FS Conversation advice

[gazzabartman]

Hello All,
I’m trying to get ideas and parts together for a conversion of my 2007 specialized enduro FS,
I’ve been looking at previous posts and it appears that rear hubs are mentioned more than CD, is that the case for full suspension?
Mostly used for trails, canal paths and a few hills around Rivington (Bolton)
The frame triangle is pretty small but I’m tempted to have a go at building something, I’m an electrician and I have got access to a couple of hundred 18650s which are two or three years old from medical equipment.
Hoping the above is enough information to get some advice.
Thanks everyone.

 

[peter.c]

Converted a specialized fs with a bafang 750watt mid drive and a triangle battery, just had to make a anti turn bracket will try and find a pic

 

[vfr400]

It's fairly easy to make a battery case out of 3mm plywood, then cover it in the really thin firbreglass cloth before painting.

Either a crank motor or hub motor would work. A hub-motor is better if you want to use your bike as general transport. A crank motor is better for off-road and sporting use.

The BBS** will be angled downwards because of the shape of your frame, so ground clearance isn't going to be fantastic for serious off-road use. It looks like you have a standard Hollowtech BB, so fitting should be very straight forward.

There's a bit more involved to fit a rear hub-motor, but the work pays off in the long term if you use your bike for general transport, commuting, etc.

 

[gazzabartman]

Thanks for the info, I don’t use the bike for anything other than leisure, would the Bafang 36 volt bbs001 be suitable? And would the standard display give enough information of the battery state etc.
Cheers

 

[vfr400]

Thanks for the info, I don’t use the bike for anything other than leisure, would the Bafang 36 volt bbs001 be suitable? And would the standard display give enough information of the battery state etc.
Cheers

Everything is suitable. It depends what you want. Lots of people on this forum use BBS** motors and seem to be very happy with them. Personally, I don't like them at all, so, for me, I'd say not suitable! I don't like the clunkiness and the frantic gear-changing all the time.

I find a hub-motor more use-friendly, cheaper, more reliable and lower running costs. A crank-motor has the advantage of being able to give high torque at low speed and give good power at high speed. You have to choose a hub-motor more carefully to get the right power characteristics for your particular ride.

 

[Moto]

I fitted a BBS01 to an older Specialized FSR and it is brilliant, in my mind! Done nearly 2000 miles in the last year.
Main problem was the battery as my shock is in a different position and the standar battery wouldn't fit. I used a bottle battery at first stuck on the seat post, which worked surprisingly well. But check your inner triangle space carefully as that is the best place to fit a battery.

What I really like is how quiet the motor is, you don't hear it at all normally.

I would like to try some hub motors as I'm curious how well they would work off-road, I don't have any huge hills round here but sometime you want to go slow but with plenty of power if the trail is rough and steep for example, the crank drive in a low gear obviously works well then.

 

[Woosh]

if you want to have a BBS01 with seat post battery like Moto's - I have the kit in stock. BBS01B + 13AH small frog battery.

 

[gazzabartman]

My neighbour has a fitted a whoosh kit a couple of weeks ago, I will try to measure his standard In frame battery to double check it definitely won’t fit in my frame, the chamfered top of your battery looks like it would help get it in?

 

[gazzabartman]

I fitted a BBS01 to an older Specialized FSR and it is brilliant, in my mind! Done nearly 2000 miles in the last year.
Main problem was the battery as my shock is in a different position and the standar battery wouldn't fit. I used a bottle battery at first stuck on the seat post, which worked surprisingly well. But check your inner triangle space carefully as that is the best place to fit a battery.

What I really like is how quiet the motor is, you don't hear it at all normally.

I would like to try some hub motors as I'm curious how well they would work off-road, I don't have any huge hills round here but sometime you want to go slow but with plenty of power if the trail is rough and steep for example, the crank drive in a low gear obviously works well then.

That looks good, does it bounce loose if you’re going over rough ground?

 

[Woosh]

My neighbour has a fitted a whoosh kit a couple of weeks ago, I will try to measure his standard In frame battery to double check it definitely won’t fit in my frame, the chamfered top of your battery looks like it would help get it in?

the standard in frame battery measures 361mm L x 90mm W x 92mm H.
You can try with a piece of cardboard. One of my customers put the battery in a triangle bag.

 

[Moto]

That looks good, does it bounce loose if you’re going over rough ground?

I did find the bottle battery vibrated a lot and found a good solution having it rest against a mudguard as per pic below.

I don't ride particularly rough trails but with an electric motor fitted it is easy to travel at quite a brisk pace and hence any bumps hit harder. I do feel that seat post mounted batteries are perhaps better suited for road use unless you ride at a relatively gentle pace.

 

[gazzabartman]

I’ve bought and received the kit and am looking forward to fitting it hopefully this weekend, I checked my frame and the standard battery does fit in but not with enough height to release it from the cradle, I’m hoping to create a foam lined bracket that will hold it in place.

 

[Moto]

When I upgraded to a conventional battery on the bike above I screwed a 5mm thick plastic mounting plate to the frame in the triangle and then mounted the batery holder on to that at a slight angle so it could slide in and out. Aesthetically it did not look good but I had plenty of clearance for my feet and legs and worked perfectly!
No photos unfortunately and have since swapped this kit onto another bike....

 

[Lumr002]

I went with the TSDZ2 motor on my Enduro which I feel is better for technical riding as you have more control when applying power. I havea medium Enduro frame and could not fit a shark battery so I ordered a small wolf pup type battery and made my own on-off switch. See pic

 

[vfr400]

You need to take off the cranks to check whether a crank drive would fit. With the emphasis more on trails than tarmac, a mid drive might be better because the mass of hub-motors affect the suspension a bit.

Regarding the battery, it's quite a lot of work to make one, so you need to consider whether you want to compromise it by using used cells. Used cells are great for experimenting with, but I think that if you want to build a battery for a bike you're going to use a lot, it's worth paying extra to get the best cells available.

 

[vidtek]

You need to take off the cranks to check whether a crank drive would fit. With the emphasis more on trails than tarmac, a mid drive might be better because the mass of hub-motors affect the suspension a bit.

Regarding the battery, it's quite a lot of work to make one, so you need to consider whether you want to compromise it by using used cells. Used cells are great for experimenting with, but I think that if you want to build a battery for a bike you're going to use a lot, it's worth paying extra to get the best cells available.

I'm with VR400 on this, a DIY kit is not expensive, why compromise on a battery? Depending on what range you want to achieve, you could always buy a smaller cheaper but good quality battery and make yourself up a spare with your used ones. That way if you needed more range than the small battery provides you could stick it in a backpack bag and use when needed.

I bought a 15ah 48 v battery for my TSDZ2 mid-drive and I've never come even close to using it on a single ride. Mind you I rarely cycle more than 15-20 miles before my bum is screaming to get off this blasted saddle! I generally do about 10 mile cycle rides and charge the battery every 6-7 rides, but I have never managed to flatten it.