Sprocket combination question

[Rusty]

I mainly just ride around town. Speedo doesn't work
But a friend rode beside me. I'm topping out around 35
Trying to get a bit top speed. I know it will compromise
Take off. Anyway front sprocket I'm almost certain is a
17T. I just bought it recently. Rear is a stock 68 Ace not sure
How many teeth it's pouring outside. Any suggestions
Would be appreciated

[hodakamax]

You probably need to give us an exact count. A 17T front might be too high to pull top gear with a stock rear and the engines state of tune.
My thoughts--

Maxie

[Zyx]

Model specifications are posted on the Strictly Hodaka website. Choose shopping by schematic for your model, Ace 100, and on the index page is a photo of your model. Directly under the photo are two statements, the one is for model specifications, the other for shopping for manuals. Click on the one on the left, model specifications. That will get you a .pdf file of the complete model specs. In those specs are all the sprocket tooth counts for standard sprockets, as well as transmission tooth count, primary tooth count, secondary count, final ratio, overall ratios by gear and more.

The Ace 100 came with a two part sprocket. The inner part that bolts to the hub is a 36 tooth sprocket, and the overlay is a 50 tooth sprocket. I used to ride the same sprocket setup on a 100B. With a 15 front and the 50 rear, I used to get 50 or so mph. With the 36 tooth sprocket, and a 15 front, I used to get nearer to 65 or 70 which is a bit fast for one of these if not equipped for speed.

If you get only 35 mph with a 17 front sprocket, you must have a 60 tooth rear or higher. Maybe even a 66, but even then I would expect more like 50mph. For sure, with stock sprockets your top speed should be way beyond 35 in top gear.

When the rain quits, go count teeth. Something isn't right in the equation. You would have to be geared like a trials bike to get only 35mph.

[Rusty]

I'll get a proper count later. Definitely the smaller back sprocket. I'd just like to get above 40. I have more throttle just no more gear. Most roads I go on are 35. Be back with proper info thanks.

[Pep]

That does sound a little off. I can get in the low 50's on an Ace 90, low 60's on a chrome tank Squirt - using GPS, not speedo. Both are stock.

[Zyx]

Smaller back sprocket, as in 36??? With a 17 front and 36 rear you should be able to go about warp 6. If you mean the throttle is not responsive, as in at some point top speed is achieved, there is more throttle throw left, but nothing much happens if you attempt to use that throttle, then it isn't the sprockets, it may be the pipe is clogged or your air cleaner is clogged...or you just ran out of beans and need to regear entirely.

Get a tooth count, and all the details you can provide.

17 x 36 I hate to think...if you had the power to pull the combo, I would have to do the math but maybe 100? Yikes.

[Rusty]

Will do fellas. Sorry, should have had all the fact for you. The cats and dogs are
Moving out tomorrow. So I'll get a count tomorrow. I did give the pipe a good chain cleaning
Not to long ago. Would like to hear advice on a proper full cleaning

[Zyx]

There is a video recently posted here on cleaning the pipe called "what's in your pipe." Do it with a torch, but really, if you have a removable silencer/spark arrester, take it out and try it that way. If it makes a big difference, that's it. Also check your air filter.

The Ace 100 doesn't make a ton of power, so you may just be hitting the ceiling with the sprockets you have, and current state of tune, but with 17" wheels and tires, and assuming 17/36 sprockets and good power, you should be looking at more like 55 or so, perhaps a bit more. I don't think you could pull redline with that gearing, but who knows. Bottom line, 35 isn't enough and something is holding you back. As I said, I used to get over 70 out of mine with 18" tires and laying down on the tank with 14 or 15 front, 36 rear.

Should be interesting to hear the details once you take a look. And if you happen to have a GPS, take it for a ride. They are usually fairly close on speed.

[Rusty]

Hi all, looks like a 15T and a 36T. Downloaded a speedo
App and took a ride said top speed was 70! There's
No way I was going 70. So have to ride beside a friend next.
Anyway what should that sprocket combo be getting me?
So I have an idea. Trying to track down an oxy tank to
Clean exhaust.

[Zyx]

Math will give you a rough idea of potential speed. Book says red line is 7,500 but I doubt the bike will peak in fifth with that gearing, say 7,000 if it is running well. Book specs show an overall drive ratio in fifth gear of 8.7:1, which means the crank turns 8.7 times for every turn of the rear wheel. At 7,000 rpm, the rear wheel turns 804.5 times per minute. If you have a rear tire around 24 inches in total diameter, the circumference is pi times that number, or roughly 75.4 inches, times 805 ( rounded up) per minute gives you 60,697 inches per minute. Divide by 12 to get 5,058 feet per minute. A mile is 5,280 feet. 5,058/5,280 yields 0.957 miles per minute, times 60 gives you miles per hour, 57.47 mph.

This formula can be simplified by reducing constants to a single constant but the idea is there. At 7000rpm you can go about 58mph, which ain't bad for a 45 year old 100cc bike. More if it is a screamer.

Having never used a gps app on a phone I have no idea whether they work. Sounds like maybe not. I have used various Garmin units over the years and all are accurate to a degree better than your average luxury sedan. Maybe you can borrow one from a friend, reset the trip meter and the top speed function, go for a speed run, and read top speed achieved. That way you don't have to read the screen while riding flat out.