Need Solid Bush!

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Speed Freak
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Re: Need Solid Bush!

#31 Post by Speed Freak » Tue Jan 13, 2015 11:38 am

I would not take the original collars as a sample, at least not if you are planning to use a different type of bushing.
They seem to be quite soft as the plastic bushing causes wear on them.

I will search for the correct values for the 2 types of bearings in the evening if i find some time. I don`t have all the infos here in the office.

Regarding the Olite material, checked the SKF brass bearing catalogue and according to the catalogue the correct material for this type of load would be normal brass + maintenance, not sintered.
Sintered brass is better for high speed applications because the oil in the pores will lead to a good sliding film - if the surface velocity is too slow it`s better to have a big contact surface (will be reduced by the holes in sintered material).
My bikes:
RD500 YPVS 1GE
RD350 YPVS 31K 1985
Honda CBR 1000 RR SC57
Yamaha R1 RN04

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Smoker
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Re: Need Solid Bush!

#32 Post by Smoker » Wed Jan 14, 2015 6:20 am

Kalim wrote:
Speed Freak wrote: If you have someone for machining and hardening, please let me know how much you pay for it.
If they can be done in pre-treated steel, I'll try to get them done at my office workshop.
I'll keep you posted if I can get some sets done
I'm also interested in a set of steel collars.

The machine shop I use can probably make them, if necessary. (But it would probably take a long time.)

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Re: Need Solid Bush!

#33 Post by Speed Freak » Fri Jan 16, 2015 3:54 pm

Sorry, didn`t find time to make the drawing...
Holidays are over and don`t want to start Pro/engineer in the evening after 9h working in Catia :smt005
My bikes:
RD500 YPVS 1GE
RD350 YPVS 31K 1985
Honda CBR 1000 RR SC57
Yamaha R1 RN04

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Re: Need Solid Bush!

#34 Post by Kalim » Fri Jan 16, 2015 4:52 pm

On my side I have measured the collars at 36 HRC, not that hard.

David

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Re: Need Solid Bush!

#35 Post by Smoker » Sat Jan 17, 2015 12:24 am

Kalim wrote:On my side I have measured the collars at 36 HRC, not that hard.

David
I found the HRC of 6AL-4V titanium, which I believe is (interestingly) 36.

Also, I plan to titanium nitride coat the collars, which should increase the surface hardness. Trying to find the HRC of TiN coating.

EDIT: Hard to find the HRC of Titanium Nitride, but I found this: "harder than carbide and chrome, off the Rockwell C scale".

Also not sure if TiN coating will do anything to help the collar-cracking problem. :smt017

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Re: Need Solid Bush!

#36 Post by Speed Freak » Sat Jan 17, 2015 11:37 am

Here the picture how it looks original (dark gray are the frame collars):
Image

Some numbers for KOYO needle roller bearing inner ring surface:

min. 58HRC on the surface and min. 52,3HRC at the depth of ~0,1*Dw (Dw = roller diameter ~2mm for the 18/24 bearing)
Surface finish below Ra0,2, shaft diameter tolerance j5 (+0,005, - 0,003 mm) for minimum radial clearance.

Loads:

Static load C0 for the bearings:
DL1812: 19,6kN
DL1816: 29,6kN

Just for comparison, the caged version:
HK1812: 11,11kN
HK1816: 16,8kN

C0 for the 2 big original bearings: 58,3kN


=> 116,6kN is the target.

4x DL1812: 78,4kN
4x DL1816: 118,4kN

C0 is defined as static load where damage occurs at the baring parts, the real load is much below this value - the more load the less bearing lifetime.
So this value doesn`t mean that 4xDL1812 will not work, it just means this bearings will fail earlier than the 2 big bearings in the big relay arm.
As the load case is much more complex in the 2 small relay arms, i would guess it is better to use 4x DL1816 to be on the safe side.


Now the version with brass bushing:

Alowed load:
Bronze: Dynamic 25N/mm², static 45N/mm²
Sintered bronze: Dynamic 10N/mm², static 20N/mm²
Max. available projected surface (collar with same dimensions as original but without groove on the inside): 18x30 = 540mm²

Possible load per side:
Bronze: 13,5kN dynamic, 24,3kN static
Sintered bronze: 5,4kN, 10,8kN static

Doesn`t look good in comparison to the needle bearing, but hard to say if the values are comparable...


