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Discussion Starter #1 (Edited)
I will ask this because I would like to know ..

Why a solid bearing or bushing is considered an upgrade over needle bearings in swing arm useage ?

The SR500 Yamaha used needle bearings with seals O/E ..

You would think that solid should be less costly to manufacture and if actually better, that yami would have used such..

Mine are still in perfect condition while having been in the bike since '78..

It's my thought that unless its considered a major upgrade to a Yami's ride I will stay with the needles...

I will be reading in the Industial Press Machinery's Handbook this evening to learn more on specific property's yet wanted insight from members usage and thoughts on these two in real world conditions.. thanks
 

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Discussion Starter #4 (Edited)
ok I can see that i may be clouding the issue with my own confusion, thats why I asked ..

the 78 SR500 has NEEDLE bearings, (could a US bike bike different to AU version?)
I just looked at them now and I have had this bike since day one..

You do see here on the forum its almost always recommended that Honda's arms have solids installed so wondered if it was such for all.?

yes it is entirely possible those are plastic units you speak of and that they are not needles ,just changed from a bad choice of using plastic and not bronze or needles ?

I do know that the YG1 has a live rubber style bushing that would be prone to quick failer if overworked..
 

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I'm pretty sure the Hondas had plastic / nylon bushings and the bronze replacements are the upgrades. Same as some RD's.

I've never known a bike with needle bearings to be "upgraded" by bushings - if bushings were superior in this application, then all the new bikes would have them instead of needle bearings....but they don't.
 

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Needle bearings are far superior. Well. If a cb125 bog stock with period correct tires on it has, say bronze bushings installed. They'll be tits. Especially if you're riding through somewhere with great roads and riding it as it was intended. No worries.

Take a ride up the bell curve and shit gets troublesome. Correctly maintained needle bearings deal with higher stresses and action.

Theres a reason adding needle bearings to an applicable camshaft is an upgrade. That's over a well lubricated plain bearing.
 

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Oh and what you're looking at is typical Yamaha. They build something magnificent as the SR, but they build something totally horrible like the TX500. They're a company of a lot of firsts and not taking the easiest way IMHO. Ever ridden on OWO1? Holy shit that made me like Yamaha. Reverse cylinder TZR's which for a few years they sold with the vtwins, 5 valves per head (blah blah blah interesting), the first R1, going to triples now, Rossi, fearsome two strokes, handling over horse power?

Donno. Used to be my least favorite out of the big 4. Have to love them now.
 

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Discussion Starter #8
thanks for setting my mind at ease with this..

To sum up so far, top to bottom ideal useage..

1. needles or roller bearing
2. solid bearing or bushing (metal)
3. solid bearing or bushing (plastic)
4. sleeved live rubber bushing

As I look at the list , I assume this is also likely the history of swing arm bearing useage, needles being the norm now days (at least on the jap 4)
 

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They build something magnificent as the SR, but they build something totally horrible like the TX500.

The TX 500 is not horrible..... :( Yeah, you can't let it overheat even a little or the head will crack, it is an overly complicated engine with way too many internal chains to adjust , the stock carbs suck , it could have used a 6 speed vs. the 5 speed .... but horrible? It's basically a scaled up RD350 with an eight valve twin 4T. It is not overly heavy, the power band is awesome, it's narrow and handles very well. The chain driven counter balancer actually works, providing a comfortable ride and it shares a ton of parts with other yammies. I have a TX500 and two XS500's . Yes, they are odd-ball bikes but not horrible ....
 

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I think there has been a push to use oilite bushings as well in swingarms as an upgrade. For those that don't know an Oilite bushing is a powdered metal bushing that is impregnated with oil during the forming process - it is self lubricating which eliminates the need for the zerk fitting and grease schedule on most arms. How many guys lube their arms anyway? if you are riding often you are supposed to lube that arm every couple of months. I can't remember the last time I did it on blue though.
 

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Poor blue had a bit of yaw in that swingarm haha. Mind you how many miles on that bike? And in NYC? Jesus.

