Project Eliza...

bikaholic

"I ain't nothin' special but I got dreams of bettering myself", it said.

"See, that's why I come 'ere to you",...






So, you were a worn-out Silverfox Constrictor BSO that changed hands for a tenner.

bikaholic

URT rear suspension design: active when seated, less so when standing. May act like a bucking bronco on a gentle downhill run when the front brake is applied.

The frame specifications:

- Aluminium
- Disc Brake Specific
- Size: 16" CTT
- ETT: 22"
- CS: 17.3"
- HT: 1.1/8 x 120mm
- BB Shell: 68mm, British 1.370" x 24tpi
- Rear Shock: KS-258 w/ 750 lbs coil spring, 140mm i-2-i
- Replaceable Hanger
- Dropout Spacing: 135mm
- Seatpost Diameter: 27.2mm
- Seat Clamp Diameter: 31.8mm
- FD Clamp Diameter: 31.8mm
- Weight: 2877g (as pictured)

Although I would normally turn my nose up at BSOs, curiously, this frame fulfills my absolute minimum build requirements.

paul.skibum

bikaholic wrote:

Although I would normally turn my nose up at BSOs, curiously, this frame fulfills my absolute minimum build requirements.

Absolute minimum being it will make a bike even if its a crap one?

bikaholic

paul.skibum wrote:

bikaholic wrote:

Although I would normally turn my nose up at BSOs, curiously, this frame fulfills my absolute minimum build requirements.

Absolute minimum being it will make a bike even if its a crap one?

Maybe, we shall see...

It will be built up using bits and bobs that I have in my spare parts box.

paul.skibum

But surely unless you have a spare rear shock the right length and stroke kicking around its always going to be an undamped pogo stick and even then its going to have pedal feedback in the only gear that you will ever be able to use to get its considerable mass moving?

I'd imagine that frame is worth more than 10 quid in scrap metal though so you are quids in if you quit the project now!

bikaholic

I've already visualised what the finished bike will look like - this is one of the rules to keep in mind if you're a prolific builder.

Spare rear shocks:






They are Fox Float R Propedal (165mm x 38mm) and Fox Float RP23 (150mm x 38mm).

Both are affected by the stuck down problem - which means that the seals need replacement. This is a relatively easy job to do.

Both shocks would still work on the frame despite the out of spec i-2-i lengths. Which one I'll use depends on which one best suits the forks that I choose.

Incidentally, URTs are not very prone to chain growth or pedal bob, which is why the majority of BSOs are URTs as they can cope with the poor quality chainsets fitted to them.

Beardface

Should be an interesting thread! I think it was leaflite (another forumite) that did a 'project BSO', with an Apollo.. actually turned out alright!

Darkstalker420

Good luck with it mate. (love these rags to riches BSO conversions). I had planned to do the same with an old Shogun XC200 frame (nice 4 bar linkage rear sus). But the damn thing had a broken chainstay near the bb suspension pivot .

Would have been a great bike for the mrs (chipped her coccyx a few years ago). But i wouldn't trust a weld job on something as critical as that. Post lots of pics if you can.

Thanks.

paul.skibum

I take pleasure in building a bike and repairing/maintaining them. I just dont see the point for something I would never ride.

Also, it appears to me from your photo that the headtube angle and seat tube angle mean they are converging above the bike (not to mention they are a little steep) so you put the seat up and get closer to the bars. Surely this is what might be described as a design flaw?

Discuss.

nicklouse

An air spring on a URT! Don't think you will get the air can to hold the air pressure you need.

What is the spring rate on that coil now?

bikaholic

nicklouse wrote:

An air spring on a URT! Don't think you will get the air can to hold the air pressure you need.

What is the spring rate on that coil now?

The spring rate is stated above, albeit, missing part of the units of measure (ie lbs/in) due to an errant touchpad.

An air spring on a URT is not a new idea - I will get useful data whether it works or not.

bikaholic

Repeat after me, "The rain from the jetstream plane falls mainly on my window pane".

Then, we'll choose some ornaments that befits your station:





I think I'll go for some workman-like Shimano Deore shifters, Deore FD, Shadow SLX RD to match the other components.

nicklouse

so travel and shock stroke?

currently with current shock.

Giraffoto

bikaholic wrote:

Repeat after me, "The rain from the jetstream plane falls mainly on my window pane".
. . .

Not big into chucking your old stuff on eBay then?
You must have more drawer space in your garage than me!

nicklouse

old stuff! i wonder what stock taking is like?

Twelly

bikaholic wrote:

Repeat after me, "The rain from the jetstream plane falls mainly on my window pane".

Then, we'll choose some ornaments that befits your station:





I think I'll go for some workman-like Shimano Deore shifters, Deore FD, Shadow SLX RD to match the other components.

Is there a Deore 9spd RD in there you want to sell me cheap?

leaflite

Stav wrote:

Should be an interesting thread! I think it was leaflite (another forumite) that did a 'project BSO', with an Apollo.. actually turned out alright!

You called

Looks interesting! Does that frame weight include the rear shock? Significantly lighter than an orange five if it does!

sdavies141

i cannot wait to see this built ......

bikaholic

The spreadsheet:




Pictures to follow...

bikaholic

Giraffoto wrote:

...
Not big into chucking your old stuff on eBay then?
You must have more drawer space in your garage than me!

It's what happens when you horde all the broken bits and bobs from bike repairs. Collect two identical components with damage at different places and you'll have a donor for the other.

bikaholic

"All I want is to be at a place somewhere,
Near enough to the buzzin' atmosphere.
Warm heart, warm face, cool drink,
Aow, wouldn't it be loverly?"

















More pictures here: http://s855.photobucket.com/albums/ab117/dazza56/Silverfox%20Constrictor/#!cpZZ1QQtppZZ24

nicklouse

so what pressure do you need in the shock?

bikaholic

nicklouse wrote:

so what pressure do you need in the shock?

Around 110-120PSI for a 10mm sag, zero rebound, zero compression lever position, Beto shock pump.

VWsurfbum

Liking the remote on the rear shock, i want to do something simular

paul.skibum

My momma always told me you cant polish a turd.

Looks like she was right.

lawman

paul.skibum wrote:

My momma always told me you cant polish a turd.

Looks like she was right.

Rather rich coming from someone who can't stand bike bling or expensive components...

Looks pretty good considering its origins, loving the DIY remote for the shock too, genius!

bikaholic

VWsurfbum wrote:

Liking the remote on the rear shock, i want to do something simular

If you want to make one the easy way, just modify a Schrader valve adapter that has an independently rotating part on top of it. Drill the top part for the cable.

I used a metal nosed ferrule at the cable entry point but would have preferred to use a v-brake noodle instead in order to get a neater cable run - however, there was not enough material on the top part for the bigger hole needed.

The 3-stage Propedal compression lever on the shock needs to be drilled so that it describes the same circumference as the lockout unit on top of the forks. I drilled mine a bit further out simply because I couldn't find any stronger springs in my spare parts box. I then lined the hole by supergluing a small metal tube (found on tag folders or a cut down ultra thin cable end crimp) into place.

As is, my setup works perfectly with almost no margin to spare.

Darkstalker420

Nice! . What's it ride like then? I love these BSO conversions.

Thanks.