Anyone wish to compare gear ratios

[Mussels]

Shimano make a bottom bracket mounting plate with arm that can carry a changer, but I think it only fits certain BB types and it's not an easy item to find.

I looked into those and they need a specific setup and I dont think it will work on the 905. I don't quite remember what it needed but I think the frame needs to be designed specially to take them.

To be honest I think you only really need one chainring on the folder.

It's not so much about having an extra chainring as having something to keep the chain in place, both problems have a similar answer and need similar mounting points which aren't available on Wisper or Ezee bikes. A factory fitted braze on mount would be nice.

 

[Wisper Bikes]

I looked into those and they need a specific setup and I dont think it will work on the 905. I don't quite remember what it needed but I think the frame needs to be designed specially to take them.

It's not so much about having an extra chainring as having something to keep the chain in place, both problems have a similar answer and need similar mounting points which aren't available on Wisper or Ezee bikes. A factory fitted braze on mount would be nice.

We have looked ad adding a second chain ring to the 905's but the battery casing would get in the way and the chain would touch. Unless anyone can come up with a solution?

Regards David

 

[Old Timer]

I think this thread was about the Cyclamatic? I have a double chainwheel on mine (no mechanism to change them) just fingers.

Are people saying that with a second chainwheel if the chain dislodges it`s more than likely to jump down to the smaller chainwheel?

 

[Andy_82]

We have looked ad adding a second chain ring to the 905's but the battery casing would get in the way and the chain would touch. Unless anyone can come up with a solution?

Regards David

You can forget about it David, I was thinking about it but there is no way to shift the gears after, even though you could extend the bb axle but still you can fit the dérailleur at the front. I rather think that two cogs at the front are useless. On my own bike i have never had a hill that i could not cope with, it's just a great motor that has to help you out and 8FUN Bafang certainly is. BTW I'm an absolute fan of these motors, I think they are great.

 

[Wisper Bikes]

Ooops

Hi and a belated happy birthday!

Yes sorry for that, I should have opened a new thread to discuss Andrews comment.

All the best

David

 

[Wisper Bikes]

You can forget about it David, I was thinking about it but there is no way to shift the gears after, even though you could extend the bb axle but still you can fit the dérailleur at the front. I rather think that two cogs at the front are useless. On my own bike i have never had a hill that i could not cope with, it's just a great motor that has to help you out and 8FUN Bafang certainly is. BTW I'm an absolute fan of these motors, I think they are great.

I agree Andy, it's more about marketing than a necessity on the bike.

All the best

David

 

[Artstu]

No, it's about using the front deraillieur as a guide to keep the chain in check, you can also buy a simlpe none moving guide similar to a derailleur.

My chain has always fallen off to the outside and as the bike is nearly always in top gear that makes sense.

 

[Mussels]

We have looked ad adding a second chain ring to the 905's but the battery casing would get in the way and the chain would touch. Unless anyone can come up with a solution?

Regards David

A second chainring would work on my 905 as I have it fitted to the inside of the spider at the moment and it doesn't foul on the battery, I did notice on the '09 905 I borrowed that the chain was closer to the battery box so it wouldn't work there.

 

[Mussels]

No, it's about using the front deraillieur as a guide to keep the chain in check, you can also buy a simlpe none moving guide similar to a derailleur.

My chain has always fallen off to the outside and as the bike is nearly always in top gear that makes sense.

That's the main reason I wanted to fit one although I think a second ring is needed for the hills I ride up and down. The original chainring provided by Wisper had chainguides attached to the ring so it wasn't a problem there but I found it was overgeared for the hills and I replaced it with a much smaller chainring. To stop the chain coming off the outside I fitted a bashguard similar to this, but it still comes off on the inside occasionally.

The bashguard is also a nice idea as it stops the teeth digging into my leg if I have an accident.