Day One - New Project

[Zyx]

I will post a close up today. Curiously, my extended swingarm, compared to a model 98 arm, is longer. Even though the later models like the 97/98 had longer wheelbases than the 92, the extra length was in the frame and/or perhaps the rake angle, not the swingarm. I can give you dimensions when I post the photo.

I can tell you that my bike handles far better than it did back when I was racing it, only differences in frame and suspension being the Progressive shocks and the extended swingarm. More plush ride, no pogo. Not that it rides like a modern link rear end, but better than it used to. Your photo of extended axle position looks like what I did.

[Zyx]

If these post upside down, let me know...

Extended arm-Z plate insert

From original minimum axle position to new outer arm (chain tensioner) 5 inches, or roughly 2 1/2" increase in total length.

Close up

Side by side 92 extended v. 98 stock

Close up comparison

Dimensions: 92 original minimum distance from pivot axle to wheel axle ( shortest chain position) 15.75"

98/97 swingarm stock, minimum distance axle to axle 16" (quarter inch roughly more than stock 92 but also uses a thicker axle, so total difference around a third of an inch, not much.) Max axle to axle 17.625" stock.

92 as extended, 17.5" minimum distance axle to axle, 19.125" swingarm axle to chain tensioner.

Using a 100/100 Kenda Washougal on the rear, tire width max at the knobs is 4.9". The radius from axle center to knob at the widest point is 11". Width of the swingarm 11" forward from minimum axle position:

92 stock 5.2", as extended 6"
97/98 swingarm stock 5"

Hope this helps. Bottom line is than moving the axle back two inches should yield an extra inch in total tire clearance, half inch on each side. It is about the only way to mount a 100/100 knobby and still clear the chain. You are using a 17" wheel, so the radius will be shorter and clearances a bit more than mine. I don't have a chain guard but it would be tight putting one in. There is about an eighth inch, not more than a quarter inch between knobs and chain, and an eighth inch clearance on the other side. Other brands of tire may be narrower and fit better. The Kenda is a very wide tire for a 100/100. The 3.50 Nitto I ran back in the 70's (it's out in the shed) looks like a bicycle tire compared to the Kenda.

[hodakamax]

Thanks AZ, I'll study and measure. Strange, they do post upside down but enlarging them with a mouse click and they are right side up when enlarged.

Max

[Zyx]

Stupid iPad does that. I have no idea why.

[Dale]

Just FYI, I noticed that the picture displays upside down and is still upside down when opened using Internet Explorer. However, using Chrome, the picture still displays upside down but is right side up when opened. Someone at Apple is laughing right now...

[hodakamax]

My 92 has a 909126C (at least on the schematic) swing arm and measures 15 1/2'' from center to center in the close position. 100Bs show a 939126 swing arm. Was there a 929126? Anyway it appears they all measure about the same length. I'll probably extend mine 2'' as we said.

Max

[RichardMott]

Mike Perrett extended the swing arm on my Ace trialer a few years ago. We were not looking for a beautiful esthetically pleasing arm, more of a utilitarian functional arm.
That's my story and I'm sticking to it.

[hodakamax]

It appears to be peened for more strength.

Maxie

PS--Innovating stand by the way.

[hodakamax]

Max is not a metal fab person. After some blasting it's off to my local expert Rod Blackburn to lengthen the swing arm by two inches. I checked on him this morning to see the progress. Wow, this guy does it right. I'll have the finished picts soon.

Maxie

[hodakamax]

Ah, this is much better! I would have painted it for you but I can't decide red or black. Any votes? I'm torn between red frame, white fenders and tank or black frame, white fenders and orange tank with cool white bold graphics on the tank. (Red graphics on a white tank.)

Maxie

PS--I think I've located a 19'' front wheel.

[Dale]

It is going to be cool no matter the color, but... red would be the coolest.

[hodakamax]

Thanks Dale, one vote for red.

Max

[dcooke007]

That looks like a good mod for the swing arm. Also noted the reinforcing gussets. Excellent workmanship.

