First build help: Know the kit I want, but which bike?

[johnxsi]

Hi all, apologies in advance for another "newbie what-bike-do-I-get" thread

I've been lurking and reading for a while now, and am about to pull the trigger on a build. I'm pretty set on what I want for motor (the cellman combo: Mac 8T 1000W kit with 52V 11.5Ah A123 square pack). The only slight variation being is I want to mount the battery in a pelican case on the front ala Oatnet's awesome build: http://endless-sphere.com/forums/viewtopic.php?f=6&t=24329&p=368010&#p412946.

But my biggest problem is figuring out what kind of bike to get. I've narrowed it down to 3 options and wanted to get some opinions from the experts:

1st: $400 - Trek 4900
Logical choice. Great condition, cheap, good platform and probably best for commuting.

2nd: $500 243 Hardtail
Frankly I just love this because it looks fantastic. Tougher cromoly frame, giant forks make mounting battery on front easy, and hard tail keeps a bit of efficiency. Haven't test ridden it yet, cockpit might be too cramped for any kind of meaningful pedaling. Is it silly to try and commute on frame geometry like this?

3rdly: $600 - Norc Atomik
Added this because everyone seems to love full suspension when they finally go there. Wondering if I should just skip some steps and start right there Concerned about losing pedal efficiency with a rig like this though.



I currently commute a few times a week on a no suspension hybrid. It's a ride of 20 miles (each way) to work varying between smooth, well maintained bike trails to highway shoulder riding, with a few mild elevation changes and the odd construction zones sprinkled about. There's only one bit that really kills me, and it's a 10-12degree hill in the last mile before home. Kills me in the evenings.

Would be nice to make this commute a daily thing with an ebike. I'm a bit worried that the hardtails will beat me up on the 40mile round trip, but still would like the bike to be reasonably pedal efficient. Torn between efficient ebike build and meaty curb hopping machine.

*EDIT* Happy with 25mph speed and expect to do additional pedalling. I would recharge at work.

Thanks!
John

BTW, so glad I found this place; the signal to noise ratio here compared to the rest of the internet is fantastic!

 

[neptronix]

the trek
the trek
the trek



Look at my MAC and 20" magic pie builds. Look at the torque plates i was able to, very easily, make for those bikes.
They have bombproof frames too.

The tapered and flat lower tubes make for great mid mounting of batteries. Add a falconEV bag to a 19" or 21" model and it just fits like a glove.

But honestly $400 is asking WAY too much... i spent $160 on my gray one, and $65 for the frame of the larger black one.
Talk him down to $250.

I love my Treks and it took going through 6 different bikes to find the perfect rear drive hub motor hardtail chassis to find something this good.

 

[randel24]

Norco!

 

[iamsofunny]

Get something like a Kona Stinky or a Rocky Mountain that has the triangle frame with the shock not taking up too much space. Then place the battery in the triangle. your battery is pretty small so it should fit.

That norco has a 24" rear wheel I think whereas the others look like 26

That first one would sell for, like the previous poster said, 250

I would never ride a hardtail again though.

 

[d8veh]

Full suspension is better for comfort when commuting - especially as far as 20 miles. The bumping from a hard-tail gives you a sore a*s after about 30 mins and every bump makes it worse. I've never experienced any loss of efficiency from it because most of the power comes from the motor, and no need to stand up on the pedals so no bobbing.

 

[neptronix]

Full suspension is better for comfort when commuting - especially as far as 20 miles. The bumping from a hard-tail gives you a sore a*s after about 30 mins and every bump makes it worse. I've never experienced any loss of efficiency from it because most of the power comes from the motor, and no need to stand up on the pedals so no bobbing.

Rear suspension is nice but your battery mounting options always kinda suck, so do the dropouts..

I've been looking for a rear suspension bike with good triangle space for over a year.. only certain models of 1990's trek, proflex, and cannondale seem to fit the bill.

