‘18 popping out of gear

[dan williams]

Spring has sprung. Let the fettling begin. Clutch holder tool fits perfectly.

(Edit) Oh this is getting interesting. After pulling it apart the stock indexer is different than the “stock” replacement. Where it contacts the cam is way off from what I expected. The shifter indexer/cam looks a bit like a thrown together assembly of mismatched parts. I’ll post an update later.

Edited April 15, 2019 by dan williams

[dan williams]

Well still working the problem but here’s the latest discovery. I ordered a cam indexer to make measurements on since it was winter and I didn’t have a warm place to pull the motor apart. Last week I did pull the shifter assembly apart to put in the indexer I had made.

So here are the indexers. The first is what was in the bike. 14mm diameter, 3mm wide and loose as can be. The replacement from Beta, 16mm diameter, 5mm wide. The indexer I put together, 13mm diameter, 5mm wide.

What I learned seeing the actual assembly in situ is the indexer is offset from the cam and only hits the very end of it. A situation made worse by the offset of my design. I have to rethink that a bit. Beta seems to be using collections of whatever parts are in the bin. The stock bearing on my bike was crap.

I put in my replacement indexer anyway and went riding. It popped out a few times when I did halfhearted stabs at the shifter but never popped out when I did a proper shift. Shifting also felt more positive snicking neatly into place when done correctly. So it is improved but not perfect.

So where to go from here? I have custom cams machined that’ll be arriving in a few weeks. Deeper re-profiled notches and extra holes to move neutral between any two gears. Unfortunately they are not offset to match the indexer so I may have to rethink their design.

 

 

 

 

Edited April 20, 2019 by dan williams
Fixed incorrect diameter OEM indexer

[dan williams]

I'll wait to see the first revision of the custom cam. I may go for a modified version if there's clearance for the actuator.

 

[Sir Real Ed]

On 4/18/2019 at 9:13 AM, dan williams said:

Well still working the problem but here’s the latest discovery. I ordered a cam indexer to make measurements on since it was winter and I didn’t have a warm place to pull the motor apart. Last week I did pull the shifter assembly apart to put in the indexer I had made.

So here are the indexers. The first is what was in the bike. 14mm diameter, 3mm wide and loose as can be. The replacement from Beta, 16mm diameter, 5mm wide. The indexer I put together, 13mm diameter, 5mm wide.

What I learned seeing the actual assembly in situ is the indexer is offset from the cam and only hits the very end of it. A situation made worse by the offset of my design. I have to rethink that a bit. Beta seems to be using collections of whatever parts are in the bin. The stock bearing on my bike was crap.

I put in my replacement indexer anyway and went riding. It popped out a few times when I did halfhearted stabs at the shifter but never popped out when I did a proper shift. Shifting also felt more positive snicking neatly into place when done correctly. So it is improved but not perfect.

So where to go from here? I have custom cams machined that’ll be arriving in a few weeks. Deeper re-profiled notches and extra holes to move neutral between any two gears. Unfortunately they are not offset to match the indexer so I may have to rethink their design.

 

 

 

 

Dan,  Thanks for the update.  Very interesting.  It seems obvious, that the smaller diameter bearing on the indexer should provide more positive engagement.  In regards to the 16mm diameter bearing, WTF are they thinking?  As you said, they are probably using whatever gets sent to the assembly iine.  So far on my 2019 EVO 250, it has only come out of gear once, during the first couple hours of running.  I don't recall if it was first or second, or whether I was lazy engaging the gear.  I'm not too concerned since it is a new bike, so for the time being, it is a non problem in my mind.  My first oil change (after two hours) was to Amsoil 10w-40 Synthetic Motorcycle oil, but I've switched to a non-synthetic 10w-30 to allow a little quicker break in.  I'm a firm believer in non-synthetic oil changed every couple hours during break in.  Gotta let the self-machining process run it's course.  When you see the chips attached to the drain plug magnet after only two hours of running.... 

What oil are you using?  What is length of the axial overlap between indexer bearing face and cam face?  Please keep us informed. 

Side note:  A friend's 2018 EVO 250 has a cracked rear hub around one of the wheel bearings.  He did not say which side.  Sounds to me like the bearing bore was machined a bit too small, and they cracked the hub by forcing the bearing into the bore during installation.  He has informed his dealer, and Beta is fixing it under warranty.  I was impressed that Beta would do so.  I don't think many other OEM's would do that on a competition machine that has been in use for a year.  Take care.

Edited April 22, 2019 by Sir Real Ed

[dan williams]

It's kind of ironic that when I first got the 2018 I posted on here that it was the best shifting Beta I've owned. I suspect that as the indexer bearing has worn the position of the shift drum has been allowed to move leading to the problems I had. I was thinking about this a bit more and I think one of my assumptions may have been off the mark. Since it pops out of gear usually on a hit I thought it was probably the lever deflecting that was moving the shift drum. The problem with that idea is the lever sits centered position on either side of the cam and would have to travel with sufficient force to move the cam off the indexer. Now I'm wondering if the indexer was so loose that what was holding it in gear was the friction under power of the dogs. When the rear sees a bump the loading on the transmission is momentarily released allowing the dogs to disengage. The custom cams should be in in a few weeks. I have to press the pins in and then I can try one to see how it works. I wish I had taken it apart before I had the cams made to see the offset but hindsight...