Danny

[Bullfrog]

. . . and another vote for red

Ed

[hodakamax]

Here's a before and after of the swingarm lengthening. Not only did it give me more clearance by bringing the most forward part of the tire to a wider part of the swingarm but it just looks better in the fender circle.

A little history on lengthening swingarms. When we started racing 90s it wasn't long until we had doubled the horsepower and the bike was wheelie prone and quick handling in a slide. A mere two inches cured most of these two problems. When the first 93 Super Rats came out we took two examples out for my teammate and I to campaign MX in our area. After finding out that they had weak fork tubes we outfitted both bikes with leading link forks and 21'' front wheels. (The weak fork tubes were quickly replaced under warranty.) Our next problem involved a pushing front wheel in an accelerating slide with the new front set-up. Again 2'' added to the swingarm cured the problem.

Maxie

[dcooke007]

Looks much better and should handle better too.

Danny

[hodakamax]

Yikes, I wish I hadn't cut that fender off before lengthening the swingarm, I may have to add a mud flap to prevent the proverbial back stripe. I also should mention that a swingarm lengthening is not for everyone or they would have done it at the factory. This is a modification for racing to slow down handling when adding more power. Longer wheelbases allow for better starts and better controlled slides. It also helps to add clearance when fitting larger rear tires.

Max

[hodakamax]

Hey Gang, still mocking up stuff. I did a little research on the K&N filter site and came up with a couple of possibilities for the project. There's also a optional cover that can be fitted to guard against water splashes and heavy dust. I think if it was a performance bike I'd go with the larger one but for my slower pace version perhaps the smaller one. The angle is 40 degrees. Check it out.

Maxie

PS-the inlet diameter is 43mm (24mm carb). Now I notice that with the smaller one there would still be room for a handy tool box.

[hodakamax]

While mocking up I may have made an epic discovery. I don't have a tool box but being a photographer I found that my old stainless steel film developing canisters fit right into my frame. I will have to cut it down slightly on length and modify the lid with some locking mechanism. Can someone give me a outside diameter measurement of the lid end of a Hodaka tool box? If I was real lucky a stock lid might fit. These cans are quality spun stainless and look real cool. Thanks !

Maxie

[Dale]

Max,
I measured one tool canister and found:
3.44 inches (outside of can at the lid end)
3.46 inches (inside of lid)
Dale

[hodakamax]

Hmm--A new measurement reveals that the film can OD is slightly oval at 3.43-3.53. The lid that fits is 3.50 ID. Looks like it might be a little tight unless the ID varies a bit on the Hodaka lid. I can make my lid work with a little modification. The project is far from stock and it will still be cool.

Hey, thanks Dale!

Maxie

[hodakamax]

Another small milestone. The Ceriani fork stem has now been modified to fit the Hodaka fork head. I had to order a 25mm x 1.0mm die to extend the threads on the Ceriani stem. The stem also required a little lathe work to accept the Hodaka lower bearing race. The fork tubes were slightly bent and are being sraightend as we speak. I still have to manufacture some handlebar hold downs and fork stops. It seems for every milestone there are new challenges.

Also the new K&N filter has arrived and the stainless steel toolbox has been shortened and mounted. A really nice 19 front wheel has also arrived.

What fun!

Maxie

[Bullfrog]

I really like the re-purposing of the film developing cannister!

Is there a plan to protect the air cleaner from wet splashes?

Ed

[hodakamax]

Ed, there is K&N pre-charger for this model #22-8048PK which shields against splashes and heavy dirt. It fits over it like a sock. Maybe later. I do need to modify the canister lid to both lock and not look like a film developing canister lid.

Max

[hodakamax]

OK, one last mod before I sleep. I had envisioned boring a 7/8'' hole in an aluminum block and sawing it in half to make some non-existant handlebar hold downs. The stock Hodaka hold-down was too long to use. A countersinking of the holes and some cool allen bolts from the local Ace Hardware and the power hack saw made for some quick handlebar hold downs. A minor mod but one that was worrying me. Maybe some aluminum ones later.

Maxie