Dual sport gearing

C

capehorn23

New member
Finally got a tag for my 2005 144MC. Gearing is 13-50 which is extremely low. I can only get about 50 mph wide open, which is way to low. I need to be able to run 50-55 at 1/2 throttle. I was thinking about going to a 46 rear. I am using the bike as a modified dual sport to connect trail sections. Thoughts?
Terry
 
I am running 13/49 on my 02 EC200 I love it way less shifting.It was supposed to have the ports polished and a 9 oz FW but I do not know for sure. I do have to fly up or abuse the clutch on big hills.
 
I can't imagine such a small capacity being much fun pulling gearing that tall. I mean it'll likely cruise at low revs, but it might not pull well under load, not to mention how much ridability you'll give up in the process.

Using a 144 for dual sporting is a bit like using a whipper snipper to mow the lawn, when really a mower would do the same thing much better.
 
Jakobi said:
I can't imagine such a small capacity being much fun pulling gearing that tall. I mean it'll likely cruise at low revs, but it might not pull well under load, not to mention how much ridability you'll give up in the process.

Using a 144 for dual sporting is a bit like using a whipper snipper to mow the lawn, when really a mower would do the same thing much better.
Click to expand...


I have a KTM 525 MXC that I use as my primary dual sport bike. I use the term dual sport very lightly for the GG. I need the GG to be able to connect trails by using forest roads. With 13/50 gearing the GG sounds like it is redlined at 40 mph. My goal is to get 50 mph for connecting trails. I am using your jetting recommendations to clean up the powerband. I am a retired from enduro racing as an "A" rider so I do understand gearing so any suggestions you have on setting this bike up would be greatly appreciated. The GG was Fred Hoose's factory ISDE ride in 2005.
Thanks--Terry
 
No dramas Terry.

I haven't had any exposure jetting 125/144/200's of this colour, but I'll assume you've taken that into consideration already with your experience.

Mainly, all I was getting at was that its always a compromise, and that 13/44 would probably be a bit too far for that little engine. I find the 250/300's will cruise OK around 80km/hr, just coming onto the pipe with 13/50. I don't think I'd go less than 13/45 on them for mixed riding.

Can you fit a 14T on the front as a cheap test to see how it'll run? that'd be similar to 13/45.
 
13/46 would be fine for a vet A rider.

You should be able to get the final drive ratio specs from the service manual.And calculate the top speed you are after with a gearing calculator.Tire height and width will be a factor.
 
I agree in most cases a talented rider will prefer taller gearing and carry more speed everywhere, but I still question the engines ability to pull the taller gearing, particularly in the higher gears. Even at 13/48 there is a noticable dip between 4th 5th and 6th gears if shifting too soon in the rev range. I can't imagine how it would be with taller gearing on an engine half the capacity.
 
Sounds like this could be a specific gearing requirement for a specific loop or loops.Probably a closer to home practice loop.Giving up some on trail performance for road speed between trails.Range is probably a consideration also.
Vet A.
And "retired"

Are the key words here.
 
desertgasser300 said:
What does that have to do with gearing?
Click to expand...


That he is a very experienced. rider and offroad racer.He knows the taller gearing will rob the bike of optimum performance.He rides a KTM 525 also.He isnt asking us if we think it's a good idea to gear the small bore that high.Or to speculate on performance.

He is asking how can he make it more manageable Jacobi knows the Gassers.Torque off the bottom is going to be critical.Can you tweak the poweralve, jetting options, spacer at the carb, boot, pipe options etc. Any other options, some flyvwheel weight, beef up the clutch,, ignition options, mapping etc.

Vet A,
Hatch, Hawkins, Freddette, Hoess, Summers, Roesellor, Watts etc.
All guys you may find at a Vet A starting line near you.
And all the guys that race against those kind of guys.
 
sweeper said:
That he is a very experienced. rider and offroad racer.He knows the taller gearing will rob the bike of optimum performance.He rides a KTM 525 also.He isnt asking us if we think it's a good idea to gear the small bore that high.Or to speculate on performance.

He is asking how can he make it more manageable Jacobi knows the Gassers.Torque off the bottom is going to be critical.Can you tweak the poweralve, jetting options, spacer at the carb, boot, pipe options etc.

Vet A,
Hatch, Hawkins, Freddette, Hoess, Summers, Roesellor, Watts etc. etc.
All guys you may find at a Vet A starting line near you.
And all the guys that race against those kind of guys.
Click to expand...
........Uh huh!
 
My 2003 Gas Gas manual shows the EC models all share the same transmission ratios.
6th gear 0.791 (19/24)

Primary reduction ratio 2.85 (57/20)
Final reduction ratio. 3.692 (48/13)
Overall drive ratio. 8.149

Run those numbers through a gearing calculator targeted for a topspeed mph.
This will give you your gearing options.

And go from there.

I'm not sure if these trans specs are
identical to what you have.But you should be able to get a ball park.The gearing ratios look pretty standard to me at a glance.
 
Jakobi said:
No dramas Terry.

I haven't had any exposure jetting 125/144/200's of this colour, but I'll assume you've taken that into consideration already with your experience.

Mainly, all I was getting at was that its always a compromise, and that 13/44 would probably be a bit too far for that little engine. I find the 250/300's will cruise OK around 80km/hr, just coming onto the pipe with 13/50. I don't think I'd go less than 13/45 on them for mixed riding.

Can you fit a 14T on the front as a cheap test to see how it'll run? that'd be similar to 13/45.
Click to expand...

Thanks for the feedback. I think a 46 to start and go from there. Trying to find the right jetting set up had me stumped, finally found a small tear in the intake manifold which was causing all sorts of problems. The replacement manifold was hard to find as it is a 1999-2000 YZ125 part. Found one on ebay should be here next week and then I can start the jetting process over. I believe the little GG is going to be a blast to ride in the woods. It brings back fond memories of Penton 125 six days. I don't think a 14 would fit unless you have any ideas.
Thanks for all the help from everyone,
Terry
 
I went with 13/44 for first testing. 1st gear seems just a little high if starting out in deep sand or a technical section but the trade off of being able to carry more speed on fast sections is worth it. The ability to run in 3rd and 4th gear in two track sections is a real blast. Now for some jetting work. The little bike is fun to ride.
Terry
 
I ended up with a 48 on the rear. Rode a 110 mile dual sport event at Perry Mountain Alabama. The gearing was a little short on the fire roads 50-55 MPH but in the tight single track and technical sections the gearing was spot on. It is amazing how fast this little bike is, I only wish I was 40 years younger. I also think I have the jetting pretty close, getting 25 MPG and plug looks good.
Cheers,
Terry
 
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