I also found out that polyamide/PTFE (maybe the material of the original bushing) is much better than bronze:
Dynamic 40N/mm², static 80N/mm²

=> 21,6kN dynamic, 43,2kN... comes closer to the 58,3kN of the needle bearing.


Maybe this is the reason why Yamaha has used plastic bushings... Needle bearings cracked because of the wrong load and too much load for brass.


Anyway...
Shaft tolerance and hardness for bronze and PTFE/polyamide bushings:

Bronze: e7, min. Ra1,0 and 165-400HB (quite soft, 400HB are ~43HRC)
Polyamide/PTFE: h8, min Ra0,8 and 100-300HB


Now it`s time to decide :smt003
My bikes:
RD500 YPVS 1GE
RD350 YPVS 31K 1985
Honda CBR 1000 RR SC57
Yamaha R1 RN04

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Re: Need Solid Bush!

#37 Post by Smoker » Sat Jan 17, 2015 1:40 pm

I think those sintered bronze numbers are for Oilite.

Super Oilite is an iron based material that is harder, stronger, and cheaper than Oilite. It's rated for slower speeds, but it can handle higher loads. Common applications include farm equipment, winches, sheaves, conveyors, and pulleys.

Super Oilite 16 is Super Oilite that has been heat treated to a hardness greater than HRC 50. This material is used for extreme loads and slow oscillating motions. Common applications include cranes, hoists, machine presses, and conveyors.

Still not sure what the HRC of Super Oilite is.

What is the difference between DL1816 bearings and HN1816 bearings? I can't find the kN values.

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Re: Need Solid Bush!

#38 Post by Smoker » Sat Jan 17, 2015 1:52 pm

I've also been looking at solid bushings and dry graphite bushings.

Image

Image
Last edited by Smoker on Sun Aug 06, 2017 11:57 am, edited 1 time in total.

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Re: Need Solid Bush!

#39 Post by Speed Freak » Sun Jan 18, 2015 9:55 am

DL1816 = Koyo
HN1816 = INA

There is no or at least no international standard how the bearings are named, so every supplier has his own naming system.
In general they are the same, but the INA bearing has C0 = 32.5kN instead of 29,6kN.

Not much difference, maybe coming from different material or Koyo is a little bit more pessimistic.

Another thing that comes to my mind - i don`t think the diameter 24 bore in the relay arm has the correct tolerance (i think H7 for Koyo) for the needle bearings.
But with luck it`s ok.

Anyway - i don`t like how it looks...
There is no tolerance for the seals. I`m sure the dust lip of one seal will not be on the collar if it is assembled in reality.
Image

Therefor i will try the DL1812 bearings and check them every year.

----------------------------------------------------------------------
That means i would need 2 collars with following dimensions:

Inner diameter: 10,1 +-0,05
Outer diameter: 18 j5 (+0,005, -0,003)
Length: 41,1 +-0,05
Chamfer 4x 0,2x45°

Diameter 18 needs following surface finish:
min. 58HRC on the surface and min. 52,3HRC at the depth of 0,2mm and min. Ra0,2.

Material... I have to ask on monday at work.
Best would be just surface hardened to keep the core soft to avoid this cracks.
----------------------------------------------------------------------



The numbers to the bronze bushins are coming from a SKF catalogue.
My bikes:
RD500 YPVS 1GE
RD350 YPVS 31K 1985
Honda CBR 1000 RR SC57
Yamaha R1 RN04

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Re: Need Solid Bush!

#40 Post by Smoker » Sun Jan 18, 2015 3:42 pm

Speed Freak wrote:DL1816 = Koyo
HN1816 = INA

In general they are the same, but the INA bearing has C0 = 32.5kN instead of 29,6kN.

Another thing that comes to my mind - i don`t think the diameter 24 bore in the relay arm has the correct tolerance (i think H7 for Koyo) for the needle bearings.

Anyway - i don`t like how it looks...
There is no tolerance for the seals. I`m sure the dust lip of one seal will not be on the collar if it is assembled in reality.

Therefor i will try the DL1812 bearings and check them every year.

Diameter 18 needs following surface finish:
min. 58HRC on the surface and min. 52,3HRC at the depth of 0,2mm and min. Ra0,2.

