Ebike conversion for Giant Toughroad (29er)

gsa103

1 mW
Joined
Mar 13, 2016
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18
I'm considering doing an ebike conversion to a Giant Toughroad SLR 2. The bike is a Al frame 29er (135mm OLD) with plenty of tire clearance and a carbon fork (so no front motor). Current drivetrain is 3x9 with Shimano hydraulics.

I'm a fit cyclist and looking to bring my commute times (11 mi each way), down to comparable to what they are on a carbon road bike (~15 mph ave, ~18 mph cruise). I'm looking for something the supplement the ~150W I currently generate.

I was originally thinking a basic rear hub kit in the ~500W range, but I'm really struggling to find a compatible motor. It seems like the majority of hub motors use freewheels. In general, 8-speed freewheels have a very bad reputation for broken axles, I imagine 9-speed are equally bad. I have zero interest in downgrading to 7/8-speed, I've got better components, and see no reason to downgrade, if anything, I'd upgrade to 10/11 speed. Similarly, I'm not switching to cable disc brakes, hydraulics are much better. I've also considered mid-drive, but I'm not sure how these kits fit with a front-derailleur or are they basically 1x9?

1) Are there any electric kits that take a 8/9/10 cassette and still fit in a standard 135mm OLD?

2) How important are brake disconnects? I'm planning on using pedal assist only, since it looks like most brake disconnects aren't compatible with hydraulics.

3) Dillinger has kits with a 9-speed freewheel, but how durable are these? With the extra weight it seems like broken axles would be quite common.

4) Would mid-drive be more suitable, and how robust are the mid-drive units?
 
I'm looking for something the supplement the ~150W I currently generate.
Actually, it will be the other way around, you will be supplementing the motor system.
Just so you understand, even the smallest and best free wheeling hub motor system will be noticeable to the extent that you will not want to ride with pedal power only. The most common way of combining human and motor power is to set the (in your case) PAS speed a couple of mph under your desired cruise speed and add with your legs.

Are there any electric kits that take a 8/9/10 cassette and still fit in a standard 135mm OLD?
Here are three;
https://bmsbattery.com/ebike-kit/618-q100c-cst-36v350w-rear-driving-ebike-hub-motor-ebike-kit.html
https://bmsbattery.com/ebike-kit/768-q128c-135mm-500w-rear-driving-ebike-hub-motor-ebike-kit.html
https://bmsbattery.com/ebike-kit/492-bafang-36v500w-cst-rear-driving-hub-motor-ebike-kit.html
How important are brake disconnects? I'm planning on using pedal assist only, since it looks like most brake disconnects aren't compatible with hydraulics.
There are ways to rig an Ebrake on hydro systems, for example;
https://endless-sphere.com/forums/viewtopic.php?f=2&t=78787&p=1163098&hilit=brake+magnet#p1163098
Dillinger has kits with a 9-speed freewheel, but how durable are these? With the extra weight it seems like broken axles would be quite common.
To get an 11T sm. gear on a free wheel pretty much means an Epoch DNP free wheel. Opinions vary and myself would have to say most of the time they work OK, they are just heavy and clunky. I have had the best luick with the 7-speed which is fine w/ a motor. Once the motor kit installed, only 2 to 4 gears are used(depending on system power). Still, I like cassettes better.
I have no experience with mid-drives except ocassionaly riding with them. Those were kind of noisey, but I have no idea if they are all noisey.
 
Check if the Bottom bracket is threaded. You would really enjoy a BBSHD if you want to keep your good component setup and keep it feeling like a bike. My cyclocross is a similar setup (29er all rounder with 1 x 9 ) but with dropbars and 2.25" tires. The 9 speed rear is typically a megarange , so great to go 1 x 9.
 
Raged said:
Check if the Bottom bracket is threaded. You would really enjoy a BBSHD if you want to keep your good component setup and keep it feeling like a bike. My cyclocross is a similar setup (29er all rounder with 1 x 9 ) but with dropbars and 2.25" tires. The 9 speed rear is typically a megarange , so great to go 1 x 9.

My BB is definitely threaded (currently Octalink V2). After doing a little more research, I'm coming to a similar conclusion, that maybe a mid-drive is the correct approach. I'm currently looking at kits from Luna, which look pretty good, and seem like a decent way to go.

