Broken stop boss on R100RS triple tree - problem?

[ezwicky]

After I took apart my barn-find 1980 (with '84 forks) R100RS, I saw that the left-hand stop boss is broken off, see picture. My question is: Will the RS handlebars actually turn this far, with the fairing and everything attached? for comparison, I never turn the bars on my '76 R90/6 far enough to hit the stops, unless I am doing it on purpose, to test the steering-head bearing preload.

 

[20774]

Wow! How does something like that happen?

 

[ezwicky]

I wondered the same thing!

 

[20774]

The part number indicates that item was used on every twin shock Airhead from 1970 to 1984.

 

[stevenrankin]

Stops

On an RS, the bars will turn very far indeed the stops are there for a reason it being the front wheel can be turned to a very unstable degree. Now the chances of this happening while riding at speed are almost zero but in a parking lot or handling the bike while off it and moving it around in the garage there is a chance the wheel/front end can be turned too far resulting in a drop.

As to how it happened, I can give my experience, get hit real hard on one side of the bike by a car, bending the front forks and such. Sorry to say normal wear and tear or minor bumps won't break things like you have.

Not to be a smart ass but while you have the frame apart, I would seriously look at the steering head boss/bearing housing. Look very hard for evidence of bending or damage. Not sure how to do it but check to see the unit is aligned properly. Sorry I had my frame checked out after my accident by a local shop who is no longer in business. It would not be a good thing to invest in rebuilding the bike only to find the steering head is out of alignment due to a previous mishap.

Kurt, Snowbum or someone else may have an article on how to check the steering head/frame.

I would not use the broken part, used ones are easy to find. Good luck, St.

 

[jad01]

After I took apart my barn-find 1980 (with '84 forks) R100RS, I saw that the left-hand stop boss is broken off, see picture.

Hmm... I wonder if that may relate to why the fork set was switched from the original to the '84 set? Have you checked the frame for damage/verify it's straight?

 

[ezwicky]

I thought about that, but I also have the original '1980 ATE complete forks and they look fine. Fork tubes move in and out of the sliders with ease.

I have my frame out to be powder-coated, but first I am going to ask my local Airhead mechanic if he can check the frame for straightness.

edit: I'll have to take it up to Morton's as they have a jig.

 

[m_stock10506]

I would think that a decent welder could recreate that stop on the tree without much problem.

 

[Omega Man]

My 2 cents- I would replace it. Whatever forced that piece off put the same force on the whole casting.

Before adding the heat needed to remake that stop, I would use a grade 5 bolt with a stack of washers and nylox locknut. It would be a Keebler that I wouldn’t be tap dancing happy about it.
OM

 

[stevenrankin]

Parts

Used ones are available from various sources. I wouldn't mess with welding or rebuilding. St.

 

[ezwicky]

Thanks all. I am looking for a used one as we speak.

 

[lkchris]

Thanks all. I am looking for a used one as we speak.

That's your best plan for sure.

 

[52184]

Thanks all. I am looking for a used one as we speak.

My $0.02 worth is that the key issue there is getting an unmolested tree—stem and lower bracket still together—as you don’t want one that has been pressed off it’s original stem. One of the older manuals, maybe Haynes, showed that as a procedure for changing the lower bearing.

Best,
DeVern

 

[ezwicky]

Yep I'm only looking for the whole assembly.

 

[Omega Man]

I just received an email from Wunderlich advertising owner mounted steering stops. They seem to be geared to not letting the “boss” be damaged in an extreme turn of the handlebars.

Brand new and just arrived.! These Steering Stop Sets are a simple but effective way to save your steering head area from major damage during a tip over or other emergency situation. These come in 3 different sizes to fit different models and their different steering lock ranges.

I like the concept. Maybe it will be a help to you.

OM

 

[ezwicky]

I just received an email from Wunderlich advertising owner mounted steering stops. They seem to be geared to not letting the “boss” be damaged in an extreme turn of the handlebars.

Brand new and just arrived.! These Steering Stop Sets are a simple but effective way to save your steering head area from major damage during a tip over or other emergency situation. These come in 3 different sizes to fit different models and their different steering lock ranges.

I like the concept. Maybe it will be a help to you.

OM

Thanks Omega Man. I see this: "I'm sorry, our Steering Stops, Silver does not fit your - 1980 R100 RS - Click here to view parts for your bike."

But no matter, I am getting a replacement triple tree from a local airhead mechanic.