Monthly Archives: April 2012

In Session: On Any Tuesday

Posted on by
Reply

You might not see us around town much. Sure, here and there on nice summer evenings having a beer for a while. While all of us are good for a rave-up story and some beer-fueled antics from time to time, it’s really all about the metal. We like to build machines, improve them, figure out interesting problems. That’s where learning happens. That’s where interest grows and dues are paid.

On any Tuesday night, it usually looks like this. Shop in session.

Jason

Bird's eye view. I've been rebuilding the door on the '59. All internals were shot.

Dan tweaking the RD frame on the welding table

Casey getting his sporty ready for street duty

4LS to Roadholder Fork (part 4)

Posted on by
Reply

A couple weeks back I got another chance to work on this fork conversion. I just never got around to putting the pics up. Things have been hectic lately.

When we left off, we were modifying the fork to work with the original Suzuki axle for this hub. The answer to the bonus question from last round? I’d bushed one fork leg but not yet bored it to allow access to the fork damper retaining screw. Bill Becker was the first to point this out, just minutes after the article was posted. If anyone has an nit-picky eye for detail (and style), it’s him.

This time I modified the axle and related hardware to finish this job.

Here we go.

I was able to mount the fork leg to the milling machine table vertically with just enough room to get the boring head setup. However, there was no way to keep the leg secure enough with it acting as such a long lever and having limited contact where mounted. I then decided to mount an extra vice we had in the welding area to the table with a large angle plate. This allowed me to hang the leg off the side of the table so it could be clamped closer to the work area.

Big old vise mounted to an even bigger angle plate. This setup worked pretty well, even if I did scar up the fork leg a bit. Nothing a little sanding and polishing won't fix.

Leg after bushing has been bored to match existing bore in axle boss. Now you can get the damper retaining screw!

There needs to be a means to secure the axle while tightening down the axle nut. I don’t want to rely on the pinch strength of the boss on the other leg as it seems lame and likely to stress the leg. It also leads to incorrect installation as the last step of securing the wheel is to tighten the pinch (after axle nut is torqued) so that the legs are parallel and not pinched together. I decide to make a small diameter hole in the axle for insertion of a screwdriver or rod to keep it from turning. Old Harley Hydraglide forks use this setup and it works. In our case there is no axle protruding so I made the hole so that it lines up with the damper retaining screw hole under the leg. Hidden. Functional. I did realize afterward that while I intended to drill the larger end, I messed up and did the smaller end. Dammit.

Axle secured in a v-block. Located under the quill using a "wiggler" for drilling.

Axle drilled. Hole is perfectly centered. Drilling on a milling machine is so much easier.

Whole setup assembled. Note the access hole for securing the axle.

I turned down the axle nut to leave room for a lock washer and made up a thick flat washer to spread the clamping force over the original fork material and the new reducing bushing I installed. The washer has a flat ground in it to engage the lower fork casting so it doesn't rotate when tightening.

That’s it for this session. I have to drop some parts off for chrome and polish the lower legs then we can assemble this and ship it home.

Jason

Fixing dented pipes

Posted on by
Reply

I picked up this set of beat-up pipes for my current project. They were typical of a 30 year old part and were rife with dents and creases. Ive heard a lot of talk of guys putting water in pipes and freezing them to push dents out. I promise you this will bulge your pipe in ways you don’t want. I decided to pull the dents out using a trick I learned working at an auto body shop years ago.

Dents

Flattened area

At the body shop we had this slick little spot welding gun that would weld studs to the sheet metal and you would pull the dents out with a slide hammer. I have neither of those, But I did have some old spokes, a torch and welder to work with.

Spokes welded to the bad areas

Heat and pull hard


After welding the spokes on I heated the area cherry red and slowly pulled to working as I went. Sometimes I had to go back and reposition the studs after I pulled it all out to get the last bit. I finally ground off all the stud mount welds to finish the job. These pipes woulnt be perfect after this but much better than before and they are getting painted soon.

pretty shapely


-Dan

The RD get a Trick suspension upgrade on the CHEAP!

Posted on by
3

So from the beginning of building this bike I knew I wanted a bike that handled like a brand new sport bike. Rd’s wernt know for their stellar rear suspension when new and the 40 years of sitting in upstate NY made these ones good paperweights. I had looked into a few different options like Progressive and Koni and was not siked on spending the $400+ on them.

Scrap metal

My wife had been out of town for work a few weeks and I spent lot of nights laying in bed thinking of options. What better way to get modern sport bike handling than with sport bike parts. Did a bunch of research on spring rates using the Racetech.com site and settled on a 07 Honda CBR1000rr showa unit. Its a nice unit with adjustable dampening and rebound and spring preload, plus a healthy aftermarket of parts as well. The spring rate is 11.5kg per mm and with the rd’s feather weight and my 195 lb self this puts me a bit stiffer than stock with tons of adjustments. A quick search of ebay yielded one from a low mileage bike for $25 with free shipping. I find its better to let the big bike mfg’s spend millions on R&D for their new machines and I’ll reap the benefits for my old junk.

New jawn off a 07 CBR1000rr

The next problem was how to make a shock with only 1.75 inches travel work in an application that needs about 5″ total with sag and not use all the fancy linkages that honda uses on there bikes. After much thought my solution was to make second arm attached to the swingarm but shorter to reduce the radius. After a lot of math I hadn’t used in years on paper I settled on needing a 5.5 inch radius from the swingarm pivot to give the proper travel when the 15″ arm moves. I decided to draw it to scale on the welding table to check the math. It worked in practice too.

Drawn out to SCALE

Now was the easy part of tabbing up the mounts. The rear is made out of 1.5″ square stock and the front that I forgot to take pics of is a 660 bronze bush I made on the lathe pressed into some round steel stock with a shoulder on it for the shock mount to ride on.

The start of the rear mount

Tacked in place

I also bent some round stock to act as a gusset for the rear mount and brace the swingarm. This should help with the torsional stiffness af the old arm as well.

Ready for finish welding

Really cleans up the lines without the rear shocks on there


So final verdict is that it feels like a new bike when you sit on it, It only cost $25 and the rest of the stuff I had at the shop or could be had for short money and the fab work wasn’t crazy. Ill take it. Thanks Honda
-DAN