Need some suggestions...

[madmax-im]

Re: Gears

Originally posted by planedick
These gears are hardened all the way through and there is no way that a dremel can generate enough heat to soften them. The amount taken off is so nimor that wear or weakness is not an issue. I have done bothe 1st and 2nd gear in two XS's and riden thousands of miles without any problems and I do ride 'em hard. It is only necessary to remove about .040" from the dogs close to the gear and nothing at the end of the dog and even less from the hole in the mating gear. If you want to send them to me I will do the grinding for you for $50 + shipping.... Just PM me for addy and details..

Thanks for reaffirming what i suspected was the case...metal is hardend all the way thru its mass... And Thanks for the offer I would take you up on that,but I just got an email that the gears that were backordered just became available...so i am gonna go with new factory backcut gears after all.I do appreciate everyones comments and suggestions...TYVM

[Guy_b_g]

I beg to differ.

Motorcycle gears are case hardened.

This is a quote from Kevin Cameron, Technical Writer for Cycle World.

"Gears are made of steels that can both be adequately surface hardened and core-heat-treated to produce overall toughness. Typically the surface hardening has a depth of somewhat less than a millimeter, but the whole gear cannot be made equally hard because it would then be brittle. Correct heat-treatment and surface hardening depth are more variables to worry about - I watched a friend have alternate ratios made for his Yamaha by an outfit that normally made car gears, and as I'd feared, they batched his gears through with a load of normal production. His much smaller teeth were case hardened to a depth excessive for their size, and were therefore lacking much tough, fracture-resistant core. When he operated them, they broke."

Here is the source:

http://www.gunsmoke.com/motorcycling...anny/index.htm

High performance gearsets cannot be made from hardened steel. It is too brittle and will not withstand the shock loading effects.

This argument makes no difference however, as the dremel fix is a proven fix.

Starve your transmission for oil however, and ruin the case hardening on the gear surfaces, and then see how quickly they self destruct.

There have been motorcycles in the past with recalls for fixes for this exact scenario.

Here's one, the Suzuki T500, (with pics of what happens):
http://auction.netbikes.com.au/vjmw....1nilecsdls8q5h

[madmax-im]

Guy...thats' quite interesting...I see no reason to doubt this...It makes sense that you cannot have brittle metals in the xnsmission

[planedick]

Bull***t

Case hardening would not work with gears as the torque on the splines would not hold and the teeth would bend if they wore only hardened 1 mm deep. The secret is to harden them, but not so hard that they are brittle. Most gears and shafts are made of 4130 steel and hardened to rockwell C65. If you are so sure of your statement, just take an old gear and grind 1 mm off of it and then try to hacksaw the inner metal. You will find that the gear is harder than your blade and you can't cut it. Technical writers are not engineers and I submit have absolutely no experience with metals and hardening.

AND the links you posted don't work...

[Guy_b_g]

Well.. this discussion has degenerated into rudeness.

Flame me all you want planedick, you have the stump.

First if you read the quote by Kevin Cameron carefully you will notice that he specifies that gears are not only surface hardened but also core heat treated. Thats why they are tough enough that the teeth don't bend and the splines hold.

Second a Rockwell hardness of C65 would be suitable for files and perhaps knives (they'd be hard to sharpen.. I prefer mine at about 57-59C), but definately too hard for an entire gear to be made of. There would be no give at all and fractures would occur. Files are hardened to C65, try bending one sometime and watch it simply snap in two. A transmission gear lives in a violent environment with lots of shock loading.

Third 4130 is generally used as a structural steel, or as tube frames in cars and motorcycles, etc. Even 4130H is not suitable for transmissions. Look it up.

Fourth, Kevin Cameron is the most widely read technical writer in motorcycle journalism, with articles beginning in 1973 on a variety of technical subjects. Dynotech consults him, race teams consult him, hell...one of his sons is named after Irv Kanemoto, a famous racebike developer. He headed up race teams in the 70's. He has written two books, one being the Sportbike Performance Handbook, the other is called TDC and is a collection of his best technical articles over the years. Look up the reviews...better yet, read one of his books.

If you don't think he's qualified to make the statements attributed to him, write him at Cycle World and tell him so. You might also want to ask him for his credentials. Then please post his answer here.

Do your homework, I did mine.

PS. Can a moderator fix those links, please...he's right..they only work if you paste them in the address bar.

[Guy_b_g]

I just got off the phone with a friend of mine who is a machinist.

He told me that a gearset could be possibly be made of 4130, so I'm wrong in my statrment that it is used solely as structural steel.

However he also told me that it is extremely unlikely that such would be the case. 4130 is way more expensive than the 1100 series steels that a gearset would probably be made of. He stated that the material would likely be 1144 but would be called something else besause the Japanese use the JIS standard (Japanese Industrial Standard) and it would be a JIS number with the same properties as 1144.

