Sunlova Kit Conversion - GIANT CRS3 Hybrid

[John L]

Hi guys

Well I've managed to fit the conversion kit to my Giant CRS3 hybrid. Some observations in case anyone else decides to fit it to this kind of bike.

-The forks needed some working so that the motor had enough clearance (a little bit of filing on the righthand fork)
-The carrier fitted perfectly - no shortage of lugs on the frame.
-Fitting the switched brake levers that came with the kit was a bit problematic – I have EZ Fire EF50 combined brake and gear levers so I couldn't just take one off and slot in the new one So I decided to try to mod the righthand EZ Fire unit by taking a hacksaw to the brake lever-there wasn't any obvious way of removing the brake lever! It worked fine and I now on the righthand handlebar I have the gear levers, followed by the new brake lever and then the throttle. I've left the other gear shifter alone.
-I wanted to fit the pedelec sensor but I couldn't – the bottom bracket and spindle just wouldn't take it.

I went for a 23 mile spin yesterday in the heavy winds we had here in Ireland. I took a hilly route which I normally only take when I'm fairly fit on the bike (not too often these days ). I know now that the battery wasn't fully charged as the red light on the charger hadn't turned green – I only realised that this morning when I left the battery charging overnight.

Overall I was very pleased. It took me a while to get comfortable with the throttle control and it was a big temptation to use it all the time. In the end I used the throttle to get up the hills and on the flat when my speed dropped off. My average speed was 15.6mph which given the strong wind and hills was, to my mind, very good. I also found that I got some decent exercise as well.

I have a couple things that I could do with some advice on

1. When I rotate the front wheel I get the same resistance whether I turn it forward or backward – I expected to get no noticeable resistance when turned backwards. Is this normal?

On the road its hard to tell what kind of freewheeling I'm getting as the tyre that came with the kit is more resistant than the one I had fitted and of course the bike weighs alot more.

2. I would like to fit a pedelec sensor – is it possible to fit a different sensor that might fit the tight space I have around the bottom bracket?

Any help would be appreciated.

John

Update

Again in case anyone searches for a thread about the sunlova kit. I don't recommend fitting the wuxing cut-off brake levers that came with the kit. The levers are not designed for v-brakes and bottom out against the handlebar in the rain. I managed to get a replacement EZ50 changers with v-brake levers and now I have very good brakes again

The compromise is to cut the throttle grip to a third of its original length as per flecc's mod (see twistgrip) . Now its easy to let go of the throttle while braking. Its much more comfortable to use and its possible to fit bar ends

 

[NRG]

The Bafang motor fitted to my Peugeot has similar resistance rotated forward or backward but there is a little less going forward. My Alien also fitted with a Bafang has much more resistance going backwards so it seems it varies.

Regarding your Pedelec sensor, try fitting it to the other side of the bottom bracket, you'll need to fit the magnetic disk the opposite way 'round otherwise it won't work...

 

[flecc]

1. When I rotate the front wheel I get the same resistance whether I turn it forward or backward – I expected to get no noticeable resistance when turned backwards. Is this normal?

The internal freewheel is in play when the wheel is manually turned forward, though the orbital gears still have to rotate and therefore create some drag. When turned backwards, the freewheel is locked and you have to rotate the motor in addition at five to seven times the wheel speed, considerably increasing the drag felt. This latter case never affects your cycling of course so can be ignored.

The amount of drag varies motor to motor for the following reasons:

1) Meshing tightness and run in state of orbital gears.

2) Degree of gearing down ratio of the orbital gears.

3) Motor power specification and magnets used.

4) Gear grease density, a very thin film is best.
.

 

[sopht]

Hello John, well done for doing it! I'm still diddly daddling, on cost grounds. I was just looking at a Giant CRS 4 last night, funnily enough, £219 from Ash Cycles, very tempting - my current push bike's great but heavier.

So, I was very interested to see your post about conversion. I have to admit to flinching as you described taking a hacksaw to the brake though Clearly I need to look into this - current bike has EZ shifters too.

Looking at the Sunlova site though - kit out of stock Alien has stock again, but quite a bit dearer.

Any pics?

regards, Soph

 

[John L]

Hi Guys - thanks for the replies

NRG - Unfortunately I tried to put the sensor on the other side but there still wasn't enough room. I'll have to think some more about it.

Flecc - thanks for that - it seems I have nothing to be concerned about I had seen somewhere on youtube a video of a wheel freely rotating on a front hub motor and I thought that mine should be the same. As you mention it depends on the characteristics of the particular motor.

Soph - I had a quick look at the CRS 4 and its looks as if all the necessary lugs are there. £219 seems a good price to me. As I mentioned the forks and the brakes were the main issues - it did feel a little odd taking a hacksaw to the lever but it was either that or buy new gear shifters and then spending god knows how long setting them up! The hacksaw was the easy way out!!

I have some pictures and tried to upload them with my original post but failed. I'll take a few more and try again later. Its a tidy job and the bike looks very normal

John

 

[rosjen]

Hi John, I had the same sensor fitting problem with mine and came up with this, hope this helps works fine for me.

 

[John L]

Hi rosjen - great photo! Thats a very different looking sensor to the one I have - is it a stripped down version of the sunlova or a different sensor entirely? Thanks

John

 

[John L]

Photos of the bike so far!

