Author Topic: Materials Q for you Mechanical Engineers out there (Read 5033 times)

86Rrider · « **on:** January 31, 2017, 12:47:51 PM »

I did not want to hijack bronken1's thread asking about alternatives for Laeger's A-arm bushings, so I'll start my own:Years back I picked up a set of Laeger's +2 +1 A-arms and Elka shocks from a member on the ATV Riders formum. Great transaction, great seller. I install the parts on my 250R and I immediately notice how loose the bushings are at the frame. OK, no big deal, must be the seller rode his machine more than he advertised, I'll just get a new set of bushings from Laeger's. Horrible sales experience with Lager's, then when the new bushings show up, I install them and my front-end is even sloppier than with the stuff the arms came with! So I took a bunch of measurements, went to the local industrial materials supply house and bought a chunk of Derlin. I then took it all to my nephew and he machined me 2 sets of Derlin bushings to the correct tolerances. That was 2009 and I've worn through those 2 sets of Derlin bushings and 1 set of the bolt sleeves. Time for new ones.So here is what my post is about: when I get the next set made, I do not want to make them from Derlin again. I would like to use a more suitable material for the application - I.E. something that will wear better than - last longer than 3 yrs? I'm not a materials guy, so I do not know where to start researching this. Thought there might be a Materials Engineer or Mechanical Engineer among the group here that could help?Thanks in advance!

thesmith87250r · « **Reply #1 on:** January 31, 2017, 02:45:21 PM »

Something dont sound right .ya bought new parts that that were sloppy ? An had only 3 years before you needed a arm bushings agian. I have atock a arms i used for 18 years an were still good when removed, i have lonestars with with a few years on them no issues an housers that were used an have lots of time on them no issues. What are you riding in woods ,rough terrain? Etc.... would like to hear from other members also on how long their a arm bushing last. I have ridden with the same group of people with same bikes for years an no one has replaced a arm bushings . Also when he machined the parts did he make them so the grease zerk works correctly ?

JohnTabata1 · « **Reply #2 on:** January 31, 2017, 03:41:19 PM »

Nothing wrong with using Delrin

huntertools · « **Reply #3 on:** January 31, 2017, 09:17:09 PM »

Try using PEEK. Excellent wear properties and machines better than UHMW, Delrin or Nylon. Can be purchased from McMaster Carr. Check it out, I have used it for many bushings, pump sleeves and works it great.

Allen

JohnTabata1 · « **Reply #4 on:** January 31, 2017, 09:31:17 PM »

Nothing wrong with using Peek also. There's diff levels of Delrin, Peek, etc also. All isn't the same

croat1 · « **Reply #5 on:** January 31, 2017, 10:41:50 PM »

[MENTION=420]86Rrider[/MENTION], did you make or purchase the sleeves?

Joe

jcs003 · « **Reply #6 on:** February 01, 2017, 05:06:27 AM »

use PTFE embedded bronze.

you have your choice here: https://www.mcmaster.com/#standard-sleeve-bearings/=166060c

you might need to find a bar if your bushings needs custom geometry.

also, since you had issues with your bushings being the correct size; you might have 400ex a-arms.

John

86Rrider · « **Reply #7 on:** February 03, 2017, 12:41:37 PM »

Thanks for all the replies guys!Thesmith87250r - I agree with you that things should last longer, but unlike stock A-arms that have bearings in them, these are older model Laeger's with only the Derlin bushings and no grease zerks. However, each winter I did pull the front-end off and hand smear grease on the bolts, sleeves and bushings. Also the terrain that I ride is mostly woods trails, but once a year my group travels out of state to some kind of extreme ORV park or area. Was out in Moab, UT this past September and the front end took some really hard hits on the rocks (why I need new tie rod ends). My typical riding season is: 1 Saturday afternoon on a MX track, 4 ~ 5 week-ends of trails in northern Michigan, 1 - three day ride in Michigan's Upper Peninsula and 3 days at an out of state location (usually mountains and rocks). Yes, the replacement bushings were direct from Larger's and were sloppier than the ones that came with the arms when I bought them used. As for the sleeves - I used the ones that came with the arms, as well as the ones that I got from Laeger's. I had the nephew make the Delrin bushings so there was a little interference fit on the A-arm tube and a very nice slide-through fit between the sleeve and the bushing. You know, how bushings should fit. Where as the stuff from Laeger's had about a 0.035" clearance on the sleeve to bushing and about 0.100" clearance on bushing to tube.The nephew actually recommended UHMW instead of the Delrin.As for if they are 400EX arms vs. 250R arms - I don't know. There are no identifying marks on these arms other than the Laeger's stickers. Are there dimensions that could be checked to determine what I have?

Langbolt · « **Reply #8 on:** February 03, 2017, 01:37:10 PM »

Here's what I use:

Bunting Bearings Part# EF101212
SAE 841 Bronze Flange Bearing
5/8” ID x 3/4” OD – 1”od flange 1/8” thick
¾” Length
Quantity: 16 pieces @ $1.50ea = $24 for the complete front end!

Lasts me 2 years of Rough Cross Country Riding! And they're self-lubricating

86Rrider · « **Reply #9 on:** February 08, 2017, 12:31:49 PM »

I got a chance finally to take a set of calipers to the Laeger's A-arms and the Derlin bushings. Seems the majority of the wear was actually between the A-arm tube and the O.D. of the busing. Anyway, the tube measures out at a I.D. 0.850" The O.D. of the crush sleeves is: 0.625". So if anyone can tell from these dimensions if I do indeed have a set of arms that are not 250R, let me know.

Langbolt · « **Reply #10 on:** February 08, 2017, 12:43:20 PM »

I.D. 0.850"

Are you sure ?

My LAEGERS measured 0.750"

If it is 0.850"....then the tube is 1"OD x 0.075" wall .....Standard wall for 1"OD Tube is 0.065", 0.083" or 0.095".....Might have to make some CUSTOM Bushings

86Rrider · « **Reply #11 on:** February 24, 2017, 12:45:24 PM »

You are correct - 1" O.D. tube, but with a 0.850" I.D. that would make my tube 0.150" in thickness. Your example above would have your Laeger's tube at 0.250" wall thickness (or 1/4") . Most standard tube wall thickness is 0.095" and 0.120" for DOM. Looks like Chrome-Moly - 4130 in the 1" O.D. comes in: 0.049, 0.058, 0.065, 0.083, 0.095, 0.120, 0.158, 0.188 & 0.250. I am guessing that since yours are the 0.250" wall, I may have the 0.158" wall since the seller of these A-arms had them on a dune machine. I seem to recall years back that you could buy standard or HD arms, then light-weight dune arms. The nephew is currently making me some bushings out of the UHMW material. I also looked at Laeger's website for grins and see that they now offer what they are calling a Honda Pro Series bushing kit that is actually a retro-fit of installing a sleeve with a bearing in it in place of the bushings. Not sure if I'll put out the $250 for that kit.

jcs003 · « **Reply #12 on:** February 24, 2017, 02:53:31 PM »

I still feel UHMW is too soft. yes, it is slippery, but will deform too much under load.

jOHN