Keyne's DH Comp Build - now with liquid cooled HX35! :)

[Mark_A_W]

Hmm.. I'm pretty sure there was a serial number under the bottom bracket but I didn't really pay attention. Why do you ask?

Ooops. I just read the last two posts.

He's asking coz I asked him about the serial. I got my frame from Voicecoils and he used to have a spare, but it's sold.


Need it for insurance, and it's not in the normal spot on my frame - certainly not under the bottom bracket.

[keyne]

I think I just remembered where it is/was and that's not good news for you. I'm pretty sure it was actually on the left rear drop-out by the disc brake mount (between the holes) I chopped it off with an angle grinder so can't check. But I'm pretty sure it was there.

I'm not in the same place as the bike at the moment, so can't check for about a week. Sorry.

[Mark_A_W]

Well, I sure didn't look there!

That bit of my bike is still more or less intact. I just had a look - I can see a couple of numbers, but then the torque arm plate covers it.


I have to pull the motor out to replace the freewheel this weekend, so I can get the number then.


Sweet - that clue helped me out heaps


Thanks

Mark

[Mark_A_W]

You can see yours here:

[torker]

That bike is looking really good. I sure hope my FSR turns out good. Got my rear tire and tube today and...My spokes are on the way

[jlustig83]

Those are the most sophisticated torque arms ive ever seen You are my idol

[keyne]

Thanks jlustig83, to be honest most of the work was done by doctorbass I just made a few modifications to suit my needs. If I was doing it again I'd do it a bit differently. They are quite over engineered and weigh almost 600g for the pair!

[keyne]

You can see yours here:

Ha! I spent about 15mins looking for pics on the web to help you and it was there in my thread the whole time!

[keyne]

There was something funny going on with the handlebars on the DH Comp, they were super wide (780mm!) and amazingly strong. I finally worked out that they are actually Motocross bars (from Aero Racing) and weigh 650g!

I was wanting to swap them with some black ones anyway, so I just bought some Easton DH bars and saved 350g on the bike! Stoked!

[keyne]

I want to get two 24x3.0 Duro Razorbacks for this build (lightest 3" wide offroad tyre I can find) but I can't find anywhere to buy it that will send to New Zealand. They are on Ebay, but don't ship overseas. Does anyone know an alternative source or is anyone willing to purchase them for me and send them on?

http://cgi.ebay.com/Mountain-Tire-24x3-00-Duro-Razorback-SALE-we-are-nuts_W0QQitemZ280558566948QQcategoryZ27954QQcmdZViewItemQQ_trksidZp5197.m7QQ_trkparmsZalgo%3DLVI%26itu%3DUCI%26otn%3D3%26po%3DLVI%26ps%3D63%26clkid%3D7911932003719746177

Duro Razorback 24" x 3.0

!BzuCelgBGk~$(KGrHqMOKj0EwrjCSt(eBM(TltLRD!~~_2.JPG (6.45 KiB) Viewed 807 times

[voicecoils]

I want to get two 24x3.0 Duro Razorbacks for this build (lightest 3" wide offroad tyre I can find) but I can't find anywhere to buy it that will send to New Zealand. They are on Ebay, but don't ship overseas. Does anyone know an alternative source or is anyone willing to purchase them for me and send them on?

Naturally, I have a new pair I can send you

They don't fold easily though so shipping might be pricey!

[Mark_A_W]

I pulled my torque arm off and got the serial number on my frame.

Thanks for the help guys.

[keyne]

wow! Awesome voicecoils, please let me know how much you want for them. Where did you get them from?

[Doctorbass]

Hey.. I have something that might help any DH comp owners

Bison_69, a friend of mine and member of E-S made that for us!;

Doc

[full-throttle]

Nice build!

How did you balance the bike in the pics? Can't see any strings..

[keyne]

Finally someone asked!

