Electric bicycle

[DrNick]

I've converted an old bike to electric by fitting a motorised front wheel. Its great and is limited to 12 mph which is fine - it takes all the hassle out of hills.

Thats all fine but I can actually pedal faster than this, but even so parts of my daily commute mean that I could go faster if only I had a higher gear. (My legs won't go round fast enough!)

I thought I'd ask the fount of knowledge here if they know if its possible to change the gearing so the top gear is higher.


Its a standard 18 speed Shimano (6 at the back, 3 at the front). The gearing is nothing to do with the electric bit - that is just a motorised front wheel with its own speed control.

Any bike experts here?

 

[Darrell]

I've converted an old bike to electric by fitting a motorised front wheel. Its great and is limited to 12 mph which is fine - it takes all the hassle out of hills.

Thats all fine but I can actually pedal faster than this, but even so parts of my daily commute mean that I could go faster if only I had a higher gear. (My legs won't go round fast enough!)

I thought I'd ask the fount of knowledge here if they know if its possible to change the gearing so the top gear is higher.


Its a standard 18 speed Shimano (6 at the back, 3 at the front). The gearing is nothing to do with the electric bit - that is just a motorised front wheel with its own speed control.

Any bike experts here?

With 18 gears I’m sure you can find the sweet spot but can you tell me the amount of teeth on the fronts and back.

My race bike is 52-36 on the front and 11-28 on the back which is more than quick enough and I’ve seen 55km on just a mild slope. If I’m doing something hilly I’ll change the rear cassette to a 11-32.

 

[Darrell]

 

[MikeInWimbledon]

Thats all fine but I can actually pedal faster than this, but even so parts of my daily commute mean that I could go faster if only I had a higher gear. (My legs won't go round fast enough!)
I thought I'd ask the fount of knowledge here if they know if its possible to change the gearing so the top gear is higher.
Its a standard 18 speed Shimano (6 at the back, 3 at the front). The gearing is nothing to do with the electric bit - that is just a motorised front wheel with its own speed control.

Certainly possible but not necessarily economic.

As Darrell says, count the gearing on front and on the cassette.

It would help to know which Shimano groupset it is. (Your most likely to be on Tiagra but 105 / Ultegra and Dynace are other famous ones), and maybe the spec of the bike - just to understand the overall balance of the thing. (No sense in spending hundreds on a new groupset if it's worth more than the value or brakes of the bike, unless its a much loved bike.)

 

[BTB 500]

If the electric motor drives the front wheel directly then to go faster under power you would need to modify that. If you could somehow raise the gearing on the electric drive to go over 12 mph then you might find it would struggle to get you up hills. Does the electric drive incorporate a freewheel e.g. for going downhill?

If there is a freewheel then you must surely be able to select a gear that will allow you to pedal at over 12 mph?!

 

[DrNick]

Thanks everyone for your input. I suspect some of you may be appalled at the pictures that follow (the cycling style police should probably have words with me) but it is basically a bike pulled from a skip with an electric motor strapped to it.
So this is what we are working with. Ignore the electrics for a minute. How do I increase top gear?

With the electric it basically now has only two gears- first for starting and 18th for moving.

 

[MikeInWimbledon]

Simples. Count the gearing on the front and on the 6th.

Then check Ebay, skips, FB marketplace or skips for something with higher gearing.

Your Apollo Slammer is only worth £20 to £50 max, so there's little sense in buying new gears. (And £50 would be something serviced and in perfect condition)

There's nothing to be defensive about in using an old bike. They're less likely to be stolen and they do the runaround job well enough.

I'm wondering whether the weight of battery is going to slow you down in going over 12 mph. So much so that I wonder whether you should just "go with the flow," and not bother with that extra turn of speed.

 

[grober]

WHAT MODEL /MANUFACTURER is your motorised wheel-they may able to advise----however they may be regs/speed legal restrictions which may prevent them from revealing details

 

[neilrr]

Is this now a motorised vehicle requiring insurance, registration etc, a bit like a moped does?

 

[ALFAitalia]

Nope.....Not up to 15.5mph or 25kph

 

[DrNick]

Ok I'll count the teeth and see what is available on ebay (and decide if its worth the effort)

Just to say that even converting an old bike has transformed the riding experience. If I was doing it again I'd do it slightly differently, but this was an old kit I bought in 2011 when the idea was new and there wasn't much choice. The position of the battery is inconvenient in this case and a tubular battery mounted lower on the frame is a better idea. There are many solutions now and connections appear to have become more standardized so you can pick and choose your bits - its is expensive though.

Although the bike is geared electrically to a maximum of 11 or 12 mph (changing this for this old motor is not realistic although I could overvoltage it), it does make it easier to pedal the bike faster than this, and I find that even in 18th gear, I feel I have the strength to go faster but I cant cycle that fast, hence the enquiry. I am actually quite satisfied with the bike in reality as it makes hills go away (which is a big plus)

 

[ss201]

To be blunt...... stick with what you've got. It's a cheap and cheerful bike (they don't come any cheaper), it ain't broke, and it does the job. If you're absolutely determined to go faster, change the crank set up for a triple chainset with a bigger outer chainring - but then you'll need to make sure the front derailleur can cope with it - it may do, it may not. Alternatively, a replacement 6 speed freewheel with less teeth on the small sprocket will raise the top gear - but either way you'll need the correct tools for the job.......

So to be blunt (again!), leave well alone and just enjoy riding it. While you're doing it, think of the petrol money you're saving on your daily commute and enjoy the health benefits.

