best 2000w kit? for DH bike

[bern309]

Hi, am new to this forum. Any help you can give would be grate!

I want to convert my specialised big hit downhill mountain bike in to a hi-power e-bike. I have up to 4000 USD to spent in total (motor, controller, battery).

I would like the motor power to be 2000w+ and the whole kit has to be robust as I hope to be doing jumps and fast dh runs. I don't need hi speed just lots of torque for the hills.

I have toosl and a good workshop if I need to make brackets ECT.

So what should I spent my cash on?

Thanks

 

[John in CR]

So what should I spent my cash on?

Welcome bern. A hub motored wheel won't stand up to the jumps. That's plenty of budget, so you need the know-how, which you'll find in the non-hub section of the forum. IMHO, you should spend a nice chunk of your cash on a custom swing arm for your bike made to fit a motor.

Something to consider is how much time you want to be able to ride up those hills at high power. As a DHer you appreciate the power it takes to get up hill, since you probably hitch a ride up instead of pedaling. You may not appreciate the energy required though. Hill climbing eats battery capacity fast, so make sure you understand how much battery you need to satisfy your requirements to avoid falling short after an involved build.

 

[bern309]

Thanks, a swing-arm with motor would be good. Or a http://www.cyclone-tw.com/order-A.htm type kit.
A better quality kit of this type would be good.

Where I normally ride there is decent of around 150m. So if the kit could get me up from the bottom say 4 times that would be grate. I would not use power on the way down.
Also it would be good to be able to take it on some longer xc runs up to say 20k.

I hope that this is a realistic goal?

Will also post on the non-hub page as well.

 

[LegendLength]

Cyclones are good, although a bit weak compared to a good hub motor.

From running a 9C hub myself, even though there is a large amount of unsprung weight on the rear wheel (always a bad thing) it isn't a show-stopper. You can still go pretty hard down rocky hills while staying in control.

Of course if you're a downhill racer or someone who really pushes the envelope it may be unacceptable. But for an average rider looking to have fun I think they're a great option.

If you do go with a hub motor just be sure to get one with a high winding count. You don't need high speed off-road and it will help significantly up hills. It will also prevent overheating up hills which will happen on any hub with a steep enough hill.

Avoid geared motors if you want to do jumping as the gears get stripped. Like I said a Cyclone is still a good option but the weight is not negligible in the center of the frame. Combined with even the lightest batteries you still have a heavy bike which will handle quite differently to a normal mountain bike.

You can easily get 3 kW out of a $300 hub motor and a $130 controller.

 

[bern309]

I am just a average rider and I don't need the bike to be relay light. Just fun and reliable. Once it working well I don't want to have to keep fixing it and replacing parts.

I have been looking at

http://www.hi-powercycles.com/category.sc;jsessionid=8C7255765EB9DB2631F86091566BDFBE.qscstrfrnt04?categoryId=4

Thanks

 

[Philistine]

If you are looking for a chain drive setup better than the cyclone, there are a lot of variations using the Recumpence (see ES Member Recumpence) reduction drive for Astro RC motors.

This build thread by Timmah would have been interesting to you, but after the site maintenance I think a lot (most) of the photos have gone: http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=12687&hilit=timmah

 

[Philistine]

I have been looking at

http://www.hi-powercycles.com/category. ... tegoryId=4

Thanks

Those Black Lightning motors are geared hubs. You don't want a geared hub if you are going to hit jumps under power, as the teeth can get damaged/stripped. But other than that they are very lightweight and freewheel really well. But they can have overheating problems if you do long hill climbs with them.

Are you familiar with the winding nomenclature of direct drive hub motors? ie, the difference between torque and speed winds? Because personally I think if you want to go hub on a mtn bike for actual mountain bike riding, I would have thought a decent hub would be a slow/high torque wind 9C or say the HT35 by Crystallite, bot with at least 15S of Lipo, and say a Lyen 12 or 18 Fet controller.