Yeah, I cheated. There was a stick under the pedal and the bike was leaning slightly. I used photoshop to clone stamp the stick out then rotated it so it was vertical

Love your bike by the way! Very jealous!

[full-throttle]

Ahh.. I see. Thought it was 'ghosted' along and you have a very fast lens.

Love your bike by the way! Very jealous!

Thanks!

Umm.. which one?
Just kidding, I know which one Well, at least you can admit it without saying something bad instead.

Will be very interested in seeing how your CF battery enclosure comes out - that's where I decided to abandon my DH build.

[keyne]

Well, at least you can admit it without saying something bad instead.

I hope you don't mind, but as this build unfolds you'll see that I"m using your bike for inspiration!

[full-throttle]

Don't mind at all - go for it!

[GCinDC]

I used photoshop to clone stamp the stick out then rotated it so it was vertical...

That's hilarious! I think I notice the stamping under the bottom bracket. Great technique tho. The thing looks poised and ferocious!

[keyne]

Next Task: Beef up controller

The 18FET controller I got from Lyen has great FETs, but the 12awg cables for phase and power seemed a bit thin, so I replaced them with 8awg cable at the same time as adding solder/copper to the traces. Fitting 8awg cable into the holes on the circuit board took some improvisation - using andersons connectors in ways they were never designed to be used. See pics below.

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controller_8awg.jpg (104.31 KiB) Viewed 1250 times

I got rid of the thin rubber seal at the cable end of the controller (broke it during disassembly) and replaced it with some good cable glands.

controller_cable_glands.jpg (186.53 KiB) Viewed 1250 times

A bit of wiring to go, next I'll attack the motor and then get cracking on the fiberglass side panels.

Oh, I was stoked with the way my forks turned out with their new paint job, here's a pic

forks_paint.jpg (91.3 KiB) Viewed 1226 times

[Doctorbass]

Hey keyne,

If you get any problem with the solder of 8 gauge wire on the controller PCB, may i suggest you something i did and that work really well?

I used some great home electrical box copper terminal for the negative ( due to the size and the proximity to the 4 shunt, it also help alot to dissipate the heat from the shunt and make it more stable regarding the shunt resistance value so the current limit will not decrease as the shunt try to heat up )
It also allow putting bigger wire like 4 gauge if you wish too

For the positive i used a screw of the size of the hole of the pcb ( the thread of the screw just fitted perfect and tight

I used a screw that i can solder to the copper surface of the back of the pcb.

As you can see i also ysed big 3/16" diameter copper rod made for home electrical wiring ( 6 AWG) for the bus bar to help sharing the current to all mosfets.


Here it is!

Doc

[keyne]

Hey Doctorbass,
My andersons method worked surprisingly well, I'm really happy with the connections. I do like your simple bus bar method though, I will have to look into getting some of that!

[keyne]

Just ordered the rest of the batteries I need for the build

16x 4s 5Ahr Flightmax 20c lipo
4x 2s 5Ahr Flightmax 20c lipo ( a slightly tricky arrangement to make the width of the battery compartment only 120mm)

5000-4-20.jpg (66.37 KiB) Viewed 1196 times

That gives me a 24s 15Ahr pack.
I had toyed with 20Ahrs but the extra bulk would have made the fiberglass moulding and wiring much more difficult. (Also my wife has been making noises about the cost of the build - she just doesn't quite understand! )

[keyne]

Next task: Motor!

So I've got a crystalyte HT3525 on order, but in the meantime I'm working with the 5305 I've got lying around.

A while ago I managed to lace it into a DMR Blackline rim with 9 gauge motorcycle spokes

But in order to use a 9 speed freewheel I have to be able to dish it as much as possible. So I took out half the spokes and swapped them over to the other side

That was quite a task as you can see from this pic

I don't think I'll ever use 9 gauge spokes again, 11 gauge max I think!

I'm planning to put the new HT3525 in a 24 inch rim with 11 gauge spokes, but in the mean time I've got this motor to play with