Giant DH Comp Drop Out adapters and conversion


1 kW
Sep 1, 2009
New Zealand
Giant DH Comp/team drop out adapters.
Will suit both 135 and 150mm drop outs.
Will take up to a 16mm axel, eg, Mac, NC, Xlyte, Cromotor

USD$185 shipped to Aus and USA
USD$195 shipped to Europe

Fork Lifts for mounting batteries on tripple clamp forks

Production of the KIWI drop outs is now with ES member "Scott" in the USA. PM him.

I have finished my "no cut" drop out adapters for the Giant DH comp.
They turned out great, everything fitted perfect, which for a first shot I was pretty happy about.

I drew it all up in solidworks, then had the profiles lazer cut and turned the bosses and tig welded them together.
With the 150mm drop outs, there is heaps of room, the 9 speed cluster goes in fine, had to space the disk 6mm.
Motor dropped in, have retainer pins in case the nut loosens during riding. New disk and dérailleur mounts worked sweet.

Took like 5 minutes to swap the original wheel out for the electric.

Will finish the bike up in the next couple of days and show you the results.

I made 3 sets and sold em all allready. Will make some more. Not cheap. About $250US delivered.









Nice design!!! I like the way you moved the caliper from the origianl position. How thick is the steel you used?
The adapters are stainless steel, 10mm thick on the disk side, 12mm thick on the drive side.

The battery is mounted on what I call the "Fork Lift" rack on the front forks. This also houses the controller. The battery straps on, either in a bag or by its self. The 5kg of LiFeP04 is enough weight to have up front. Not so much the weight, the bike is nicely balanced with the motor in the back, but the inertia it causes on the steering is not so cool. Fine for commuting and trail riding, but not for mx or DH style riding. I was thinking I would go out and do some jumps for the camera, but after a bit of a ride this after noon, not so keen. Would rather have the weight on my back for that sort of shenanigans.





The "fork lift" idea is very clever. Did you machine it yourself? With a CNC? Lifepo is pretty heavy. Lipo would sure make it lighter. Nice build!!!
will these be good for 5' drops w/ 100lb bike? nevermind what happens to the wheel/motor...

what's the effect of lowering the dropouts? increase travel or decrease? or no effect?

anyone know what year dh comps do NOT have 150mm dropouts? i've got an 04 in my sights...

edit: ps. the adapters looks AWESOME!
more research... according to this
2005 Giant DH comps, rear hub spacing is 150mm x 12mm
2002-2004 are all 135mmx12...
could your adapters work w/ the 135mm between dropouts? with smaller freewheel perhaps?
I have had a request for 135 adapters, can be done, wont be quite as strong, but sufficient. I cant see any reason to doubt the strength of the adapters, I think they could handle anything you can.

The Fork Lift I designed to fit a range of fork sizes and widths and so you can lower it down to keep it as low as possible.
I will make these available soon. PM if your keen. Few changes needed. Also plan on doing one that is an enclosed case a bit later.
You need a website or a thread with all your cool designs linked to it. I really like your take on things and the execution of the builds is excellent! Nice stuff for sure!
Yep, "I can make anything but time"

Building bikes during the day and working on websites, brand etc in the night. is where I am at, also evlab on facebook and evlabnz on twitter. All the adapters are new or in development, I like to get them near perfect before listing them. None of them are on my website yet, but working on that. Just got a new camera, so back into taking photos of the things I make.

Thanks for your supportive words.
Well, this was not my bike, but one I built for a client. Sadly for me I had to hand it over today. Happy day for the client.

But I got a ride on it through our local forest before hand. Unfortunately my camera battery died 3 photos into the forest.
I soon got over the weight on the bars, sometimes when wheeling across streams or puddles I realised the extra weight, but you soon compensate. The dropout adapters were great, the forklift needs some work as it bent from the shock loading from hitting bumps and jumps. Needs to be quite a bit stronger, back to the drawing board on that one.

Such a nice bike to ride, was a stunning clear morning. I will do it again on my DH comp when its built up and get some more photos.

I swapped the knobblies of for some hookworms for the client. The bike is awesome on the road, a real motor bike feel, 43km/h flat out 48v LifePo4 NC 2808 motor which matches the pedal gearing well.

One issue I realsed today about the dropout adapter is that the chain will touch the chain stay if you are useing a 9 speed cluster with 11 tooth small ring. Ways around this are to change to a 7speed chain ring, which brings the chain in a bit, use a large front chain ring that lifts the chain a bit, or put a skid on the chain stay so the chain does not rub the frame. It wont take much to make it clear the stay, a couple of mm and its all good.



48v10ah ping on the fork lift


Heading into the Akatarawa Forrest

Slicks on ready for daily commuting role.

I am getting lots of requests for 135mm drop out adapters for the DH Comp. I will have a go, I think we will be limited to 7speed on the rear. Also now I have proven the 150's I will try to get the price down by making a few at a time.
Hey kiwi, the previous owner said my bike was an 04 DH comp. I just rough measured the spacing between the rear arms and got 140mm. This doesn't seem to match anything you've mentioned previously. I'd like to get a set of those dropouts from you!

I've determined from that my bike is infact an 03. So whatever that mean to you in regards to dropouts, that's the type I want! Also, there is currently a 9speed on the rear.
Have has request by several people for 135mm drop out adapters for the DH comp.
I have acquired a 03-4? DH comp with 135mm drop outs.
Plan is this, will get the first set of prototypes cut next week, manufacturing for the year will rap up around the 20th of December, so I will trial the adapters over xmas. Any changes that need to be made will happen in January, so first production run will be mid to late January. I will keep a development log here.

