1100 Sport i trans... swap?

[pressureangle]

Planning a 7500 mile trip this summer, with a 1000 mile warm-up/gear vet in May.
Mine's a '97 with ~20k miles. Straight-cut transmission which feels fine, if whiney.
Opinions;
Plastic race bearings, yes/no? Does it matter anymore?
Teardown, verify, fly?

I'm considering sticking in a standard transmission, which I would tear down and build up beforehand. Not only because of the (maybe) reliability/durability issue, but also because having a lower 1st gear would be nice on a long trip.

What would be the best swap? I don't really care to do a bunch of machine work that would make it unsalable later on.

[dxhall]

Do you know what ring and pinion are in the bike?  If you still have an 8/33, you could get a better first gear ratio by swapping to a 7/33.

[pressureangle]

Do you know what ring and pinion are in the bike?  If you still have an 8/33, you could get a better first gear ratio by swapping to a 7/33.

OOooo...yeah...no.

I'll be crossing a lot of open territory, some of it with no speed limits. I'd rather have the top than the bottom, if I have to choose.

[Chuck in Indiana]

My memory is always suspect, but I think the case is different enough that it would take some machine work to swap in another transmission.
When we did the Kid's Spot, we swapped in the gears from an 02 transmission. The stock gears were pretty bad from the original owner riding it like an old lady. We changed out the plastic cased bearings at the same time.

[pressureangle]

My memory is always suspect, but I think the case is different enough that it would take some machine work to swap in another transmission.
When we did the Kid's Spot, we swapped in the gears from an 02 transmission. The stock gears were pretty bad from the original owner riding it like an old lady. We changed out the plastic cased bearings at the same time.

That's an option, since it will be apart anyway. I just hate to end up with a bunch of good pieces with no home-if the straight cut trans is in good shape, I'd like to put it back in later.

Or, I suppose, I could sell the internals to pay for everything and forget about it. I don't have opportunity nor desire to ride in a style where the close ratio trans will be any difference.

[pete roper]

The cases, or at least the endcase, is different on the five speed spineys. Best bet would be to swap the internals and get rid of the ATN9 bearings. Be aware you may also have to swap the needle roller bearings from the back of the input and front of the cluster shaft as there was a brief period on a few models where they used different bearings, probably because their usual supplier had cut them off for not paying their bills.

Pete

[rocker59]

Opinions;
Plastic race bearings, yes/no? Does it matter anymore?
Teardown, verify, fly?
 

Just get on it and ride.  The bike only has 20,000 miles on the clock.  It'll be fine.

[pressureangle]

Just get on it and ride.  The bike only has 20,000 miles on the clock.  It'll be fine.

Since this takes zero time and energy, probably what will happen.
Redline superlight shockproof gear oil?

I'm overthinking it again aren't I

[pete roper]

Too a degree, yes. At least the injected Sports have/had a Cush drive in the rear hub which gave the driveline a bit more of a fighting chance. The Sport/Daytona straight cut boxes are plagued by poor hardening of pinions and their three dog engagement set up which means there is an enormous amount of backlash between power on and power off and visa versa. Boxes that are in bikes that are ridden aggressively tend to last a lot better than ones that are babied but it’s still a bit of a crap shoot.

Fifth is usually the first to go, followed by third. After that it all goes to hell in a hand basket pretty quickly.

Pete

[pressureangle]

Too a degree, yes. At least the injected Sports have/had a Cush drive in the rear hub which gave the driveline a bit more of a fighting chance. The Sport/Daytona straight cut boxes are plagued by poor hardening of pinions and their three dog engagement set up which means there is an enormous amount of backlash between power on and power off and visa versa. Boxes that are in bikes that are ridden aggressively tend to last a lot better than ones that are babied but it�s still a bit of a crap shoot.

Fifth is usually the first to go, followed by third. After that it all goes to hell in a hand basket pretty quickly.

