Belt driven off road bike (Giant Reign)

[RWP]

I've not a lot of experience with belts but is 5mm enough?

5mm HTD belts are OK for up to just over 7kw according to the charts I've seen.
Cheers, Matt.P.

Nice project. I do hope your 5mm belt system works - so I can do something like it.
The charts I have seen do show high power capacity but only at higher RPM, at low RPM the power capacity goes to almost zero...just when we need the belt to move our bikes and us from a standstill up to speed. Perhaps with the maga wrap you are proposing it will work - I hope so.

The first iteration of the eCortina had two 5mmx15mm belt systems. The second of these belts failed early on. Even with a smaller motor the primary belt eventually failed. But there was nothing to give me more belt wrap.

[panurge]

if I understood correctly you have removed the gearbox from the motor

No, this motor comes from Cyclone as a direct drive no gear reduction box.

The big pulley is made from?

See the first two pages of this thread for the pulley modification process. http://www.endless-sphere.com/forums/vi ... =6&t=10337

I've not a lot of experience with belts but is 5mm enough?

5mm HTD belts are OK for up to just over 7kw according to the charts I've seen.
Cheers,
Matt.P.

Ah ....OK, thanks for the link....sorry but I'm new here.....
Your method is fantastic.....
Can't wait to see next steps!!!!

Regards

Jules

[sico]

Hi Matt,

How does the weight compare between the motor+mount+wheel for this setup compared to the mac motor in the wheel?

I"m wandering if you have sacrificed some of the advantage of the non-hub set up by making the motor+mount part of the unsprung weight (i.e. mounting them on the spring arm)? That will mean that the inertia of the motor+mount will prevent the swingarm from moving (as) rapidly in response to a bump.

With no pedals, did you consider the idea of using the bottom bracket to hold a lay shaft?

Simon.

[AussieJester]

Might not move (as) rapidly Simon, but
Seeing Matt has the motor mounted
Next to the swingarms pivot point, it won't
Be nearly as bad as having a 15kilo 'boat anchor'
hanging off the end of the swing arm.
Matt I think also likes the simplicity of the direct
Drive, plus the lower noise of belts... I been trying ro
Talk him into RC setup for two years, the multi reduction
Thing puts him off....

KiM

[kfong]

That's a unique belt layout, I like it. Looking forward to the final design and results.

[sico]

Might not move (as) rapidly Simon, but
Seeing Matt has the motor mounted
Next to the swingarms pivot point, it won't
Be nearly as bad as having a 15kilo 'boat anchor'
hanging off the end of the swing arm.
Matt I think also likes the simplicity of the direct
Drive, plus the lower noise of belts... I been trying ro
Talk him into RC setup for two years, the multi reduction
Thing puts him off....

KiM

Haha, the Mac motors are a fair bit lighter than 15kg mate, but I can see that the geometry might give you a slight advantage though. Matt will be able to directly compare this bike to the red one offroad when its done so that will be the true test.

[AussieJester]

To get similar power levels to what mMatt will
be getting with the overvolted cyclone you'd be needing
A bigger frock than a MAC, an X5 for example, what's
the weight on those again, Simon

KiM

[sico]

Well Kim, its surprisingly difficult to find those figures, and I've never actually handled or seen an x5. Best I could find on the web is that an x5 weighs 20lbs, which is about 9kg. The Mac weighs 4.3kg according to cell-man and the cyclone weighs 4.8kg if I am looking at the right model. The 9c such as Richard and I run is 6.8kg.

So there isn't a gulf between them if weight is the main consideration.

Simon.

[1000w]

Hi Matt,

How does the weight compare between the motor+mount+wheel for this setup compared to the mac motor in the wheel?

I"m wandering if you have sacrificed some of the advantage of the non-hub set up by making the motor+mount part of the unsprung weight (i.e. mounting them on the spring arm)? That will mean that the inertia of the motor+mount will prevent the swingarm from moving (as) rapidly in response to a bump.

With no pedals, did you consider the idea of using the bottom bracket to hold a lay shaft?

Simon.

I'm not too worried about the weight and the handling. I'm happy to do a build and see how it goes.
I love single stage belt drives ever since I built the blue cruiser.
Kim is right, I like the low noise and simplicity of a single stage belt drive so I never considered the bottom bracket lay shaft idea.
This drive set up has also allowed me to gear it how I want, lots of low down power with a moderate top speed.
Of course I can change the ratio as I have 4 different drive pulleys, 18, 20, 24, 30 tooth on their way to me, in the mail.
Cheers,
Matt.

[sico]

Nice one Matt, and thanks for the link to the mountain bikes for sale too, I'll be keeping an eye out there.

Do you get the pullies from small parts and bearings? I'd love to know a local supplier since small parts are expensive and not very fast on the delivery. Excellent website and catalogue though.

Simon.

