Old Guys Simplex moto-peddle bike

[indian22]

Pete it's my pleasure & glad they please you. I too stand amazed I'd overlooked these nifty pedals & pleased I didn't trouble to fabricate a folding pedal prior to locating these. Search engines really are amazing.

I expect your latest build is progressing and I'm looking forward to the frames completion. Rick C.

 

[indian22]

Cut, drilled and bent various bits for the fork. Photos of the slipper leaf stack binding strap. I also cut the material to strengthen and extend the fork drop outs, which will also be converted to bolt through rocker pivot (no dropouts, just a hole).

Rick C.

 

[indian22]

Something I want to clarify for those who might decide to use this same style girder fork for their own version of a leaf spring conversion suspension. In order for a 26" x 2.5" tire & wheel combination to clear the spring pack and U bolt I added 2" to the fork leg length for the pivot bolt placement, center to center, measured from the original drop out location & drilled a hole at that point. There is no drop out on the extended fork as a safety precaution.

This fork is wide enough to run 3" x 26" width tires, but fork length has to be added or drop down to 24" wheels with out a spring pack.

One of my pet peeves with vendors is that most are not builders, just purveyors and don't have a clue as to how important it is to supply all the dimensions of, especially, bike frames,forks and motors. They would sell more, have less negative feed back & returns if they accurately described their products dimensions.

The original drop plates just seemed too thin, especially after extending their length. The plates are now 9/32"" thick , which is almost twice as thick as the original drop out plates.

Now I need to make it all look pretty. I might want to offer this fork on Ebay. Do you think I might get $100. for it on a "buy it Now"; if I described it well and had a pro take lots of quality photos & threw in free shipping? Rick C.

 

[curtisfox]

Keep in mind that most Monark forks have a oval shaped hole on one side to adjust, or center the wheel between the legs. It is really looking good, going to be so Kool. Just my thinking is $100. Is a little low compared to the price of others, especially with free shipping.
You did a nice job......Curt

 

[indian22]

Thanks Curt. If required (and often is) I'll adjust one side in just that way till the wheel runs true.

I'll probably not try to sell the fork since I already have more than double that $100. invested in new parts alone & that doesn't include the cast rockers which were a gift, so I'll just go ahead & use the fork on the Simplex. Rick C.

 

[fasteddy]

Avidly watching this fork come together. When I first saw the forks I thought of what a great base for a leaf spring fork they would be. Now your proving that.

Fork looks great.

Steve.

 

[MEASURE TWICE]

Just looking up through axles. I assume that the wheel hub is a totally different beast. I actually thought of trying to have a normal hub wheel be put in place by screwing the axle all from one side if it had continuous threads on it. Most I think do not have threads in the middle. Now even come to think of it, the right hand thread is on both sides, so all the nut and cone nuts could not ever work that way anyway.

Cost for this extra margin of safety I guess is little concern. Those little hook thingies on kids bikes that have an exaggerated S shape to remove before the wheel comes off I suspect is not going to cut it, morerer saferer, is betterer!

 

[indian22]

Thanks Steve. I also saw the potential, but put it on (in?) my bucket list of future projects. I actually expected someone to build a leaf fork based on this girder over a year ago but it actually took me purchasing one and installing it on my Grubee GT 5 plus being given the Simplex rockers to push me into building the leaf fork for my Simplex...that plus the idea of adding strength to the front of the Simplex to support a side car attachment. At any rate it is coming together, but not without some interesting challenges, that I've somewhat described, along the way.

MT I'm running the 26" x 2.135" rotor ready steel wheel & 2.5" clincher tire, which is already mounted on the Sunlite fork/Simplex, just using 3/8" bushings on the axle rockers. Now this may change in the future with the actual running of a sidecar; the forks are wide enough to run a small custom hub D.O.T. moped tire & rim combination, but mounting brakes might be a problem. Rick C.

 

[PeteMcP]

Rick,
Been doing some 'creative staring' at your sprung girder fork pics in an attempt to get my head round how you're going to approach fitment of a front brake. Naturally everything depends on how much up/down trailing axle travel there'll be. Have you any idea at this point what that might be?

