RGM pre-Commando belt clutch experiment for P11

The shifting problem occurs only when the engine is running, i.e., when shafts are turning. Did you assess vibration level by touching the gearbox?
If vibration level feels unusually strong compared to level at the engine, you should consider bent shafts as culprit.

- Knut
 
mdt-son said:
The shifting problem occurs only when the engine is running, i.e., when shafts are turning. Did you assess vibration level by touching the gearbox?
If vibration level feels unusually strong compared to level at the engine, you should consider bent shafts as culprit.

- Knut
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Just another good reason for a TTi gearbox. :) Molnar says the next TTi gearbox he has a failure with will be the first one that has ever failed. His race team and the teams he supports ride harder than I ever will.

Thanks for the thoughts. I will look into it.
 
Schwany said:
Just another good reason for a TTi gearbox. :) Molnar says the next TTi gearbox he has a failure with will be the first one that has ever failed. His race team and the teams he supports ride harder than I ever will.

Thanks for the thoughts. I will look into it.
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Even if you sort your stock box out, you will love the TTI. The gear ratios are perfectly spaced in the 5 speed box. And the shift is so mouth and precise. And the lever travel is much reduced. And most of all… it’s bomb proof.

You’ll have to be prepared for some messing around (cradle, perhaps chain alignment, etc) but it’s worth it.
 
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Fast Eddie said:
Even if you sort your stock box out, you will love the TTI. The gear ratios are perfectly spaced in the 5 speed box. And the shift is so mouth and precise. And the lever travel is much reduced. And most of all… it’s bomb proof.

You’ll have to be prepared for some messing around (cradle, perhaps chain alignment, etc) but it’s worth it.
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I expect the TTi gearbox will be complete transformation and make the bike a lot more enjoyable to ride in every riding situation an old guy might get into.

The drive train alignment is going to keep me busy for certain. I hope I can get it in one redesign of the cradle without too many elongated holes. I already know I have to make spacers. The mounting lugs(?) on the TTi box are narrower inside the cradle on the P11 rather than wider like they can be on a Commando. I'll also have to come up with adjusters. If there is enough space inside the cradle, I can make the adjusters work as spacers on the top lug. Remains to be seen.
 
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Note from Andy Molnar on the strength of the TTi gearbox. I asked if he had a good cush rear drum with sprocket suggestion. He said the TGA race bikes do not employ any cush in the drive train, and they have never broken a TTi gearbox since they started using them. I won't be putting anywhere near as much stress on the gearbox riding around on the street as a rider on a bike trying to win a race. I may put more miles on, but not more stress.

I believe him. I plan to continue to use my funky old rear drum brake without cush with the TTi gearbox and not worry about it at all. One less thing to replace.
 
Schwany said:
Note from Andy Molnar on the strength of the TTi gearbox. I asked if he had a good cush rear drum with sprocket suggestion. He said the TGA race bikes do not employ any cush in the drive train, and they have never broken a TTi gearbox since they started using them. I won't be putting anywhere near as much stress on the gearbox riding around on the street as a rider on a bike trying to win a race. I may put more miles on, but not more stress.

I believe him. I plan to continue to use my funky old rear drum brake without cush with the TTi gearbox and not worry about it at all. One less thing to replace.
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I rode my 850 commando for a while with a none cush drive back wheel
I was getting a nasty crunch putting it into first
And going down the box wasn't as pleasant but apart from that it was fine
 
Schwany said:
Standard TTi 5 speed. For the most part the TTi 5 speed comes in two flavors Standard and Heavy Duty. The gear ratios are listed at the bottom of the description here. I'm also considering changing the engine pulley to 28 teeth from 27. I am using a 21 tooth gearbox sprocket instead of the 19 tooth that is standard on a P11.

Only thing I'm still thinking about is if I want to go to 520 chain. The TTi 530 gearbox sprocket is special order. Although with a 20 week lead time, the whole enchilada is special order. :)

The 5 speed makes sense to me.
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Hi Schwany,

If you go with 520 chain, what will you use for rear brake/sprocket?

Ed
 
baz said:
I rode my 850 commando for a while with a none cush drive back wheel
I was getting a nasty crunch putting it into first
And going down the box wasn't as pleasant but apart from that it was fine
Click to expand...
Was that with a TTi gearbox?

I'm currently using no cush in the rear. Can't tell much difference so far. Maybe when the clutch gets more miles on it I'll notice something.
 
APRRSV said:
Hi Schwany,

If you go with 520 chain, what will you use for rear brake/sprocket?

Ed
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Got that covered I hope. I'm going to have a new sprocket/drum turned down for 520 chain if I can find a new one or a very good condition used one. I special ordered the gearbox with a 530 sprocket so I can use it with what I have now, and bought a 520 gearbox sprocket. The lead time is so long I doubt a few extra weeks waiting on the 530 gearbox sprocket will make any difference. Getting it in the frame is going to be 2024 winter project.
 
Schwany said:
Was that with a TTi gearbox?

I'm currently using no cush in the rear. Can't tell much difference so far. Maybe when the clutch gets more miles on it I'll notice something.
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No not tti just a stock 850
 
My advice FWIW is don’t machine down either of your sprockets until you’ve done a dry build as you can gain a useful amount of movement by machining one face or t’other which may help with alignment.
 
Fast Eddie said:
My advice FWIW is don’t machine down either of your sprockets until you’ve done a dry build as you can gain a useful amount of movement by machining one face or t’other which may help with alignment.
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I planned to wait before having any machine work done.

