Reinforced Passenger Peg Muffler Hanger tab on BMW motorcycle

This is one of those things I try to do to every BMW motorcycle I rebuild.

The Motorcycles Cushman Truckster is one of the more popular models of bikes in the United States. It has been around since the mid nineteen-hundreds and has always been a top seller among collectors and bike lovers. While it doesn’t come with a warranty, you can get around that by getting a Cushman Tribute package, which pays for repairs or parts that might need them in the future. There are many sources online for Cushman bikes, including parts selection, prices, and even complete restoration packages for your bike if you’re not sure what you want to do with it. When you buy this bike, be prepared to spend a little extra money up front to purchase the bike you want. But remember, it will end up being cheaper in the long run because of the extra care you’ll be taking with it.

It is almost never the engines in BMW`s that are the problem; properly serviced with clean oil at regular intervals, and no abusive riding, they should easily see 200,000 miles

This area is cracked on nearly every frame I tear down. It is the rear foot brake area which also is the muffler / silencer hanger, and where the passenger foot pegs attach. This frame is a 1978 BMW R100s. If you are considering rear sets on your bike that attach to this section, then I HIGHLY RECOMMEND doing this procedure.

cracked tab near rear foot brake pivot hole on BMW airhead framecracked tab near rear foot brake pivot hole

cracked tab near rear foot brake pivot hole on BMW airhead frame

New piece of metal to weld onto the old cracked section to reinforce the area making it MUCH stronger and no longer prone to cracking.

Welded metal onto the rear foot brake section of a BMW R100S

Finished powder coated frame with the welded metal. This area is out of sight to most people unless they take the rear tire off.

Rear set mounting

A while back we purchased some Disco Volante rear sets.
Prior to painting/coating the frame, i had reinforced and welded a better mounting surface for the rear sets. Check out the prior post here – http://beemersandbits.com/2012/01/rear-set-mount-preparation/

Rear sets can be a tricky balance to get the ergonomics of the human’s foot vs the mechanics of the rear sets.

Here is the gear shift lever.

(click the photos for a larger view)

01RearSets22

As I tried to mount it, i realized that the swingarm was in the way. There was no possible way to wiggle that bolt around the swing arm into the hole/bracket that I had welded into the frame.

02RearSets26

Then i realized that the bolts sold with the rear sets are torx head bolts. Those are OK but it would make access with any sort of wrench or socket impossible between the swingarm and the frame.

03RearSets29

So off to the local amazing hardware store a few blocks from my house to pick up a hex head bolt of the same size. Should we ever need to remove the rear set, getting a wrench between the swingarm and frame is MUCH better then having to remove the whole swingarm in order to use a torx bit.

04RearSets30

The brake arm is fairly straight forward. My only complaint is that there isn’t a grease channel or grease fitting on the pivot. Notice the design on the BMW pivot vs the rear set pedal.

05RearSets32

So a bit of grease should help.

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Now that i have the bodywork back, and transmission mounted I can sit on the bike to get a feel of the correct angle the shift lever should sit at. I had to check to make sure I can both downshift and up shift with my foot not having to bend and strain too much. Also note the sleek transmission/gear shifter from Chris at BoxerMetal.com. Disco Volante doesn’t provide a gear selector for the transmission so you have to source them from somebody else.

07RearSetAngleIMG_3740

Unfortunately, the arm that was sent to me was much too wide. I don’t know what those Disco Volante people are thinking. The hardware is nice but the levers are a bit off.

09RearSetTooWideIMG_3745

I had a spare arm from my last motorcycle build. It was much closer to what i needed but way too long. It was also slightly too narrow. This could be because of the welded bracket I added to ‘square’ up the rear set. Regardless, i need something that will mate with the ‘eye’ of the foot lever.

08RS_TooLongThinIMG_3742

Time to break out the tap and die set.
10RS_dye

i matched the thread to an M6 x 1.0 and started extending the threads down the length of the arm.11IMG_3763

Now time to cut all the excess length off (my Dremel is rusted due to my pipe breaking). i screwed on the die before i made my cut just in case the threads got messed up from cutting. this way I could back the die off the threads and if it didn’t come off easily, i would know.
12RS_CutIMG_3766

I went back and fourth from the bike to my vice countless times. It was the last thing i was doing after about 11 hours of working on the bike. At some point, i cut the arm about a quarter inch too short.
Douph!!!! Time to put away the tools and approach the problem tomorrow with a clear mind. The following photo shows the rear set lever leaning too far forward.
13RS_TooSHortIMG_3770

After a nights sleep and looking at the bike the next day, I realized that the arm never really lined up with the shifter and transmission anyway due to the bends making it too thin. I tried to re-bend it slightly prior to my threading and cutting but it still never lined up the two holes perfectly.

So, back to my local hardware store. Along with every nut and bolt possible, they also have various rods of various materials, widths and lengths.
I picked up an aluminum and stainless steel rod to make my own.
14RS_RodsIMG_3779

The stainless steel rod looked amazing but damn, there was no way in hell I could bend it or thread it with the tools i have. It is WAY to strong.
The aluminum was perfect though. I started by threading one end.
15RS_ThreadsIMG_3759

I then began my series of laps between the bike and my vice. I measured (many times) and then made my first bend using my vice and strategic pressure to bend only at the necessary junction. The rag was inserted into the vice so the rod doesn’t get chewed up by the vice’s teeth.
16RS_Bend1IMG_3784

More measuring, another bend.
17RS_Bend2IMG_3788

Right on target.18RS_CutIMG_3791

Time to cut (again).19IMG_3795

And after some more threading, I am all set! I left some extra length on the rod just ‘in case’. Once i ride the bike and get a feel for the shifting and foot movements, i can adjust the lever as necessary. If there is too much rod, i can always shave some down. But for now, it is ready to go!

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