New freeride project - LMX P1

[bzhwindtalker]

Thanks mate, there's no thing like riding your own frame!

Made good progress, this start to look like a frame :

I need to get my pivots machined. I changed the frame layout since last 3d renderings to fit the motor just next to the pivot like what Farfle dis on his Emopedcycleracer.

 

[Wheazel]

Looks bombproof. Great video aswell!

 

[Ariane]

Looks bombproof. Great video aswell!

+1

Well done Adam great work

Good day!
Black Arrow

 

[Qwiksand]

You gotta keep it like this, single sided swing arm style!!

 

[bzhwindtalker]

Thanks guys, I have an issue with my pivots, I can't get them machined at shool soon so I need to outsource.
While I wait, I can still ride my blue FR (For those who missed it in the other thread, here's the video )

[youtube]PGaQdhtnGbk[/youtube]

 

[dan974]

you're killing it @ the Doua =) memories of this place 13y ago =)

 

[Mitch3514]

nice project, cant wait to see the havoc u cause around campus with this one!

so i want to do something pretty similar for urban freeriding
so far im set on buying this KX80 rolling frame, stripping it down to the bare essentials, replacing the wheels with lighter weight mtb ones and putting an electric motor of some sort in it, 6kw peak sounds like the go!

aiming for sub 50kg with 700wh

can anyone here see a flaw with my idea? would be much nicer to be criticized now than after i sink some money into it!


Mitch

 

[Mitch3514]

alternatively i can get a lightweight trials frame for this project, hmmmmm may be the way to go...

 

[bzhwindtalker]

Welcome Mitch!

I think you should go for the ligthest frame you can find that has a geometry suitable for what you want to ride. KX85 isn't bad but a bit heavy, a trials frame can probably be modded with a diferent seat for more enduro style riding.
I made some progress on my frame :

 

[2moto]

Looking good!

 

[bzhwindtalker]

Still didn't get the pivots machined, but I sorted out a rear wheel setup with a brake I had on hand, I will need to find a left side hydro lever.
The chain clearnace looks like it will work, with 16-32t gearing. I hope to be able to easily reconfigure the 9C clone motor in delta (assuming it was in WYE in stock form) to get more rpm. I may go up to 22s but I ordered my charger setup for 20s...

 

[AussieJester]

Hrm. ...I realise it's just "mocked up“ for photos, but that head tube looks like it is a lil on the steep side?

KiM

 

[2moto]

Also noticed that the swingarm and shock angles are not ideal. You might want to review that as the rear suspension will not be regressive, i.e. get softer as it compresses. For best chassis dynamics you should aim for a linear spring rate throughout its travel, ideally within 10%. With your layout, it will be a long way from that.

 

[bzhwindtalker]

Thanks for input guys, I will try to modify the suspention to get better angles. The headtube angle is fine compared to my blue FR so I suppose it's the picture that makes it look too step.

I received my stuff from bms-battery, and imediately starded modding the motor
I was a bit disapointed it is only a 27mm stator, I hoped for a 32mm like the one I had been using in my last hub mid drive. I doubled the phase wires and rewired it in delta for more rpm Who knows if the halls timing will be off with this mod?

I hope to make progress this weekend but my car need repairs, one of the motor supports broke becase two bolts unscrewed themselfs, now the heim joints are making bad sounds and I could not get the motor back in line to screw the support back on. Dirty hands work ahead...

Some pics of the motor work on the BMS-battery 9C clone 1000W DD motor :

It has sealed bearings plus external seals. Not bad. The back iron however weigths tons!

 

[bzhwindtalker]

wait! what if you took this big motor and drive directly the wheel attaching spokes to the rotor? such a good idea I should patent it!

 

[dustyearlobe]

don't know much about these hubs but work with 3ph motors any idear what your starting amps are ganna be in delta, appreciate should get more torque than in star but low rpm runs might need some juice (motors at work starting in star 3x full load amps starting in delta up to 7x full load amps )would be interested to know if you have any figures

 

[bzhwindtalker]

Yep but I will gear for the same top speed anyway, so I should get the same torque but with better efficiency. I am not limited by gearing ratios or motor rpm, and spinning the motor faster will allow me to squeze the most out of this motor!

 

[dustyearlobe]

sounds cool ,forgot to mention looking frikin awsome

 

[bzhwindtalker]

Made good progress on the swingarm assembly and made 10mm thick motor dropouts. I went the easy way with brushings instead of bearings.

The suspention looks better with the motor in the way, it forces me to do it right haha!

 

[querlenker]

Hello,

sorry if i missed, but what wheels are you using? What wheights do they have?

 

[bzhwindtalker]

The rear wheel is a 17" front dirtbike wheel, I will use a 24" DH wheel in the front. The rear wheel is very heavy, probably 8kg+

 

[jansevr]

great work! the bike is coming along very nicely . i am curious about your mid drive set-up. not many people are running hubs like this. is there anything special you need to do other than attach a sprocket to the motor? i also noticed the pivot for the suspension is slightly behind the motor. will this be a problem with the suspension changing the chain tension - or will idler gear fix this?

 

[Whiplash]

Frames looking real good! Can't wait to see it in action!

 

[bzhwindtalker]

Made more progress, I still need to machine some parts for the rear pivot. I modified the front dirt bike wheel to accept a dual side setup as I did not have the required clearnace to run the disc and the sprocket side by side.

I added some braces to the frame but it's still quite ligth. I'm a bit disapointed by the max battery sise I can fit, I don't think 20s 15AH will go in :/

I have a 888 marzochi in the mail for the front end, that I will use with a 24" wheel with a 3" tire. In the picture, the lines on the floor are semi acurately the horizontal for the bike when it will be done, I mesured the headtube to wheel distance on my blue FR.

Left to do :
Pivots
Motor spacers
Footpegs
Zip ties supports/hooks for cables
Battery box
Setting up a left side rear brake
Wiring
+unexpected bullshit

Can't wait really!
Adam

 

[2moto]

Good stuff! Swinging arm angle look to steep, though. I'd try to half the current angle. The shock absorber will work much efficiently and more linear.