I'm leaning towards the BBS02 rather than the BBSHD based on price, and I don't know that I really need the power (& weight) of the BBSHD. My commute is pretty flat (with strong headwinds), and realistically, I'd probably be happy with ~350W (at the crank), plus another ~150W (me). Reliability, is probably more important than raw power or acceleration, so I'd even considering de-tuning the BBS02 start profiles. What are your thoughts on the HD vs the 02?

I'm struggling to find info on the rpm and gearing range of the BBS motors. Everything I've read recommends keeping a "fast cadence", but I find things that seem to indicate that the power start ramping down above 60 rpm. I routinely bike in the 60-90 rpm range, and would consider 80-110 rpm to be "fast", but it seems like the articles are really recommending anything above ~50rpm.
 
I run a BBS02 750w which is great as a commuter who likes to pedal.... I do have a megarange 9 speed ( 34t to 11t rear ) and got the upgraded 48t BBS02 front chainring so I could still input leg power above 50+km/h ( 32mph ). Just note that the BBS02/BBSHD is not the same as a big hub motor. I used to run a 2.2kw MAC10T geared hub which makes your bike a scooter... Punching the throttle would lift up the front wheel which makes it hairy sometimes etc... With the BBS02, I pedal for exercise and maybe use 1/3 throttle to boost up a bit when the going gets tough as an assist then let off when i'm at a good speed and cadence. I'm one of those throttle only when you need it people... I dont use PAS normally. If you're really slack, you can drop down a gear and just max out the throttle to cruise on motor power, but as I said, it's not as fast at accelerating like a 2.2kw hub.

With the BBS02 I also run a smaller battery (5800 mAh) which gets me 30km comfortably on juice or 50km with me pedaling alot on flats. This drops the battery weight and capacity so you can normally get a full charge within an hour with a 5A charger... I spent about AUD$200 on batteries. ( 2 x 7S 5800mAh Zippy Compacts @ AUD$80 + AUD$30 BMS + connections ). The charger is a $50 5A 14s (52v) charger from em3ev. Also good to have an 8s hobbyking balancer if you can afford the extra $30.

I figure if this battery dies in 3-5 years, the technology would have advanced enough to get a new battery.

The BBSHD is good if you're going to hit the hills with 15-20% inclines.... For commuting, the BBS02 750 is fine for me.
 
So I'm strongly leaning towards a BBS02 install with downtube shark battery pack. I think it'll be a nice clean look and plenty functional for what I want.

With the BBSxx motors, how do you handle cable routing? Currently, all the cables (1 hydro, FD, RD) run under the BB. Obviously, the FD goes, leaving just the brake line and derailleur cable. I guess just run the brake over the NDS and the rear derailuer over the DS before transitioning them to under the frame? Anyone have any thoughts/pictures?
 
gsa103 said:
It seems like the majority of hub motors use freewheels. In general, 8-speed freewheels have a very bad reputation for broken axles, I imagine 9-speed are equally bad. I have zero interest in downgrading to 7/8-speed, I've got better components, and see no reason to downgrade[...]

Hub motor axles are thick and strong and don't have the problem you describe. The problem is the 8/9/10-speed freewheels themselves. They suck. They break, they don't run true enough to work right with such tight gear spacing.

Don't fool yourself; like for like, 7-speed is an upgrade in terms of reliability, durability, and shifting precision. More speeds plays better to the cheap seats, though.
 
gsa103 said:
So I'm strongly leaning towards a BBS02 install with downtube shark battery pack. I think it'll be a nice clean look and plenty functional for what I want.

With the BBSxx motors, how do you handle cable routing? Currently, all the cables (1 hydro, FD, RD) run under the BB. Obviously, the FD goes, leaving just the brake line and derailleur cable. I guess just run the brake over the NDS and the rear derailuer over the DS before transitioning them to under the frame? Anyone have any thoughts/pictures?

I moved the brake line above the left side of the bottom bracket as it was sleeved all the way ( same with your hydro's ). My RD runs along the top. I've seen people put some rubber to space the BBS from the frame a bit so it doesnt touch bare cables. Much easier if it was sleeved though.
 