But for the money you are willing to spend, I would have thought a decent RC setup might be worth it for performance, but they will be less reliable and require more maintenance than a hub build [*ducks and hides for cover from the RC Boyz*]

 

[dogman dan]

Well,,, if you are going to go and thrash the bike, as I do, then forget that part about never having to fix stuff.
Ride hard enough with a heavy hub motor, and you'll be getting the pinch flats at least. And quite possibly melting motors as I've done several times.

Now days, my dirt setup is a low speed 9 continent motor, 20 amp 72v controller, and 72v 10 ah of lipo battery. I keep the watts so low, 1500, because I'd rather enjoy the ride than fret on how hot my motor is getting. I don't jump stuff, so I don't wreck rims and tires too often. But constant spoke maintenance is a given for as hard as I do ride.

So look for a motor with a low speed, like the HT clyte, or a 9 continent 2810 winding. I think Methods has the 2810 for sale in the sale new section here.

For a real performance bike though, you'd be wanting a non hub drive, involving a lot of your own motor mount fabrication. Then you'd really be working on something constantly, as your prototype got refined through use, breakage, and improvement.

 

[MadRhino]

There are contradictions in your requirements

You want to do jumps but don't need to go fast and don't want to have to repair or replace broken parts. You want the bike to be a fun mountain ride and want to do DH trails, but don't need it to be lightweight. First make up your mind, Know your riding style, define your real needs, set a goal. Then, we can really help.

 

[bern309]

What I what to do dose make sense. The bike will go fast down hill under gravity.
I don't need the motor to drive me fast. (30kh max on flat would be good)

I want something strong and rightable to take me up the hills at a relatively low economical speed.
Yes lightweight would be better but will have to compromise for reliability and battery life.

There is no contradiction.

 

[LegendLength]

I think what rhino is saying is that your expectations of the current technology may be a bit high. Unfortunately there's nothing really good for taking a pounding (i.e. jumps), being light and also being reliable.

From what you have said it seems your main goal is to use the motor as a 'chairlift' to get back uphill after your DH runs. If you can handle quite low speed and power I would recommend one of the smaller Cyclone motors (less than 600W). I don't have experience with them but I imagine they'll pull you up most hills ok because they're geared. And they'd be best as far as weight and weight positioning go.

Add about .5 kWh of LiPo batteries in a custom case (centered well on the bike) as well as a 6 fet Lyen controller and it should be a fairly lightweight setup for downhill riding. The bonus is that it's one of the cheapest setups you can do.

If you do decide on a Cyclone in particular be aware their freewheels are rubbish and need immediate replacement with an ENO freewheel or something of similar quality (70 USD). That much I have experienced personally!

I will add though that if you enjoy DH riding you may also find yourself enjoying flat-ground riding under power. If that happens you may wish for something with more power like a large hub motor.

 

[Timma2500]

Hey Bern,

Correct me if i'm wrong but it sounds like you moslty need a system to get you back up the DH tracks and the odd xc ride?
Your right regarding not really needing the motor on the way down, especially on a tightish DH track.
On more open hills however, you will no doubt be tempted to open up the throttle, trust me!

I can recommend the 1200w cyclone system. It peaks at a bit over 1800w on my Specialized day in day out without a problem (apart from dropping the chain at the front, guna get a chain device). With a 34/11t rear cassette and a 32t chainring on the cranks, i get around 20kph at max rpm in 1st gear and a bit over 60kph in 9th (depending on wind and gradient).

I took the Specialized up a rough track with no run-up a few weeks ago, 1st gear (no pedalling, up on the pedals like footpegs) grinding my way up at abit over 10kph till it got too steep and i flipped off the back and bailed. That was going back up a DH style track i had just had the pleasure of sliding my way down
Put it this way, if i was on my normal AM mountain bike, i wouldn't have even considered trying to pedal up it...
That sort of low speed / hi load situation i believe could kill a hub motor / controller combination at 10 - 13kph.

