Sportster 39mm midglide, 4" extension, raked triple trees, with 16" wheel

[Dennis]

The stock front end on my Stolen Sportster has served me well.   I've ridden it on some pretty rough roads (Bella Coola and Dawson City trips come to mind).



One of the coolest choppers I ever saw was in Victoria in 1982.  It had an extended wide glide front end with matching 16" center line mags fore and aft ... 8 years before Harley did the same thing with the Fat Boy. 

I would like to run the same wheels fore and aft on the Stolen Sportster, and I want slightly longer forks to get more of a chopper look.  I always said the Stolen Sportster was to be my touring chopper, but it doesn't really look chopperish enough for me.

I bought a 16" mag from a Fat Boy on Ebay.  It is obviously too wide for the stock narrowglide front end.  Many Sportsters have been converted to wideglides, but I always thought that looked wrong ...  the Sportster is overall smaller than a big twin, and the proportions just aren't right.



In 2010 Harley put a 16" wheel on the Sportster 48.  They used a "midglide."  The proportions are better.



With a pile of Ebay parts later, I am putting together my own midglide.  I found aftermarket triple trees for 39mm fork tubes.  They also have a 3 degree rake.  4" extended tubes from TC Bros, new progressive springs, new and used internal parts, and used lower sliders.

Not much travel with the damper tubes and return springs I have.  I will try these first, and maybe get longer dampers tubes later.



3 degree rake.



All assembled.



Next, making the wheel fit.

Peace & Grease, Dennis

[Dennis]

Pretty close fit.  By my calculations, I will only need Jeff to carve off circa 3mm from the right side.  The left side with rotor needs to be 2.4 mm closer to the centre, but by carving off the opposite side, it will move inward and almost perfectly centre the wheel.  The fender bosses are right next to the wheel rim which will make centring the wheel that much easier.

It's only a bit offset now.



Left / rotor side.  The gap between the rotor and the slider needs to be 2.4 mm.  You can see its right up against the slider now.



I figure I can move it to the right by carving this side down (moving the bearing inward).



The axle is a bent one Keith gave me just for mocking up.  The bearings and inside spacer tube have been removed.

Peace & Grease, Dennis

[Dennis]

I took  the afternoon off to visit Jeff.

As hoped, only one side of the wheel (the no brake side) had to be machined.



Jeff opined that the used / bent axle from Keith could be salvaged.  It had to be shortened and modified,  but saved a lot of time as compared with starting from scratch.



By the end of the afternoon, it was decided that a bit more had to be carved out of the wheel, and a few more tweeks made to the axle.  It was time to call it a day.  I left the parts with Jeff.

Peace & Grease, Dennis

[Dennis]

Machined side.  Actually went deeper than needed for clearance so that the spacer would be more robust.



Jeff made all these, including modifying the used, bent axle donated by Keith.



Its more important to be seen to be cool, than seen.  Hence, reflectors have to go.



I got the old forks removed last night.  It took heat and an impact driver to loosen some screws.  I have to re-fab the steering stop on the neck tube.  Since that will be welded, I don't want the bearing races distorting with the heat, so I have squeezed in my steel cones.



Peace & Grease, Dennis

[Dennis]

I can see why the old steering stop broke off.

There was virtually no penetration of the tiny spot weld I had used last time. 



Carved a new one ... a little bigger so more room for welding.



I need to double check before I weld, but I think this will work.



Peace & Grease, Dennis

[Dennis]

Welded in the fork stop.   Found some multi year old Bondo and hardner.  The hardner was separated into liquid and solid chunks but I figure the active compounds are in the liquid so I mixed up a batch and squeezed in on.



It seemed to dry/harden okay.

Not much shop time recently, but I want to get the Stolen Sportster on the road soon.

Peace & Grease, Dennis

[Dennis]

The new bearing kit includes races, and the old ones actually had some wear, so I had to remove them.  I tried all my tools to pry or pull out the lower one.  Nothing worked so out came the welder ...



