Burisch offroad electric bike, new for £649 on ebay

[norry]

Battery Life Update: To test the battery life I decided to ride to work today after doing 15 miles on a full battery (2nd only charge). There was a strong head wind and after 7.5 miles the battery lights went out. So about 22 miles in total, perhaps a few more after a couple of charges.

This did make for a nice experiment riding the bike home in the wet for 8 miles without any assistance (left power charger at home). The gearing range is fine for non assisted riding and overall (apart from the weather) the ride home was pleasant - the bike doesn't have much drag and rolls well.

Did highlight the fact that I need to adjust the rear gear changing as it's slipping a bit.

 

[Ajax]

Well the bike arrived this afternoon, and certainly looks the business. Now that its assembled, the first thing i've noticed is of course the pedelec sensor, which doesn't begin to compare to the salisbury.

The issue of these simpler pedelec sensors was discussed here, back in 2009, see.
http://www.pedelecs.co.uk/forum/electric-bicycles/1172-home-made-pedelec-pedal-torque-sensor.html

see also
Bike Converters: Installing the Pedelec sensor
Bike Converters: Pedelec sensor not recommended

My thoughts now are to try and salvage the sensor from the Salisbury and see if that can be used in some fashion on this bike. But that experiment is going to be some time off [closer to the end of the waranty ;]. Given the type of pedelec sensor i doubt the controller can be tweaked to affect a smooth control of the motor through the pedals. The throttle controls though, seems fine.

I wonder if fewer magnets on these types of sensors would help?

As an added thought, the sensor reading the magnets seemed on my machine to be be a bit close to the magnets, and since the disc holding the magnets was a simple push fit, i 've pushed this disc as far from the sensor as it will go. It might just be my imagination, but this now seems to result in a greater control of the motor by the pedals, ie there seems to be more now to the pedelec controls than stop and full speed. That said, the way it work, the rider barely contributes any effort to propelling the bike, this though might change on the hills.

Has anyone any thoughts?

 

[flecc]

No it won't, magnets on this type of system normally only indicate rotation to the controller and are no better than an on/off switch. Removing some could cause more response problems.

In contrast, the controller's throttle input is graduated by the progressive voltage change signalled with throttle rotation. The only effective way for the pedal crank to do that is with a torque sensor and a controller with the appropriate input, a feature on the more expensive e-bikes

Where the response is concerned, the Salisbury also has the advantage of much lower power which is automatically smoother than a higher power suddenly applied.

 

[Ajax]

No it won't, magnets on this type of system normally only indicate rotation to the controller and are no better than an on/off switch. Removing some could cause more response problems.

In contrast, the controller's throttle input is graduated by the progressive voltage change signalled with throttle rotation. The only effective way for the pedal crank to do that is with a torque sensor and a controller with the appropriate input, a feature on the more expensive e-bikes

Where the response is concerned, the Salisbury also has the advantage of much lower power which is automatically smoother than a higher power suddenly applied.

I don't know if you visted the old thread from this group, in the link above, but the Sailsbury pedelec controller seems to be along the lines of the type pictured here..

http://farm4.static.flickr.com/3033/3108269750_3e08d05677_o.jpg

 

[flecc]

Yes, I've seen that from previous threads. It's still a very unsophisticated system though, the controller's battery low voltage cutoff in particular being a crude non-latching type, so enabling power to cycle in and out with load at cutoff level.

With higher power on pedelec control, there's no substitute for a torque sensor, it's an area where most Chinese made e-bikes have fallen far short of European ones. The better ones are at last catching up now though.

 

[Ajax]

Just to follow up, I had my first proper outing on the bike today, and wow does it go.

With the throttle on, it does what you would expect, with responses and limits as you would expect, 15 - 17mph according to my cheap speedo. If you peddle without engaging the throttle there is even more raw power, i've not tested the limits of this yet.

I find the best mode is to engage the throttle, and then add any necessary peddling. There seems to be more control in this mode, so saving the 'peddle only' mode for when I require that extra out and out pace. Remember With power comes great responsibility.

Hills climbing seems fine, or at least compared to my last ride. For example i had no problems with a very steep incline from an underground car park. What the bike would do under that constant load is something I've yet to try, but i don't doubt it would handle that too.

Final word, great bike well pleased with this.

 

[tcblue]

Is the motor noisy ?

 

[GaRRy]

Is the motor noisy ?