Pete

Is it a bearing issue, or actually stripping the dogs off the gears? Or losing teeth?
I had a mind to swap it out, have it cryo- and surface treated before re-installing.
I have little knowledge of the bike's history but to say it was filthy, once crashed, and ran like shit if it ran at all.

[Old Jock]

Pete will know, I think it's the gears because of the 3 as opposed to 5 dog engagement, means the gears get a lot of shock loading on and off throttle as Pete stated

The ATN 9s is a problem with all the bikes unless it's waaaaaaaay back. The plastic cages can fail and the all metal version is just a so much better solution, that it's a no brainer, depending on where you are they might not be cheap.



If it was me I'd do all the seals O rings and return spring too just while you are in there. I wrote a guide on the older boxes but the sport is almost identical to make no difference. I won't bother posting a link as you sound more than competent to do this, so I don't want to insult your skills

 

[pressureangle]

Pete will know, I think it's the gears because of the 3 as opposed to 5 dog engagement, means the gears get a lot of shock loading on and off throttle as Pete stated

The ATN 9s is a problem with all the bikes unless it's waaaaaaaay back. The plastic cages can fail and the all metal version is just a so much better solution, that it's a no brainer, depending on where you are they might not be cheap.

If it was me I'd do all the seals O rings and return spring too just while you are in there. I wrote a guide on the older boxes but the sport is almost identical to make no difference. I won't bother posting a link as you sound more than competent to do this, so I don't want to insult your skills

;) I know your guide well, and Pete's. I rebuilt/shimmed the box in my '85 LM1000 and it works like magic.
Please do remember to torque the output shaft nut, tho, or it doesn't shift so well what with the shaft running back and forth in there.
I'm ... competent... yes, but without the requisite hands-on experience one can always tease a bit of trouble out ahead of time by shutting up and listening to them what's done it a bunch.

[Groover]

Too a degree, yes. At least the injected Sports have/had a Cush drive in the rear hub which gave the driveline a bit more of a fighting chance. The Sport/Daytona straight cut boxes are plagued by poor hardening of pinions and their three dog engagement set up which means there is an enormous amount of backlash between power on and power off and visa versa. Boxes that are in bikes that are ridden aggressively tend to last a lot better than ones that are babied but it’s still a bit of a crap shoot.

Fifth is usually the first to go, followed by third. After that it all goes to hell in a hand basket pretty quickly.

Pete

Is this for the Sport 1100 straight cut gear production, or is that for all straight cut gears used by Moto Guzzi (e.g. Le Mans 4 variant)?

[Old Jock]

Is this for the Sport 1100 straight cut gear production, or is that for all straight cut gears used by Moto Guzzi (e.g. Le Mans 4 variant)?

Only really applies to Sport Carbs, Sport Injection and Daytonas/Hi Cam engines with the 5 speed boxes, not sure about Centauros

Bikes preceding them had 5 dog engagement and cush drives so a lot more robust and less prone to digesting their own inners

[rocker59]

Is this for the Sport 1100 straight cut gear production, or is that for all straight cut gears used by Moto Guzzi (e.g. Le Mans 4 variant)?

Carb Sport 1100 and a few early injected Sport 1100s had the 3-dog straight-cut gearboxes.

This doesn't affect LeMans 1000.  (and it doesn't affect all the Sport 1100s, either).

[Chuck in Indiana]

Only really applies to Sport Carbs, Sport Injection and Daytonas/Hi Cam engines with the 5 speed boxes, not sure about Centauros

Bikes preceding them had 5 dog engagement and cush drives so a lot more robust and less prone to digesting their own inners

Centauros had the normal box. What Rocker says.. the Kid's very early 1100 Spot had the three dog box, and it was rooted. (Austrian technical term) 

[Groover]

Ok, thank you for the responses to that side-question.

[Old Jock]

Yup my Sfida 1100 despite being registered in 99 must have used an early injection engine trans, dreaded 3 dog straight cut box

At some point I'll need to do 5th gear minimum