Can't really find them for a reasonable price used though.

I found that really friggin' fat tires on the rear, a springer seat, and a front shock make a hardtail very liveable.. i felt stable at 40mph..

 

[motomech]

I'm pretty set on what I want for motor (the cellman combo: Mac 8T 1000W kit with 52V 11.5Ah A123 square pack
[*EDIT* Happy with 25mph speed and expect to do additional pedalling.
/quote]

...but still would like the bike to be reasonably pedal efficient. Torn between efficient ebike build and meaty curb hopping machine.

Then why go with a motor/battery combo that will top out well over 30 m.p.h.?

Pedal efficient to me means a geared motor[you will have that]and a motor happy speed range where your input will be meaningful. Gearing has a lot to do with this. The reasonably easy to do combo of 11/48 is good in the 24 to 27 m.p.h, range. You won't be adding much above that unless you go to a 52T or larger chainring, which will add more expense to your build.

Frames-You might want to read this thread;

http://endless-sphere.com/forums/viewtopic.php?f=3&t=32056&hilit=suitable+frames

I currently converted to Lipo, a mistake. Now I have have uncontrollable urge to keep adding bricks[more range]
Cell_man's great A123 packs will help you resist this urge[although there is an easy way to hook two of his packs together].
Good power range for true pedal assist seems to be be in the 900 to 1300 Watt range. Not so much as to be a watse, but enough to maintain good speed up hills.

This is my bike currently undergoing it'd third revision[second rebuild];



2003 Rocky Mountain Edge X-country. 4" travel frt, 5" rear;

Battery space-Great![I.M.O., the worst place for a battery pack is on the forks]

Rear drop-out strenght-sucks, very wimpy chain stay[hence two mini-motors]

Comfort-very good.

The unsaid downside to FS bikes-with the suspension un-loaded, they are tall. With the suspension loaded, pedal to ground clearance is minimal.
One learns to live with the latter, don't pedal when leaned over.
With medium to large frames, rider with 28 to 30" inseams should look for 3 to 4 ' suspension travel. Those blessed with longer legs, the sky's the limit, although more than 5" is not needed on the street.

Whatever I thought I wanted when I started has recently evolved into a quest for comfort and range[battery addiction].

 

[dogman dan]

Here's the dilemma in a nutshell. 40 miles a day at 25 mph will beat the crap out of you, and the rear tire and rim, unless the pavement is really nice all the way. Sounds like it's not. So you do want full suspension.

But you also need a lot of range, and 15-20 ah of 48v battery will not carry nice on the fork anymore. Too big, too bulky, too heavy. It almost has to carry on the frame. So if you did choose the norco, then your only choice would be saddle bag type boxes attached to the frame.

I use em on my dirt bike, but they DO interfere with pedaling. No problem, my dirt bike is seldom pedaled at all. Big problem on a commuter.

I suggest a compromise. Get the Trek bike, or one very similar that's even cheaper for the first go. While getting some experience with that, you will be searching out a deal on a FS bike with better triangle space, allowing at least 50% of your battery to be carried there. The remainder could be rack mounted or fork mounted.
This does mean your battery may be a two part setup. A hardtail bike with a generous triangle can fit a 48v 15 ah pingbattery. But a FS may only fit 10 ah. At a slower, 20 mph speed, this would be enough range (15 ah of 48v). If you are a hard pedaler, then a freewheeling gearmotor could help, allowing you to motor off ride about 4 miles and make 15 ah plenty of range at 25 mph.

 

[Drunkskunk]

the signal to noise ratio here compared to the rest of the internet is fantastic!

And now I have that Cure song stuck in my head.

The battery you picked is 2/3 to half the size you'll need. you might be able to occasionaly make it 20 miles on that battery, but not consistantly, and not without hurting the battery long term.

