Yamaha speedbox2 query

[Gdogg]

Hi,can anyone shed some light on my speedbox 2 for the Yamaha PW motor.I fitted the box a couple of weeks ago on my haibike 6.0 SDURO and in derestricted mode it works fine,but in normal 15.5 mode the motor assistance now cuts out at 10 mph and the trip meter seems to be recording 2/3 of the distance traveled as well,has anyone else experienced this ? Is there a way to do a reset? Please help if you can.

 

[Gdogg]

Hi,can anyone shed some light on my speedbox 2 for the Yamaha PW motor.I fitted the box a couple of weeks ago on my haibike 6.0 SDURO and in derestricted mode it works fine,but in normal 15.5 mode the motor assistance now cuts out at 10 mph and the trip meter seems to be recording 2/3 of the distance traveled as well,has anyone else experienced this ? Is there a way to do a reset? Please help if you can.

So since I posted this I emailed speedbox and got a reply that said although the display was in mph the chip was converting back into kph and to switch over my display.So after a bit of testing I can report that in Kmh mode the display is accurate in normal mode assistance cuts off at 25kph and in de-restricted mode the bike will hit 50kph or 30mph.Its not to much of a hassle to convert speeds in your head and I’m really pleased with how the bike just keeps on going! You may also be interested to know I changed the damper in the stock yari forks for the new charger2 damper,and it was super easy to do, with the speed increase I’m glad I changed the damper over as the front end has so much more grip and feel.The next thing on the list is to increase the front chainset as I’m getting to the point of over peddling.

 

[Trail Cruiser]

The next thing on the list is to increase the front chainset as I’m getting to the point of over peddling.

You can replace the 44T chain ring with a 48T and your cadence at 28 mph will be a more comfortable 80 RPM instead of 88 RPM. Besides, the yamaha motor is happiest in the low 80's RPM and below anyway, so that would be a big performance gain.

 

[Gdogg]

You can replace the 44T chain ring with a 48T and your cadence at 28 mph will be a more comfortable 80 RPM instead of 88 RPM. Besides, the yamaha motor is happiest in the low 80's RPM and below anyway, so that would be a big performance gain.

Thanks Mark,I am indeed going for a 38/48 ring swap,I’m also planning to swap out the brakes for hope e4’s and the shifters for xt one’s,all in all I love this bike! The best decision I made this year was to go electric.

 

[david salisbury]

i just installed my second one today.. i can confirm the mph inaccuracy

 

[Gdogg]

Hi David thanks for your reply,I’m now interested in doing the chainring swap to a 38/48 front set up but I’m worried that there won’t be enough height on the front Mech,can you help?

 

[david salisbury]

I have not converted to 38 / 48 and probably wot. 1 . i like using 1 chain teh sram at 118 links is exactly the right length. 2. i am worried about having to pedal it when its flat. On dirt .. Is fast enough now the limit has gone.

 

[Gdogg]

So I’ve been busy since my last post,in a quest to get my e mountain bike quicker on road sections but still retain all it’s off road abilities.Orignally I thought a quick ring change on the front would give me the extra speed I was looking for,but this proved to be almost impossible without damaging the frame.Then I thought about the rear cassette and BOOM the answer was so simple,I built a new back wheel with an e*thirteen 9-42 cassette,and what a difference! I can now get 65kmh at 95 rpm and easily cruise at 50kmh for a cadence of 60 rpm.

 

[kit holmes]

Gdog, I'm in the process of acquiring same bike as you. The one I demoed did everything I needed, except one Very steep climb I apparently don't have the leg power to keep the cranks turning.
Any suggestions? Maybe add a ring to the cassette? Or maybe a lower granny chainring? Or, would the speedbox fix that? Thanks, Kit

 

[Gdogg]

Hi Kit,I know what you mean,it’s a very good and capable bike but when the assistant’s stops it’s quite a sharp drop off,if you just want something simple go for a speedbox2 they are dead east to fit just plug and play it should take you around 30 mins to do there is no damage to the bike or the loom and the nice thing is it’s permanently off until you turn it on so you can switch modes when you want with just a button press,and all the values on the display read as normal unlike some of the tuning options out there.I hope this helps and if you need any more help or advice please don’t hesitate to get in touch.

 

[kit holmes]

Thanks muchley, I'll look into that for sure.

