Evolution of Skill....

[gwhy!]

The 800lb spring I have at the mo do give me my required sag and also the gap between the coils do not hit before the end of the shock stroke but this spring is where it needs to be before you start adjusting ,so ideally it needs to be around a 1000lb spring, I might get away with using this but My next concern as regards my bicycle rear shock is the damping may not be strong enough which will be even more of a problem but on a plus note the rebound appears to be fine . I am using a tough shock FDR ( it is a budget shock and very good for the price for what it is ). I also have a fox shock rear body but it has no mounting hardware so I have just ordered some bearings so I can try this shock to see if the damping is any better, fingers crossed.

 

[johnrobholmes]

I would suggest the heavier shock. I am in the exact same dilemma you are with my tribred build, and the fastace is the only shock that I found that is cheap and will do the job with the geometry of the bike. I have another shock from my bullit that I want to work because of the weight, but it just doesn't have a heavy enough spring.

 

[Lenk42602]

I would suggest the heavier shock. I am in the exact same dilemma you are with my tribred build, and the fastace is the only shock that I found that is cheap and will do the job with the geometry of the bike. I have another shock from my bullit that I want to work because of the weight, but it just doesn't have a heavy enough spring.

Definitely starting to look like the moto shock is the proper solution. I was checking out the total weight of a Stealth Bomber, and it appears that they are in the 115- 125 pound range depending on batts. I though they were lighter than that. My goal was 90 pounds, but I don't think that is do able, probably closer to 100 + lbs. Looks like they are running a moto shock. If its good enough for the benchmark, should be suitable for my cobbled - together creation...

Definitely going to have to pull more electrons through that motor though... I have a crystalyte 72/40 digital controller that I will start with. I've never ridden a 5303 in 20" wheel before, so I am sure that will help my thrust, but eventually I will probably have to change controllers/battery capacity once the project reaches the "warp drive upgrade" stage.

Len

 

[gwhy!]

The 800lb spring I have at the mo do give me my required sag and also the gap between the coils do not hit before the end of the shock stroke but this spring is where it needs to be before you start adjusting ,so ideally it needs to be around a 1000lb spring, I might get away with using this but My next concern as regards my bicycle rear shock is the damping may not be strong enough which will be even more of a problem but on a plus note the rebound appears to be fine . I am using a tough shock FDR ( it is a budget shock and very good for the price for what it is ). I also have a fox shock rear body but it has no mounting hardware so I have just ordered some bearings so I can try this shock to see if the damping is any better, fingers crossed.

Got my needle bearings today for the fox shock body and I have and put them in ( But now i need to make some new spacers because of the seals ) I have had I little bounce around on the bike ( nothing to mad because it dont have any spacers ) and first impressions are.. the damping feels sooooo much better and will be more than usable, I dont know if its my imagination but the 800lb spring on the fox body also feels stronger :? must be something to do with the better damping.

edit: Spose id better say how heavy my bike is : 25kg ready to ride (55lbs) and im 79kg (179lbs)
edit: just weighed my bike as I was guestimating and its actually 26.4kg (58lbs)

 

[Lenk42602]

Have a sense the next bit of movement on this project is going to happen over the next 7 days. Next six days off!

Anyway, some bits and pieces showed up since I last posted:

Rear wheel with new 11.75" disc rotor!


Front fork - clip ons + front brake setup on wheel - Gator brake 6 piston. Rotor is 203mm... Have a nice heavy, moto feel to them. Me likey. Caliper GRAAABS that disc.... Need to spend a bit more time getting them dialed, but in due time....


Going to try and get the head tube on the main frame tac welded in and finaled before finish welding, same for the swing arm (BB and pivot point juncture) over this time off....

Len

 

[Whiplash]

OHHH! Looking good! Now its getting exciting huh?

 

[GCinDC]

very, VERY exciting. 1 wk off. keep the camera handy. we want more pics! looks awesome!

 

[Lenk42602]

Whiplash, gwhy,

Tell me about bearings used on your bikes - what size tubing (ID/OD), & what size cartridge bearings you fellas are utilizing for your pivot points. I was going to just use a steel bushing with a zerk fitting, but I might as well go all the way for my swingarm pivot.

BTW, a friend of mine who works here http://www.dominationchassis.com/

has offered to finish weld everything with a TIG once I get it where it needs to be.... I might take him up on it...