Soph - I haven't managed to work out how to post photos directly to the forum but here are some links to the photos on 23hq.

23: Gear shifter without the gear lever. The new switched... - Enuf
23: Controller with cables wrapped in self-amalgamating tape.... - Enuf
23: Full view - with panniers its hard to tell that its now... - Enuf

Hope that worked!

Feel free to ask anything about the conversion - if I can help I will be glad to

John

 

[rosjen]

Hi John,

It is worth noting that i have cut most of the original metal ring away, I have not seen the sunlova sensor but would have thought it was the same as mine before the chop?

cheers
rob

 

[Old Timer]

Hi guys

Well I've managed to fit the conversion kit to my Giant CRS3 hybrid. Some observations in case anyone else decides to fit it to this kind of bike.

-The forks needed some working so that the motor had enough clearance (a little bit of filing on the righthand fork)
-The carrier fitted perfectly - no shortage of lugs on the frame.
-Fitting the switched brake levers that came with the kit was a bit problematic – I have EZ Fire EF50 combined brake and gear levers so I couldn't just take one off and slot in the new one So I decided to try to mod the righthand EZ Fire unit by taking a hacksaw to the brake lever-there wasn't any obvious way of removing the brake lever! It worked fine and I now on the righthand handlebar I have the gear levers, followed by the new brake lever and then the throttle. I've left the other gear shifter alone.
-I wanted to fit the pedelec sensor but I couldn't – the bottom bracket and spindle just wouldn't take it.

I went for a 23 mile spin yesterday in the heavy winds we had here in Ireland. I took a hilly route which I normally only take when I'm fairly fit on the bike (not too often these days ). I know now that the battery wasn't fully charged as the red light on the charger hadn't turned green – I only realised that this morning when I left the battery charging overnight.

Overall I was very pleased. It took me a while to get comfortable with the throttle control and it was a big temptation to use it all the time. In the end I used the throttle to get up the hills and on the flat when my speed dropped off. My average speed was 15.6mph which given the strong wind and hills was, to my mind, very good. I also found that I got some decent exercise as well.

I have a couple things that I could do with some advice on

1. When I rotate the front wheel I get the same resistance whether I turn it forward or backward – I expected to get no noticeable resistance when turned backwards. Is this normal?

On the road its hard to tell what kind of freewheeling I'm getting as the tyre that came with the kit is more resistant than the one I had fitted and of course the bike weighs alot more.

2. I would like to fit a pedelec sensor – is it possible to fit a different sensor that might fit the tight space I have around the bottom bracket?

Any help would be appreciated.

John

Hiya John

You could do away with your third small chain ring to make some more room, I did that on one bike. To be honest you probably will never need that grannie ring anyway now.

Dave

 

[John L]

Hi John,

It is worth noting that i have cut most of the original metal ring away, I have not seen the sunlova sensor but would have thought it was the same as mine before the chop?

cheers
rob

Hi Rob

I prized open my sensor and it is very different. I expected to see something similar but there is nothing so solid as yours - Old TImers idea might so the trick.

John

 

[John L]

Hiya John

You could do away with your third small chain ring to make some more room, I did that on one bike. To be honest you probably will never need that grannie ring anyway now.

Dave

Hi Dave

Yeah that might well be the solution - definitely don't need the small chain ring with the motor. I'll have to have a look as I think that ring may well be riveted in - yep just had a quick look and they are all riveted in - its a Suntour SR set. I could drill out the small ring but I have a shimano set on my road bike and I might be able to transfer it. Its a good idea

Thanks

John

 

[sopht]

Hi John, thanks for the pics - it really helps to see the finished article and to hear about the snags along the way - that throttle/shifter solution looks perfect - way better than in my imagination

One of the reasons I was looking at another bike for conversion, apart from weight, was that I tend to like larger frames which means that my saddle's not a long way above the seat post. Could you give an idea what sort of clearance you do need?

best, Soph

 

[Trevor Holloway]

"Looking at the Sunlova site though - kit out of stock Alien has stock again, but quite a bit dearer."

New kits due in early August, just got my deposit down for one with a thumb throttle (as I have twist grip gear changers), now all I have to do is be patient for a month - thank goodness I will be away on holiday for half of the time !
They have also kept the price as on the web.

 

[Gaynor]

I haven't managed to work out how to post photos directly to the forum but here are some links to the photos on 23hq

If you click your photo again, and have so then you have just the url of the photo, then click on photo icon and copy that url into the the insert image box, like this..

 

[John L]

Hi John, thanks for the pics - it really helps to see the finished article and to hear about the snags along the way - that throttle/shifter solution looks perfect - way better than in my imagination

One of the reasons I was looking at another bike for conversion, apart from weight, was that I tend to like larger frames which means that my saddle's not a long way above the seat post. Could you give an idea what sort of clearance you do need?

best, Soph

Hi Soph - I think I understand your clearance concern - its hard to say exactly what clearance you need. Looking at the photo below you can see that you need at least two inches above the seat stem to clear the carrier. But with the shocks in the seat post the saddle would be well above the carrier anyway. So it may depend on the kind of seat post you have.

Hope that helps.

John

 

[John L]

Hi Gaynor - thanks for that - it worked fine - just need to resize the photos a little John