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New frame, 3R!

Spitfired

Monkey
Jun 18, 2004
489
0
Rochester, NY
Ok, so I've been making frames for a few years now and this one is the first suspension frame I've made which is damn near production quality.
I have a number of small improvements to make on the design, mainly to get it to said production state, but already I am so pumped. I finally took it out for a little ride around campus last night and it was awesome. I dropped it a few times (about 8 to 10 feet, depending on speed) and to say I felt the landing would be a lie. I'm pretty stoked for this one!
Surprisingly, it is VERY stiff. I was going to add a swinglink, but I don't know if I'll even need to anymore. I probably will anyway for the next one.
And yes, Zedro, I'm going to put a brace in the swingarm up by the bulkheads.

Heavy Bicycle Company
3R Specifications

***Geometry***
Frame Construction: Aircraft 4130 Chomoly Steel
Rear Travel: 8"
Head Angle: 66* (8" fork)
Bottom Bracket Height: 15" (static)
Chain Stay Length: 16.875"
Wheel Base: 45.75"
Seat Post Height: 15.5"
Seat Tube Angle (Effective) 73*
Seat Tube Angle (Actual) 66*
Top Tube (Effective) 24.5"
Top Tube (Actual) 23.4"
Front to Center: 29"
Rear Axle: 12mm thru axle
Tire Clearance: 2.75"


***Components Specs***
-Prototype:-
Head Tube: 1 1/8"
Bottom Bracket Type: Euro
Bottom Bracket Width: 100mm
Rear Hub: 150mm (dished for 165mm spacing)
Rear Damper: 9" e2e 2.75" stroke
Seat Post: 27.2mm

-Production (Intended):-
Head Tube: 1 1/8"
Bottom Bracket Type: Euro
Bottom Bracket Width: 83mm
Rear Hub: 135mm (dished for 150mm spacing)
Rear Damper: 9" e2e 2.75" stroke
Seat Post: 27.2mm

***Frame Features:***
>This frame utilizes the Heavy Modular Dropout System which allows it to use most dropouts we manufacture.
>High-back pivot location makes for a rearward arcing axle path which is similar to the direction the fork compresses. This allows the bike to maintain speed through rough terrain and harsh landings.
>Neutral chain routing - Because of the high pivot and the huge amounts of chain grow, the chain is routed via a neutral pulley around the pivot. The benefit of this, apart from zero drive line chain growth, is that the pedaling forces are reduced. Of course, given the nature of the bike, the body's own mass shifts during pedaling will induce some frame bobbing, however there is no suspension lockout or compression/extension caused from actual drive forces.
>Floating disc brake mount eliminates brake jack.





 

xy9ine

Turbo Monkey
Mar 22, 2004
2,877
278
vancouver eastside
thats very cool. nice work. can we see the other side - whats going on with the shock linkage?

*edit* ahhh, i see shock linkage pull bars now. neat!
 

WheelieMan

Monkey
Feb 6, 2003
937
0
kol-uh-RAD-oh
motomike said:
no, it's 15".
That's crazy. Looks like the bottom bracket is at least a couple inches higher than that. Must be designed for climbing over logs or something, I can't imagine why you would possibly need a bottom bracket 15 inches or higher.
 

mcA896

Turbo Monkey
Aug 15, 2003
1,160
0
Cape Cod, MA
i am planning on doing a full sus. frame sometime between now and september, can you give me any tips/tricks? it will be a steel single pivot, as i do not have access to a cnc machine for linkage etc.
 

Spitfired

Monkey
Jun 18, 2004
489
0
Rochester, NY
Transcend said:
is it just me, or is that BB like 17" high?
Yeah, it is.
I cut those little pull links too short so the tighten up the frame a whole bunch.

I have some Ti for the new ones, I just need to make them now.
 

Transcend

My Nuts Are Flat
Apr 18, 2002
18,045
0
Towing the party line.
Spitfired said:
Yeah, it is.
I cut those little pull links too short so the tighten up the frame a whole bunch.

I have some Ti for the new ones, I just need to make them now.
Ah cool, i was wondering if it was my eyes, or if it sagged like 4 inches or something. I just looked at the rear axle and notice it was way WAY higher then that.

Besides that it looks good, nice dropout system.
 

vitox

Turbo Monkey
Sep 23, 2001
2,939
1
Santiago du Chili
got a couple more qs for you,
pulley assembly looks to move with the swingarm is that so? also i was looking at the chain/seatstay and there is nothing bridging them, would that be superflouous? oh and last, seeing that it is pretty similar do the pdc dh1 id say you might want to look into some more chain guidance at the roller.
 

Spitfired

Monkey
Jun 18, 2004
489
0
Rochester, NY
The main pully is right on the pivot, so it doesn't really move at all (other than spinning with the chain). The lower one is just a cannibalized MRP guide and it's fixed aswell - just picks up all the slack in the long chain.
Yep, I'm going to bridge the seat/chain stays. That was my note to Zedro, I figured he'd be the first to call me on it.
Indeed, I intend to put another roller on top of the main pully to keep the chain in, however I havn't had a problem yet so we will see.

Thanks for the excellent comments everybody, it's really great to hear - this is what keeps me going on these things.
 

PatBranch

Turbo Monkey
Sep 24, 2004
10,460
8
wine country
Thats looks flexy (joking). I noticed you need to put the swing arm together, and I remebered you said you were going to.

How much travel does it have currently have? And will it come in rootbeer? ;)
 

Spitfired

Monkey
Jun 18, 2004
489
0
Rochester, NY
lovebunny said:
looks nice greg. whens you starting mine?
We're going to do one more prototype/show bike for Nick (my business partner) and then yous guys will follow shortly after. So, end of november? After that, I have another 3 or 4 sales lined up for some friends who really seem to want one. Does anybody want hardtails? I wanted to do a run of those, but that market is so flooded. I might just scrap those entirely, at least for a while.
I have a feeling the Cali trip isn't going to happen, mainly due to money. Maybe over the summer, or in the spring time? We will see. I really want to get out there and ride with you all.
 

zedro

Turbo Monkey
Sep 14, 2001
4,160
0
at the end of the longest line
very cool, i'm jelouse. Pretty inventive linkage setup too. I'd say this bike has all the things i think were missing on the Balfa BB7; shock linkage, thru-axle dropouts (nice system btw), concentric floating brake mount...
 

Spitfired

Monkey
Jun 18, 2004
489
0
Rochester, NY
zedro said:
very cool, i'm jelouse. Pretty inventive linkage setup too. I'd say this bike has all the things i think were missing on the Balfa BB7; shock linkage, thru-axle dropouts (nice system btw), concentric floating brake mount...
Thanks, Zedro.
As you can probably tell, this bike is very Balfa inspired. The aluminum bulkheads in particular - It's a very effective way to cram a lot of stuff within the width of the BB shell.