Sozza Dean, I thought I'd have to explain myself to someone who owned one after I typed it. The design for the time? Brilliant. Lighten the valves by shrinking them and throwing in 4 more? Brilliant! Balance the thing with some fandangaled contraption that does work? Brilliant! But let's add an extra chain for that one. Oh and let's make sure we make the head out of two parts, not one. We really like pissing off mechanics here at Yamaha. Oh and lets only use a few complete gaskets, make sure everything else is a string gasket. Millions of string gaskets.

Lots of recalls for the head cracking, and as you said over heating.

I've built two engines now. My favorite instruction is the cam towers. 70 inch pounds to tighten them. That's just over finger tight. Have lock tabs to stop them spinning off. On both engines, man of the studs holding the towers were snapped in two. Scary shit.

Now if everything was new, and was the last update of the engine, I'm sure it could be great. But I'll skip the work and take an SR anyday.
 

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yeah.... I know, I know.... do you think the same engineer who decided 6m studs were enough for the cam towers also had a string gasket fetish ? :rolleyes:
 

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Discussion Starter #13
Still do love how simple the SR is... :) Simplicity is what sold me on this bike. Just didn't know at 19 how wise that choice was to become!!..
.......O.K......well just after I learned how to start it properly..
:rolleyes:
me being 135 lbs. in those days it was a mule to kick over, especially when done wrong...
 

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Poor blue had a bit of yaw in that swingarm haha. Mind you how many miles on that bike? And in NYC? Jesus.
About 50K under my ownership (it's a rough estimate - I lost the log book in the move). She got new bronze swingarm bushings in 2000 but that was 10 years ago and she has been in an accident and a shit ton of NYC miles since then. Probably hasn't been lubed in 10 years. At least the mullholland shocks are holding up well.

I have to take the wheel off this weekend to have a tube changed in the tire (she's totally flat), so I might grease her as well and tighten the pivot bolt. the more I can't ride and tinker the more I am heading toward a partial restoration on the bike.
 

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Any type of rolling element bearing will give less friction but they are not really the best thing for a swing arm bearing
The contact is less than with properly fitted and sized bushing and will 'Brinnel' on higher horsepower/heavier bikes or if used for drag starts
As a swing arm has limited movement (maybe 10~15 degrees rotation?) the same 2~3 bearings take all the load from drive chain on a line contact.
If there was a method of keeping bearings rotating 360 degrees they would be a far superior method of locating swing arm
The pressures can be high enough to cut through any lubricant which then accelerates wear. the machining has to be more accurate to keep everything in line (which is a good thing)
Bushings have much more surface area but also much more friction, they can support swing arm better but need much more regular lubrication
 

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I think that with proper installation and maintenance, nobody will be able to tell the difference between either a metal bushing or needle bearings in any application, including racing. Like PJ pointed out, the range of movement is so small, it just doesn't matter. What does matter is any free play either laterally or radially will be noticeable as evidenced by poor handling in turns and a tendency to have headshake and tankslappers while in a straight line if they are sloppy enough.

Ken
 

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Bearings are far more expensive than bushings, so there must be some sort of advantage about them for just about every bike to run them nowadays. If the Japs thought they could get away with skimping on this they would be doing it.
 

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Bearings are far more expensive than bushings, so there must be some sort of advantage about them for just about every bike to run them nowadays. If the Japs thought they could get away with skimping on this they would be doing it.
I think they key reason the factory would use bearings is that everything needs to be properly fitted to work correctly. With bearings it is simply a matter of good alignment during installation, something that a machine can do. For bushings, to get ease of installation they need to be set up loose. In that case, a bearing will work noticeably better than a loose bushing. A properly set up bushing needs to be installed by hand, checked and possibly reamed for the pivot shaft. That is almost never done. I have only reamed swingarm bushings once, on a race bike. That is why I like bearings.
 

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I'm holding out for a set of "rotational magnetic axis bearings" - no friction or lateral movement to worry about... Think it's BS - checkout synchrony.com or premanentmagnet.com..
 

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I'm holding out for a set of "rotational magnetic axis bearings" - no friction or lateral movement to worry about... Think it's BS - checkout synchrony.com or premanentmagnet.com..
do you mean permanentmagnet.com?
 
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