Material... I have to ask on monday at work.
Best would be just surface hardened to keep the core soft to avoid this cracks.
That's good news on the INA bearings. I ordered those last week and held off on the Super Oilite.

Thanks for the tip on the grease seals. The space for the relay arms is over 42.60mm, so perhaps I can make new relay arms 41mm wide - with the proper bore size for INA bearings. Then, any bushing material could also be machined to the new bore size (if needed).

I also plan on checking for cracks at regular intervals, so no need for grease fittings.

If the cracking problem is related to the surface hardness of the collars, TiN coating should fix the problem.

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Re: Need Solid Bush!

#41 Post by Speed Freak » Sun Jan 18, 2015 6:37 pm

I think the cracking problem mainly comes from the bending load.
One side is pushed against the frame collar, the other side is lifted up => stress in the center of the collar.

If the small collar and the special nut are big enough (soft press fit) there shouldn`t be a problem anymore.
It is good to have soft material. Just as example - you can`t break a chewing gum ;)
This is why gears are often surface hardened - hard wear resistant surface and soft core that prevents the teeth from breaking off.

Maybe the original material is also not the best, then it should be solved with a new high quality collar.
For needle bearings it is anyway necessary to use good quality steel.

Summary:
- Special nut and collar with tigth fit in the frame
- Needle bearings
- Good quality surface hardened and grinded collar for the bearings

This should solve all problems :grin:
My bikes:
RD500 YPVS 1GE
RD350 YPVS 31K 1985
Honda CBR 1000 RR SC57
Yamaha R1 RN04

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Re: Need Solid Bush!

#42 Post by jredgrave » Sun Jan 18, 2015 11:39 pm

I'm also rebuilding a RZV and working on the linkage at the moment. I've come to the conclusion that the special nut is a bad idea, and that bushings should be used at both ends of the bolt, and then a shorter special nut which doesn't contact the hole in the frame should be used to clamp the assembly. Having the special nut need to be tight to the frame and turn in the frame to undo seems like a recipe for not being able to undo it in the future.

jason

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Re: Need Solid Bush!

#43 Post by Kalim » Tue Jan 20, 2015 6:10 am

Agree with Speed freak that the breakage comes from the bending load, induced by the assembly which doesn't follow the state of the art.

I also agree with Jason, fitting a bigger special nut on one side and a bigger spacer on the bolt head side won't improve much.
The frame shapes are not precise enough there to allow having a good contact to receive load.
Ideally there should be bushings on both frame sides, which would be perfectly aligned with the current bushing, so they would guide the special nut and the spacer, and they would have the role of collars.

Not sure that's really clear... :-?

Speed Freak wrote: Now it`s time to decide :smt003
I'll go with sintered ferrous bushings from Metafram, which is an French equivalent to your Oilite I guess.
They make Ø18-Ø24 in standard, 22mm long but I can get them machined to the right length.
Two by relay arm, length around 14mm, pressed to the right position allowing to fit the current seals.

I will go then with current style collars, treated to higher hardness, around 50 HRC if I can.

I don't expect to ride a lot the bike, so if I check every year or two, it should be way enough for me.

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Re: Need Solid Bush!

#44 Post by Smoker » Tue Jan 20, 2015 7:53 am

I also like Jason's idea and will be making 2 frame bushings and some kind of shorter tube nut for the special bolt.

It will require a longer special bolt to get through the second frame bushing and into the new tube nut.

Just waiting to get the new bolt and collars done before designing the tube nut.

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Re: Need Solid Bush!

#45 Post by Speed Freak » Tue Jan 20, 2015 12:41 pm

Ok, then i will get my own collars, 42CrMo4 induction hardened to min 58HRC.

Regarding the special nut - it still can be like original, but for assembly you have to know that it is necessary to turn the bolt and not the nut - but also original you shouldn`t try to turn the special nut by this tiny hexagon :smt005
To get it back out you just need to remove the bolt, the relay arms with the collar and then it is possible to push the frame collars out with a long rod.

I will press in collar and special nut before i tightening the bolt.

Edit2:
Forget edit1 :grin:
The thread ends too early to simply cut the original special nut:
Image

My plan is to simply make a small sleeve over the part of the special nut that is in contact with the frame.
My bikes:
RD500 YPVS 1GE
RD350 YPVS 31K 1985
Honda CBR 1000 RR SC57
Yamaha R1 RN04

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