Trouble with Noise is its subjective. I have ridden a number of so called "silent" bikes (according to reviews/manuacturers claims) and I guess my hearing is good as yet to ride one that makes no noise at all (or even just whisper levels). So what may be noisy to you can be acceptable to someone else.

 

[Ajax]

Is the motor noisy ?

I happen to like the sound of the motor, and no i wouldn't say it was noisy.
Its powered transport mate.

 

[tcblue]

Yes i know,thanks

 

[OxygenJames]

Is the motor noisy ?

Well I've got a Burisch and an Oxygen e-mate and there's not much difference in the noise - not to me - maybe the Burisch is fractionally nosier but not that it bothers me and I am usually pretty sensitive to that kind of thing.

 

[Blew it]

I don't know if you visted the old thread from this group, in the link above, but the Sailsbury pedelec controller seems to be along the lines of the type pictured here..

Ajax,

The device in the photo is the 'Victory Sincerity' torque sensing unit which was fitted to my Rush Trek pictured below. There is a thread about the machine entitled 'Voyager' elsewhere on the forum.

At around that time there was at least one other machine fitted with this unit, the Urban Mover.


The 'Victory Sincerity' unit was actually a combined torque sensor/rotation sensor. While the machine was stationary, no amount of pedal pressure would result in the machine shooting forward.....torque sensing only activated when the pedals were turning. The way in which these early units functioned was a bit 'Barny Flinstone'. The chainwheel was joined to the pedal shaft via radially positioned coil springs in the chainwheel, the degree of deflection of these springs measured by a hall sensor.

Long-travel sensors of this type resulted in a strange spongy feeling when pedalling, which many riders hated. Fortunately, we now have more sophisticated 'load-cell' sensors available which are not detectable when pedalling. These come in two forms for hub-motored machines.

TMM4 load-cell torque sensors are incorporated into one of the rear drop-outs of hub-motored machines. The TMM4 comes complete with its own special drop-out, and is therefore only really suitable for OEM fitment at the frame manufacturing stage. The output from the sensor is 0-4v, similar to a throttle, but it is supplied with its own dedicated motor controller. Whether the two signals could be combined to give dual control is beyond my understanding.

The other use of load-cell torque sensing will be found built-in to at least two hub motors, the Bionx, and the motors used in the A2B Metro and Hybrid. Both motors are believed to be manufactured by the same company. Interestingly, the A2B Metro has both chain tension sensing and independant throttle, hence my belief the two 0-4v signals can be paralleled.

Have fun with your two bikes.
Regards
Bob

 

[Ajax]

Final word, great bike well pleased with this.

Well almost the final word.

I tried testing the upper limits of the bike and I have to agree with OxygenJames, in peddle only mode the gearing is too low. I am no heavy weight, but my cadence could not keep up with what the bike was prepared to offer. On the flat in peddle only mode my speedo topped out at 20mph and that was only because i could not add anything more with my rapid cadence to push the bike any harder.

So the next question i guess is who has the best / cheapest source for a 50T chain ring.

 

[Ajax]

Ajax,

The device in the photo is the 'Victory Sincerity' torque sensing unit which was fitted to my Rush Trek pictured below. There is a thread about the machine entitled 'Voyager' elsewhere on the forum.

At around that time there was at least one other machine fitted with this unit, the Urban Mover.

The 'Victory Sincerity' unit was actually a combined torque sensor/rotation sensor. While the machine was stationary, no amount of pedal pressure would result in the machine shooting forward.....torque sensing only activated when the pedals were turning. The way in which these early units functioned was a bit 'Barny Flinstone'. The chainwheel was joined to the pedal shaft via radially positioned coil springs in the chainwheel, the degree of deflection of these springs measured by a hall sensor.

Thanks for the extra info Bob. Just on appearance, the sensor looks so much like the device on the Salisbury that i have to wonder if it wasn't at least manufactured by the same company. Now that i have 'retired' the Salisbury i'll have a chance to take a further peek at the mechanism.

I have to say there was no sense of a 'spongy' response when peddling the Salisbury. Responce was always immediate and evenly proportioned to the motor output..

An extra note. As the simple magnet pedelec sensors seems to be the standard for most kits i've seen. Are they all simple on off sensors? It seems to me you could have an induction type device, so that magnets created a voltage proportional to speed of rotation. The motor could be left to sense the torque, by sensing current necessary turn the motor. I have the feeling i might have just reinvented the wheel..

 

[OxygenJames]

Well almost the final word.