I tried several time and increased the heat, but I could not get a strong enough weld to hold while hammering on the rod.  Plan B ...



For the top one I cut the washer in half, wedged it in the small gap behind the race, bolted and welded them in place with readi-rod.  This worked.  I wished I'd done this on the lower one.



While welding, sparks fell on a solvent soaked rag and I had a fire.   Good thing I had my piss jar handy.



Masked and ready for paint.



... and painted.



Peace & Grease, Dennis

[stevecrout]

I had to change the races in my R80 I was using in East Timor and finding tools was a challenge. The race had an annoying flat spot right on dead center so I would always feel it.  I ended up using a piece of 1/2" re-bar bent to about 5 degrees off, 3" from the bottom then hammered a bit of an edge on the protruding bit. When you lower this into the neck the bent bit was just enough to catch the lip of the race inside the neck. After about 30 or 40 light whacks going around in a circle it popped out.  I did the same in reverse for the upper one but it came out real easy. No heat used.

[Dennis]

As I recall from Rick's BMW garage night, the bearing races and access to them posed a very similar problem to the Sportster; there is a small gap left behind the race after it has been seated, but the neck tube is narrower than the bearing race, so getting a drift or something push it out is nearly impossible.

Query: I have been using Permatex Copper Anti-Seize recently in a few applications other than just bolt threads (ex. the mufflers on the BMWR65ls).  I was thinking of smearing some on new races races before installing them.   

Good idea or bad?



Peace & Grease, Dennis

[stevecrout]

I would imagine as a corrosion inhibitor this would be a good idea.  The film doesn't add any substantial amount to the already limited clearances. 

[Dennis]

What should have been a simple putting together my finished parts ... wasn't.

The fork stop was too big and was rubbing against part of the lower triple tree.  That meant some hand filing and repainting.





Then the nubs on the lower triple tree (which bump up against the fork stop) were rubbing against the fork tube, enough that they inhibited the smooth turning of the forks.  I had to carve them down.



On the stock Sportster front end, the wires from the gauges and handlebars pass in front of the upper triple tree and were covered by a chrome cover.  There was no room for the wires to pass through the front so I had to carve out a passage way for them to come out the back.  I wrapped the wires in foam where they pass through to deter abrasion.



Using the stock brake line for now.   I have a Goodridge line but will need some different ends before I can replace this.



The fender came painted gloss black.  The Stolen Sportster is semi-gloss.  This will do for now.



Otherwise it is finished.  I haven't ridden it yet. 



Peace & Grease, Dennis

 

[Dennis]

Bugs worked out.

On first test ride, the front end was intolerably stiff, bumpy and mad a huge CLUNK any time I hit a significant bump. 

Tire Pressure:  Oops.  When seating the bead I cranked it up to 90 plus psi before the bead snapped and sealed.  I always leave it that way for awhile.  I forgot to drop it down before riding.  At 30 psi it was better.

Triple tree bearings:  I'm thinking that the bearing races must have settled in bit further after the first bump or too because I discovered that they were not tight.  With the front end off the ground, I could make the forks move back and forth.  I tightened the nut/screw almost 2 full turns before the bearing were tight again.  Better.

...but still not great.  Gave Russell a visit.  Russell is all about suspensions these days and getting all of his bike front ends to compress and rebound like his Ducati 920, the gold standard.  He showed me how he measures pre-load and opined I could probably reduce mine quite abit.  The pre-load is determined by the plastic tube inside the fork.  Cutting lowers pre-load.



Much better.  The difference between fully extend fork spring (measured with wheel off the ground) and with the bike sitting with just its own weight is approximately an inch.  Much nicer on the road now.

Peace & Grease, Dennis

[stikman]

Just run a bead of weld on the inside of a bearing race that is difficult to remove.  It'll pop right out.  The weld shrinks it.  Usually only need to run a bead part way before it's ready to go.  I wouldn't bother with anti-seize.

[Dennis]

Seems like a good photo to end this thread.

Neil took this one 2019, and the top one 2018.

Peace & Grease