Short ribbed/ Long ribbed cases 1941 BT cases

[Paultrehberg]

At what time in the 41 production year did the BT cases go from short rib to the long rib ??

[Matt McManus]

Very very late in the production year, around the 6000 VIN range.

I had a 41FL58?? and it was still short rib. I have another 41 that is long rib its 41E6200, that the highest 41 VIN I have ever seen, has May 41 date code on the inside of the case. The factory long rib 41's are rarely seen, most 41's that at long rib have had the left case replaced at some point.

[Jerry Wieland]

I've looked at hundreds of 41 OHV cases and only 3 were long ribbed and Matt's is one of them.

Jerry

At what time in the 41 production year did the BT cases go from short rib to the long rib ??

[Chris Haynes]

My 4,000 range FL case has short ribs. And yes it is broken.

[nukkel]

Mine is 41EL612x and has long ribs as well..
Rein

[Rubone]

My 41EL55XX=short ribs. MMMMM, short ribs!!

[Paultrehberg]

How is it there are often long ribbed BT bikes on ebay with low serial numbers.??

[Rubone]

Cases regularly failed in '40-'41 and were replaced. That is the diplomatic answer...

[Jerry Wieland]

Cases regularly failed in '40-'41 and were replaced. That is the diplomatic answer...

...and probably true a lot of the time.. Jerry

[Spag]

Were 1941 short rib cases used as replacement cases from the factory or dealer stock for the short rib ones (1941) that blew up or was the cause of the damage related to a cause other than a defect in the left-side cases?
Richard

[Rubone]

If a dealer had a set of blank cases he may have used them for a repair but if he had to order a set they were most likely long rib as the factory didn't replace the 40/41 short rib with another short rib. The casting date would be a good place to look. On an EL could be a different story as they weren't breaking as much as the FL. The problem was caused by the move to the large OD flywheels and consequent thinning of the cases. My best guess is that each issue was dealt with differently by dealers and owners. Lots were just welded up.