As for the bikes, that Norco is sweet. 2 problems though, the battery won't fit, and the rear wheel. Sure, you'll be replacing it with your MAC, but the point is someone has fitted an expensive 24" SunRingle Doubletrack to that bike. Thats not the kind of thing done for show, likely meaning that bike was road hard, DH style. and that isn't a DH bike.

The 243 probably can't hold enough battery in the triangle, but its a sweet bike. putting the battery someplace other than the triangle on that bike would upset it's balance, so not worth the premium price.

The trek is by far the best bike to convert here. its overpriced in my part of the world for a used bike, but might be right in your market. But put the battery in the frame with that bike. You'll also want to upgrade the tires to slicks, 2.5" balloon tires like Hookworms is what I'd recoment, to take the edge off the bumps.

Full suspension is sweet, but it makes for a complicated first build. Almost all of us here end up building more than one bike eventualy, as experiance teaches us what we like and don't like about our first builds. Its a personal thing, your experiance will be unique, and what you'll want different in an ebike by next year will be diffrent from now, and from anyone else. So yes, you'll want a full suspension eventualy, but save that for later, and untill you can find a better bike to convert. Do something like the Trek for now. You'll love it.

 

[dogman dan]

Yeah, 11 ah would have to be ridden sub 20 mph to make it 20 miles. I didn't really pay much attention to his motor and battery choice.

Get a bike with a triangle space, and put that first 11 ah there. Then look at other possibilities for more range. Maybe a second cellman pack, or a small lipo pack in a backpack or handlebar bag. Till you sort that out, pedal and coast all you can on the easy parts of the ride.

There are some cheap entry level mtb's with FS and a frame space at walmart. Cheap enough to prototype with, while the search goes on for a quality FS bike cheap enough. Should be able to get 2000 miles out of the cheap bike, with a bit of good maintenance.

Vancouver, well,,, Might be lots of good FS bikes on the used market, but all thrashed from blasting down ski runs. One nice thing about here in the boiling desert. Lots of virtually unridden bikes on the used market. One ride in 110F and they get parked for years.

 

[johnxsi]

Thanks all! Seems like the clear consensus is to a) get the Trek, and b) only ride full suspension.

For my first build it sounds like Trek is the simplest way to get up and running quickly. I wish there were bikes like these lying around for $250 up here, but it's slim pickings finding a bike in decent shape that fits me (I'm 6'2").
I know the 8T seems a bit overkill for what I'm planning, but I would like to go faster later on down the track, once I figure out my battery range. When you guys quote range, is that based on no pedaling at all?

I really prefer the fork mounted rigs over the triangle, but clearly there's not a lot of love for the fork mounting here. I had a front mounted kid's seat last summer on my bike and it didn't bother me at all (32lb kid attached to the stem for several 20-30 mile rides). To be fair though, I didn't try him jamming him in the triangle for comparison

As for the bikes, that Norco is sweet. 2 problems though, the battery won't fit, and the rear wheel. Sure, you'll be replacing it with your MAC, but the point is someone has fitted an expensive 24" SunRingle Doubletrack to that bike. Thats not the kind of thing done for show, likely meaning that bike was road hard, DH style. and that isn't a DH bike.

The 243 probably can't hold enough battery in the triangle, but its a sweet bike. putting the battery someplace other than the triangle on that bike would upset it's balance, so not worth the premium price.

Great points, thanks Drunkskunk!

What's the charge time of the A123 battery pack on a 5A charger?

Cheers!

 

[dogman dan]

Should be fairly quick. 5 amps per hour is 5 amphours. So about 2 hours, 3 if needing balancing.

Long seatposts, tall stems and riser handlebars is my route to making bikes for a 5'9" teen fit my 5'11".

 

[johnxsi]

Yeah, 11 ah would have to be ridden sub 20 mph to make it 20 miles. I didn't really pay much attention to his motor and battery choice.