 

[DrNick]

Completely and absolutely the right answer! No question.
Except I like to tinker (hence the bike in the first place) and this is an opportunity to learn something about bikes.
I am going to leave it as it is for the moment but once the weather closes in and it gets rainy I may revisit this, and also look to step the battery voltage up. I notice Amazon are offering some 36 to 48 volt step up converters that would survive the power for £15….
Thanks for all the good advice and opinions.

 

[Darrell]

To be blunt...... stick with what you've got. It's a cheap and cheerful bike (they don't come any cheaper), it ain't broke, and it does the job. If you're absolutely determined to go faster, change the crank set up for a triple chainset with a bigger outer chainring - but then you'll need to make sure the front derailleur can cope with it - it may do, it may not. Alternatively, a replacement 6 speed freewheel with less teeth on the small sprocket will raise the top gear - but either way you'll need the correct tools for the job.......

So to be blunt (again!), leave well alone and just enjoy riding it. While you're doing it, think of the petrol money you're saving on your daily commute and enjoy the health benefits.

Exactly this. If you start dicking about too much it’ll just create more problems.

 

[Darrell]

Completely and absolutely the right answer! No question.
Except I like to tinker (hence the bike in the first place) and this is an opportunity to learn something about bikes.
I am going to leave it as it is for the moment but once the weather closes in and it gets rainy I may revisit this, and also look to step the battery voltage up. I notice Amazon are offering some 36 to 48 volt step up converters that would survive the power for £15….
Thanks for all the good advice and opinions.

Where did you buy the original kit from? I fancy some tinkering.

 

[ChipChop]

Changing only one part of the drivetrain on a bike can cause issues due to different levels of wear on chainrings, cassettes, jockey wheels and chains. Only sure fire way to ensure no slip when pedalling is to change the lot. Quite a lot of expense.

From the pics of your bike the front chainrings look to not be replaceable, as in they look to be riveted as opposed to fixed using allen key bolts. If that is the case replacement would mean a new/ unworn secondhand (hens teeth) chainset. Square taper to fit your exisiting bottom bracket.

If you are not getting any slip when exerting force on the pedals (going uphill for example) currently i would leave things as they are. Longer term possibly consider buying a more modern bike second hand to fit you electric motor set up to.

 

[Darrell]

Changing only one part of the drivetrain on a bike can cause issues due to different levels of wear on chainrings, cassettes, jockey wheels and chains. Only sure fire way to ensure no slip when pedalling is to change the lot. Quite a lot of exp

When I change my cassette I need to swap the chain.

The OP’s groupset is really at the cheaper end of the market so it’s not really made to be adjustable.
I’d be leaving it alone.

 

[PaulXC]

Where did you buy the original kit from? I fancy some tinkering.

I've done a couple of e-Bike conversions. We carry these around on the bike-rack of our Camper truck so we have some something to scoot around on when parked up.

The first one was really straightforward using the front wheel motor Swytch kit added to my wife's ten-year old bike. Took about an hour to do the whole conversion. Just replace the front wheel and wire it up. Think Ikea level of constructional skills required to build it.

It's neat, works well and very simple to use. The battery unclips so when parked up so it's less valuable to steal.





Second one was for me, I bought a half price bike in the GoOutdoors sale, which is a susprisingly good piece of kit for the £300 I paid. I already had a 36v 500w battery as it's the range extender battery I use on my big, proper e-mountain bike.

I then purchased a Tongsheng mid drive motor for £225 and installed it. Easy enough to do but I did end up having to buy various specific bike tools for pulling crank arms etc.

This conversion requires a bit more it then way of mechanical skills to build but there are plenty of builds on Youtube to follow.

Converting an old bike is great value for money compared to an new, off the shelf eBike and also they are nice things to build.

 

[Darrell]

I've done a couple of e-Bike conversions. We carry these around on the bike-rack of our Camper truck so we have some something to scoot around on when parked up.

The first one was really straightforward using the front wheel motor Swytch kit added to my wife's ten-year old bike. Took about an hour to do the whole conversion. Just replace the front wheel and wire it up. Think Ikea level of constructional skills required to build it.

It's neat, works well and very simple to use. The battery unclips so when parked up so it's less valuable to steal.

View attachment 128558

View attachment 128559

Second one was for me, I bought a half price bike in the GoOutdoors sale, which is a susprisingly good piece of kit for the £300 I paid. I already had a 36v 500w battery as it's the range extender battery I use on my big, proper e-mountain bike.

I then purchased a Tongsheng mid drive motor for £225 and installed it. Easy enough to do but I did end up having to buy various specific bike tools for pulling crank arms etc.

This conversion requires a bit more it then way of mechanical skills to build but there are plenty of builds on Youtube to follow.

Converting an old bike is great value for money compared to an new, off the shelf eBike and also they are nice things to build.

View attachment 128560


View attachment 128561

I’ve just watched a YouTube vid with the Swytch conversion but I prefer the second example. Much neater I think.

 

[DrNick]

The Swytch is an updated and packaged version of what I did. Mines old, as I said, as I converted it in 2011. This bike is the second donor bike to use the same kit!

If I was doing it again, I'd mount the battery much lower as a high battery makes them top heavy - there are more choices now. Its not cheap though - battery prices are very high at the moment, but you don't need a big battery as its easy to charge every night.

Swytch would be a good choice. Mine's easier to fit as it uses a manual throttle lever mounted on the handlebars whereas the Swytch has something fitted to the crank to automatically assist you - this may make it more complicated to fit.

There are now loads of kits or individual parts on ebay to make your own. It makes commuting sensible as it gets rid of all the hills. It was a real revelation when I got on mine for the first time!

My commute is about 9 miles each way and it took me 35 mins this morning so an average of 15 mph, with a couple of reasonable hills. I guess improving my top speed by 10/15% isn't really going to make a lot of difference in the great scheme of things!