I tried testing the upper limits of the bike and I have to agree with OxygenJames, in peddle only mode the gearing is too low. I am no heavy weight, but my cadence could not keep up with what the bike was prepared to offer. On the flat in peddle only mode my speedo topped out at 20mph and that was only because i could not add anything more with my rapid cadence to push the bike any harder.

So the next question i guess is who has the best / cheapest source for a 50T chain ring.

Good news and bad news. You can get 50T chainrings - they are not cheap though - I paid £50 - and you know what? Its still too slow AND the chain comes off a LOT - as in I had to stop it going into first gear and even then the chain comes off - I have now got an 11-28 rear freewheel cassette all the way from the USA (though somebody here said I could have gotten one in the UK) - and I have bought a 7 speed changer - and I am going to swap it over as soon as I have the time.

I will probably try to go down to a 48T to stop the chain coming off to often - but with an 11T at the back I think that should just about get it at the right cadence. We shall see.

 

[OxygenJames]

Good news and bad news. You can get 50T chainrings - they are not cheap though - I paid £50 - and you know what? Its still too slow AND the chain comes off a LOT - as in I had to stop it going into first gear and even then the chain comes off - I have now got an 11-28 rear freewheel cassette all the way from the USA (though somebody here said I could have gotten one in the UK) - and I have bought a 7 speed changer - and I am going to swap it over as soon as I have the time.

I will probably try to go down to a 48T to stop the chain coming off to often - but with an 11T at the back I think that should just about get it at the right cadence. We shall see.

Sorry I meant its still too fast peddling with a 50T chainwheel and 14T at the back.

 

[Ajax]

Sorry I meant its still too fast peddling with a 50T chainwheel and 14T at the back.

Any ideas on how fast you were going?

Also does anyone know if there is a relationship between the numbers of teeth on a chain ring and the likelihood of the chain coming off? Or would this just be down to chain tension? Just asking.

 

[Blew it]

Chain length and chain alignment

Two things which will throw the chain off the sprockets.

1) Chain tension (length).
2) Chain alignment.

Setting the correct chain length is covered by Sheldon Brown on the link below.

Derailer Adjustment

Chain alignment:

If a single front chainwheel is used, and with the chain on the center cog of the rear cluster, the chain should appear perfectly straight when sited along it's top run. In other words, optimum chain alignment should occur when the derailleur is shifted to the middle cog on the rear cluster. The chain is designed to cope with the shallow angle created when shifting to top or bottom gear.

If optimum chain alignment occurs, say in top gear (smallest rear cog) then it stands to reason when the chain is running in bottom gear (largest rear cog) the chain will be running at an acute angle, and may climb off the chainwheel. Vice versa if optimum chain alignment occurs when running in top gear ( smallest rear cog ).

Curing misalignment problems can sometimes be effected by fitting the chainring to the opposite side of the spider, fine tuning if needed with spider bolt spacers or even washers to bring the front chainwheel into perfect alignment with the center cog of the rear cluster.

Welcome to the world of the mechanics of custom building.

Regards
Bob

 

[tcblue]

You can get a 48t chain ring that fits that bike from here as advised to me by ryan from burisch really helpful guy

Shimano CHAINRING Alivio FCM411 48T Outer BLACK 1GL9811 | eBay

He does say that the chain will come off every so often and he is working on a solution

 

[OxygenJames]

You can get a 48t chain ring that fits that bike from here as advised to me by ryan from burisch really helpful guy

Shimano CHAINRING Alivio FCM411 48T Outer BLACK 1GL9811 | eBay

He does say that the chain will come off every so often and he is working on a solution

Unfortunately I think the proper solution is a new frame! (front and rear cogs are too close basically).

With the Chainring (front large cog on the crank for those new to the names here) and rear-set that close my hunch is that anything beyond a 46T messes up the geometry too much - which is how come I have gone got me an 11T rear gear - to keep the front chainwheel size down as far as I can - but the closer the two cogs are to eachother (front to back) the more, obviously, the change is as you move through the gears (and a larger chainwheel amplifies this - effectively making the distance between the chainwheel and rear-set even shorter).

I have adjusted mine so I dont use the 28T rear at all - because any attempt with the 50T to go into first threw the chain off.

I've not put the 7 speed 11T-28T on yet - I have to cut the wires that go to the motor to do that as the Burisch does not have a plug-in/out connector (which Ryan says is being changed on the next batch they make) - so its going to be an interesting time with the stanley knife at some point in the near future.

But seeing as all it does is rain having stuff to do on the bike inside aint such a bad thing is it?