Mountain Bike Reviews Forum banner

1 - 20 of 40 Posts

·
Registered
Joined
·
399 Posts
Discussion Starter · #1 ·
I've been lusting after eMTBs for several months. Bought a Sondors Thin for urban bike trails & errands in June. Its been a hoot!

My SC Hightower is almost perfect, but I'm not. Frankly tired of pushing it up hills to ride down. Then need a recovery day afterwards. Grrr...

Friends got eMTBs next. WOW, I think I need one of those to rescue my knee from pushing MTBs up hills!

Did much reading research & decided to demo the 2 that seemed the closest matchs to geometry, slackery, & all-mtn suspension of the Hightower. Wednesday was eMTB demo day!

Demos: Local hills with hero dirt & a little mud in the shade on a Specialized Turbo Levo (Brose, no dropper). Later I returned the TL & went to the other shop & street demoed the Trek Powerfly 8 FS (Bosch w dropper).

Friends rode their LaPierre hardtail w front susp (Bosch) and a Bulls Stream FS Enduro (Brose). We traded off & tested everything!

2077.jpeg

The TL seemed strong in the middle (trail) of three assist modes. Climbed the 900-ft hill easily. I needed to stop & pant 2-3 times, but it waited patiently!

It had a cheap 3-fixed-position dropper added by the shop that I had issues with occasionally. Made me miss my reverb. The TL had tubeless Minion HDR2s, just like my Hightower. :) I felt very comfortable getting frisky with these tires on familiar trails!

Flowing down hills the brakes, tires, & TL worked great! My only complaint was my fit to the large frame. The seat post was too tall for me. With dropper fully compressed, the seat was still too high to get comfortable in a downhill, ass-behind-the-seat position.

Back to climbing switchbacks with the TL in Trail or Turbo assist modes, it was difficult to stay vertical, balanced, & pedaling lightly thru the turn. The power assist would sometimes drop out & surge back causing a loss of balance.

Hmmm ... I see why the TL owners around here say they only use 15-20% assist for tight turns. This softens the surge/no-surge felt in the 50% Trail & 100% Turbo settings. Maintaining balance is easier.

The surge off the bottom has a benefit if you are a stunter. Its very easy in turbo mode to one-stroke pedal up into a mono from a stop!

The surge/no-surge is minor issue if not turning tightly & seems to be associated with your applied torque dropping below (or rising above) some threshold, without a change in pedal cadence. Didn't really noticed a lot of change in assistance vs pedal cadence above the minimum torque threshold.

In my case (5'6", 29" inseam), a TL with medium-size frame & a software upgrade to smooth low-torque power delivery would be hard to resist.

The Bosch in the LaPierre was noticeably smoother in power delivery & very predictable assist vs. the TL. Felt a little stronger than the TL Brose. Easily pedaled around every switchback without losing balance. Faster cadence got more torque (than Brose). Sweet! Frame size too long for me.

The Bulls has the Brose pa like the TL, and really didn't seem any different PA-wise to the TL. Much tighter frame, bars to seat. Fluffy long-travel suspension. Ready for Downieville.

Then over to Sharp Bikes in Lafayette, CA to demo a Trek Powerfly 8 FS.

2079.jpeg

The Powerfly (PF) is very similar to the TL, but 130mm suspension vs TL at 140mm. The PF LT in Europe is 150mm, but we can't get it here. Grrr...

Latest Bosch CX pedal-assist system, display & controls. Biggest visual difference is the separate battery pack behind the downtube. The TL battery is kinda hidden _in_ the downtube. TL is more stealthy. The PF battery is 500WH vs. 460WH in the cheaper TL models.

Climbed up & down some steep 400-ft hills near the shop to test the pa, downhill balance, & brakes. All I could really do with a paved-only test ride. Dropping at speed the PF handled well & felt balanced.

Immediately I noticed 3 differences with the Bosch pedal-assist system vs TL's Brose; smoother power delivery, more-responsive linear torque increase vs. cadence speed, and ultimately MORE torque.