 

[Ken M]

I have my 2016 Haibike Trekking RC model with the Yamaha motor unlocked but I have found that it's not really that effective over 20mph. I think this is because if you are riding say at 25mph you are on the largest front chain ring (48T on my bike) and the smallest rear (11T on my bike) which effectively reduces the provided motor torque to the rear wheel by over 75%. Also since it's virtually impossible for an average rider to be applying high torque into the cracks at that speed / cadence the Yamaha programming tends to limit the assist to around 30% of the max possible. That is the part that bothers me because I want the motor to provide full assist at high speeds when I'm trying to climb fast (I'm ridding as an urban commuter so the great climbing performance you get from the Yamaha motor when mtn biking at slower speeds is just not there).

Note: it's bothersome when you riding at 20mph and trying to keep that speed up say a long gradual slope and the motor assist never gets above 30% on the meter and you're killing yourself to maintain speed.

I think this is why some of the high end urban speed pedelecs have stayed with the hub motor configuration. The higher unsprung weight of the rear wheel doesn't matter much when urban riding and the assist torque it provides is entirely delivered to the rear wheel (the gear ratio at high speeds hurts the mid drive motors as I just outlined above - maybe less on the Bosch mid drives with the 2 - 2.5 cadence small front chain rings as they will deliver the torque more efficiently at higher speeds).

I think Yamaha needs to use the speed parameter to reduce the crank torque needed to max out assist as the speed of the bike increases.

 

[Ken M]

I wanted to add that it seems that the mid drive programming wants riders to go slower on ascents to max out assist but going slow when you are urban commuting kills your commute times.

I'm wondering if the Speed Box / Speed tuning companies could improve the performance at high speeds and not simply unlock the top assist speed.

 

[Gdogg]

Hi Ken,I had similar problem on my haibike all mountain 6.0 which is why after de restricting it I was looking at ways of extracting more out of it,this is why I went over to the e*thirteen cassette the ten and nine teeth sprockets really made a difference (and I’m forced to run a 32/44 at the front)with the de restriction on and the power on the max setting the bike is easy to pedal at 25mph,even 35-40 is not difficult to achieve on a paved surface.

 

[Gdogg]

Of course another option is to get a 500wh Yamaha Motor,if you are in the U.K. these are available to order

 

[Ken M]

Quick question....if you are riding at say 25mph and come to a reasonable incline that would be very difficult to maintain that speed on a non-ebike does the power meter on the LCD show that you are provided full assist power before you go slower and slower because you are getting a bit gassed?

When I try to maintain 20mph on my Yamaha mid-drive Haibike the power meter never really rises above 1/3rd level assist so it's seems to be far too prioritized towards how much torque a rider can put into the cranks and at high speeds that is a lot less than it is at low speeds.

I'm confused as to how gearing would increase the assist as the torque sensor is entirely based on torque delivered by the cranks to the bottom bracket shaft.

 

[Gdogg]

Ok so on my bike If I put the power on high and turn the de restriction on and climb I get full assist,most of this is due to keeping the motor spinning in its sweet spot which in the case of my motor (a Yamaha PW) is between 60-80 rpm what I find helpful is putting the display in to rpm mode so you can see your cadence not just feel it.to make the most of this you must be in the right gear which is why I swapped cassette.Between 11-35 it feels like a normal haibike when it’s a really steep climb the 42t cog is a massive help and on the flat the 10/9 means you can get a higher cadence for less effort.The thing with all mid drive bikes is you need to keep them spinning for max assist,if you relax or get gassed out the assistance will tail off accordingly.Most of the hub motor bikes you see have a thumb throttle which I think is what you are getting confused with.

 

[kit holmes]

Another quick question for owners of the Yamaha PW motor. I've only have about 50 miles on mine, but the motor is noticeably louder in the higher assist modes than initially.
Is that normal, maybe during break in time?

 

[Gdogg]

Yes this is completely normal mine did exactly the same (and still does in higher assist modes) this is just the motor spinning faster.I also found quite a lot of noise coming from the rear wheel and disc,the wheel just needed the spokes tensioning.I would be interested if you bought your bike online or from a physical bike shop? I bought mine online but my local bike shop are e-bike certified so I’m lucky to have a useful resource on my doorstep,if you did buy your bike online it’s very important to get a service after 2/3 hundred miles or roughly 6 weeks.

 

[kit holmes]

Thanks again! That relieves some stress for me!

I bought my bike from a shop that a friend works at. However the shop isn't close to me at all. So unless I have warranty issues I'll try my local shop.
I'm lucky in that I've done all my work on my pedal bikes other than wheel work.
And thanks for the heads up on a service. I'm assuming that's necessary to keep warranty up to date?

I already had to adjust the front derailleur, It would shift fine in the stand, but not with me in sagged position. & I'm a light wt., ha.

I'll keep & eye on those spokes , I know often factory built wheels need attention after some use.

I'd like to get my brother to get one of these as well.