[1000w]

Hey Simon,
I use, https://sdp-si.com/eStore/
Click on the metric button at the top left then have a look for what you're after.
I have made 3 or 4 trouble free orders with them. Their shipping is very reasonable and there is no minimum order when using a credit card.
My latest order of 4 pulleys and 2 belts was $101 parts and only $15 shipping and handling.
Cheers,
Matt.P.

[sico]

Thanks mate, I just ordered a couple of pieces. They are much cheaper than small parts, I reckon they'll be quicker too (why does it take so long to get stuff from over east?)

[gtadmin]

Thanks mate, I just ordered a couple of pieces. They are much cheaper than small parts, I reckon they'll be quicker too (why does it take so long to get stuff from over east?)

Because Oz ends at the Blue Mountains, west of that is treated as another country

Great project, I love it

[dingoEsride]

Because Oz ends at the Blue Mountains, west of that is treated as another country

That may be true, it is a big land but here in the west there are those that make me proud to be a west aussie like Matt and his fine builds, looking at this one

[1000w]

Thanks Dingo,
Just a quick photo showing the rear frame triangle after the acid tank, ready for welding.

[AussieJester]

Thanks Dingo,
Just a quick photo showing the rear frame triangle after the acid tank, ready for welding.

Looks good Matt!! I didn't even think to tell you when i was speaking to you then, mate SnaPPeR
he just bought a sand blaster from Auto One for 36 bucks i think, comes with a 1liter bucket
of sand too! DiDn't i see a snad blast enclosure at your place? or was that someone else?

Anywayz, looking good mate, keep practicing the TiG and then get this sucker going! i wanna drag teehehe

KiM

[1000w]

I have finally found some time to weld the extended dropouts on to the rear end. I added some 10mm x 10mm bar at the top to help brace it all together.

[etard]

Simply beautiful Matt! You're welds are fantastic and that dropout is SOLID!

I too love the single stage reduction drive except one of these days I want to see how some of this #25 cam chain holds up in a similar application.

You are truly a pioneer in this aspect.

[magudaman]

Just curious if your planing on doing any sort of heat treating on the frame now that you welded it? Doesn't it create uneven strength on the metal creating brittle and soft areas from the heat?

Not sure how many watts your running but I found I was good to about 3300w on my 5mm gt2 setup with a 27T driver. Much smaller than that and I ran into problems with it hopping. Your idlers will help.

[sico]

Excellent Matt, looks like there should be plenty of strength there.

I guess it won't be ready for the group ride though, maybe the next one?

Simon.

[farmkid4]

lookin good! very nice job on the dropout

Will be watching

[1000w]

Thank you for the kind words etard.

Just curious if your planing on doing any sort of heat treating on the frame now that you welded it? Doesn't it create uneven strength on the metal creating brittle and soft areas from the heat?

Not sure how many watts your running but I found I was good to about 3300w on my 5mm gt2 setup with a 27T driver. Much smaller than that and I ran into problems with it hopping. Your idlers will help.

I'm hoping that I have over engineered this set up enough because I'm not planning on any heat treatment.
Whats involved in heat treating aluminium after welding it?
I've run 3700w with a 20T 5mm HTD driver faultlessly for 3000km and the charts say up to around 7000w is ok. This will be good test as I'm aiming for 6000w to 7000w on this build.
This photo shows why I needed an idler on the drive side of the belt to clear the frame.

I guess it won't be ready for the group ride though, maybe the next one?

I was hoping to have it ready for this ride, but I don't think so. Cheers, Simon.

Cheers, farmkid4

Ok, I have the rear end pretty much done now. The motor mount is in and the belt drive runs true and smooth.
I had to weld some small tabs on to the drop outs so I could use these nice tensioners that were kindly donated by Aussiejester.



Some minor interference with the brake caliper.



I made a plate to help brace the idlers.



Some general photos.

[E-racer]

Looks good! You can normalize the part in your oven at home if you wanted to. I'm no expert here but around 500degrees will realign the grain structure. I've heard of people using the oven clean setting to get their parts up to the required 750+ degree F it takes to get back to T6.

[GITech]

Wow, just saw this. Very nice job! What a work of art! I'm jealous! I need a welder!

Nice with the rims and tires! I bit the bullet and jumped right into something similar with my rim and tire choice to go with my design.

And Lily bit it too! "Is this my new teething ring daddy?" :mrgreen:


I can attest too the oven to re-harden 6061 aluminum when I did the front bumper for my custom 1/5 short coarse E-Maxx (my "SC-Maxx"). After annealing at 1000f+ so I could do the bending, it was very soft and very easy to bend, I think softer than 3031. To re-harden it I think I shot for about 375f for 7 hours in the oven. Doing this brought it back to I'd guess about 80% of it's original hardness.



I'll be watching your progress!

Later,
Jay

[sico]

Gee, I hope you have a massive oven then Mine certainly wouldn't fit it in.

I guess AJ won't let you get away without a few more lightening holes in the motor mounting plate. That cyclone motor isn't small at all is it? Looking sweet anyway dude.

Simon.