work so far!

Youre in a bit of a corner with the height of your brake pedal unless you can countersink the bolt that it hits against. Either that or slice a bit off the end of your lever - im sure you will be able to find a way.

I had some nice Harris rearsets fitted to my Bandit 1200. They were multi adjustable and after a lot of tweaking I got a really nice setup on that bike, very comfortable indeed - and looked the business.

Id like to see some pictures of the CL - thats another trail bike isnt it?

Nick

jamoni · « **Reply #23 on:** March 28, 2012, 08:12:08 AM »

Brass Machine, carbon fiber? Awesome!
I think I'm going to rock a center stand on this bike. It'll look cool, and let me hand start the bike.
Madnick, My plan on the brake pedal was to mill a flat bottomed hole around the nut, make a large, flat, round nut with a couple holes in the top, and use a pin wrench to tighten it up. Obviously there are easier ways, and if I ever build another set of these they will have the cross brace redesigned to be less intrusive. I also have some ideas for adjustable pedal angles. Live and learn!
The CL360 is a scrambler. It's basically a CB360 with more fender clearance, side mounted exhaust, front and rear drum brakes, and off-road handlebars. It may have a slightly longer suspension travel, not sure. I've got it set up for 90/10 riding, 90% road, 10% trail. I've wanted one of these bikes forever, and I got mine on craigslist for $500. $1000 worth of work later, and it runs great!
That's new tires and fork seals, new wiring harness, clutch, carb cleaning, valve adjustment and tuneup, new handlebars and grips, etc etc etc.
EDIT: I've realized the main problem with the brake is that you are pushing it backwards while you are moving forwards. So the harder you press it, the harder you are moving away from it.

Adjusting the angle a bit will help. It will, of course, require a new pedal. I think I'm going to skip it for some time. Frankly, this bike is so light I rarely use the rear brake anyway, I just engine brake.

jamoni · « **Reply #24 on:** March 30, 2012, 08:14:48 AM »

Well, I got the rear light sorted out. No pics, cause it's ugly and temporary, but it works! I also mounted the license plate. So now it's street legal, woohoo!
Took it for a longish ride yesterday, and it was great! The only issue was that I dragged my toe once while trying to upshift in a turn. I decided to raise the front suspension back to the stock position, which should stop that from happening. My seat pan is no longer horizontal, but so what?
Anyway, I'm very pleased. After I've made sure it's safe, I'm going to hit the highway and see if there's any increase in top speed with the fairing and new riding position.

News:

Author Topic: DT-100 Bucket Racer (Read 30936 times)