I could turn tight figure-8s with the PF on the side of a steep paved hill and never lose balance, in any of the four power modes. I could only do that on the TL in ECO (20% assist) mode. The PF has smoooother assist & most noticeable in slow tight turns.

The oem tires on the PF are ok on the pavement, but I didn't trust 'em much. Coming back down the steep hills, I got some speed up & did some hard brake testing. Front did pretty well, but the rear got worse with heat. After 300-ft of elevation drop on the rear brakes, I could no longer lock the rear tire when I tried to slow to a stop. Had to go vertical & hammer the front brakes.

Hmmm ... that surprised me how the rear faded with heat. I wonder if they are really that cheap or need bleeding?

Hmmm ... the PF brake system specs are missing in link above. Just like the TL rim specs are missing in that link. Hmmm ...

So $5500 for TL COMP (w dropper), add better tires & maybe wheels someday.
$5000 for PF (w dropper), but it will need better tires & brakes now!

I wish I could dirt demo a PF, but mediums are not a popular demo size around here <sigh>. I can't believe I'm considering a new eMTB that needs better brakes immediately. GAH!?!

Anyway, I got dealers to call about brakes & price quotes tomorrow.

Wednesday was the 1st day in my life I actually pedaled all the way to the top of that hill. With a bad knee & a BIG-ASS grin on my face! :)


Catfish ...
 

·
Registered
Joined
·
5,536 Posts
900 ft hill? Doesn't seem that big. How often do you ride? Which OEM tires? Maxxis are pretty good where I ride in MA.
 

·
Registered
Joined
·
1,406 Posts
Thanks for the interesting review. My off road excursions are mainly on a DIY BBS02 hardtail with rpm PAS; learned pretty quickly not to enter a switchback too fast.
 

·
Registered
Joined
·
121 Posts
Call crazy Lenny's in Madison for a price on the bulls. I'm not sure if they carry trek or la Pierre, don't think they do specialized...but the prices are nuts. I've bought a few bikes there now, most recently the bulls fs3 E stream 27.5, which is such a fun bike! Might get a killer deal for a new years sale...I got my bulls on a 1 day sale they had when the cubs got into the world series...paid closer to the price of the bulls non electric version of the same bike.

Before you buy, have you ridden an sduro from haibike with the Yamaha motor yet? I've got one of those too and really like the way their motor responds.
 

·
Registered
Joined
·
399 Posts
Discussion Starter · #7 ·
...
Which OEM tires? Maxxis are pretty good where I ride in MA.

My oem reference was to the Powerfly with Bontrager Chupacabra TLR 27.5x2.80 tires. What I wrote is so terse, the missing details are not obvious. Sorry.

That very-round tire profile with a its raised-spot pattern works GREAT in most conditions. Pump 'em up & rolling resistance should be low if roading. Nice big contact patch, if it finds something to bite.

My initial lack of trust comes from my local trails. When dry, its a thin layer of loose dirt on hard pack. Very skatey if the tread don't cut thru loose & bite the hard. When wet, the clay fills those large open areas in the first revolution. 2nd revolution & beyond its sticking to itself & you are on Mr. Toad's Wild Ride until your front tire locks. Wheee!

Today, those tires worked well on the sticky hero dirt 4 days after last rain. When my Minion HDR2s come in, I'll go tubeless & be ready for normal conditions.

Thanks for the interesting review. My off road excursions are mainly on a DIY BBS02 hardtail with rpm PAS; learned pretty quickly not to enter a switchback too fast.

Yes, its taking a lot of practice to learn & stay balanced! The trick appears to be as little assist as you really need. Which means maybe shifting & reducing assist for each switchback. Handlebar-mounted assist control seems necessary for old or tired riders using higher assist levels normally.


My surging complaints about the TL-Brose PAS sound worse than they really are. AND I learned today that the PF-Bosch can be as surge-y as the TL-Brose when in Turbo assist, lowest gear, and riding a rough cow-pocked trail. The torque multiplication of the low gear makes the turn-on acceleration of the motor will WAKE you right up!

It was the older Bosch Performance Line PAS on the LaPierre that was the smoothest in Turbo mode, not the PF-Bosch. Sorry.



