40 mile round trip commute - 20mph - help please :)

R0881E

Pedelecer
Sep 11, 2017
60
4
UK
Ok,

Despite the below issues I had a quick test down the road using the thumb throttle. On my stand it hit 44kph and on the road I hit 35 without pedalling or adopting a good position or going further than may 150-200m.

Issue 1: Wheel didn't fit in dropout (I have shaved them down).

Issue 2: 130 width on my rears and the wheel is 135.. (I stretched it, hopefully evenly).

Issue 3: The wheel was pointing left. (You guys were correct, the wheel was horribly out and the LBS is going to dish it).

Issue 4: My SRAM Apex has basically no gap to fit the PAS sensor plus magnets.

He suggested buying a new crank and fitting it, which is going to cost $200 AUD (£115) which is what I paid for the whole Specialized road bike in the first place.

I have been reading the threads and trying to find a solution.

A) Buy a different bike and sell the Specialized (I may even come out on a profit).

B) Pay to have a new crank fitted

C) Try to fit one myself (but probably fail). Would need to buy the crank and kit to switch..unless I can just changed the BB?

D) Find a clever way of fitting a PAS sensor. I have seen other threads where people have tried to glue on etc but the bike is now at the LBS and I cannot do this anyway unless I take it all off and have a go. I had planned on going on the left side but it would have to be the right side no doubt if I can find a workaround.

ps: The bike is https://www.specialized.com/ca/en/secteur-elite-apex/p/23482 and I guess it is possible to glue it a segment at a time without removing the crank?

Spent way too long trying to sort just the wheel out on Saturday :(

Any suggestions please :)
 
D

Deleted member 4366

Guest
No, that won't work. Its 12v and 4 wires. You need 5v and three wires.
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
7,845
5,785
The European Union
Could I not use this mount to hold the 12 magnets on the chainring but then use the original sensor to go with it?
Yes you can.
 
D

Deleted member 4366

Guest
Yes you can.
Did you test one?

When I retro-fitted a 12 magnet PAS to a Freego recently, it wouldn't work until I removed every other magnet to convert it into a 6 magnet one. All the magnets were oriented the same way and it wouldn't work at any speed. I guess there wasn't enough gap in the magnetic field to let the hall sensor be pulled back down.

There's lots of different types of hall sensors in different PASs , and there's different arrangements and electronics behind them, so it would be unwise to make any assumptions.

All you need to do is glue some magnets to your chain-ring and fix the sensor on your own bracket so that it's near the magnets. The sensors are only screwed to the bracket.
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
7,845
5,785
The European Union
He has a KT controller and LCD-3 I think?

So yes I did try: went from an 8 magnet disk to a 12 magnet one and I changed the settings to make it work smoother. It worked with 8 magnets but setting the number to 12 made startup much smoother.
 

R0881E

Pedelecer
Sep 11, 2017
60
4
UK
I got my bike back from the LBS who charged me about 60GBP equivalent to true the wheel and add the rivnuts / battery. I hate paying over the odds but I am unsure how long I will be in Australia and it wasn't worth the hassle of buying the tools and trying to sort it myself.

I need to do the PAS but I have cycled to work today.

I was probably doing about 42kph/26mph indicated (I set it to 700c on the SLCD3) and I really didn't even break sweat.
I watched the wattage and it was probably around 350 on the flat. I badly need the PAS because the thumb control is a PITA and I want to increase my manual effort and improve range.
I cycled to the ferry (21km) and it dropped 1 battery bar just before I got there. I won't achieve my aim of 34km x 2 on a single charge until I change to PAS and reduce the assistance.

Acceleration is really good. It literally feels like I am cycling downhill all the time when on a flat and uphills feel like cycling on a flat. I went past a fast group of roadies up a hill and it was as if they were old men struggling.

The biggest downside was the vibrations I was receiving on the road at that speed. It will reduce once I fit the PAS and my speed drops.

Thanks d8veh for the suggestion, really pleased with the setup :)

The battery was not warm though it felt warm underneath once I removed it from the case to check. It wasn't hot though.

Slightly concerned about the Sydney heat over the next few summer months. It will be 28 when I cycle home today.
 

BornAgainCyclist

Pedelecer
Apr 22, 2017
148
28
45
Sanderstead
He's using a throttle. He hasn't fitted a PAS yet.
Ah. As you are aware Dave that was a pain in the backside for me. Robbie, look for the thread I started as I ended up pulling together a number of helpful posts. Level 3 which gives about 270 watts lets me ride at about 25 mph on the flat on a boardman hybrid 50 11 gearing.
 
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R0881E

Pedelecer
Sep 11, 2017
60
4
UK
What level of assistance are you riding on the flat with? Assume you have 5 levels plus an off (0)
Hi, Thanks for the reply.
I am on PAS1 but it still ramped up the watts if I left it on full throttle (so I was trying to hold it partially but it is difficult. I couldn't even attach it to the handlebar properly because it doesn't fit so currently on with an elastic band.

The watts go to about 800 at a guess up a hill / starting up. Measuring what I am hitting on a flat is difficult and I was definitely not cycling in my usual manner due to trying to hold the throttle on the top bar.

I think (from reading a few weeks ago) that I may be able to adjust the amps for each settings to change my assistance?
 

BornAgainCyclist

Pedelecer
Apr 22, 2017
148
28
45
Sanderstead
Yes but that only impacts the pedal assist I believe. The default levels on the 20A controller I have work just fine. Level 2 for normal, 1 or 0 for just cycling, 3 for get a move on, 4 for an obvious hill and 5 for over 10%s with proper attack pedalling going on.
 
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R0881E

Pedelecer
Sep 11, 2017
60
4
UK
Yes but that only impacts the pedal assist I believe. The default levels on the 20A controller I have work just fine. Level 2 for normal, 1 or 0 for just cycling, 3 for get a move on, 4 for an obvious hill and 5 for over 10%s with proper attack pedalling going on.
I haven't done much testing but it seemed like get a move on on PAS1 for me. I had it on 5 on the way back from the bike shop before switching to 1 and they both seemed rapid.

All up my bike is 17KG and is on 23 tyres.

I will try to test further on the way home.

How many watts would you see if you were on PAS1 and didn't pedal?
 

BornAgainCyclist

Pedelecer
Apr 22, 2017
148
28
45
Sanderstead
None as I don't have a throttle. About 100 watts when pedalling. 200, 300, 500 and then 800-900 respectively. All indicated. I doubt the throttle pays any attention to the level except between 0 and non 0
 

BornAgainCyclist

Pedelecer
Apr 22, 2017
148
28
45
Sanderstead
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Deleted member 4366

Guest
The throttle gives the same power whether you have it on level 1 or 5. After you fit the pedal sensor, it changes its behaviour. It works independently like before when you don't pedal, but as soon as you pedal, it gives fixed level 5 power.
 

R0881E

Pedelecer
Sep 11, 2017
60
4
UK
I believe that I have found a solution. Glad I spent 2 dollars on the 2 piece now..I cut and then filed it down to fit. I will probably just remove the sensor from the metal holder and epoxy it to the frame :)



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