Derestricting a Forza?

[Hillrider]

Hi Pedelecs,

This is my first post, so forgive me if I've created a new thread unnecessarily.

Actually I'm not entirely sure what a new thread is.

Anyway, my question is:

Is there any point in derestricting an Ezee Forza?

I read with interest the Q&A regarding the Ezee Torque and the derestriction question, but couldn't quite fathom whether it would be worth me giving it a go.

I live in the Lake District and have some fairly hefty hills to deal with. The Forza starts out well on a fairly steep climb but eventually conks out about a quarter of a mile up a 3/4 mile hill. Shame that, as this was the one hill I hoped the bike would help me with.

To be fair,it does make up for it on other routes...just.

So I got to wondering whether derestricting i.e. increased speed, might lead to increased hill climbing capacity?

Any thoughts/suggestions regarding this question would be very much appreciated.

Regards

hillrider

 

[flecc]

Hi Hillrider, I'm afraid the answer is no. Derestricting only increases the speed from the restriction of 15.5 mph to the motor's natural peak speed, giving around 20/22 mph.

The point of maximum torque which is needed for hill climbing is around 12 mph, which you have already. Your motor gives you around 680 watts of gross power at that point, and anything else needed to climb a steep hill has to be from you.

Cutting the climb speed to around 6 mph puts the motor well below it's peak with around 350/400 watts, but the climb needs much less power at that speed, so your contribution can then reduce as well from what was needed at 12 mph.

The hill in question must be very steep indeed if you can't climb it with the Forza and a reasonable effort from you pedalling. To give you more information I'd need to know the gradient of that hill and your weight ready for cycling.
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[flecc]

P.S. Further to my above answer, could you let me know if it actually cuts out on that hill leaving power off?
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[Hillrider]

The hill in hand

Hello again

Thankyou flecc and fiftycyles for clearing that up for me.

I will check the gradient of the hill tomorrow. I currently weigh around 10 and a half stone.

Flecc, I am not too sure that I understand your question:

"P.S. Further to my above answer, could you let me know if it actually cuts out on that hill leaving power off?".

The Forza I have has been adapted so as to feature a throttle instead of the standard system.

I have not attempted the hill in the ebike mode i.e. without peddling.

I have tried to make good use of the gears and have kept peddling throughout.

The hill is undoubtedly steep and long. However, I am not clear as to whether it actually gets steeper halfway up, or whether the cutting out is due to the length of the climb.

I will let you know the gradient. For now though thankyou again for your thoughts on this subject.

I will not now attempt the derestriction.

Regards

Hillrider

 

[flecc]

It seems from your answer that the power is actually cutting out. As we've both said, your contribution is essential since it is primarily a bicycle, and it's on a steep hill that your input is most important. It will be the length of the steep climb that causes the problem, since when there's a high continuous current drain from a battery, it tires and can eventually reach a point where the current delivery can't match the excess demand.

Odd though it might seem, you can get better results by using less than full throttle when climbing a difficult hill. Try commencing the climb with around half throttle at a moderate speed with a fairly low gear selected for you to help, ensuring that you are spinning the pedals at a reasonable speed and not labouring very slowly on the pedals. The lower the throttle level you are able to use while still getting the motor assistance, the better it is for the bike to maintain it's power consistently all the way up the hill.
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[Hillrider]

The hill and the throttle

Hi Flecc,

I have finally found a signpost that tells me the gradient and length of one of the hills I regularly climb on my way to work. It is a 10% hill that lasts for one mile.

I have tried to reduce the amount of throttle applied as you suggested.

It is hard to keep the throttle at a constant level but I think this is helping.

However, one thing is clear. Had I not had my Forza converted to feature the throttle/ebike option I could be left with a very heavy bike to push, as I believe the system which now comes as standard is pedal actgivated only.

Once I dismount the bike, the ebike facility allows me to use the throttle and as it were, trot alongside the bike whilst ascending until the gradient is reduced at the top of the hill.

I'm sure 50cycles has already considered this fact, but if not, I would like to suggest that in the future when cyclists living in hilly areas express an interest in the Forza they recommend the throttle conversion, as pushing the bike up a 10% mile long hill may not make for a good travelling experience(I know this as I recently ran out of charge and pushed the bike up...not good).

Thanks again for your help.

Hillrider

 

[Ian]

I agree with you Hillrider that the ability to use the throttle to help "walk" the bike up a hill is very important, it's the way I get my own Torq up the steepest hills. Unfortunately if, as seems likely, the EU regulations on e-bikes are adopted in their entirety then all new bikes will have to pedelec only

 

[Hillrider]

EU

Hi Ian,

I didnt realise that. Do you know of a link to the EU plans?

Surely a "Hillthrottle" mode could be argued for.

Hillrider

 

[Ian]

A to B magazine cover the legal points at the bottom of this page. The EU law has always stated that power can only be available while pedaling and because of this only pedelecs are available in other European countries. The UK, as a member state is technically bound by EU law but at present enforces the pre-EU legal requirements that permit power without pedaling but only allows nominal motor power of 200W as opposed to 250W in the EU.

With increasing e-bike usage and an imminent very large tender for e-bikes from the Royal Mail likely, the general opinion is that the UK will have to fall in line with the rest of Europe.

 

[Hillrider]

Hi Ian,

Fascinating. Thanks.

I am definitely looking to question the result of any legislation that does not take hills into consideration.

Much as I'm sure that the various statutory bodies involved would like the world to be flat and unchallenging, they must surely acknowledge that there are inevitably ups and downs.

Thanks again Ian, I shall keep an eye open for updates.

Regards

Hillrider

 

[Ian]

All the legislation is made in Brussells, I've never been there but understand that it is very flat.

 

[Hillrider]

Hi Ian,

Fair point.

Cheers

Hillrider

 

[flecc]

I agree Hillrider, and am in a position of the throttle while walking the bikes up a short 1 in 3 bank to my home being essential when there's an added 10 kilos of shopping on the back.

At least existing bikes won't be affected by any change in the law, so a revolving updating is possible. First refurbish with a new up to date motor/battery/electronic set, then at a later time renew the cycle side. Hey presto, a new bike, but in law just a well maintained existing one which can legally have a twistgrip.
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