 

[indian22]

Pete I'll be using a disc brake with the caliper mounted on an axle type adapter. These are quite common and most typically offered in two designs one that attaches to the fork leg & wheel axle the other, which I typically use, only attaches at the axle. These are usually very simple to install, just a matter of proper spacing of rotor to caliper, on leading link designs, as the caliper can't rotate past the stationary fork leg even if the axle bolt were to loosen.

With the trailing link design leaf fork it's a different story since the caliper must be kept from moving into, let alone be fastened to, the stationary fork leg during suspension travel. To phrase it differently: the wheel hub, rotor, caliper & adapter all run unattached at any point except at the rockers. If I'd chosen to use a drum style brake I'd also be doing some creative staring; especially if the drum used an actuator lever like the Sturmey Archer. With disc brakes, either cable or hydraulic, installation is straight forward & though it's not classic I normally use disc brakes on the front of my builds, the Harley "Peashooter" being the only exception to date. To keep the caliper to axle adapter from turning on the axle I could use either a key or even a small hardened bolt orientated with the dropout slot to positively lock the caliper and adapter in proper position. All the adapters that I've bought had a tab milled into the adapter that in theory would position the adapter in the drop out slot & keep it from turning, but I've not liked where it located the caliper & so I've eliminated the tab opting for the above outlined solution instead. Rick C.

I'll probably limit overall suspension travel to 2" max after loading to prevent tire to fork lockup. The two disc photos are from my V twin lead ing link fork but show the type of adapter/disc setup I intend to use on the leaf fork.

 

[PeteMcP]

Thanks for the explanation Rick. As I mentioned a few posts earlier in this thread, you're inspiring me to consider building a similar sprung girder fork for a future project - and so my 'creative staring' was aimed at figuring how to maybe make a SRAM roller brake (same as the one I've fitted to my current project) work with this kind of fork set-up. I reckon I can make it work - but I can understand why you opted for a disc set-up....

 

[indian22]

No worries Pete & though I've never used the SRAM roller I've been a dedicated devotee to both Avid and SRAM products for many years, both their shocks and brakes, quality for certain & with nice attention to styling as well.

I do like the stopping power & performance of a good disc brake setup & don't consider the look objectionable in a "rider". For a classic style show or parade bike I prefer the look of drums however.

Something to consider early on is the type of leaf suspension design you feel is best suited to your bike & you as the rider. I went with trailing link, but I'm convinced there are good arguments to be made for leading link as well, both have been used with success on leaf fork suspensions. I 'kinda flipped a coin in the end, but really think the leading link design might be a little easier to set up with a leaf spring and feel that it would be, under braking, closer to what most riders are accustomed to. I'm guessing that handling, at moderate to higher speeds, will be more a factor of neck angles, amount of positive trail & tires than is the type of link design employed.

If my design is off I'll just adjust to suit & so will you Pete. Do overs are just a part of the process of "topping out" insurmountable obstacles! Rick C.

 

[indian22]

I'm at the point of mounting my leaf fork to the Simplex for a trial fit and test run. I decided to hold off on paint & any final flourishes until I see if I'm close to having a fork that actually works. Though confident I remain skeptical 'til certain facts are entered into evidence.

The Simplex hand lever shift also requires a finish up& then I can proceed with modifying the drive off bike stand for a wider & more secure stance while parked on uneven surfaces of varying composition. With these three items checked off I'll begin the conversion of the rear coaster brake to disc brake.

All these modifications need be successfully completed before beginning fabrication of side car mounts for the Simplex. My plan's to share the sidecar with my V twin build that's not getting much of my attention at the moment other than some progress on fabrication of the torpedo fuel tank.

Rick C.

 

[curtisfox]

Yes try first, there is always some adjustment to be made, and changes, I know Mr B also had a lot of changes before done, different rockers and such...........Curt

 

[indian22]

Right you are Curt. At the moment I can see the possibility of having to shorten the spring pack from the back end, an inch or so, and drilling a new rear bolt hole through the three leaves & that might in turn lead to making a length adjustment of the spring actuator legs etc.Thanks to the build threads of others, Mr. B included & your advice along the way I'm certain I avoided some mistakes Curt, but I'm still not out of the woods entirely. Change one thing and the altered geometry dictates the next move, but I'm glad I used adjustable spring rods & a bolt up spring pack design instead of welding everything solid...at this point bolted up is much better than totally screwed the #*@! up and F.U.B.A.Red solid!

