jdizon
XS650 Guru
Thanks man! Saved me 50 dollars
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5th overdrive gear grooves/mod?
- Thread starter desmodromic
- Start date
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- Tags
- engine
Thanks man! Saved me 50 dollars
danfr
XS650 Member
If you have an earlier engine said:
alwaysmonday
XS650 Addict
I have a 5th gear OD in the garage that was ordered from Mikes XS. I finally got around to putting it on the shaft this afternoon and I am running into a problem.
The ID of the 5th gear OD sprocket is slightly too small for the OD of the splines on the transmission shaft.
Has anyone else ever run into this before? I have searched the forum and didn't find one mention of this. I don't own a set of calipers available to make very precise measurements but I would estimate that the ID and OD are exactly the same size.
The engine is a 2FO from a 1979 Special. The transmission sprockets have have 2 groves cut in them so from everything I have read, it should fit properly.
I have read Mikes XS website and it references that the shaft has to be smaller than 24.82mm. Does this mean I should have to modify the OD of the splines? Again, I have not read anyone else having this issue or modifying the splines so hopefully I am just misunderstanding this whole install.
Any help with this would be great!
Jon
The ID of the 5th gear OD sprocket is slightly too small for the OD of the splines on the transmission shaft.
Has anyone else ever run into this before? I have searched the forum and didn't find one mention of this. I don't own a set of calipers available to make very precise measurements but I would estimate that the ID and OD are exactly the same size.The engine is a 2FO from a 1979 Special. The transmission sprockets have have 2 groves cut in them so from everything I have read, it should fit properly.
I have read Mikes XS website and it references that the shaft has to be smaller than 24.82mm. Does this mean I should have to modify the OD of the splines? Again, I have not read anyone else having this issue or modifying the splines so hopefully I am just misunderstanding this whole install.
Any help with this would be great!
Jon
desmodromic
XS650 Addict
I recently purchased 5 -5th over drive gears, within the past month, none fit 4 different transmissions (80',79',81' and 82'). I looked into this problem (ID on the 5th overdrive being to small) and apparently Mike's XS had a bad batch. Maybe someone knows more about this, I did not look into the problem in depth.
alwaysmonday
XS650 Addict
lots of threads about problems with these OD gears . Some have remove them and gone back to original gears because of problems. Do a search
Just found it. Looks like a bad batch if gears from Mike's supplier. I ordered mine about the same the as the ones in this thread. Thanks Peanut.
http://www.xs650.com/forum/showthread.php?t=31092&highlight=overdrive
youre welcome buddy. there is an interesting thread somewhere about gear selection and sprocket choice.
I think from memory the OD 5th gear gives an rpm reduction of about 250rpm at 60mph in 5th gear ,which is not a lot to be honest.
You'd achieve the same reduction by slowing up about 4mph !
the other way of looking at it if you don't mind spending the money on the 5th overdrive.......is.
By using a 5th overdrive and reducing the rear sprocket to a 33 tooth the bike will retain all the torque from the start without having to over rev and slip the clutch, gives lower revs when cruising equivalent to around a 2 tooth (32 tooth) reduction in the rear sprocket.
Could just put a 32 tooth on the rear but even with that there is some loss of take off speed without over revving
By using a 5th overdrive and reducing the rear sprocket to a 33 tooth the bike will retain all the torque from the start without having to over rev and slip the clutch, gives lower revs when cruising equivalent to around a 2 tooth (32 tooth) reduction in the rear sprocket.
Could just put a 32 tooth on the rear but even with that there is some loss of take off speed without over revving
I have a 33t rear sprocket and the OD 5th. I'm just now installing the motor so I haven't experienced the new 5th gear. When I did swap in the 33T sprocket there was a drop in acceleration from a standstill and I could cruise in the city in 4th gear. Also could stay in each gear longer when running through the gears. I'm happy with my choice so far.
barr toy
XS650 Member
Hi Barry here I have mikes 5th gear. In my 79 special it jumps out of gear at 3500 to 4000 rpms Why?
Barry, here's a long thread:
http://www.xs650.com/threads/overdrive-5th-gear-dropping-slipping-out-to-neutral.41539/
http://www.xs650.com/threads/overdrive-5th-gear-dropping-slipping-out-to-neutral.41539/
We were overheard at rockerbox while discussing "mikes 5th". guy claimed he had installed 3 with no problems.
Reminds me of lemon laws, some just ain't rite.
Imagine the uproar if a random 10% of the world's beer bottles were filled with water, or worse, Ex-Lax...
Imagine the uproar if a random 10% of the world's beer bottles were filled with water, or worse, Ex-Lax...
Or if most computer software randomly locked up and misbehaved in erratic ways. What would happen to the world?
And while typing this the latest win10 update threw off a out of memory error and locked up Chrome...
That's been an issue for about the last week now.
Back to old yamaha's; The factory assembler could grab gears from the bin and trial fit and build a tranny with parts that all worked together. An aftermarket vender is stuck trying to make his ONE part fit all the various production tolerances seen over several years. Yes I am aware there are two versions of this OD gear (to fit 15 years of production).
If I ever have my cases open again, I'm going to check to see if the casting forces the assembler to put the right gears in the right places. Haven't heard of one with two 4th gears for some reason...
not a random set of ratios xjwmx but tolerances say between the 3/4 gear pair and how it fits, slides on the shaft.
