TLS and Swing Arm question ?.

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Josh Cox

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Sep 24, 2010
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When pulling apart my front brakes, found a little piece of aluminium blocking the side mesh vent, is this standard ?, what purpose does it serve ?.
TLS and Swing Arm question ?.

Here are some photos of my swing arm, the spindle and bushes appear worn, which was easily seen by 20 odd mm of movement at the swing arm end, but, the bushes are worn on the outside and slide reasonably easily into the swing arm itself ( the metal in the swing arm looks OK ), I was expecting the need to apply a little heat to remove them, is external wear on bushes common ?.
TLS and Swing Arm question ?.

TLS and Swing Arm question ?.

TLS and Swing Arm question ?.

Here is the headset I've just pulled out, 6205 bearings, is this a common mod ?, any thing to be wary of ?, the manuals have little to say about this set up.
TLS and Swing Arm question ?.

TLS and Swing Arm question ?.


Thanks,

Josh
 
Josh Cox said:
When pulling apart my front brakes, found a little piece of aluminium blocking the side mesh vent, is this standard ?, what purpose does it serve ?.
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Yes, part 060845. http://www.nortonmotors.de/ANIL/Norton% ... 17&Part=25

Leave it off if you want more cooling air to flow through the brake, although it will also allow more water to get in, but that may not be a problem for you?



Josh Cox said:
the spindle and bushes appear worn, which was easily seen by 20 odd mm of movement at the swing arm end, but, the bushes are worn on the outside and slide reasonably easily into the swing arm itself ( the metal in the swing arm looks OK ), I was expecting the need to apply a little heat to remove them, is external wear on bushes common ?.
Click to expand...

I don't recall anyone having that problem before.


Josh Cox said:
Here is the headset I've just pulled out, 6205 bearings, is this a common mod ?, any thing to be wary of ?, the manuals have little to say about this set up.
Click to expand...


I can't remember ever seeing that mod. before.
 
Good time for a Colorado Norton Works needle roller conversion for the swingarm, especially with the US dollar at the moment.

I'd just replace the steering head bearings. That looks like a standard setup and they do not give any problems. I was thinking of going to a tapered roller conversion and then I thought "Why"? Matt does an attractive stainless steering head kit that replaces the nut and washer setup with stainless bits. Pretty !!!!
 
Fullauto said:
That looks like a standard setup
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But only from '71-on. The standard setup on Josh's 1970 Commando would have been the adjustable cup and cone bearings.
 
The standard setup on Josh's 1970 Commando would have been the adjustable cup and cone bearings.
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Which is confirmed by the shaft being integral with the lower yoke, but if the later 6205 2rs bearings fit then they are the better option than the cup cones and loose balls. The spacer needed is there and this ensures the inners of the 6205's are carrying the load.
 
My 69 had 2 unsealed roller bearings that fit into the top and bottom of the head. No spacer. I just replaced them with sealed bearings. I only learned about any spacers lately. Was it typical there is no spacer?

Dave
69S
 
DogT said:
My 69 had 2 unsealed roller bearings that fit into the top and bottom of the head. No spacer. I just replaced them with sealed bearings. I only learned about any spacers lately. Was it typical there is no spacer?
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No spacer would be necessary with the original adjustable cup and cone bearings-as that would rather defeat the object.

However, normal ball races aren't designed to take excessive amounts of side load, and overtightening of the stem securing nut could force the two bearing inner spools inwards if there was no spacer between them to prevent it, just as wheel bearings have a spacer tube between them for the same reason.
 
My 69 had 2 unsealed roller bearings that fit into the top and bottom of the head. No spacer.
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If they were taper roller no spacer is required for the same reason the cup and cones need no spacer. As soon as you put ball bearings in then you need the spacer.

If you have replaced unsealed taper roller with sealed taper roller no spacer is required.
 
Hmmm. I may need to revisit my steering head. The bearings I took out are R&M 29LJT25 and also say 'thrust' on the same side opposite the felt. They don't look like taper bearings, there is a round groove the balls ride in and the balls and inner race do not come apart, at least not by hand pressure. I replaced them with standard 6203 sealed bearings from the auto store. I tried to look up the 29LJT25 and didn't find anything except a few pdf locations, even went to the R&M and searched with no results, or where do I get the taper bearings since I don't have a spacer.

Ideas?

Hope I'm not hijacking this thread?

Dave
69S
 
Spacer is just a mild steel tube cut to length, a welding frabricator will have loads of tubes in stock, just bring your yoke and bearing to him and try them out until you find one that fits.

