Bench Grinder

[E-bike Gum!]

Hello, I'm new here & Yep! I've used a £30 bench grinder from Lidl to turn my ten-year-old hybrid bike into an electric bike!

250w, replaced the grinding stone(s) with a reversed free-wheel running via chain to the large sprocket (gear 1, which I've seldom used).
Power is derived from a 12v 20ah Scooter Battery running through an inverter. Controller is a pattress box with a floor lamp switch wired in. All held together by a load of Cable ties.

The intention was to help me tackle my 22 mile hilly commute, especially a 2 miler on the way back home, hence nominal assisted speed of 7.8mph & range of about 6 miles.
All in spent about £190 on everything (including some hand tools) and has been working pretty reliably for over 100 miles now (and plenty more not-so-reliable miles before that!).

Anyway, thoughts?

 

[Nealh]

You have gone the stealth mode and hidden everything .
Some more enlarged pics of your set up ?

 

[E-bike Gum!]

You have gone the stealth mode and hidden everything .
Some more enlarged pics of your set up ?

A side effect of trying to shelter the leccy bits from the Yorkshire Pennine weather

 

[E-bike Gum!]

 

[Nealh]

Oh my wow, it must be quite noisy and obviously quite heavy ?
It won't be everybody's cup of tea and certainly not mine, but that doesn't matter.
If it works for you then that is good enough.

Definitely an eccentric ebike and rider but that is good even I think I'm eccentric, life would be boring other wise.

 

[E-bike Gum!]

Haha, I've probably added about 9-10 kilos but now got it to the point where it's better to have it than not.....
And weirdly the most noise comes from the chain as it runs through the guides fashioned out of an old oven grill. It works though so daren't make any attempts at refining it and you can barely hear it when there's traffic about.
Already set my sights on 4 Headway 15ah cells to replace the lump of lead when it conks out (may be a while because I bought a decent quality one)

 

[Fat Rat]

Hi welcome to the site

Which one of the A Team are you ?

 

[vfr400]

When I was very young, we used to get a guy come round on a bike with a grinder on the back, who would sharpen knives and scissors. It wasn't you was it?

 

[E-bike Gum!]

Hi welcome to the site

Which one of the A Team are you ?

Mr Tea? And a real man uses blunt blades on his Dick Strawbridge-esque beard

The biggest challenge was working out how to attach the freewheel to the grinder's drive shaft. In the end, a small Allen key through a drilled hole in the drive shaft and a groove cut into a freewheel remover within the freewheel seems to have done the trick. Then rubber door stops tightly packed into the gaps.

 

[Fordulike]

Absolutely love it. That's what Pedelecs is all about

 

[Tarka]

It reminds me of the circular saw drive bike:

 

[ttxela]

Brilliant! What speed can you get out of it?

 

[JPGiant]

Brilliant, well done.

 

[E-bike Gum!]

Thanks guys The above pics were when it was geared 1:1. Nominal speed was 10.8mph and was fine for assistance on flat/very mild slopes. Since then, I've geared it down to the middle cog (3:4) making it more of a hill climber at 7.8mph.
I'm now wondering if I should've got a bigger battery. With the inverter, I've calculated it'll draw about 287.5W from 240W.

 

[Deleted member 25121]

Excellent, well done. What range do you get from your battery now?