Have run the design through in my head, and all seems ok. Same issue with chain line as the 150mm adapters, chain touches the stay in smallest gear. There are ways around this.

Should have idea of price in Early Jan.


The test bike, having to do a bit of work on it, new bushes, forks, bars...

I have the prototype fitted now. I found I could modify a 150mm adapter to test the theroy of the 135 adapter with out having to make a new one.
I had to mill away some material to get out to the 135mm measuremet. When I make the new drop outs, these changes will be made to the parts.

I have read some stories that have made me nervous with all the high power junkies out there, so to cover my ass, I am going to beef up the adapters, with 12mm thick on the disk side and 16mm thick on the drive side.


The drop outyou can see above is 6mm, but I will make this 12mm

After this weekends testing, I may consider clamping drop outs, while I dont think it will be necessary, its not to hard to do, just more time.

I have fitted a 7speed cluster with a 14t small ring. The chain does not touch the stay, but my feeling is it will with an 11 tooth. If you went to 5 speed you could have an 11t small ring. (if you can get that)

The HS motor will have to have the stupid plastic cable protector taken off. I will try to make some nylon bushes available to replace the seal and stop cable chew.
The nc motor fits good.

Over all it is looking good. I have a bunch of improvements to make to it when it goes to manufacture that should help get the price down and the strength up.
ES power junkies will really appreciate clamping drop outs; especially those using regen :twisted: :mrgreen:
Well progress has dropped back a bit with a few challenges and christmas and family taking time priority.
I have the wheel fitted now, I found once I installed the disk I had a bit of a space issue.
I went to build up the HS and found my spokes were not suitable, so I laced up a new model NC motor.

For those of you who dont know, the next versions of the rear nine continent motors will have the cable exiting the side of the axle, not the end. So like the HS motor. Only NC have done a better job.

How ever, I found that once I spaced the disk out to fit a normal disc brake caliper, there was only just enough room for the cable.
The heads of the screws that hold the disk on just brush the cable outer.

I can compensate for this in the design.

It was a good idea to mod the 150mm adapters, it has taught me a lot.
Also I have had the request to make them clamping. THis I can do.

Dont hold your breath for getting them before xmas. But they are going to be very cool.


WOW. I don't own one of these bikes... and never will.. but as a passer by, i'd like to say, what a work of art, dude!! keep this good stuff coming :)
Looking good Kiwi. I am running an 11-32 tooth on my HS 3540. Do you figure the 11 tooth I am hoping to run will let the chain clear its chain stay with the new design you are working on?

For me I would be fine with opening up my drop out holes to slots in my frame I think, if your bolt on versions would require that, should you need to change its design for chain rub issues. I am not sure what you have planned but I am guessing it may make things easier on your side to keep the original brake mounts and axle height within the frame as originally located if you choose this as a design compromise. Even if your units mounted outbound of the bikes original drop outs and the non drive side units fastened themselves to the frame with longer machine screws to the frames original brake mounts which would mean the original brake mounts could still be used for brake mounts as well as holding the new drop outs for the non drive side. Just a thought if the unforseen causes you grief with spacing issues.

I am sure many like the idea of not cutting into the frame in any way but for me I am over that part of it. As long as the units look good and bolt on with out alignment issues etc I would be very satisfied with this kind of work around for making the frame hub ready. Say once the new units were bolted on you would have a nice line to follow for cutting the 10mm slot in the old drop outs and file to finish. Could be very easy for owners to instal still, even though a bit of cutting and filing if this compromise would work for you on your end.

I am sure you will come up with a clever work around for the issues at hand, just thought I would send along this idea for you should you be looking for any input or feelings from potential end users. Good luck with the process and keep us in the loop.

while I have not proven it, I am quite sure that the chain will touch when on the 11 tooth. Only ways around this is to run a bigger front sproket to lift the chain clear of the stay, or run a 5 speed 11-32 if there is such a thing. This would bring the chain in.
I have sold out of my 11-32 clusters, so currently cant prove it.
I have spent way to much time on this to go changing it now. If I was charging my normal design rates these would be worth thousands of dollars each, but as this is also my hobby and I love es, and am trying to establish an ebike component design business, I am basically selling at manufacture cost to ES members just to get some of my work out there. I have a few improvements to make, but these will remain a no cut solution for the Giant DH comp.
Sounds good Kiwi. Awesome! In my case I am cool with just not using the 7th gear. I believe my 6th gear on my 11-32 is a 13 tooth and that would be just fine by me for my tallest gearing. So for me, don't worry about chain rub on the 11 tooth sprocket..............wayne
Hi everyone.

Firstly, a sort of apology for the parts taking a while. I know you are all keen as beans to get riding.
With out elaborating on circumstance, I had my life rocked in a rough way over xmas, one of those WTF moments that seem to keep getting worse. Things have calmed down now, but I am still on alert, but back into bikes. My only advice, if there is sh*t gong down with the people you love, get it out on the table early, don't pretend its not happening or it will blow up in your face and be a hell of a mess to clean up.

So, the 135 clamp adapters are designed and will go to get cut tomorrow.

You all asked for the clamp, but i have my doubts if you will be able to make the drop outs flex with the bolt, as they are 14mm thick. Still it will give you the security your wheels not going to fall out.

Also, they are really 138mm adapters, you will flex the frame 3mm, which it does easily, it was the only way to get the disk caliper to fit.

Here they are.
Drive side


Disk side