7205 may be the equivalent to 29 LJT 25, a 7205 is an annular contact ball bearing, a half way house between a plain ball bearing and a taper roller. This will take much higher side forces than a ball bearing, question is does it need the spacer.
 
kommando said:
7205 may be the equivalent to 29 LJT 25, a 7205 is an annular contact ball bearing, a half way house between a plain ball bearing and a taper roller. This will take much higher side forces than a ball bearing, question is does it need the spacer.
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If it is an angular contact bearing (as DogT's are marked with a "thrust" side, then I expect they are) the spacer wouldn't be necessary, and it could be adjusted in the same way as the cup and cone bearings. http://medias.schaeffler.de/medias/en!h ... 7205-B-TVP
 
I think you are right. Finally found the LJT is an angular contact bearing. http://www.timken.com/en-us/products/be ... gular.aspx 'designed for combination radial and axial loading'

I would think if I wanted to use a spacer, I would have to take the bearings out and measure the distance between the bearing seats and make a tube of that dimension. I see some Timken 7205WN for $20 on fleabay. Don't know if they are sealed.

I could just put my old ones back in. They don't feel or look bad after I clean them up. I may just do that, although it means taking the whole front end apart again.

Thanks,
Dave
69S
 
DogT said:
I would think if I wanted to use a spacer, I would have to take the bearings out and measure the distance between the bearing seats and make a tube of that dimension. I see some Timken 7205WN for $20 on fleabay. Don't know if they are sealed.
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If you are using ballbearings then you have to take it apart and put in the spacer. Old Britts has them $9 for new, $4 used. With ballbearings the upper bearing isn't going to seat against anything in the headstock, it has to float on the spacer. Technically, it carries no axial load at all.
 
bpatton said:
If you are using ballbearings then you have to take it apart and put in the spacer. Old Britts has them $9 for new, $4 used. With ballbearings the upper bearing isn't going to seat against anything in the headstock, it has to float on the spacer. Technically, it carries no axial load at all.
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if they were normal radial ball bearings I would agree, but as DogT's are angular contact bearings then they are similar to a one-piece version of the original cup and cone bearing. http://siteme.biz/npbmail/1Newletters/0811NL/0811NL.htm

TLS and Swing Arm question ?.
 
I've already taken out the 6205 sealed bearings I put in the head and replaced them with my original 29LJT25 bearings after I cleaned them up, cleaned the felt seals and I have it all back together now except for the front wheel and a few cables.

Dave
69S
 
L.A.B. said:
if they were normal radial ball bearings I would agree, but as DogT's are angular contact bearings then they are similar to a one-piece version of the original cup and cone bearing.
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I agree, I was referring to the 6205's Dave had in the bike at the time of the post. He has since swapped them back out for the 29LJT25's.
 
Josh,
Looks like you got hijacked here, anyhow, in the spares book for the 68-70, page 18, there is a washer, item 41 that is not appearing in your parts. Since you have the 6205 bearings, it looks like, and the spacer, maybe that washer is not required?

I sure would replace the bushings on that swing arm, and the spindle, and maybe even have it reamed out oversize if the spindle is at all sloppy in the cradle. That means reaming the bushings too, because you will need an oversize spindle, which are available. I had mind completely done at Nithburg and he even put some extra screws in the end of a new SS spindle to give it more support, kind of like the Kiegler mod. The bushings should be a tight fit in the swing arm, new ones may help. Check out hobot's swing arm, he put zerk fittings in the swing arm for the bushings, then you can forget about the oil dripping out, just grease it once in a while.

Dave
69S
 
Josh,
Looks like you got hijacked here
Click to expand...

You bastards..... :D

Headset: have found 7205 bearings locally, sealed not possible apparently.

Swing Arm: The new bushes and spindle have arrived, I will be re-powder coating the frame before rebuild, certainly must ensure no powder coat finds its way into the headset bearing recess or the spindle or bush recesses in the swing arm,but:

Question: what of the frame at the swing arm, should it be painted or taped off and clear of paint ?.
TLS and Swing Arm question ?.
 
I masked my cradle where the swing arm attached from any powder coat with more clearance than the cupped washer that holds the o-rings in, but not as large an area that Old Britts did. You need to mask off enough to get the swing arm on, especially if you powder coat. I left it unpainted until I mounted the swing arm and then painted the exposed area with some good enamel black paint. It will probably leak enough you don't have to worry about rust, if you use oil in the swing arm. Don't over fill it like I did. All you need is oil to the bushings and the spindle to keep it lubed a bit. If I did it over again, I'd put some grease fittings on like hobot.

Dave
69S
 
The sealed thrust bearings were the original spec after the loose balls were given up. Brian Slark told me they got nixed by the beancounters shortly into production because of their cost. But they are clearly the superior setup. Jim
 
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