Anyway, I tested the Powerfly again yesterday to be sure of things. It tried to follow me home. Actually it failed my brutal steep-paved-downhill with rear-brake-only test twice more. So its repeatable. Requires a lot of applied force.

At normal temps I could easily lock rear tire. But when hot the lever stopped same place, but NO SLOWING with rear only! Once it cooled off, it worked normal again. Hmmm...

When I returned it to the shop I said we need to talk about rear-brake upgrades & end-of-year discounts. They said OK and made me a cup of coffee. :) After a round of negotiations, I got an XT rear disk installed & a nice discount.

Rode it home today, put my good seat on it, and headed to some local FUN trails! No brake problems at all this afternoon!

I'll continue this NEW EMTB announcement after a good ride & some photos tomorrow. Time to CELEBRATE!!! :)

Catfish ...
 

·
Registered
Joined
·
254 Posts
Love it! 57 year old Hightower and Soma-B-Side eMTB rider here. Debating on being the first to add electric to my Hightower because I love the bike so much, but would like (need?) the assist on climbing. The Hightower is a dream going down...

I've got my eye on the Focus Jam2 with built in extended battery option. Not sure if they are available yet in the US, but I know they are coming.

Can't wait to hear more about the "old fart" group out having fun!
 

·
Registered
Joined
·
25 Posts
Enjoyed reading your "fun" review. Love that ebikes allow you to dial in how much suffer you want taken out. I own the Bulls 27" myself. The Brose motor is amazing.


Sent from my iPad using Tapatalk
 

·
Registered
Joined
·
397 Posts
The mission control app on the turbo levo lets you change the take-off speed regardless of torque setting (which is also adjustable).

Great post!
 

·
Registered
Joined
·
399 Posts
Discussion Starter · #12 ·
Love it! 57 year old Hightower and Soma-B-Side eMTB rider here. Debating on being the first to add electric to my Hightower because I love the bike so much, but would like (need?) the assist on climbing. The Hightower is a dream going down...
...
Can't wait to hear more about the "old fart" group out having fun
Thank you & everyone else for your nice replies & encouragement!

OMFG, if a Bosch CX PAS could just magically appear on my Hightower!?!

But it would take magic I suspect to mate to an existing carbon frame not designed for it. But I can almost get a woody just thinkin' about it! ;-)

I bought the Powerfly & put 116 miles on her the 1st week. After a little more suspension tuning & ergo adjustments, you won't be able to get me off cloud 9!!! :)

A crappy video of 3 slow old farts with their new eMTBs on New Years Day!



Catfish ...
 

·
Registered
Joined
·
254 Posts
Thank you & everyone else for your nice replies & encouragement!

OMFG, if a Bosch CX PAS could just magically appear on my Hightower!?!

But it would take magic I suspect to mate to an existing carbon frame not designed for it. But I can almost get a woody just thinkin' about it!
Here's a little teaser for your dreams... :eekster:

 

·
Registered
Joined
·
208 Posts
what you got going on there?? I have a bfang mid drive on my full suspension bike and absolutely enjoy it, but the bike is a older motobecane I am looking to add another mid drive on a much nicer mountain bike and looking for options. I believe a bfang would hang way to low on that bike. I have herd different reports on doing this to carbon bikes, but I would if I knew it can be done successfully
 

·
Registered
Joined
·
1,406 Posts
A BBS02 has been fitted to some carbon bikes but, in general, the thickness of the bottom bracket presents a problem. The Cyclone series of motors may be a more feasible option, but the light weight of carbon over aluminum is somewhat minimized with a motor. Look at the Surface 604 carbon hardtail; it uses a (Castelli, I think) mid-drive installed in the BB AFAICT.
 