He also stated the the gear hobs used to manufacture the gears would last much longer using an 1100 series steel, and that it was simple economics which lead manufacturers to use the least expensive material, and the easiest to manufacture which would do the job well.

By the way, 4130 is quenched in an oil bath after being heated to 1500 degrees at a rate of an hour per each inch of thickness, and the hardest it will get is Rockwell 52. It is possible to surface treat it with arsenic and get a harder surface, but not to much depth. It is also very tough steel, and harder to machine than the 1100 series steel used in mass production of gearsets.

He also reiterated what I've found in other sources, gearsets are surface hardened, and core heat treated. He should know, he's done it himself.

I trust Nick's knowlege on this, he has a lot of experience machining parts for sprint cars, and many machining jobs for Lockheed and Raytheon, as well as direct work for the DOD.

[TopCatGr58]

Originally posted by Guy_b_g
PS. Can a moderator fix those links, please...he's right..they only work if you paste them in the address bar.

Hey Guy, I activated them, but the 1st one doesn't take you exactly to the page, it defaults to some Gunsmoke ad!?
T.C.

[Guy_b_g]

Thanks TC:

I saved that search and the article is still active...here's the link again:

http://www.gunsmoke.com/motorcycling...nny/index.html

You have to scroll down 2/3rds of the article to get to the correspondence with Kevin Cameron.

The article itself is interesting to me..shows how to change a gear ratio by changing only one of the two gears in a set...which according to Kevin is common practice in road racing. Costs a pocketful of money though...

[TopCatGr58]

Hey Guy,

For some reason the URL button doesn't seem to work right. So...when you want to post any future links, and don't need to type in a different name/description for the link, just insert the link directly as text on its own line, and be sure the AUTOMATICALLY PARSE URL's check box is checked, and the forum will make it active automatically.

What seems to be happening is that it's creating a beginning tag, with the http:// portion inside of the tag, and that's what's killing the tag. I've just gone and removed that from the [URL] tag, and then they work.

Great info, BTW. And does confirm what I had learned, and I think even saw on some Discovery channel show about HOW IT'S MADE or such on gears, and the extra surface hardening steps!
T.C.

[Guy_b_g]

Thanks for figuring out the problem, and fixing the links.

I will use your advice in future posts, (about just posting the text of the URL and having the automatic link parsing button switched on).

BTW, I just want to reiterate that I am NOT advising people to avoid doing the Dremel tool fix, it is a good fix. I asked Nick's opinion of undercutting the dogs while I was discussing gear manufacture, just to be sure.

He stated that it's common practice all over the racing and high performance world, because it results in more positive shifts. Since since the dogs and slots are on a common shaft (as I stated before), the undercutting isn't a problem.

I am only repeating this because it is what this thread was originally about (before I caused the derailment).

[jetmechmarty]

Well I for one had some concerns, or at least, a little uncertainty. I paid for piece of mind, and I'll sleep better, whether it was necessary or not. I have new gears in hand. Now I just need a couple days to replace them. I believe I'm going to turn the bike upside down as TC suggested.

[Guy_b_g]

Marty,

I don't blame you...you can hardly go wrong with the new gears. Some people will be comfortable grinding the dogs, others won't. I would grind my own, but I just got an 81 tranny that already has undercut (factory) dogs. I'll still do the washer fix tho.

[blue giant]

Washer fix?

[Guy_b_g]

Here is a thread that covers it:

http://www.xs11.com/forum/showthread...t=trans+repair

There are also several other threads for the same thing.

It simply involves removing the circlip on the 2nd gear wheel, removing the washer behind it, removing the gear wheel, and then putting the washer back on the shaft first, followed by the gear ring, and then the circlip. The washer is now on the opposite side of the gear ring, moving the slots and the dogs closer together by the width of the washer. You now have a washer thickness worth of extra engagement between the slots and dogs.

There may be more involved, such as a bevel on the washer or the circlip...I haven't tackled this yet...help, anyone?

[madmax-im]

I am only repeating this because it is what this thread was originally about (before I caused the derailment
Guy...Since I am the originator of this thread I can say your discussion has proven interesting.I think it is clear that ppl do not all agree on everything ...I am not happy this got rude to you or to anyone else for that matter.So for those of you that were not as tactful as the rest of us...either learn to disagree in a intelligent manner or not at all...in my thread....As to the matter of dremel fix vs.gearset exchange.I am sure the dremel fix does what ppl have said it will do...I have opted for swapping out the old gearsets for new ones...hopefully this will save a few hours work in the process...as was mentioned elsewhere..