question for the experts here.would it be okay to put a mac rear hub motor,1000 watt 6t on a alum frame 2011 dawes roundhouse 2500 full suspention mtb?bike is from bikesdirect.com.would use 2 torque arms and always pedal starting out so i would likely keep the amp draw fairly low.i am a aggressive pedaler and use the motor for headwinds and hills.any thing i should look out for?getting cold here in minnesota so will be a winter project.
alum. frame
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Drunkskunk
100 GW
While thats not a bike I would ever recommend, It should be fine with good torque arms.
Drunkskunk
100 GW
Those frames come as a knockdown kit from Taiwan for various companies to build into bikes. They aren't that great to begin with, and come with a pogo stick spring instead of a real rear shock. That might be fine for a budget build, and 4 link suspensions are very cushy to ride (if it had a real shock) But they are horrible for pedaling. One of the worst designs for pedaling efficiency.
If it were a real bike, with optimized geometry, you could tune it to work well enough for pedaling, if your riding style keeps you seated all of the time, including hill climbs. But it's not, and you can't, and since you like to pedal, thats going to be a miserable bike for you.
And it has a 27mm seat post. That's a size appropriate for kids, or lightweight road bikes. but I'd never take that thing off a curb fast. Its a bike frame designed to look cool, thats then been outfitted with some fairly acceptable components. (it has an actual rockskox front fork and shimano slx components. low end but not junk.) but those don't change the nature of the base frame being essentially a toy.
You can get a real bike used for that price. A Giant Trance, or Giant Anthem ought to go for around $500 used, and would be 10 times better.
If it were a real bike, with optimized geometry, you could tune it to work well enough for pedaling, if your riding style keeps you seated all of the time, including hill climbs. But it's not, and you can't, and since you like to pedal, thats going to be a miserable bike for you.
And it has a 27mm seat post. That's a size appropriate for kids, or lightweight road bikes. but I'd never take that thing off a curb fast. Its a bike frame designed to look cool, thats then been outfitted with some fairly acceptable components. (it has an actual rockskox front fork and shimano slx components. low end but not junk.) but those don't change the nature of the base frame being essentially a toy.
You can get a real bike used for that price. A Giant Trance, or Giant Anthem ought to go for around $500 used, and would be 10 times better.
Drunkskunk
100 GW
Big Dummy is a Nice bike! Have you considered electrifying it?
nuevomexicano
100 W
I recently converted a Dawes Roundhouse 2500 to an ebike. Mine is a much smaller sized motor (500W geared with 48V LI ion battery) than you're proposing. I use a single torque arm from Amped Bikes. So far there's no problems with it electromechanically in the 200 or so miles I have on it.
I'm not entirely sure why it isn't a good bike to convert in some people's minds. I'm really happy with the full suspension as I have a 12 mile commute that includes some genuinely rough roads and a few blocks of unpaved trails along with the typical bike lanes. Full suspension is much better than my previous front-only suspension converted into an ebike. The Roundhouse's Dart 2 front shock is fine with decent dampening compared to most any department store bike and lots of lower end bikes from actual bike shops. The rear suspension is nothing special, but also nothing worthless. It doesn't pogo stick/bounce around on me. I feel it smoothing out the bumps on my spine and keeping the wheel on the road for better handling. The geometry of the suspension is excellent compared to most Y-style bikes and the slightly heavier weight is negligible when it comes to converting to electric. Its not a $1200 bike, but it is better than many of the name brand bike you'll find for about $200-300 more. I have indeed taken it off curbs (before the conversion to electric) and it does fine. But I'm not expecting it to be a bike I huck off cliffs. I want suspension on my on my bike to act like the suspension I've had on motorcycles and scooters, neither of which I rode off jumps.
The disk brakes are fine for their price and much better than any bike I've owned with rim brakes. The shifters and derailuers are excellent, though I tend to only use 1 or 2 gears since its electric. The frame is solid. The fact that the shifters and brake handles are separate components make for a much easier mounting of a throttle compared to bike with them in a single pod. Many of the similar priced name brand bikes have such a set up.
The downsides are typical of any full suspension ebike. Where to mount a battery is the basic concern with any full suspension bike. Your choices for a beefy rear rack are limited compared to a hard tail. Right now I've got the battery and controller in a rear bag on seat post mounted rack. That hasn't been a problem since the weight of it all is less than 12 pounds. But I'm considering trying out a front bag for the battery just to compare handling. The Roundhouse doesn't have a lot of space in the frame for batteries. But I've been pleasantly surprised that the battery on seat post rack is no big handling problem.
