Old Guys Simplex moto-peddle bike

Fed Ex shows wheel hub delivery for this coming Monday. Really quick turnaround considering Labor day holiday for some. Guess I'd better hump & at least get the springer fork mounted and tested with the electric hub prior to tearing the rear up. I like to compare apples to apples or as close to as possible when changing a major component. Before and after effects are more accurately assessed in this manner.

Rick C.

Solo springer installed, still need to set the brake caliper up and this awaits cutting a new brake cable of proper dimension and clearance the brake assembly and that's a 'morrow morning task as will be the initial test ride. It turned off unpleasantly warm after lunch and I retired to air conditioned comfort for siesta.

I'm quite pleased with the look of fork on this bike...hope the ride proves as satisfying. Fotos manana.

Rick C.

Hi Moto, it's CNOL Motorsport import & yes they use Ebay. I widened it for another project that's stalled out and I changed it back to 100mm width for Hybrid e- motor. Pete used this fork on his beautiful third build and it turned out so well I ordered one and it's sat for over a year now. I posted incorrectly that I've purchased three forks from CNOL but I recalled today it's actually four now, all are a step or three better than bicycle forks commonly sold for cruiser and classic style builds quite robust.

This particular fork lends itself easily modified with side mounted leather dampers for rebound control that I may add after testing it as is, and to widening for use with larger tires, hubs and brakes.

Rick C.

Yes for classic style the girders show well and builders used them as the base frame for many of the early suspension style forks, but the un-sprung girder has always been a very racy, strong and elegant design...especially on the minimal board racer designs, think Cyclone and it about wraps up minimal, clean and racy; with a basic girder fork.

Rick C.

Thought I'd post a photo, taken in harsh light, showing the bikes basic stance with the spring fork mounted. Pretty comes later of course. I'll again be taking the bike apart this week to make adjustments, additions & changes; several already mentioned in past posts, but some not addressed are the temporary battery mounts will be changed out bringing the lithium pack 1.25" closer to the frame for extra ground and tire clearance & with a .25" offset to give more clearance between battery/pedal side sprocket... this will also contribute to a more permanent & finished appearance. I'll eventually get around to painting the glaring aluminum finish on the wheel black, an important finish detail that doesn't really matter till the major changes are completed.

Just a look at what's actual to date....

Rick C.

PeteMcP said:

That 'leccy hub and disc look like they were made to go with the girder fork Rick. Nothing jars the eye about this set-up in your shot. Once you take care of the details, it'll look perfect.
To answer the question you asked in my thread re fork rebound, yes, it all comes down to adjusting the fork nuts accordingly. Speaking from experience, getting a pal sat aboard is easier than trying to do it yourself from the saddle. I have a feeling you'll want to go down the route of adding leather dampers to the fork just to add a little finesse.

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Thanks Pete, big help...and have an assistant or many able to hold a seated position and call it work! Dampers definitely in the realm of possibility as rebound on these minimal design can be problematical. Riding will tell of course...

Thanks again, Rick C.

Ludwig you've survived what I'm seeing as a dangerous inherent design flaw of the articulated spring girder I'm working with. There is the problem of uncontrolled rebound in any simple spring suspension not utilizing a shock to control the violent return of the fork assembly after spring compression and this can be dangerous, causing loss of control, but in most cases it's just very wearing to the ride of both bike and rider.

The significant danger of over compressing the springs and causing the forks steering crown down onto the tire is quite real using this fork when running a 26" wheel assembly. This particular design will allow this and as I've cautiously tested and you've violently experienced, the result of tire to fork lockup is rider ejection.

My thoughts for correction are to provide a positive "bump stop" to limit suspension travel well before tire to fork contact can possibly occur & also provide a certain degree of suspension rebound control as well.

The rake and trail of this fork and frame setup is rather straight up and down, much less fork angle compared to Pete's setup and I know this adversely effects the forks length of allowed travel cycle with the installed factory spring and design loads. A 24" wheel and tire combination would probably be a fool proof option for safe operation on this bike and fork setup.

I used a girder fork and leaf spring on my Simplex and that design simply won't allow enough spring compression to allow a tire to fork "strike" the top leaf is just to stiff for the relatively light weight placed on it to compress, thus the top leaf is the bump stop and taking this example to the coil spring isn't a great stretch either. A stronger spring coil of the same length could replace the existing spring it's true, though it might kick like a mule on rebound and absolutely require a shock be added.

I'm working on it, just a problem to solve.

Rick C.

Wheel and hub arrived, but motor drive sprocket shipped separately & arrive when it does, of course the six hole pattern is different than any in my rather large sprocket collection. I'm pleased it spins true and the machined hub looks great.
All things considered it's coming along well.
Rick C.

Billet rear hub & 26" wheel. High quality sealed bearings spins forever! Steel powder coat wheel & 12gauge stainless spokes. 7/16" axle...should deal well with 85 lb. dry bike weight & my buck 75.

Rick C.

curtisfox said:

NICE! That from Grubee? Going to be nice when done...........Curt

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No definitely not the Grubee wheel! Just the Grubee frame.

Rick C.

I've been riding the hybrid & am gaining confidence in the fork setup I'm running and the ride is noticeably improved. I've a couple of more spots to weld on the fork before I run at speed over "washboard" roads to see how she tracks with the stock wheelbase. If all's good I'll continue with the drop out extensions and the changes to the battery mount and also add saddle suspension.

Dual pull brake lever & cables for the twin disc brakes will be required.

Rick C.