sixth gear

[officerbill]

Has anyone ever thought about installing a sixth gear in a 79 GS850G? Coming to work today she kept whinning for more gears but five is all I have. Is it possible to add sixth?
b

[Dogma]

We've all thought about it. The closest thing you can find is to maybe swap out the final drive for something with a different ratio, or maybe fool around with larger wheels/tires. I don't wanna hear from you chain people.

I got used to it, and the bike is perfectly happy spinning 5k or more for hours on end. Mine can generate a numbing vibration between 60-65 mph (55 on my speedo), but that's easily solved by going faster.

[officerbill]

I'd be happy to faster once I get around all the H-Ds

[errorcauser]

I'd be happy to faster once I get around all the H-Ds

Hump up over the tank, drop it into 3rd and run it up to near redline, then shift into 4th and and do the same thing again. By the time you get into 5th you should have the H-D's attention.

[marvinsc]

The short answer to your question is No! The long answer is anything is possible with enough time and money but as far as I know, anyone who has ever tried it ran out of time or money.

[Steve]

Dogma mentioned changing the final drive ratio, but the only one that's readily available is from a GK and the difference is so slight that it's not really worth it.

Changing ratios by changing tires will also be a rather small percentage.

When properly tuned, there is virtually no vibration (get the hint, Dogma?) and the bike is very happy cruising along at 5,000 rpm, which, by the way, is 70 mph. I have not checked for any difference between an 850L with a 16" rear tire and an 850G with a 17" rear tire, but the L is doing right at 14 miles per 1000 rpm in top gear. This is actual GPS speed, which is happily not much different than what is indicated on the speedometer.

.

[1948man]

I have a Suzuki C50 Blvd with a modified C90 Blvd final drive. It greatly reduces the hwy speed rpm' but that 805cc engine sure doesn't produce much torque now. I'm going to take it off and sell it. Everybody at VolusiaRiders.com is hot for this mod. I kind of wondered if something similar had been done on GS bikes although I must say I'm not bothered by the rpm's.

[TheCafeKid]

If your bike is literally WHINING, check the gear oils...Final drive and secondary gear box...(not the motor oil) There should be no problem running that 850 at 70mph or more. They LOVE runing above 5k..they're designed for it..

[Nessism]

The 1983 and 1984 1100G rear end is the tall ratio version. A little hard to find but they are out there. As mentioned already, if you have an L model, with 16" rear wheel, swap it out for a 17" and that will increase the gearing some as well.

[49er]

I'm running the higher ratio diff in the '79. It drops the rpm at 100 kph from 4500 to 4200. It extends the usable torque in 3rd & 4th gears, without dropping punch in top too much.

The '83 onward 850's also had a higher top gear. The extra tooth gives it another 6% increase in gearing, which would bring the rpm down to 3900 at 100 kph when running the higher diff. Now that 600 rpm drop is significant.

I have Tomcat24551 to thank for this information. I have a new set of 5th gears just waiting for the time when the cases are due for splitting.
My engine will have enough punch to handle the combined higher gearing in 5th.

[Nessism]

I'm running the higher ratio diff in the '79. It drops the rpm at 100 kph from 4500 to 4200. It extends the usable torque in 3rd & 4th gears, without dropping punch in top too much.

The '83 onward 850's also had a higher top gear. The extra tooth gives it another 6% increase in gearing, which would bring the rpm down to 3900 at 100 kph when running the higher diff. Now that 600 rpm drop is significant.

I have Tomcat24551 to thank for this information. I have a new set of 5th gears just waiting for the time when the cases are due for splitting.
My engine will have enough punch to handle the combined higher gearing in 5th.

In the US market, many of the models using a 16" rear wheel had a taller 5th gear. Sounds like a nice mod if anyone needs to crack the cases.

[harris]

...the bike is very happy cruising along at 5,000 rpm, which, by the way, is 70 mph..

Thanks for verifying this for me. I took my 750 out on to 95 recently (it was my first visit out on the interstate, so it was only a one exit trip). And 70 mph @ 5000 rpm was exactly what my gauges read. However, the cages were blowing by me so I got on the throttle a bit more. By the time the gauges read 80-85 mph @ 6000 rpm I was at the next exit. Whew.

[Dogma]

...
When properly tuned, there is virtually no vibration (get the hint, Dogma?) ...
.

yeah, yeah. The vibration is some kind of harmonic under the seat, not the engine. Maybe it's my cracked tool tray. Who knows. Oh, and for the record, my L has a 17" rear already. Maybe the PO put it on there about the time he put on the '79 G exhaust and twisted the rear fender.

Back on topic... I'm not sure I would want to be turning 3.5-4k at 70 anyhow. Even at 5k, there isn't a ton of surplus power at 70 mph.

[49er]

yeah, yeah. The vibration is some kind of harmonic under the seat, not the engine. Maybe it's my cracked tool tray. Who knows. Oh, and for the record, my L has a 17" rear already. Maybe the PO put it on there about the time he put on the '79 G exhaust and twisted the rear fender.

Back on topic... I'm not sure I would want to be turning 3.5-4k at 70 anyhow. Even at 5k, there isn't a ton of surplus power at 70 mph.

If your bike's tuned properly, there should be bucket loads of torque in top gear at 5000 rpm. Torque shouldn't max out until around 7500 rpm with a stock setup.

[bwringer]

Grab that thing on the right, twist it, and stop sniveling...


That engine is designed to spin. It likes to spin. It wants to spin. SO SPIN IT!

6,000 - 9,000 rpm is the sweet spot.