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Ah, so cheap used RSU forks come off race bikes where the racers sell them off for the price of just the bushings because they are fitting USD forks so they can go race open modified class and you are telling us that's the reason RSU forks are cheap, not because 51000 motorcycles are stolen in your country every year. :unsure: I totally believe that
TR,
Not what I said my friend. Most of the 41 mm RSU forks I was talking of came off bikes being built as Cafe "STREET" motorbikes. Where the guys were trying to improve handling by going with USD ones. For the most part I have gotten my bits from fellows that I know or ones whom I do work for. Oh, one other point most of the motorbikes stolen (I think that the number was actually around 41.8 K but who's counting ? Down 4.5%) already had RSU forks (think H/D's @ 20% of the bikes taken) I suspect that the Racer Boys with the USD forks do a better job of protecting their rides or go by to fast to be followed to where they are parking.

I will admit that there are times when I pull the licences plates off my truck and meet guys in dark alleys to buy my fork fixes. Now that you mention it these fork pushers often were wearing masks but I had always attributed that that to Covid................Hummmmmmmm.


As far as the forks for the race bikes most sanctioning organizations (Road Racing) do allow fork upgrades. This up-grading, for the most part does not allow you to change fork style (RSU to USD) but will let you go to a more modern and larger dia. fork. This usually does mandate a fork tube no larger than 41 mm except for some of the Italian manufacturers where the even older bikes have RSU forks that are 41.7 mm. Because we race with plethora of sanctioning bodies we have chosen to go with the lowest options (such as the Showa 41 mm RSU forks) to avoid switching forks back and forth along with always chasing the proper set-up.

The Suzuki SV's also use the Showa 41 mm forks and for some crazy reason they are often even cheaper. Maybe because these bikes started off cheaper in the first place.

All in good fun but I really don't deal with bike thieves. Most often only with people I know. That or well known breakers that I have a relationship with. I will hit a flea market from time to time but those have been non-evident since the plague began. Cheap bits are more about the looking than the hooking and also where to look.

Rich
 

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Fortunately somebody is counting:
"In 2020, 53,111 motorcycles were reported as stolen in the United States. This is an increase from the previous year, when 40,830 motorcycles were reported stolen." source:U.S.: number of reported motorcycle thefts 2020 | Statista
You win you get the last word. You certainly have a strange list of what's important. The only thing that had mattered to me is the thought that I was being dishonest and buying from thieves.

I does matter to whom's statistic one is referencing but I give what ever you say and cheers !:sleep:
 

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What list there is no list, you stated "used 41 mm RSU front ends are really cheap"
I'm going to a good motorcycle breakers tomorrow, I'll look for forks and trees that would work for him and I'll get a their best price on anything they have that fits that description, but I can tell you right now they will cost more then your 25US$ that much will buy you 1 litre of fork oil.
 

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I don't have a dog in this fight, but I believe Rich said the forks were $100 and the used brake calipers were $25.

Regarding fork oil - I would reckon that a 1981 motorcycle would be happy with ATF fluid - that's what my 1970's factory Honda Service Manual for my CB 750s recommended.
 

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Going to be a cold ride to the bike wreckers today, it dropped below freezing last night. :coffee:
Ya Rich said forks are 100$ each and I just priced out the front axle for my 41mm RSU forks on flea bay at 120$ US plus shipping, that's for only the used axle. His guesstimate prices are unrealistic unless the seller is getting parts for free. 'Front forks' and "really cheap" does not compute unless you are rich I guess.
 

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I just priced out the front axle for my 41mm RSU forks on flea bay at 120$ US plus shipping, that's for only the used axle.
You could probably get one turned down at a machine shop for peanuts....but then, it wouldn't have the zinc coating. I have seen Youtube videos where guys do home-made zinc coating - might be worth a thought.
 

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Discussion Starter · #49 ·
What list there is no list, you stated "used 41 mm RSU front ends are really cheap"
I'm going to a good motorcycle breakers tomorrow, I'll look for forks and trees that would work for him and I'll get a their best price on anything they have that fits that description, but I can tell you right now they will cost more then your 25US$ that much will buy you 1 litre of fork oil.
It's really hard to find a front end that's not tweaked at the bone yard around here. If I could find a whole front end for 200$ I'd be all-over it.