Get a bike with a triangle space, and put that first 11 ah there. Then look at other possibilities for more range. Maybe a second cellman pack, or a small lipo pack in a backpack or handlebar bag. Till you sort that out, pedal and coast all you can on the easy parts of the ride.

There are some cheap entry level mtb's with FS and a frame space at walmart. Cheap enough to prototype with, while the search goes on for a quality FS bike cheap enough. Should be able to get 2000 miles out of the cheap bike, with a bit of good maintenance.

Cool, I'll have a look at the Walmart/Canadian Tire bikes. I don't mind if the battery is a little small as I'm happy to do a fair bit of pedaling, and at least the limited range will keep me from getting too lazy... though I just finished installing a Supercharger in my car, so I'm already worried that by next year I'll be asking about how to build 100V Lipo packs.

Could be the wrong time to be looking for FS bikes deals in the middle of summer, maybe heading into winter the bikes will get cheaper.

 

[johnxsi]

Just to follow up: It's been a while in the making, but she's up and running!

Ended up with the 2006 Trek 4900 with a 1000W 8T Mac. Build was heavily inspired by Oatnet & Kiwi's fork mounted battery builds. 52V 13.8AH A123 battery is mounted in Pelican case on forks with a 40A controller underneath.

Dropouts were fabb'd up by a friend who has a milling machine. Slight overkill in teh steel thickness, but never hurts of overengineer I suppose. Running 26" Hookworms with downhill tubes and Mr Tuffy Bike Liners. Converted to a 52T single speed up front, and changed rear from trigger shifters to gripshift (much nicer to ride with). Stock brakes so far, but have some Avid BB7's coming soon, as the standard brakes are no coping as well as I'd hoped.

I've been commuting 30km each way to work the last few weeks and it's been a blast. With pedaling I can hold 50kph the entire trip, and have 30% battery to spare. It's nice to be able to hold a lane with traffic in some parts of the commute.

I realize there's miles of frame space that I didn't use, but the plan is to move to a full suspension frame in the next iteration, hence the fork mounted battery. Plus it looks a little more stealthy.

Thanks again for all the advice! I'm amazed at all I've learnt form this forum in the past 6 months.

Full res here:
http://imgur.com/DB8m3
http://imgur.com/ijpwp
http://imgur.com/3hUmc
http://imgur.com/mmTQ6

 

[Beachcruzer]

Great build.

 

[kudos]

Nice build.

Can I ask why you want to go full suss? Are you finding the hardtail too punishing for the distance you cover?

Kudos

 

[johnxsi]

Nice build.

Can I ask why you want to go full suss? Are you finding the hardtail too punishing for the distance you cover?

Kudos

Cheers! The original plan was to do a simple first build on a hardtail & then convert to full suspension later on, as I was worried 60 km/day might be too much on the body... plus I have an old Stinky frame sitting around that I was planning to use.

Having said that, the bike's nicely sorted now & so far the ride's been great. Because I'm pedaling all the time, I find I'm out of my seat a fair bit, and will stand up on the pedals going over transitions/bumps. The odd pothole that I've hit while sitting down was not something I'd want to do regularly

I imagine if I was just treating like a motorbike and sitting down the entire journey then I'd be hurting a lot more. But for now the hard tail is doing the trick, so I might keep it as is.

 

[spinningmagnets]

If you are certain you will eventually be going with a full-suspension frame someday, save your money for that (and research). that being said, the possibility exists that you will be happy with just front suspension since you're only doing 25-MPH max. If you think you will be keeping this a long time, consider a Thudbuster seat-post. They are about $120+.

If you get one, you will probably end up keeping it even if you ever sell the bike.

 

[kudos]

I've got a build much the same as yours, only with controller and lipo in a falconev frame bag.

Seeing as your bike is so sorted, maybe try a thud buster seat post?

I've also got a full Suss build I'm nearly done with, but the weather has turned here so I'm not sure when I'm really going to get a chance to use it in anger to see if there's a big difference.

All the best,
Kudos