Suzuki 2 Strokes

Does there exist a pair of gears that can be swapped on the 5th gearset to get a little taller gearing? Nice bike and all, but it still seems to have a 4-1/2 speed tranny than a 5 speed.

Nova's close ration transmission is about the only option got the T500:

http://www.novaracing.co.uk/suzuki-gt500.htm" onclick="window.open(this.href);return false;

but it's not cheap!

Jim

You could try changing you sprokets
Andy

You could try changing you sprokets
Andy

I started out with a 15/40 on the RedZone Rocket ship. I figured the smaller primary gear would give me the hole shot I was after. Turns out that all it did was make first gear totally useless. Upped it to 16/40 (the stock gearing for that year) and it made a world of difference. Take a close look at your sprockets and if they are not stock, replace them and replace the chain at the same time. Rule of thumb, always replace the primary sprocket, wheel sprocket and chain at the same time. That goes if any of the three are showing wear. That looks like a heavy hit up front, but they will last you a long time if properly care for.

It is not a problem with the sprockets. When you shift from 4th to 5th, the gear ratios are so close that it acts more like a 4-1/2 speed instead of a 5 speed. Look at the numerical differences of each of the gears and you will see there is much less change from 4th to 5th. Does not make sense to me. I am finding myself checking that I changed to 5th or not. I have to look at the rpm's and actual speed to be sure I was in 5th. So I was wondering if a pair of gears from another bike would work.

I had the same problem until I restored my K-model about 2 years ago. The first thing was making T500 and H1 gearing comparison in excel and as I liked Kawi's ratio between 4th and 5th, I decided to go similar with T500. Stock gearing is 23:20 for 5th. The easiest and cheapest way (standard teeth) were 24:19. If I remember correctly, I was asked 380$ for both by a local machine shop.
I've been riding over 2000 mls by now and I like the mod. The bike is capable for 65 mph at 3500 rpm, it's about 600 rpm less than stock.

The black ones on the left:
http://www.bilder-hochladen.net/files/bfqr-39-jpg.html" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

Argo

Argo1974, do you have any drawings to go by for a machinist? I would like to explore the possibility to have the gear pair made here in the states. This might be a practical mod for a lot of T/GT500 owners.

rbond, I made the drawings on the paper as I didn't have any suitable software on my PC.
The machine shop still has the drawings, I may ask for them after annual turnover. I will visit the shop anyway for my H1's fork bushings.

What sproket sizes are you using, and what kind of rpms are you running when you are shifting and riding? It is normal for transmission ratios to get more narrow going up in the box. If you stop and think about it, wind resistance increases non-linearly as speed inceases making the engine work harder - hence narrower gears at the top to better allow holding a speed or accelerating. I used to scream at my T500 when going from 1-2-3 because it would bog down so badly due to the gaps, but never saw an issue with the 3-4-5 gaps. Drive sprocket ratios multiply the transmission ratios, so altering drive ratios does effect overall gearing. A stock T500 with stock 15/33 sprockets is way over geared. I think they did this to get around the engine vibration/shaking at around 4000 rpm. I think I remember that a T500 will actually reach top speed in 4th. I would try a 13 or a14 tooth countershaft sprocket - 13 if you don't hit the superslabs too often. They are pretty cheap as modifications go. HTH....

BTW: Look at the ratios on the Nova racing site. They kept 4th and 5th identical to stock, and barely altered 3rd. The big changes were to 1st and 2nd.

When optimizing the bike for top speed, increasing the jump between 4th and 5th is definitely harmful. But I was more for better shifting and for continuous running at 60-70 MPH. My bike has 15:33 rear ratio and is pretty much overgeared on the 5th. On the other hand, it is nearly vibration free on that speed (I have double rubber mounted engine as well). As this solution works exceptionally well below 4000 rpm, I will go a teeth less on front sprocket for better acceleration. And, I think, this will also improve fuel consumption as the bike made more MPG before that mod.

Argo