Obviously if I were a professional I'd split the cases and make sure the drum/forks were in the optimal position but that's a lot of work.  

I've tried several oils but currently Castrol edge 10W-30 titanium. Once the clutch mod is done the oil just doesn't seem to make much difference.

The bearing overlap is about 2mm. Kinda sub-optimal with a 5mm wide bearing and a 5.5mm wide cam.

Edited April 23, 2019 by dan williams

[Sir Real Ed]

On 4/23/2019 at 1:03 PM, dan williams said:

...........

I've tried several oils but currently Castrol edge 10W-30 titanium. Once the clutch mod is done the oil just doesn't seem to make much difference.

The bearing overlap is about 2mm. Kinda sub-optimal with a 5mm wide bearing and a 5.5mm wide cam.

Thanks for the update.  yeah.  2mm of overlap just does not seem right with 5mm available.  Very low load situation, so wear should not be an issue.

[dan williams]

Well yes and no. How's that for commiting to an answer? Typically in a cam follower needle bearings are used with a thicker outer race because the force is concentrated at one point on the outside of the race. A typical ball bearing isn't meant to have the outer race under constant asymmetric pressure so there is a concern long term of unusual wear when a ball bearing is used as a cam follower. But I agree that in this situation the concern is probably minimal. I don't like that there may be torque on the bearing that could twist it.

[Sir Real Ed]

22 hours ago, dan williams said:

Well yes and no. How's that for commiting to an answer? Typically in a cam follower needle bearings are used with a thicker outer race because the force is concentrated at one point on the outside of the race. A typical ball bearing isn't meant to have the outer race under constant asymmetric pressure so there is a concern long term of unusual wear when a ball bearing is used as a cam follower. But I agree that in this situation the concern is probably minimal. I don't like that there may be torque on the bearing that could twist it.

True.  I was thinking about the only load on the cam follower is provided by the spring force. 10-40 lbs?

[dan williams]

SIT REP as Jeremy Clarkson would say. Second day out on the bike with custom indexer installed and stock cam. No false neutrals and shifting on the loop very positive. A couple of times a shift wasn’t right on and a split second later the box snicked into gear on its own. Strongly points to my original issue being the wonky bearing on the indexer.

[Sir Real Ed]

On 4/28/2019 at 6:08 PM, dan williams said:

SIT REP as Jeremy Clarkson would say. Second day out on the bike with custom indexer installed and stock cam. No false neutrals and shifting on the loop very positive. A couple of times a shift wasn’t right on and a split second later the box snicked into gear on its own. Strongly points to my original issue being the wonky bearing on the indexer.

Sounds like confirmation of your analysis to me.  Good bearing obviously better than bad bearing.  Smaller OD bearing should also be an improvement.

[dan williams]

For those following along on the home version of WTF is Dan doing now. I think a change of plan. Instead of re-re-designing the cam to make the bearing line up properly I'm going to try something different. The way it sits now the bearing is offset from the center of the cam. Rather than offset the cam I'm looking at something much simpler (famous last words). Making the pivot pin 3mm longer and flipping the bearing to the other side. This allows the bearing to be centered using shims if necessary. I just have to crack the motor open again to see if there is adequate clearance to fit the indexer arm with the bearing flipped.

 

[guy53]

Dan I've never seen the parts you are modifying but from the drawing you just posted, would'nt it be simpler to machine the shoulder of holding pin so you could slide the spring further in and compensate with a washer outside the indexer ?

I have followed your thread with a lot of interest since the beginning, I tip my hat to your patience and the fact you share your find.

Guy

[Sir Real Ed]

Also speaking from a position of ignorance, I agree that guy53 has a good point.  But it is all about the available space envelope.  Some times physics says "Screw you!  You gotta do it my way!"  Stupid physics.

Go for it Dan.  Where would the world be without "famous last words?"   ?

Ditto on the thanks for your time, effort, and sharing.

Edited May 4, 2019 by Sir Real Ed

[dan williams]

I’m worried the spring might get cocked sideways and act weird. I know that’s poorly said. I also only have the machining capability afforded by a vice and a dremel. It’s easier (but not cheaper) to farm it out to eMachineshop. Oh well that’s what the day job is for. To pay for what I want to play with.

Day three out with the custom indexer and still flawless. Starting to get my confidence back. Modifying the pin to flip the bearing will probably be my last modification on this issue. Already over $900 in the hole. But I’se gotsta know.?

But I’m back to lovin’ my bike again and how much is that worth?

[pindie]

Priceless