Triple chainwheel removal

[mike_j]

I think that I have decided to convert my 24 gear hybrid (cross) Giant bike rather than buy a complete electric bike. Partly (well largely) economy, partly because the bike and I have got used to each other and I can't see a new bike in my price range being built with the same quality of components. The modification will be the 8fun kit.

Some questions which I would greatly appreciate help with please:

I note that some forum users describe putting the pedelec sensor on the left had side retaining full chainwheel changer functionality. However I read in much of the literature that only a limited selection is gears is needed, mainly the high gears. Would it be better to remove the inner and middle chainring and mech then fit the pedelec sensor on the RHS?

How important is the brake cut off? If I keep the chainwheel thumb control I cannot fit the special cut off brake mechanism. Similarly I can't fit the motor only throttle lever. If I do remover the chainrings and associated brake/shifter assembly I can fit the brake lever and the throttle lever (on the LHS) though the bike will have odd brake levers which will look strange.

Also I am a bit concerned that the front hub motor will impose excessive load on the front suspension - should I change to rigid forks?

Any advice welcome, thank you.

 

[Gogs]

I think that I have decided to convert my 24 gear hybrid (cross) Giant bike rather than buy a complete electric bike. Partly (well largely) economy, partly because the bike and I have got used to each other and I can't see a new bike in my price range being built with the same quality of components. The modification will be the 8fun kit.

Some questions which I would greatly appreciate help with please:

I note that some forum users describe putting the pedelec sensor on the left had side retaining full chainwheel changer functionality. However I read in much of the literature that only a limited selection is gears is needed, mainly the high gears. Would it be better to remove the inner and middle chainring and mech then fit the pedelec sensor on the RHS?

How important is the brake cut off? If I keep the chainwheel thumb control I cannot fit the special cut off brake mechanism. Similarly I can't fit the motor only throttle lever. If I do remover the chainrings and associated brake/shifter assembly I can fit the brake lever and the throttle lever (on the LHS) though the bike will have odd brake levers which will look strange.

Also I am a bit concerned that the front hub motor will impose excessive load on the front suspension - should I change to rigid forks?

Any advice welcome, thank you.

Hi Mike,
I have just fitted an 8 fun kit on my Saracen tourer and kept all the three chainwheels.
I decided to keep all the gears for the simple reason that if you run out of battery at any stage, the bike is much easier to ride home if you have the lower gearing available to you, electric bikes are heavy!
I fitted the pedalec sensor on the left side by making a bracket to hold the sensor which was bolted underneath the chainstays.
I am going to do a detailed description of this with pictures soon, some pics of my bike here:
Pictures by gogs4 - Photobucket

I did not use the brake cut-offs, and don't have any problems without them, I kept the thumb throttle though.

The suspension forks seem well able to handle the 8 fun motor though if you are worried I believe that there are torsion stays available for the front forks from conversion kit suppliers on the forum, someone will advise on that, Frank maybe!

Good luck with the conversion.

Gogs.

 

[banbury frank]

Hi

we do a simple torque arm for £20 delivered

Just A thought Have you looked at the NEW kits from juicybikes cost a bit more


Juicy Bike Accessories: stylish electric bikes and scooters

But the reports on there bikes and kit s is good

support from Bob is second to none

Please ask other members for there recommendations

Frank

 

[mike_j]

Thank you both for the information.

Gogs, your conversion looks neat, I'm sure that I can fabricate a suitable bracket so may go with your layout. The 8fun kit seems to use a carrier mounted battery. I should think your frame mounted bottle battery is better as it lowers the C of G. I will see if it is available.

Frank,
It wasn't so much the torque that I was worried about though I can see that there is an argument for a torque arm. It is mainly the extra unsprung weight on the suspension that I am concerned about.

I looked at the Juicy Bike website, it's not very detailed but they only seem to offer 26 inch wheels and they cost about 1/3 more than 8Fun so I think that I will sick with 8Fun. Thank you anyway.

Michael

 

[banbury frank]

Hi the 8 Fun / sunlova New kits have bottle battery just haven't upgraded there site give them a call

Sunlova Product Page


Your forks will be OK


Frank

 

[John L]

Hi Michael

In order to fit the sensor I ended up changing the bottom bracket (my bike is a giant also) with this RPM Square Taper | Buy Online | ChainReactionCycles.com - although I have just noticed that the 122.5 version is no longer listed. In any event a slightly wider axle might allow you the necessary room. Don't go too wide as it will effect the chainline which will make it very difficult to get the derailleur working properly.

In addition to the 122.5m bottom bracket I also got a new chainwheel - alivio 48/38/28 - which sits a bit closure to the frame so I had to remove the smaller chainring. This worked well and now I can fit the sensor comfortably.

Only problem is that my sensor isn't working But thats another story.

In relation to the brake cut-off lever I tried several things which worked to a certain degree.

I assume you're using an integrated shifter and brake unit (8 speed shimano EZ50s) - my initial solution was to cut the RHS brake lever out with a hacksaw. This made room for the cut off brake lever. But now I won't recommend that as I found that the sunlova cut-off brake lever wasn't really suitable for v-brakes as it bottomed out against that handlebars when pulled in the rain

My next solution was to remove the left hand switcher/brake lever and the front derailleur. I put the chain on the middle chainring. I then fitted the brake cut-off lever to the back v-brakes which isn't under the same pressure.

At this stage, however, I think the best solution is to buy one or both alivio shifters (eg Shimano Alivio M410 8 Speed MTB Shifters RRP £45 | eBay) I'm sorry I didn't do that at the start.

Sorry for the long winded reply

John

 

[Caph]

Hi Mike, I've fitted the 8FUN kit and although I haven't fitted the pedelec sensor I can see that it won't quite fit on the drive side with my 127mm BB and all three chainrings, however 127mm looks about perfect for the non-drive side. Don't worry about the chainline, my 127mm BB gives me a chainline of about 53mm which is 3mm over the recommended max Shimano MTB chainline but my gear changing is perfect with my Alivio front and rear mechs.

I'm using RockShox Dart3 front suspension forks and I don't get any problems with the 8FUN motor.

I don't use the brake cut-offs but then with only using the thumb throttle they are completely redundant anyway.

 

[mike_j]

Well the kit was ordered today, I'll let you know how it goes.

Thanks for all the help and comments.