Unanswered DIY Conversion question

[A_Centaur]

I am currently researching my rear drive hub options for an old (2007) Stumpjumper FSR Pro that I would like to convert. It currently has a Sram XO rear derailier and my dilemma is that most of the kits you can get online have a FREEWHEEL and 7 speed cassette, not a FREEHUB with the Shimano spline setup. I really want to keep my current setup because the Sram kit has lasted all these years and works perfectly. My desire is to install a 1000 - 1500 watt rear hub with disc brake and a freehub that will allow me to use the 9 speed derailier. I don't know if something like that is out there but I can't find it. If I have to, I can go with a lower wattage hub to get the clearance necessary but at this point, I'm just looking for the FREEHUB setup that will allow a 9 speed derailier. Anybody have any ideas?

 

[Al Boneta]

I am currently researching my rear drive hub options for an old (2007) Stumpjumper FSR Pro that I would like to convert. It currently has a Sram XO rear derailier and my dilemma is that most of the kits you can get online have a FREEWHEEL and 7 speed cassette, not a FREEHUB with the Shimano spline setup. I really want to keep my current setup because the Sram kit has lasted all these years and works perfectly. My desire is to install a 1000 - 1500 watt rear hub with disc brake and a freehub that will allow me to use the 9 speed derailier. I don't know if something like that is out there but I can't find it. If I have to, I can go with a lower wattage hub to get the clearance necessary but at this point, I'm just looking for the FREEHUB setup that will allow a 9 speed derailier. Anybody have any ideas?

We don’t get a lot of conversion discussions on this forum. In my shop we are prohibited from our insurance company from installing conversion kits. Especially when you consider what stresses a 1500w load will put on a frame not engineered to be an Ebike.

There’s also the legality of riding a bike with more than a 250w on a trail that’s only approved to type 1 bikes.

After having said all that, here’s my best advice:

Have you looked at a mid drive conversion kit instead of a hub drive?
The bike will handle a lot better and you can keep your stock rear wheel.
The reason you’re having a hard time finding a 9-speed hub drive motor is because most of these kits are pretty low quality. Most of the rims on hub drive conversion kits are pretty flimsy for riding off-road as well.

I know Bionx makes one, but the cost is almost as much as buying a complete Ebike.

Have you considered picking up a used Haibike, Bulls, powerfly
or Levo? With all of the newly anticipated 2019 Emtbs, you could probably pick one up on the cheap.

 

[Dax]

The issue I always found when looking at DIY builds was where to put all the batteries. Something like a giant with a lot of space in the middle triangle looks like the best bet.

I would go test ride a levo and see if you still want to ride an 07 stumpy, let alone electrify it.

 

[Doomanic]

I thought about converting my 2016 Mega, but ultimately it's just not worth the grief over a factory bike in my opinion.

 

[A_Centaur]

We don’t get a lot of conversion discussions on this forum. In my shop we are prohibited from our insurance company from installing conversion kits. Especially when you consider what stresses a 1500w load will put on a frame not engineered to be an Ebike.

There’s also the legality of riding a bike with more than a 250w on a trail that’s only approved to type 1 bikes.

After having said all that, here’s my best advice:

Have you looked at a mid drive conversion kit instead of a hub drive?
The bike will handle a lot better and you can keep your stock rear wheel.
The reason you’re having a hard time finding a 9-speed hub drive motor is because most of these kits are pretty low quality. Most of the rims on hub drive conversion kits are pretty flimsy for riding off-road as well.

I know Bionx makes one, but the cost is almost as much as buying a complete Ebike.

Have you considered picking up a used Haibike, Bulls, powerfly
or Levo? With all of the newly anticipated 2019 Emtbs, you could probably pick one up on the cheap.

I have no intention of taking this bike on the trails after the conversion. I am an avid mountain biker and I'm not ok with ebikes on the trails. I mainly wanted to do this as a fun project and something to tool around on. I appreciate all your advice and I'll definitely continue to look around before I actually put $$ down on a kit. I am completely open to different options including a mid drive kit. I have a 2018 Santa Cruz Tallboy CC that is my main MTB and I just didn't want the old Stumpy to end up hanging on the wall as an ornament.

 

[Dax]

I've ridden a bafang mid drive on a mid 90s rigid marin with an ammo tin full of batteries bolted into the triangle. It was a laugh, 30mph on the thumb throttle on tarmac and lots of wheelspin and wheelies on dirt. I'll definitely build one at some point, but it's unclear where I would use it, as it's illegal for most offroad use in the UK.

 

[Doomanic]

I am an avid mountain biker and I'm not ok with ebikes on the trails.