What i'm getting at is if you need really hi torque at really low speed, a geared system might be right for you.

Just my 2c

Either way you go, just make sure you post your build here for all to enjoy :wink:



Paul

 

[MadRhino]

My every day mountain ride is about the same elevation, that is not much for fast freeride. I end up putting alot of throttle downhill, and need alot of power uphill. In fact, on that size of mountain, uphill trails are about the same feeling as DH with a non motorized bike, that is if you have enough power to climb them with some speed. I use DD hubmotors, they have a regen resistance to freewheel and it's not at all the same as freeriding downhill.

I can't really jump with my bikes, they are in balance and jump nicely, but the heavy hub makes for too much stress on the wheel landing on any drop and jump more than a foot high. I do 2 feet quite often, but have to true the wheel daily when I do, and the wheel building job doesn't last the season. Then, when you jump and ride fast DH, maintenance is a must and some expenses can't be avoided, that is even more with a motorized ride since your suspension and brake components, bushings and bearings, have to suffer the extra weight and are often pushed to their limit. Suspension and brakes will soon need to be upgraded to the very best, with any kind of hard riding and performance.

Building a good jumper requires more work, time and money. It has to be a mid drive, that leaves your wheels and suspension with their optimal resistance. It makes for a lighter build, and is easier to balance CEG in the build too. It is easier to have alot of torque, but high speed is much more money involved. Reliability is a concern, more mechanical components require more maintenance. My experience with mid drive is very limited, for I'm still experimenting, but I'm already looking for the new electric trial from Gas Gas since I doubt that I can build better myself, and likely prefer to upgrade the speed of this one than start from scratch.

 

[georgefromvt]

The EGO isn't cheap but looks like an excellent hill climber. If you purchase it, please keep us updated! It's on my wish list but my wallet says No. Interesting ad concept--naked man on bike. Only in Germany
http://www.ego-kits.com/?wptheme=egoennew
http://www.ispo-brandnew.com/Egokits.html

 

[M1k3]

Really pleased with my cyclone 1200w on a downhill bike(kona stinky)I am sure there will be refinment issues ,but the EGO that I wanted looks just like my cyclone at about 5 times the price,I am running 24" back wheel like the early big hits ,And as Timma says great hill climbing.

 

[AussieJester]

Listen to Timma2500 he has built two of the nicest e-MTB's on this forum possibly the world!



^^ This is a pic of Paul's (Timma2500) Specilised utilizing cyclone kit.




^^^This is Paul's other bike a Norco using an Astro motor, much higher price but much higher quality also, see forum member Recumpence for these motors and reduction drives they are da bomb used em & recommend em... Matt (Recumpence) is one of the nicest people i have met and has some seriously nice products everything you need to get your bike going, cept batteries i think? You selling packs as well now Matt? Hobby King for lipos if not.

I would highly recommend NOT using a hub motor for the
riding your wanting to do, as mentioned above it wont be upto the jumping and abuse it will see...

KiM

 

[dogman dan]

I agree with most of what was just said. Hubmotor will pound itself to death hucking, or at least the rim and spokes will get a beating. Hubmotor will also fry itself trying to climb straight up a blue square ski slope. Some could climb back up a green square route, with pedaling and watching the temp.

So you want a chain drive, Cyclone, RC homebrew, something like that. It's not going to run flawlessly with no broken chains though, if you climb ski slopes. Either way, you pretty much can kiss ride it and ignore it goodby. Either route, you're just gonna break stuff doing real DH riding .

It really just depends on the kind of trails you ride. I'm very very happy with my slow winding hubmotors, but I ride crosscountry, not DH. I pound hell out of the bike riding 25 mph on rocky roads, and hit big dips crossing streambeds at 15 mph. All hard on the bike, but tolerable for the hubmotor. Pretty much no leaving the ground at all for me though. I could go much faster on the downhill runs, but like to eat rocks and cactus at 15 mph, vs 25.