·
Registered
Joined
·
208 Posts
A BBS02 has been fitted to some carbon bikes but, in general, the thickness of the bottom bracket presents a problem. The Cyclone series of motors may be a more feasible option, but the light weight of carbon over aluminum is somewhat minimized with a motor. Look at the Surface 604 carbon hardtail; it uses a (Castelli, I think) mid-drive installed in the BB AFAICT.
thanks for the info, that's what I was thinking about the carbon thanks for the confirmation on that, the good thing is they make some really nice aluminum bike as well.

then issue is a lot of the new mountain bikes have that curve in the frame next to the BB making ground clearance a little lower then if tube went into the BB straight like they all used to do. concerning the middrive mounting place
 

·
Registered
Joined
·
254 Posts
YIKES! Let me know where your build thread will be, as I wanna watch!
Right now it is more of an experimental exercise in seeing if an eMTB can be created that only uses pedal assist when climbing and “feels” like a normal MTB when the power is turned off. Focus E-bikes seems to be on the forefront of trying to produce an eMTB that “feels” more like a normal MTB. Their Jam 2 is very interesting and the prototype Project-X is really neat.

So far I have a dual chainring mount for the Race Face crankset and a free wheel sprocket for the motor. That will allow the bike to be pedaled without power while only turning the second chain to motor and small free wheel. A throttle based variable assist will be used only when climbing assistance is needed. Because of that, I can run a very small and light weight battery. If it all works out in that configuration, then I can think about replacing the crankset with a freewheeling one that doesn’t require you to turn the second chain when power is off.

It’s kind of a love-hate relationship when it comes to adding a light weight mid-drive to a CS Hightower. Everything about the bike is great for my style of riding, but I can certainly use the assist when climbing and I’m not getting any younger.

My stock Hightower XL 29er weighed in at just under 30lbs. If I can keep the additional weight of all the E-assist components under 10lbs. it might not feel that bad pedaling it without power, plus if I design the BB to bottle nuts mounting bracket right, hopefully the motor can be easily removed along with the battery to have the blissful Hightower human powered ride anytime I want.

I will let you know if I follow through with this little experiment…
 

·
Registered
Joined
·
169 Posts
I gathering info to purchase my first pedal assist e-mtb.
The only bikes I have demo'd so far are the Turbo Levo ($4500 model, I would want the dropper post model) and then the Trek Powerfly 8 FS ($5000) and that was both on the street.
I rode the TL months ago and the PF 2 days ago so it is hard to make a comparison of the motor performance.
My first reaction was i would not like to be with out the left thumb power assist switch like the PF 8 has.
The Specialized dealer said that handle bar power assist control was not needed.
I can see how reducing the assist when negotiating switch backs could be a big plus considering how strong the PF 8 assist came on at low cadence in turbo mode.
I do not remember how the Brose motor responded in comparison to the Bosch.
It is also good to know your groups experience with the PF brakes and tires since the only reason to go up a hill is to come down.
I was wishing that both bikes would have at least 150mm suspension travel.
I am hoping to demo A Haibike with the Bosch motor in a few weeks.
Haibike has an All mountain 7 series with the Bosch and 150 mm of travel and 3.0 tires if I have the facts correct.
So if you do not mind some questions here goes.

1 Is there a clear cut preference between the Bosch and Brose motors?

2 Which bikes are getting the Shimano motor or are they out yet.

3 I noticed the PF 8 has a slight over run when you stop pedaling. Is that an issue or only when about to go over a cliff?

4 I have been riding dirt bikes for 50 years and feel the more suspension travel the better. Should that be a consideration when choosing between the PF-130mm, the TL-140 mm and the Haibike 150mm ?

5 I wish the Haibike with the Bosch did not have that idler sprocket to route the chain. It seems that idler would cause extra drag, maintenance and less chain wrap around an already small front sprocket. Any comments.

6 Seems like the Bulls bikes with the Brose motor have the power assist control on the handlebar. If that is so could the TLevo with the Brose motor be retrofitted with a handle bar power control?

7 Is the proprietary battery issue with the Brose motor a good reason to go with Bosch?

I appreciated and enjoyed the comparison info you shared.

Thanks for your consideration.
I will plan on buying a bike soon but need your experience to direct me to the right one.
I feel that buying these e-bikes is like buying a computer that will no longer be the latest and greatest in 6-12 months.

Herman
 
1 - 20 of 40 Posts
Top