I found an article from a 1981 issue of cycleworld that reviewed the LTD and spelled out the differences in the frame geometry between the LTD and the E models:
Kawasaki Kz750 Ltd | Cycle World | JANUARY 1981



" the LTD has a couple of frame geometry tweeks worth noting. Naturally an LTD must be equipped with leading axle forks. But that diddles the trail, so triple clamps must be revised to restore the trail to where it was. The LTD gets more than that, though. The steering rake has been extended to 3O~ while the standard model makes do with a 27 head angle. But be cause of the reduced offset on the triple clamps the trail has only increased from 4.2 in. to 4.8 in.

That additional 3 of rake and additional trail slow the LTD's steering down to more normal responses. Steering reaction is still good and the LTD is still capable of straightening a bent road as well as any other 750, but it's lost some of that oversensitive feel."

I went to the all balls site to look for front end conversions, there are a million possible options, but that's just bearings, do I need to be worried about the races too? and has anyone here ever shortened and rethreaded a stem? What did you use to cut the threads?
 

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but that's just bearings, do I need to be worried about the races too?
Not sure what you are asking, bearings are races and caged bearings, or races with 'free' ball bearings (like on your bicycle steering stem) for the old school roller bearing set up.

There is no 'just bearings' unless you are buying a bag of ball bearings the same size as those of your steering head bearings.

I would recommend replacing both sets with tapered roller bearings....but others might disagree.

The steering stem is just a threaded hollow tube. Take it to a machine shop to shorten it and thread it - but why are you now shortening the steering stem?
 

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Discussion Starter · #51 ·
I'm stupid. I meant "cups" the part that is pressed into the head, and as far as shortening the stem this was a hypothetical question, in case the donor stem is longer and runs out of thread before it's tight
 

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I'm stupid. I meant "cups" the part that is pressed into the head
Same thing as races, mate....and if you have 'free roller bearings' look at the surface of the race/cup, if you see discolouration (grey colour meaning that the case hardening has worn) or pitting - get rid of them, but again, you should replace all with new anyway.

.....and you haven't explained the shortened steering stem......I'm curious about that. :unsure:
 

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find a donor set of forks from a bike that has about the same headtube length of your current bike. take a tape measure to the junk yard, its not hard, then all you need is bearings no need to cut /machine. i would try the fzr600 series first. i think you are in over your head.
 

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Discussion Starter · #55 ·
Same thing as races, mate....and if you have 'free roller bearings' look at the surface of the race/cup, if you see discolouration (grey colour meaning that the case hardening has worn) or pitting - get rid of them, but again, you should replace all with new anyway.

.....and you haven't explained the shortened steering stem......I'm curious about that. :unsure:
 

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Discussion Starter · #57 ·
find a donor set of forks from a bike that has about the same headtube length of your current bike. take a tape measure to the junk yard, its not hard, then all you need is bearings no need to cut /machine. i would try the fzr600 series first. i think you are in over your head.
yes, in way over my head.
I do know how the front end of a bike works - I'm questioning....again....why you are shortening the steering stem (#16 in your diagram).
It was a hypothetical. In case the donor stem is longer
 

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You could probably get one turned down at a machine shop for peanuts....but then, it wouldn't have the zinc coating. I have seen Youtube videos where guys do home-made zinc coating - might be worth a thought.
Except it's titanium, that was my BMW axle I was pricing because I knew Woody had some scrap beemers.

I found an easy 6 donor bikes with decent 41mm front ends today, I'll post a couple of photos in a few minutes, just burning up some steaks at the moment.
 

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To get an entire front end for just a few hundred US$ you'd be looking at needing to remove the parts yourself and barter some. These bikes are near Perth Ontario if you are interested, and your US$ is worth a buck 28 up here, plus US visitors are not subject to our 13% sales taxes if your purchases are under a grand

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... notice most of these scrap bikes have the key in the ignition (y) that's because this inventory was not stolen.
 
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