Posted by

BrianR925

Jan 13, 2011 at 16:12

2011-01-13

Location:

Benicia, California, United States

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Homemade DH Bike

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This is a frame I made in School. There was a lot of influence from the Superco Silencer. I've been riding it for 2 years now and have raced it several times, it's a blast to ride and takes the abuse.

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14 Comments

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sidermang (Apr 8, 2011 at 22:21)

thats a fine looking bike, i love how you made your connecting linkages, that's pretty clever! a very clean looking bike, with a simple but proven suspension design, bikes with high pivot single pivots, and rearward axle paths, ride so nice, it must fly on choppy rocky terrain! the quality looks top notch!

cedrico (Dec 11, 2011 at 16:09)

it must pedal well because of the axle path and it has no chain stretch! that's unreal!

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bluezac17 (May 8, 2011 at 13:18)

wow if i had mad welding skills like that id be doing the build....on 29's! and i probs wouldnt make the tubing look like it belongs on a dobermann lepink...

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BrianR925 (May 8, 2011 at 13:25)

Congrats! you win a prize! I did use a Kona DOPE kit as I didn't have time to machine all the little bits and It fit so nicely! Smile

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mcdermott (Dec 19, 2011 at 4:56)

look like brooklyn machine works Razz

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dhb7 (Jan 13, 2011 at 16:58)

nice! cool to see the bike in it's fully finished form...definitely diggin' it!

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cedrico (Dec 11, 2011 at 16:13)

awesome! I wish these kind of bikes were available on the market

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COxYDuDE (Jan 21, 2011 at 9:31)

dude that bikes sweet i want one Smile

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AlexBurdick (Feb 7, 2011 at 16:02)

edit

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AlexBurdick (Feb 5, 2011 at 12:27)

What?? Thats sick! I would wreck that rear suspension so quickly though.. Look like a good Forest terrain kind of bike..

freeridersean (Feb 6, 2011 at 5:09)

Are you kidding Alex? What do you weigh? 95# soaking wet? C'mon man, you aren't wrecking this or any other bike. What is forrest terrain? It's an 8"+ travel DH bike...

It's a nice design based on other jackshaft frames that have been proven to work. Its cool that the builder designed and built it. Hopefully we'll see some videos of it in action soon.

BrianR925 (Feb 7, 2011 at 7:54)

I'll have to post a video of me taking it off a 30 ft. step down... got find it in my library.
Alex: unless you weigh 300 pounds and your hucking it off a roof to flat ground; it won't break.
I engineered all of the components to withstand a 10ft drop to flat with a 200 lb rider and a factor of safety of 1.5. I have abused the hell out of it at Northstar, Pacifica, etc. and have had no problems at all! Remember, it's made of STEEL!
Thanks for the comments, they're titillating.

AlexBurdick (Feb 7, 2011 at 16:02)

For some reason I thought the rear drop suspension came to close for comfort when it comes to getting through large techy rock gardens. There has been some incidents where I have seen rear suspended bikes, partically within a verticaly rear suspended bikes (Sunday) get there frame and shock components smashed against rocks because of the longer travel for a shorter frame and the fact that there suspension is riding so low to the ground.. Basically saying the geometry of the bike, which appears to be a much shorter frame and the rear shock that travels so low to the ground would be more prone to being bashed by a rock rather than say the demo 8 or tr450 that ride with a horizontally aligned shock on a longer frame.. However I could be wrong, I would take your facts over mine any day..

Not at all saying in any way whatsoever that this bikes geometry or whatever is off.. It looks like a fantastic bike..

-Alex

spudlord (Feb 10, 2011 at 9:33)

Alex i dot think you really know what you are talking about are you saying that the position of the shock in the frame affects the way a bike will handle a rock garden?
well that is not the case it is all to do with the leverage ratios on the shock (which can be altered using linkages) and the rear axle path which determine how the bike handles so the actual position of the shock has little to do with that (apart from weight distribution) and as you can see the shock is well protected by the downtube. Take a look at the old glory frames

http://autobus.cyclingnews.com/photos/2006/tech/shows/eurobike06/eurobike063/Giant_Glory_DH.jpg

their suspension system actually takes the shock through the downtube and they are not supposed to damage rear shocks more than any other dh bike.
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or is it that the idea of the bottom bracket coming closer to the ground when the suspension is compressed will damage the frame as it may get hit by rocks?
in that case every fully suspended mountain bike will have that problem as when the suspension is compressed the bottom bracket will go closer to the ground, without that there is no way to dampen the vertical component of the force caused by the riders weight pushing downwards on impact thus causing a very very rough ride its would feel more like a hardtail without that (also that is generally why the chainring/drivetrain on dh bikes is usually protected by a bashguard/taco device)
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and i wouldn't say this is a particularly short frame it actually looks like a rather long wheelbase bike to me and the shear amount of rearward displacement in the rear axle path means it should be a very smooth ride especially over rock gardens where there will be allot of square edge hits
kudos to the designer/builder that is a damn nice bike Big Grin

i like the way it ramps up the ratio at the end of the stroke Big Grin

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Do i spy an adapted kona DOPE brake kit to fit the frame? or did you machine your own?

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