Overall, you can find cheaper priced used bikes on Craiglist in most places. And you can spend more (a lot more) and get a new or used downhill mountain bike with more suspension travel and higher end shocks. But you'll have trouble finding a new bike at a sporting goods store or bike shop with the same components and frame for the same price at the Roundhouse 2500. And most everything I've heard about repairs and warranties has been positive. I've owned a lot of bike over the years and the Roundhouse is a decent bike at a decent price. You can easily spend more and get very little more for your money.
I'm not entirely sure why it isn't a good bike to convert in some people's minds. I'm really happy with the full suspension as I have a 12 mile commute that includes some genuinely rough roads and a few blocks of unpaved trails along with the typical bike lanes. Full suspension is much better than my previous front-only suspension converted into an ebike. The Roundhouse's Dart 2 front shock is fine with decent dampening compared to most any department store bike and lots of lower end bikes from actual bike shops. The rear suspension is nothing special, but also nothing worthless. It doesn't pogo stick/bounce around on me. I feel it smoothing out the bumps on my spine and keeping the wheel on the road for better handling. The geometry of the suspension is excellent compared to most Y-style bikes and the slightly heavier weight is negligible when it comes to converting to electric. Its not a $1200 bike, but it is better than many of the name brand bike you'll find for about $200-300 more. I have indeed taken it off curbs (before the conversion to electric) and it does fine. But I'm not expecting it to be a bike I huck off cliffs. I want suspension on my on my bike to act like the suspension I've had on motorcycles and scooters, neither of which I rode off jumps.
The disk brakes are fine for their price and much better than any bike I've owned with rim brakes. The shifters and derailuers are excellent, though I tend to only use 1 or 2 gears since its electric. The frame is solid. The fact that the shifters and brake handles are separate components make for a much easier mounting of a throttle compared to bike with them in a single pod. Many of the similar priced name brand bikes have such a set up.
The downsides are typical of any full suspension ebike. Where to mount a battery is the basic concern with any full suspension bike. Your choices for a beefy rear rack are limited compared to a hard tail. Right now I've got the battery and controller in a rear bag on seat post mounted rack. That hasn't been a problem since the weight of it all is less than 12 pounds. But I'm considering trying out a front bag for the battery just to compare handling. The Roundhouse doesn't have a lot of space in the frame for batteries. But I've been pleasantly surprised that the battery on seat post rack is no big handling problem.
Overall, you can find cheaper priced used bikes on Craiglist in most places. And you can spend more (a lot more) and get a new or used downhill mountain bike with more suspension travel and higher end shocks. But you'll have trouble finding a new bike at a sporting goods store or bike shop with the same components and frame for the same price at the Roundhouse 2500. And most everything I've heard about repairs and warranties has been positive. I've owned a lot of bike over the years and the Roundhouse is a decent bike at a decent price. You can easily spend more and get very little more for your money.
nuevomexicano
100 W
Drunkskunk said:
I have yet to find such a bike in my area for a used price of $500. They're most often asking near $1000.00, which is a lot for a used bike that's going to be converted to electric and very well may have been ridden hard.
Also, I find your "real" bike concept fairly insulting. The Roundhouse isn't a toy. It isn't a downhill race bike, but not all bikes are meant to be that kind of machine.
A picture of the rear dropouts would help. Some bikes have strong dropouts with a nice flat surface for making a torque plate work out.. some have bizarre origami designs that would require 3D CAD designs to make something work.. :|
I have two aluminum trek bikes from mid 2000's and they have disc brake holes in the rear. I've used those holes to attach a thick steel torque plate to. Ran 4000w through them repeatedly with the MAC motor and a DD hub and the dropouts are still in fantastic shape.
The main reason i went with this chassis is the simple and flat rear dropout shape.
I have two aluminum trek bikes from mid 2000's and they have disc brake holes in the rear. I've used those holes to attach a thick steel torque plate to. Ran 4000w through them repeatedly with the MAC motor and a DD hub and the dropouts are still in fantastic shape.
The main reason i went with this chassis is the simple and flat rear dropout shape.
nuevomexicano
100 W
neptronix said:
From the Bikes Direct website:
Oh man.. 
+ Weak rear disc mount surface as it has holes in it and isn't solid.. won't handle too much power.. also the distance from the dropouts to the disc brake seems quite far. You could make a decent plate that would work here, but i'd guesstimate that ~2000w would be a safe limit. If you're gonna run a MAC motor, the 6T 1000w would be best as it doesn't kick out too much torque.