Rick C.

 

[indian22]

Great forecast today & I'm in the process of swapping fork's on the Simplex & I'm still cautiously optimistic. Photo's later.

I ended up with a 14.5" center axle to leaf pack measurement under full suspension compression so with my 27" tire and wheel height I should be golden with 2" of tire to spring pack clearance. That would be plenty to allow running a fender with this leaf fork as well. The rear spring pack bolt and/or the spring's U bolt might be used to attach a heavy duty fender mount.

I should be fine on the overall spring length also 'cause I've not been able to lock the rockers up during suspension rebound while bench testing,

Looks as though I'll have two days to work things out.

Rick C.

 

[PeteMcP]

Fine tuning aside, sounds like you've got this fork licked, Rick.
Wish I had that sort of tyre clearance on my latest build's girder fork. Running a 26 x 2.35 Schwalbe up front, the moulding pips on the tyre actually brush against the bolt head which secures the coil spring. Will have to swap the bolt out for a countersunk or buttonhead replacement if I opt to fit a front fender - and even then, things will be mighty tight..

 

[indian22]

I really like the Schwalbe in 2.35 mounted on wide wheels, but they really stand tall and wide. I"m running 2.135" x 26" on the CNOL girder fork I mounted on my Grubee GT-5 frame & it barely clears...no way could I mount a fender on that one without some alterations like you have in mind.

Just now came in to catch some lunch & return calls etc. I got the leaf fork mounted this morning. Took about 5 hours to fit and adjust & I'm still not finished to the point of riding the Simplex, but the fork really changed the bikes look. I tried some pics but the suns very harsh today & they didn't turn out. I'll try again about sunset & show before and after.

I'm not bothering with the caliper just yet, but the rotor clears & I really don't see any brake issues.Rick C.

 

[indian22]

The ride went well, no front brakes so I kept it under 35 mph...felt good no stabilizer so steering was light. Fork felt good going over the railroad tracks. Not really much of a test, but I'm pleased. I'll get the caliper mounted up front and see how it cruises. Brakes first test after...

Photos cleaned up a bit, but still not good, use your imagination. Rick C.

 

[indian22]

Found time to mount the Avid caliper & center the wheel assembly on the leaf fork, flopped the wheel so the brakes run on the left side now & she now stops great. Testing the fork with just a coaster brake kept me on absolutely flat terrain with little traffic. Not my best judgement even at that! The experience did re-enforce my decision to convert the Simplex rear wheel from coaster bikes to disc however. Though the coaster/disc combination works pretty well with my lightweight bikes the jump to 150 lbs.(Harley with a Sturmey Archer front) & 170 lbs. (Simplex with Avid 160 mm front) makes the addition of disc brakes to the rear wheel a necessity When I add the sidecar to the Simplex I'll opt for an additional foot pedal operated outboard disc brake on the hack as well. Keep in mind the main reason behind all the Simplex modifications I'm currently working on are in preparation for safely adding a side hack, but while I'm at it I'm also looking to benefit the safe, efficient operation & improved appearance of the Simplex as a solo ride to boot.

The quill stem stands too tall & will need a replacement to sort the bars. I'll also paint the forks black, of course & add an acorn nut or so to the fasteners.

I'll sort the hand shift next and then turn my attention to installing a much smaller rear sprocket (54t to 30t) & converting from coaster rear brakes to Avid disc setup. The ratio as it stands is low enough that 2nd. & even 3rd. gear can be used as start ups. My Harley Peashooter uses a 44t with an identical engine/drive train and 2nd. is perfect on it to use as a low gear. I'll also make a sprocket change & perhaps a disc brake conversion from coaster on the Harley after I'm satisfied with the modifications on the Simplex.

The folding pedals completely clear the kick start lever & simplify startups plus storage of bikes is greatly enhanced. I'll test these for durability over a few months on the Simplex & Harley (that also had the same start/pedal lever clearance issue) before installing on the rest of my stable... just because of improved storage. These things are great! Rick C.