Len

 

[Lenk42602]

Head tube is in!Main frame good to go....



View attachment 1



Head tube angle turned out a smidge steeper than I wanted - going to have to use the suspension sag/rear mounting locations to compensate.....

Later,

Len

 

[Lenk42602]

.....and of course the obligatory mock up while scarfing down a sandwich. Much better than staring at TV...

 

[johnrobholmes]

Heck yeah! Getting real close!

I would take your buddy up on getting it tig'd by a professional. No reason to turn that down if the price is right and he can do it fast.

 

[nicobie]

Heck yeah! Getting real close!

I would take your buddy up on getting it tig'd by a professional. No reason to turn that down if the price is right and he can do it fast.

Yep, It would be worth every penny to get it pro welded.

 

[gwhy!]

Whiplash, gwhy,

Tell me about bearings used on your bikes - what size tubing (ID/OD), & what size cartridge bearings you fellas are utilizing for your pivot points. I was going to just use a steel bushing with a zerk fitting, but I might as well go all the way for my swingarm pivot.

BTW, a friend of mine who works here http://www.dominationchassis.com/

has offered to finish weld everything with a TIG once I get it where it needs to be.... I might take him up on it...

Len

Hi Len,
Im using 12mm id x 28mm od x 8mm bearings the tube is 32mm od with a id of 27mm so I had you take a tad off the inside.

 

[Lenk42602]

so the bike is still mocked up in the living room. I have been staring at it all night, and this am over coffee. My better half is not quite as excited as I am to see this hunk of steel in the house... Anyway, After checking the square-ness and plumb-ness of the head tube relative to the main frame, I gotta say I nailed it. Bugger is dead nutz!

Also was comparing general measurements from a 26" mountain bike for handle bar height & bb height, checking to see that I have not overlooked anything yet. With the clip ons, the height from the ground appears quite low, but upon further inspection , it is a function of the 20.5" wheel diameter dropping the whole bike down 2.75" vs. a 26" wheeled bike. The BB height is going to be about an inch lower than the 12" height on a 26" bike, once rear/front sag is set. This allows me run the same crank arm length.. Gaining a sense that with 20-22" wheels, I will be long and low to the ground. Just the ticket for my application, mostly commuting, and gravel fire roads(at 30-40mph)... Almost feels like a low-slung electric dirt -tracker.....

I played around with my clip ons and an old pair of motocross bars (cut them in have for a little rise) to get a sense of where I want to be. Took a few more pics while admiring the beast.
View attachment 1



Anyway this is where she sits until tomorrow. Off to install an exhaust in car #1, and then off to buy car # 2 today.... For the record, I have been car free for the past several months.... Lost my winter weight pedaling a bicycle in the crappy weather all spring. This is just a fun car for bad weather days...

If I can draw a bead on the bearings needed for the swing arm pivot, I may be finished cobbling that together by sunday.

Len

 

[Ypedal]

Looking good !!!

plenty of room in there for lots and lots of batteries !.. woot !

 

[GCinDC]

looks nice! i want one! are u gonna have any more bracing to keep it from folding?

ps. nice book choice for the top of your stand... :lol:

 

[Lenk42602]

looks nice! i want one! are u gonna have any more bracing to keep it from folding?

ps. nice book choice for the top of your stand... :lol:

Thanks! Folding ..... ouch, that's a painful sounding term... After the primary sections are complete (main frame, swingarm) and joined together, the entire frame gets tig'd. Then I hafta start figuring out my batt mount system inside the frame. Then come the gussets at critical junctures. Right now I am definitely planning on gussetting all the welded angle seams, the head tube junctures, seat tube suports, swingarm & suspension pivots.

Actually got so far as to finish the seat tube last sunday.




Was waiting for a proper length bottom bracket over the week end - Needed this in order to tac weld the swing arm together while ensuring a straight chain line, so I had to hold off. The other piece that is hanging me up is getting a good tube diameter /proper bearing size/configuration combo for the main pivot that connects the main frame to the swing arm. Still searching for a suitable set up....

I work part time in a machine shop, and I have access to robotic welding equipment, albeit limited at this point.... Certainly would make welding a dozen or so of these frames together a real possibility in the far future. This frame should be a roller by late may, and I should be able to start ride tuning with my 74v/10ah lipo set up and 72v/40 amp crytstalyte controller by June.....