I got the AMC gearbox box working fairly well under power. I did three things to it while I had the inner and outer covers off, so I'm not positive what got it shifting better. I'll take the win though. It might be the fourth thing that got it working, and that is ordering and putting a deposit on the TTi gearbox. :)
 
Schwany said:
I planned to wait before having any machine work done.

I got the AMC gearbox box working fairly well under power. I did three things to it while I had the inner and outer covers off, so I'm not positive what got it shifting better. I'll take the win though. It might be the fourth thing that got it working, and that is ordering and putting a deposit on the TTi gearbox. :)
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Schwany, I guess I'm as crazy as you. I ordered and put a deposit on a TTI 5 speed yesterday. Mine is for a Commando though.

Ed
 
APRRSV said:
Schwany, I guess I'm as crazy as you. I ordered and put a deposit on a TTI 5 speed yesterday. Mine is for a Commando though.

Ed
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Yowza. Let that crazy flag fly!

It should be a fairly straightforward install on a Commando. You'll be done before I am.
 
I just swapped out the 20mm 860 length belt for a 25mm 890 length belt. Obviously, I changed the engine pulley. In this case I choose a 28 tooth x 27mm width pulley. The 860 belt was running on a 27 tooth x 21mm width engine pulley. I did it because I felt the 20mm belt was not right for the engine in this bike, and I wanted a higher gear in the primary. I was always afraid to give it the beans with the smaller belt.

While in the primary I discovered that the back of the clutch drum was too close to the inner case. I had 2 sets of shims on the case/foot rest mount. One set behind the inner case and one set between the inner and outer cases. Both were .00625 too tall. With everything tightened up it pulled the inner case outward at the rear behind the clutch dome. You would have to experience it. The inner case is not as structurally rigid as the outer case. The perimeter screws pull the rear of the inner case out rather than pull the outer case inward. Terrible design with the foot rest mounting bolt going through the cases, but it's just a dirt bike for those crazy Americans of which I am one. lol
 
Schwany said:
With everything tightened up it pulled the inner case outward at the rear behind the clutch dome. You would have to experience it. The inner case is not as structurally rigid as the outer case. The perimeter screws pull the rear of the inner case out rather than pull the outer case inward.
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If your outer cover is flat, how can it pull the inner case halve outward at the rear? That is impossible, unless your outer cover is deformed. A result of the shimming perhaps?
I can assure you, the factory is not responsible for your odd experience. True, the inner case is not very stiff, but stiff enough for its intended purpose, and that's what matters. Maybe you should consider having a new inner cover machined, similar to the Commando's primary cover.

- Knut
 
mdt-son said:
If your outer cover is flat, how can it pull the inner case halve outward at the rear? That is impossible, unless your outer cover is deformed. A result of the shimming perhaps?
I can assure you, the factory is not responsible for your odd experience. True, the inner case is not very stiff, but stiff enough for its intended purpose, and that's what matters. Maybe you should consider having a new inner cover machined, similar to the Commando's primary cover.

- Knut
Click to expand...

It is possible. I could watch the inner cover move outward at the rear when tightening up the perimeter screws/bolts. You don't have to believe it or assure me of anything. I'm OK with my own thought stream. If you had a P11 and knew how it is put together you might actually understand how it is possible.

I don't need a new inner cover. I did say it was the shims I added. In this case I should have only mentioned the shims between the cases. I was using them to spread the center of the outer case a little, but it backfired and didn't work like I thought it would. The outer case does not flex much at all.

Doing the kind of things I do is why the title says experiment in it. The end solution was adding two more handmade perimeter gaskets until I get another sheet of aluminum 12" x 24" x .0125" thick to make another full perimeter spacer. I can hand cut the .0125" thickness easier with the tools I have. Otherwise I'd use .25" material.

Anywho enough said. I will return to talk about installing the TTi 5-speed gearbox in a P11 and then disappear leaving you boys to you own devices.
 
Schwany said:
If you had a P11 and knew how it is put together you might actually understand how it is possible.
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As a matter of fact I do own a P11, several G15s, and a G80CS, all using the same primary case arrangement. I thought you had a balanced centre spacer and perimeter spacer. Without this, the inner cover will bend for sure.

- Knut
 
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mdt-son said:
As a matter of fact I do own a P11, several G15s, and a G80CS, all using the same primary case arrangement. I thought you had a balanced centre spacer and perimeter spacer. Without this, the inner cover will bend for sure.

- Knut
Click to expand...

Hmmm, I remember when I first joined up here you thought my engine and gearbox cradles were custom 3rd party pieces because they were made of aluminum. A P11 owner would know that is standard. Maybe you hadn't unpacked your P11 yet. To me it just meant you didn't have one. Such is life.

The foot rest setup on an G15 is not the same as a P11. There is not a long chain case center stud from the rear engine/gearbox cradle through the primary inner and outer cases that attaches to the foot rest hardware. The frames are very different as well.

I did make a full perimeter .125" aluminum spacer that works fine with the 20mm belt. The extra 5mm of the new wider belt needs additional spacer width. I made an error saying the spacer was .0125" thick earlier. It is 1/8".

I also have the OEM chain case center stud for the primary and foot rest, but I use a piece of 3/8-18 all thread and spacers so I can change the length. The OEM part is a little short for my foot rest hardware with the case spacer.

That is all until I have something useful to say. That may never happen though. lol
 
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