In general or because of the access issues? That is, if the access issues were resolved would you still be against eBikes on the trails?

 

[A_Centaur]

In general or because of the access issues? That is, if the access issues were resolved would you still be against eBikes on the trails?

I think it's because I've spent a lot of time and effort developing skill and conditioning which gives me ticket of sorts to enjoy the kind of speed and fun that I've earned over time to be able to ride at the level I have trained to. That doesn't mean that I don't think they should be out there at all because I think they have their place....like dramatically increasing your range on a discovery ride or being able to ride uphill at a venue where you'd normally take a shuttle to get to the top. I guess that my main concern are CC trails that can be ridden in both directions and that ebikes might take some of the fun out of them for unassisted riders.

Don't get me wrong, I'm all for the techy aspects of it and I love the idea of riding them. I just think we have to work out where they belong in the whole bike ecosystem so what is fun for some doesn't detract from fun for others.

 

[Doomanic]

what is fun for some doesn't detract from fun for others.

Doesn't that work both ways? Or do I have to "earn" my fun?

 

[ccrdave]

How can riding my bike minding my own business , not getting in anybodys way, and having fun detract from other peoples fun?

 

[Dax]

How can riding my bike minding my own business , not getting in anybodys way, and having fun detract from other peoples fun?

I guess if they got offended?

 

[khorn]

This is what I have built and its my daily ride to and from work, 70 km every day

The forum that can help you with your project is:
Home - Electricbike.com Ebike Forum

Btw my old Specialized is built with a 1000w mid drive and as a fact legal in Denmark. do yourself a favour and go for a mid drive instead.

Karsten

 

[Doomanic]

How can riding my bike minding my own business , not getting in anybodys way, and having fun detract from other peoples fun?

I guess if they got offended?

What have they got to get offended about? Surely it's all MTBing unless someone is being a dick (and there are dicks on both sides of the arguement)?

 

[Dax]

What have they got to get offended about? Surely it's all MTBing unless someone is being a dick (and there are dicks on both sides of the arguement)?

I was making a joke about the millennials who make a hobby of being offended. Im with @ccrdave on this one

 

[A_Centaur]

Doesn't that work both ways? Or do I have to "earn" my fun?

Please don't misunderstand me. I'm definitely on your side and I'm all for having e-bikes out there. I love the idea of increasing my range and saving my lungs on long climbs for the fun of the downhill. The main reason that I joined this forum in the first place is because I want to build one and enjoy the fun myself. Ultimately, I think it'll work out so that there may be trails designated for multi use and others that are for non-e-bikes only. Maybe based on visibility or something like that. I've heard that there are already places that are starting to do something like that. All I mean is that it is a very new thing to share the trails with e-bikes and there's a lot of details to figure out.

 

[A_Centaur]

This is what I have built and its my daily ride to and from work, 70 km every day

View attachment 4134

The forum that can help you with your project is:
Home - Electricbike.com Ebike Forum

Btw my old Specialized is built with a 1000w mid drive and as a fact legal in Denmark. do yourself a favour and go for a mid drive instead.

Karsten

Very cool setup. I've been hesitant about the mid drives because of the additional stress on a drivetrain intended for only leg power. I've heard that it's a good idea to get a stronger chain and other drive components if you want it to last. How many miles do you have on it so far? Has it been holding up for you?

 

[khorn]

Very cool setup. I've been hesitant about the mid drives because of the additional stress on a drivetrain intended for only leg power. I've heard that it's a good idea to get a stronger chain and other drive components if you want it to last. How many miles do you have on it so far? Has it been holding up for you?

Don't be concerned, I have about 1500 km on the new setup and the chain was not even new when I installed the middrive. My driveline is X0 originally 2X10 but now 1X10 with the Bafang. Secret to long lasting driveline is a gear cut off. Every time I change a gear, power is turned off and thats where accidents happen if you have 1000 watts on the chain.

Karsten

 

[A_Centaur]

Don't be concerned, I have about 1500 km on the new setup and the chain was not even new when I installed the middrive. My driveline is X0 originally 2X10 but now 1X10 with the Bafang. Secret to long lasting driveline is a gear cut off. Every time I change a gear, power is turned off and thats where accidents happen if you have 1000 watts on the chain.

Karsten

Ahhh....that makes sense. I have read that some e-bikes shifters will only change one gear at a time too. What 1X10 setup did you put on? You buy an entire drivetrain kit with shifter, cassette and derailier too?
I have a "vintage" 3X9 Sram XO setup on my bike now but I wouldn't be shy about changing it if the whole thing would work nicely. How about your speed limit? Does it limit you to 25kph?