Zen and the Art - funny, I first read that almost two decades ago. Ignited the fire behind my two wheeled escapades. I was too broke to afford a motorcycle to ride across the country, so I did it on a bicycle. I also was too young to absorb very much of that book at the time, so my brain just replayed the more romantic aspects of Pirsig's narrative. Picking it up again about five years ago, I was able to see many more layers to the work.

If you have not read "Shop Class as Soul Craft" I highly recommend it........

Later,

Len

 

[Lenk42602]

Swing arm Pivot; start at noon yesterday, and finished by 7 pm. My trusty old Dremel valiantly gave its life. Dead. Motor is burned up. Took much longer than anticipated to ream the ID wall of the pivot tube .5mm. All done by hand. Also had to turn down the pivot shaft bushing diameter (~ 4.5") from 22.2 to 22mm on my home brew lathe.

Pivot Tube: (welded member of swingarm)


Needle bearings inside Pivot Tube:


Shaft Bushing inside needle bearings:



Swingarm Axle (not to length) & Bearing Dust Caps:


Complete Pivot Assembly:



Bearing dust caps are leftover items from a Kawa KZ Bobber project in the garage.... Fit like a glove...

By the way,, If I just reamed out the pivot tube to the proper ID at the machine shop instead of doing this all by hand, I would have been finsihed in about an hour.......


Later

 

[Lenk42602]

BB shell welded into swing arm! Yeehaw! Looks like the chainline is going to work well if I run a multi gear rear set up.

A few shots of the swing arm - need to weld the pivot tube in the proper location to the swingarm, perhaps tomorrow before work....




Once the pivot tube is in, I the final step in joining the swing arm with the frame commences. The lower tubing to the main frame which accepts the pivot tube axle will be mounted square with the swing arm, then joined to the main frame..

a few mock up pics:




After she's joined together, I the have to start all the little stuff; weld shock mounting points, weld in the seat post/supports, rear disc brake mounts, gussets, finish weld all seams, weld in bracketry for batts/controllers, derailleur hanger.

Later,

 

[GCinDC]

looks great! serious rotor you got there! keep it up!

 

[Lenk42602]

getting closer.

Right now I am working on the lower section of the main frame that will accept the swing arm. This area:





gonna grab some food and then post up the tube sections that will be welded in. a few split collar clamps for pivot axle coming tomorrow. Need those in order to weld up the lower section.


Len

 

[GCinDC]

what sizes are the square pipes you're working with? the frame section looks much beefier in those pics.

 

[Lenk42602]

Hi Greg,

The square tubing used on the main frame is .75" square tubing, .083" wall. The tubing used on the swingarm is 1.5" X .75" rectangular tubing, .065" wall.

Matt (recumpence) long ago suggested I reduce my tubing wall size, originally .125" in order to reduce weight. This thing is going to be a pig. The X5 I am running will feel right at home....

Going to have do some crazy voltage/amps to make it feel quick.....


Len

 

[Lenk42602]

Man i'm getting somewhere.....here is the lower portion of the main frame that clamps the pivot axle, holding the swing arm in place.
View attachment 3

Started with two of these. Wanted to have the clamp bolts pointing upward, but these are heavy duty, solid steel units 15mm wide with 6mm cap bolts. I should be okay with some loctite...



This is the entire set up to be welded on the frame, mock up perspective from the rear drive side. Pivot tube (ultimately part of the welded swing arm) is assembled with axle in picture, supported by the block of wood. That axle tube will get cut to length once i get everything sorted.

View attachment 1

Another one, profile.



Couldn't visualize on paper how tight my chainring/chainline clearance was going to be due to the swing arm pivot location and width.

From what I can see I have about 12 mm of chain/chainring clearance with my 127 mm bottom bracket. The actual pivot tube width is ~70 mm, and I have two 29 mm wide needle bearings inside. That gives me 22 mm to narrow the tube, giving me ~ 11 mm of space if I move the axle clamp mounts inboard on each side. That should do the trick. Once the pivot tube is shortened, I should be fine running anything from a single 42t front chainring (pictured) to a 48T.....

Thats next, then the pivot tube gets welded to swingarm.....


Len

 

[johnrobholmes]

I see what you did there. Pretty slick