Looks like he is going to go with a mid-drive,

Regarding Freewheels, Sunrace, not suntrace, Sunrace makes higher quality 8 and 9 speed freewheels, designed/made for e-bikes

550 miles on my 8 speed one and it is working fine so far, I will post if it does ever develop any problems, it is working fine , it is about double or more the cost of the cheep DNP freewheel , ( about $ 40 )
so in this case you do get what you pay for.

Also

I went in to my local bike shop the other day, while there I expressed my concern with having to build up another hub motor that was only freewheel capable, I have 10 speed drive train on it now, and told the mechanic how I
loathe having to go to mountain bike 9 speed shifters, derailleurs and chain to work with the hub motor, and told them that I only heard bad things about the DNP 10 speed freewheels, he nodded his head and said the same.

He then said that IRD is now making a 10 speed freewheel. I looked it up on the IRD website, and found no such 10 speed freewheel,
The Mechanic said he will look into it, perhaps he saw a prototype at interbike over at Las Vegas a few months back ?

Anyone here know about a new 10 speed freewheel from IRD ?

Keep in mind that even though many people here only use a few cogs on the back when converting a bike to an e-bike, and they therefore , wrongly surmise that you only need a 7 speed freewheel, the fact is that many of us have 10 speed component group sets, and find it a silly / stupid thing to have to buy new shifters/chains/derailleurs / etc. both in wasted money and time . We want to use the components we already have on our bikes. even if we / or you only use 4 or so of the rear cogs. ( I live in a hilly area so I use all 10 cogs on the bike of my non powered bike ... and all 8 on the rear of my e-bike so as to match my cadence to the speed of the motor/ in other words I use all the cogs in order to keep my cadence up )
 
You can replace a seven speed cassette and shifter with what a ten speed chain costs, and still have money left over for the next seven speed chain.

Saving money by keeping high gear counts is a total fallacy. They were only ever meant to cost you extra.
 
But what about the 10 speed front derailleur, and the rear 10 speed derailleur, If I were to put on a 7 speed freewheel , with 7 speed chain, I would have to get new derailleurs too, and shifters,

So

The cost goes way up, when you also factor in the Derailleurs , and shifters, as well as the chain.

And

There are other things I would like to do with my time, besides, switching out components. even though I do prefer to do most DIY items.

( If I remember right, I buy 10 speed chains when they are on sale , under $ 18 ) so they do not cost too much, I only go through one a year anyway.
 
BTW Chalo

I lived in Austin for a few months , some 15-18 years ago, where are there cheep accommodations these days ?

Is there still any campgrounds around the lake to the west side of Austin ?

Back then, so I am guessing that still , one does not want to be on the East side of Austin or has gentrification occurred and it is safe now ?

I would love to go back to Austin again for a few weeks and ride all the great bike paths , and even to the countryside and ride some single track trails to the East of Austin ,

You can PM me if you do want to keep this thread on topic.

For anyone who has never been to Austin, there are many miles of great bike paths there , as well as great country roads to the south and west of Austin, and Fun Single track trails to the East.

If your are a bicyclist, Austin is very high on the Good Places to Live List.
 
Derailleurs don't know how many gears they are shifting. We only have "10 speed" derailleurs because 10 speed systems require so much more precision than lower counts to work halfway decently. A 10 speed derailleur shifts fewer gears just fine. You might need to use 8 speed chain even if you are shifting 7 or 6 speed, because chains get narrower as gear counts rise and at some point there can be clearance issues.

ScooterMan101 said:
If your are a bicyclist, Austin is very high on the Good Places to Live List.

Stop saying that!

Austin's still good, but much more expensive than you remember. East Austin hasn't caught up to the niceness of West Austin, but it has caught up to the cost. I've been living on the East Side since early 2007; I bought a house here. I wish I'd bought it earlier. Just the property taxes amount to more than rent would have been when you were here.

I wouldn't swap the gentle terrain and compact scale of the East Side for any other part of town, now that I bike for all my regular transportation.

My no-fooling assessment is that we don't have any real productive industry, it's unbelievably hot, the economy only functions because so many people keep moving in, and you'd have to be crazy to relocate to Austin. Please help me spread the word. We're hugely overdue for our regularly scheduled collapse. Buy now if you want to be trapped here for years until your place recovers some value.

If nothing of the above bothers you, you might like it here.
 
Might be too late for this one, but I often advise a real cyclist to avoid ruining his favorite bike with a motor.

