ebike kit for classic '95 Stumpjumper

[jonathanrugg]

Hi,

I've been interested in an ebike for a while and have decided to electrify an old '95 Stumpjumper; it's a pretty decent base bike, I'm upgrading a few bits like the headset and chainset and have a few questions:

1. I was looking at the Oxydrive system but it looks expensive at £850 next to the 8Fun rack system, which is currently on offer for £415.99. I appreciate the Oxydrive system has an attractive LiPo battery, a decent digital display and an well thought out cabling system but its there a convincing argument spending twice as much as the 8Fun system.

2. If I go for a standard rack setup for the battery (rather than bottle cage) will I easily be able to upgrade it in the future for something with better range, and is there a way I can connect batteries in parallel to boost the range when needed?

3. I'm going to by a new crank for the Stumpjumper, I'd really like to go for an Octalink Hollowtech option, will this be a real pain to fit the pedelec sensor to?

4. Other than the 8Fun kit is there anything else I should consider, ideally I'd like to be able to cruise at 20mph will great range, I don't mind spending £850 or more if the kit is materially better in these respects?

Thanks for the advice.

Jonathan

 

[rpurchon]

i have the 8 fun kit in 700c wheel. top speed 16mph with 36v bottle batt.
26" wheel will be a tad slower.
now gone to 48v 12s lipo and will go 20 mph top on flat.
i would buy the kit again as its a good starting point,and it works.
and you know what youre getting.re motor and batt and bits.

pedlec fitting. i epoxyed the magnets to chain wheel and epoxy sensor to frame
richard

 

[Deleted member 4366]

1 The Oxydrive kit has speed as well, It'll do 24mph max, but doesn't have any more power than the 8Fun kit. If you're light and your rides are mainly flat, you can get the speed advantage, but don't expect to cruise at 24mph: That's only with favourable conditions.
2 Doing it yourself you can choose whatever battery you want. You can connect batteries in parallell as long as they have the same voltage.
3. Octalink is OK,but you might have to make a spacer for the pedal sensor and you'll have to drill out the centre of the magnet disK.
4 The 20 mph is tricky. The problwm is to find a motor that goes at that speed as most are designed for about 18mph. I think the Ezee kit is the only one that can sustain 20mph, but you need to confirm that with Cyclezee. If you want to start with a bare motor, the Bafang CST would be a good contender. I'll be getting one in the next couple of days, so I'll be able to report on its performance soon.You need to be more specific about your range, but a Bafang CST and 20aH 36v battery will set you back about £500. Then you'll need rim, spokes,wheelbuilding and other stuff.
You can adjust the speed of any motor by using a higher voltage battery if you want to apply a bit more DIY.

 

[jonathanrugg]

Richard,

Thanks, so if I understand correctly you're still running the 8Fun kit bit have simply upgraded the battery?

Are there any constraints on this, could I select any battery or do I have to work within the constraints of the controller/motor?

Thanks,

Jonathan

 

[jonathanrugg]

d8veh,

20 mph isn't essential, but 15 mph is too slow, having tested 2 Giants and a Spencer Ivy (all 3 damn heavy beasts) I was still zipping along at mainly over 15mph and therefore not really feeling the benefit of the assist, which seemed to phase out after that. So I'm keen to get closer to 20mph, 18 mph would be fine I think, but I wouldn't want to drastically cut the range, as my commute is 22 miles each way.

Would be great to know how you get on with the motor, if I put together my wn components is there anywhere you would recommend I course them from?

Thanks,

Jonathan

 

[jonathanrugg]

Ahh the Cyclezee kit is geared... that is interesting! Thanks for the tip

 

[Deleted member 4366]

I get nearly all my bits from BMSBattery.com or Greenbikekit.com. They have similar products apart from the range of batteries, You get no warranty, but the stuff is cheap enough to replace, and I've never had anything fail out of about 12 motors, 20 controllers and 5 batteries. You can select a motor kit and then choose an appropriate battery to go with it. There's always a bit of DIY involved with fitting any kit.

 

[rpurchon]

yes same controler.but 16 cell lipo.i tryed soldering the shunt but it didnt like it.
throttle worked all the time then wouldnt work same with pas,so scraped all the solder off.
the caps in the controler are 50v same as lipos straight from charger but its still working after 300 miles
i have a 1.2 mile long hill to cycle home every day.with the bottle battery 10mph.
with lipos 15 mph.
another reason for going to lipos they are lighter 2 x 5000mah = 1.2 kg and about 12 miles.
bike now weighs 17 kg.
bottle batt 3 kg.but you can plug the charger in and walk away.
richard

 

[Cyclezee]

Ahh the Cyclezee kit is geared... that is interesting! Thanks for the tip

Hi Jonathan,

If is performance and reliability you are looking for and support from a UK supplier Cyclezee can help you.

Regards,

 

[Deleted member 4366]

yes same controler.but 16 cell lipo.i tryed soldering the shunt but it didnt like it.
throttle worked all the time then wouldnt work same with pas,so scraped all the solder off.
the caps in the controler are 50v same as lipos straight from charger but its still working after 300 miles
i have a 1.2 mile long hill to cycle home every day.with the bottle battery 10mph.
with lipos 15 mph.
another reason for going to lipos they are lighter 2 x 5000mah = 1.2 kg and about 12 miles.
bike now weighs 17 kg.
bottle batt 3 kg.but you can plug the charger in and walk away.
richard

Soldering the shunt wouldn't normally have any effect on throttle or pas function. It only changes the amount of current the controller allows to come from the battery. Are you saying that you were having cut-outs? These can be caused when the BMS of the battery won't allow the amount of curent that the controller's demanding, the controller goes over-temperature due to lack of cooling, or voltage sag in the battery causes the LVC to trip when the battery isn't strong enough to give the current that you're demanding. The normal bottle batteries are only rated at 10 amps,so they're already pressed with the 15 amp controller, so any shunt soldering with one of those would give problems, but with lipos you can go as high as you like.

 

[rpurchon]

throttle would not turn off same with pas.good job brake cut outs worked.
this was with lipos.removed solder, back to normal.
richard