+ On the derailleur side, forget about a plate there. You could use something like an ampedbikes torque arm to add some support/insurance there.
And for a front motor, that Rockshox Dart 2 is also a sorta weak fork.
I see the appeal of the bike as it's a cheap dual suspension with half decent parts. But it's definitely going to limit the power you can run through the rear axle.
+ Weak rear disc mount surface as it has holes in it and isn't solid.. won't handle too much power.. also the distance from the dropouts to the disc brake seems quite far. You could make a decent plate that would work here, but i'd guesstimate that ~2000w would be a safe limit. If you're gonna run a MAC motor, the 6T 1000w would be best as it doesn't kick out too much torque.
+ On the derailleur side, forget about a plate there. You could use something like an ampedbikes torque arm to add some support/insurance there.
And for a front motor, that Rockshox Dart 2 is also a sorta weak fork.
I see the appeal of the bike as it's a cheap dual suspension with half decent parts. But it's definitely going to limit the power you can run through the rear axle.
dogman dan
1 PW
Rockshocks dart is a poor fork for a motor mount. The allen screw on the bottom interferes with the torque arms. You can notch the arms and make it work. but it's also more narrow between the tubes than some forks, so some motors will never fit. 9c motors will though.
In the cheap fs bikes, my favorite remains the mongoose blackcomb, that you buy shipped to store at wallmart, if you are in the us. Nice steel rear dropouts.
In the cheap fs bikes, my favorite remains the mongoose blackcomb, that you buy shipped to store at wallmart, if you are in the us. Nice steel rear dropouts.
Yeah, but the mongoose weighs a ton and has no triangle space for batteries.. will require custom mounting to work.. and the rear suspension design leaves something to be desired.
Solid, but has it's problems.
The dawes 2200 is worth looking into, seems to have a different rear setup. I can't find pics of the dropouts though
Solid, but has it's problems.
The dawes 2200 is worth looking into, seems to have a different rear setup. I can't find pics of the dropouts though
Finally found a proper review of the 2500.
http://forums.mtbr.com/all-mountain/dawes-roundhouse-2500-a-691964.html
edit: yeah seems to be ~35lbs, which is 11 pounds lighter than the mongoose blackcomb.... and it's got triangle space.
A bit more $, but i think we found another value champion in DS bikes here.
http://forums.mtbr.com/all-mountain/dawes-roundhouse-2500-a-691964.html
edit: yeah seems to be ~35lbs, which is 11 pounds lighter than the mongoose blackcomb.... and it's got triangle space.
A bit more $, but i think we found another value champion in DS bikes here.
Chalo
100 TW
Drunkskunk said:
For what it's worth, 26.4mm to 27.2mm seatposts have been standard issue on mountain bikes since the beginning. Maybe you're thinking of 22.2mm?
Back when I weighed 400 pounds, I used a 27.2mm Thomson seatpost in my Surly 1x1 MTB with over 10 inches of post showing. It never bent or gave me other problems (though lesser seatposts did at other times).
Even a scrawny 13/16" (20.6mm) post like that of an old Chicago Schwinn is plenty strong if the extension is kept very short. That's just a matter of using a tall frame to minimize standover clearance.
I agree with you that a cheap full-suspension bike is most likely a bad choice, both generally and for powered conversions specifically.
Chalo
27mm is kinda bad, i'll agree..
But.. get an extra tall frame that doesn't require extending the seatpost out by more than half a foot and you'll be OK even if you're a heavier fella.
As for the bike, the frame may be quite light actually. I recognize some of the components on there, and they are quite heavy, particularly the front chainring/cranks. 3-5lbs could fairly easily be shaved off the bike. Looks like the rear shock can be replaced with a variety of shocks as well.
But.. get an extra tall frame that doesn't require extending the seatpost out by more than half a foot and you'll be OK even if you're a heavier fella.
As for the bike, the frame may be quite light actually. I recognize some of the components on there, and they are quite heavy, particularly the front chainring/cranks. 3-5lbs could fairly easily be shaved off the bike. Looks like the rear shock can be replaced with a variety of shocks as well.
Drunkskunk
100 GW
Chalo said:
Yes, but you had a Thomson. Most of those are machined out of a single Billit of high grade 7000 series aluminum, instead of some rolled tube of questionable grade. you won't find high end quality like that in this price range.
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