I know it's horrifying to think of it, but you might try converting a semi decent, quite possibly older 7 speed bike if you do head in the direction of a hubmotor.

But if you do convert your nice bike, I'd have to say you are very likely to prefer a mid drive, and likely run it at relatively low power.
 
I recently experimented with replacing a 10-speed cassette and chain with an 8-speed combo, but removed it because I could never stop the sound of the chain rubbing against the deraileur cages when in the two largest rings. I think the combination of wider chain, narrow cage and large offset caused the chain to rub.. It worked well and I am sure would have been cheaper and stronger, but it needed an 8-speed rear deraileur in addition to an 8-speed indexed shifter to work quietly. Maybe when I wear out my 10-speed system, I'll give it another try.

Any hydraulic disc can be wired up to work with a PAS system using rare earth magnets and one of the various sensor cables.
 
Front derailleurs are basically tongs for your chain. There's no rule against bending them to suit your purposes. I do it all the time to quiet a fussy bike without impairing its shifting.
 
Chalo said:
Front derailleurs are basically tongs for your chain. There's no rule against bending them to suit your purposes. I do it all the time to quiet a fussy bike without impairing its shifting.

Can I do the same at the rear? That's where the rub is with the 8-speed chain and cassette.
 
WoodlandHills said:
Chalo said:
Front derailleurs are basically tongs for your chain. There's no rule against bending them to suit your purposes. I do it all the time to quiet a fussy bike without impairing its shifting.

Can I do the same at the rear? That's where the rub is with the 8-speed chain and cassette.

In some cases, you can get slightly longer bolts-- for instance from an older derailleur-- to hold the cage plates farther apart. A thin washer on either side of the pulleys is all you need to make up the width difference between chains.

In other cases it's not so simple. Worst case, you can still use narrower 9/10/11 speed chain with 7 or 8 speed systems; the only problem with that is the increased cost of narrower chains.
 
dogman dan said:
Might be too late for this one, but I often advise a real cyclist to avoid ruining his favorite bike with a motor.

I know it's horrifying to think of it, but you might try converting a semi decent, quite possibly older 7 speed bike if you do head in the direction of a hubmotor.

But if you do convert your nice bike, I'd have to say you are very likely to prefer a mid drive, and likely run it at relatively low power.

Don't worry, it's not my favorite bike. I've got a very nice carbon road bike and great full-suspension bike. This bike was bought for the purpose of commuting and errand running.

I looked into buying a used bike, and eventually decided that going new was a better route. I live in the SF Bay area, and so craigslist tends to be full of delusional sellers (3 yr bike listed at MSRP). The other thing was that I wanted a 29er and hydro disc brakes, no matter what. By the time I got a used bike then replaced the cables, and re-did the brakes, I was looking at a similar price as the Giant.

It sounds like downgrading to 7-speed might be a reasonable option (the shifters are super cheap). So far I'm struggling to find a good vendor for 29er disc brake hub motor wheels (pre-built). I'm not looking to get into wheel building (yet). Anyone have any recommendations?

I do like the look of the BBS02 mid-drive, it seems like a very clean integration, which is appealing. I'm not a fan of needing the extra controller for most wheel motors (need to find a clean mount). With a BBS02, basically all I need is a Luna shark pack, and the assorted display/cables. I'm a bit concerned about the accelerated drivetrain wear with a mid-drive.

As far as I can tell, there's negligible cost difference between a motor wheel and a mid-drive, so it seems like the mid-drive is the way to go. Are wheel/hub motors really that much better than a mid-drive, especially at the ~750W level?

I'm still debating if I really want to pursue this project. The main issue is, will a motor get me enough speed to change how I commute? My current commute involves some near freeway (65 mph), free & easy parking, minimal traffic. Even doing 30 mph, I'm still going to be slower by 10 min each way. Unfortunately, there's a relatively high buy-in cost to test out if it would actually change my behavior.
 
I'm still debating if I really want to pursue this project. The main issue is, will a motor get me enough speed to change how I commute? My current commute involves some near freeway (65 mph), free & easy parking, minimal traffic. Even doing 30 mph, I'm still going to be slower by 10 min each way. Unfortunately, there's a relatively high buy-in cost to test out if it would actually change my behavior.
Buy a gas powered motor scooter.
 
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