Hello from Ashland Oregon

[Mzee Richard]

Newbie with a Dost bike out of Vancouver BC. I joined to get some insights about strange throttle behavior plus a few other bits and to share any relevant experience I have to offer.

 

[JRA]

The Dost uses a Bafang BB02 motor IIRC and there is a chance that you can fine tune your throttle response with a cable and windows computer. Contact Dost to see if that is possible?

Plus I'm sure you will be happy to have an eBike in Ashland, the hills there can be brutal!

 

[Mzee Richard]

Given that , am going to increase the rear large chain ring (existing is 34 t . I’m heading to hopefully a 40 t ring. Am prepared to go to longervthrow derailleur and adding a few links to my chain Thoughts advice anyone?

 

[Mzee Richard]

Given that , am going to increase the rear large chain ring (existing is 34 t . I’m heading to hopefully a 40 t ring. Am prepared to go to longervthrow derailleur and adding a few links to my chain Thoughts advice anyone?

 

[EMGX]

welcome. Are you planning to go to Crater Lake for the east rim road ride on the 10th and/or 17th?
If your current derailleur isn't rated for 40t (you can sometimes use a cassette with a couple teeth more than what they are rated for) you can buy a derailleur extender and probably be able to use your current derailleur. Some of the inexpensive cassettes on Amazon come with a complementary one included. I have one on a bike currently and it works fine for me (SRAM X4 with 11-42t cassette). I used one on a bike with Shimano 105 and it didn't shift as smoothly, but I also used a 10 speed cassette instead of 11 speed so the indexing might have made a difference. So I put that bike back to a compatible 10-32t cassette.

 

[Solarcabin]

My son, grandson and his wife live up in Oregon.

Beautiful place but too much rain for me.

What is your throttle issue?

 

[Mzee Richard]

welcome. Are you planning to go to Crater Lake for the east rim road ride on the 10th and/or 17th?
If your current derailleur isn't rated for 40t (you can sometimes use a cassette with a couple teeth more than what they are rated for) you can buy a derailleur extender and probably be able to use your current derailleur. Some of the inexpensive cassettes on Amazon come with a complementary one included. I have one on a bike currently and it works fine for me (SRAM X4 with 11-42t cassette). I used one on a bike with Shimano 105 and it didn't shift as smoothly, but I also used a 10 speed cassette instead of 11 speed so the indexing might have made a difference. So I put that bike back to a compatible 10-32t cassette.

 

[Mzee Richard]

My son, grandson and his wife live up in Oregon.

Beautiful place but too much rain for me.

What is your throttle issue?

Hello Solar Cabin, from not very rainy Ashland these days !

We live up a 20% grade with a street distance up that grade of ~ 0.5 km in Ashland. My bike won't climb it unless I pedal like hell wth its supplied largest rear 34 tooth cog. Even then, the motor is near stall : Its not a situation conducive to its longevity. I want to upgrade to 40 or even a 42 tooth if possible. ( I am 93 lbs: My wife is 57kg and her Dost bike for some reason, came with the largest cog of 36 teeth in the rear cassette== all of which gets her up the grade around Ashland with far less strain on the motor although she cannot rely upon the throttle alone to do this: She has to pedal up it ).
Beyond the threat to my failing male ego...

I'm told that the motor has been internally wired by Bfang to limit the throttle to 30Km/hr, even though, with pedal even ghosted, it will go far faster or go up a far greater incline-but still not a 20% incline of this length. One cannot apparently change this using the programming cable process as its "hard wired" into the controller.

Bfang apparently changed this controller in 2017 in reaction to more stringent regulations for pedal assist to effectively dominate the throttle. Before that Im told, the throttle would not only maintain but override the pedal assist if necessary. I fail to access technical support from Bfang USA because I did not buy a motor from them but maybe someone on this list knows how to contact them ?

Im seeking a way to change the controller back to its former "throttle-dominant" position but if not will just goto a larger rear cog. I don't see another solution.
Thanks in advance for your insights,

Mzee Richard