pedal help

[billyboya]

Hi all I had fitted a while back a pedal assist disc to my pedal shaft. but only have now noticed, that the pedal arm now seems to wobble, reason being, is because the disc isnt flush to end of pedal shaft, but if you look at pictures, I cant have disc fully to back of pedal shaft as it needs to be close to the senser, can anyone suggest a better way so pedal can go fully on shaft with pedal assist disc too

any help will be most appreciated

 

[saneagle]

You can buy a longer bottom bracket. They don't cost much - £10 from Halfords. measure the length of the one you've got and see what options there are for a longer one. Your one looks quite short, so probably 113 mm:

Halfords Bottom Bracket 68mm | Halfords UK

Shop the latest Halfords Bottom Bracket 68mm at Halfords UK

www.halfords.com

 

[thelarkbox]

Can you mount the sensor on a different part of the bike?

Perhaps just filling or grinding down the rear of the pedal arm top rear by a few mm removing its mass that is hampering a good fit or replacing with a lower mass pedal arm??

The cheapest 1 piece pas sensors have a few mm profile and may fit .. a pas sensor is a pas sensor..

 

[Cadence]

You have the sensor mounted on the downtube. Can you fit it on the seat tube instead, which is narrower? This would allow you to move the disc further inboard and tighten the crank on the square taper?

 

[billyboya]

You can buy a longer bottom bracket. They don't cost much - £10 from Halfords. measure the length of the one you've got and see what options there are for a longer one. Your one looks quite short, so probably 113 mm:

Halfords Bottom Bracket 68mm | Halfords UK

Shop the latest Halfords Bottom Bracket 68mm at Halfords UK

www.halfords.com

I wont have a clue how to change the bottom bracket. dont you have to remove all the spokes etc chain.

 

[billyboya]

Can you mount the sensor on a different part of the bike?

Perhaps just filling or grinding down the rear of the pedal arm top rear by a few mm removing its mass that is hampering a good fit or replacing with a lower mass pedal arm??

The cheapest 1 piece pas sensors have a few mm profile and may fit .. a pas sensor is a pas sensor..

there is only 1 more part of bike i can fit sensor, and it wont achieve anything as will be same as before.

whats a 1 piece pas sensor do you have a link

 

[billyboya]

Can you mount the sensor on a different part of the bike?

Perhaps just filling or grinding down the rear of the pedal arm top rear by a few mm removing its mass that is hampering a good fit or replacing with a lower mass pedal arm??

The cheapest 1 piece pas sensors have a few mm profile and may fit .. a pas sensor is a pas sensor..

when you say grinding down pedal arm do you mean in image_9640 the part in inside what goes over shaft

there is a lip on inside or the pedal in image_9640 maybe i could grind that down a few mm i have a angle grinder

 

[billyboya]

You have the sensor mounted on the downtube. Can you fit it on the seat tube instead, which is narrower? This would allow you to move the disc further inboard and tighten the crank on the square taper?

Tried that but no good as then disc magnets wont see the sensor

 

[thelarkbox]

amazon link £10

ali express £2

 

[thelarkbox]

when you say grinding down pedal arm do you mean in image_9640 the part in inside what goes over shaft

while a bit tongue in cheek the grinding is the sort of thing i may resort to late in the day and would apply to the rear hidden back of the pedal arm where the tapered square opening is at its widest.

edit opening the taper wider would WORSEN the situation.. grinding could remove the rear of the pedal arm pressing on the disk, but is a drastic solution guaranteed to make you wince every time you look down and see the evidence of the grind. or proud? depending on personality i guess..

 

[saneagle]

when you say grinding down pedal arm do you mean in image_9640 the part in inside what goes over shaft

there is a lip on inside or the pedal in image_9640 maybe i could grind that down a few mm i have a angle grinder

Grind this bit off to get an extra 3mm clearance. I've done that a few times. It doesn't do any harm:

 

[billyboya]

amazon link £10

ali express £2

That looks better, I think my 1st pas had that type, I believe I need the orange connection. so is the sensor built into this where lead is, do Aliexpress charge shipping or tax as I believe they do which costs more then

 

[billyboya]

Grind this bit off to get an extra 3mm clearance:
View attachment 60138

 

[billyboya]

yeah thats what I had thought about doing really as I do favour this type of disc really, ok i will grind that lot off, maybe at a later date can change the pas disc.

just like to thank all of you here who has helped me its most appreciated believe me

 

[saneagle]

That looks better, I think my 1st pas had that type, I believe I need the orange connection. so is the sensor built into this where lead is, do Aliexpress charge shipping or tax as I believe they do which costs more then

I don't think you have enough room for one of those. You could try one, but you'll probably have to grind the pedal arm anyway.

 

[thelarkbox]

Before you plug in a grinder try a few pop tin shimms to bulk out the square taper and secure the pedal arm further out on the axle with no wobble? just be mindful of sharp edges

 

[billyboya]

Before you plug in a grinder try a few pop tin shimms to bulk out the square taper and secure the pedal arm further out on the axle with no wobble? just be mindful of sharp edges

Well too late as I have now grinded down end of pedal. so will now check it should be better now, do you think I need to place a washer behind and in front of disc or just fit arm on with out any just the pas disc only

btw what are pop tin shimms

 

[thelarkbox]

Pop tin aka coke tin or beer tin, can be cut with scissors to provide sub mm thick shims of aluminium.
Useful for adding a bit extra thickness or girth to things that require a precise fit, the edges can be razor sharp however ..

The traditional cyclist use is to add a bit extra girth to handlebars for additions like bels brake levers etc that are too loose without the shim. today milk cartons provide soft hdpe for the job without sharp edges but pop tin shims still have their place..

 

[billyboya]

Pop tin aka coke tin or beer tin, can be cut with scissors to provide sub mm thick shims of aluminium.
Useful for adding a bit extra thickness or girth to things that require a precise fit, the edges can be razor sharp however ..

The traditional cyclist use is to add a bit extra girth to handlebars for additions like bels brake levers etc that are too loose without the shim. today milk cartons provide soft hdpe for the job without sharp edges but pop tin shims still have their place..

Well Thats a new thing Ive learnt today. thanks for that

 

[saneagle]

Well too late as I have now grinded down end of pedal. so will now check it should be better now, do you think I need to place a washer behind and in front of disc or just fit arm on with out any just the pas disc only

btw what are pop tin shimms

No washers.