having trouble fixing pedal sensor

Jammyb

Finding my (electric) wheels
Jun 30, 2016
24
0
40
southampton
#1
Hi my Yose power kit turned up today. Still waiting on the 9 speed freewheel to arrive before I can complete the install but decided to get everything else in place, all going fine apart from the pedal assist sensor. Its an all in one unit left crack sensor ( KT-V12L ).

Its seems to fit on ok but once the pedal crank is back on and tightened up it seems there's not enough room for it. The pedal crank fouls against it meaning the pedals cranks are stiff to turn once in place. Is there anything that can be modified or is this simply not compatible with my bike - need to purchase a narrower sensor ?

Any pointers appreciated

IMG_1748.JPG IMG_1745.JPG IMG_1742.JPG IMG_1750.JPG

actually looking at this photo it looks like its just to thick once the pedal is on fully ;-(
IMG_1752.JPG
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
6,115
125
55
West Sx RH
#2
You will have to remove the BB and get a longer one, measure the minimum axle length you need and buy the nearest length BB, or simply take in to Halfords or where ever and get a one.

If it's only a couple of mm you might get away with grinding a little off the crank arm inner face :eek:.
 
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Jammyb

Finding my (electric) wheels
Jun 30, 2016
24
0
40
southampton
#3
You will have to remove the BB and get a longer one, add the thickness of the sensor to the end of your current one and measure the minimum length of axle required.
Measure the one you have or simply take in to Halfords or where ever and get a one.
Oh brilliant that simple! wouldn't have thought of that, cheers will pop down Halfords tomorrow
 
D

Deleted member 4366

Guest
#4
About £10 in Halfords for a longer BB. Personally, I'd use the cheaper option of grinding off 2 or 3mm from the inner face of the crank arm.
 

Jammyb

Finding my (electric) wheels
Jun 30, 2016
24
0
40
southampton
#5
About £10 in Halfords for a longer BB. Personally, I'd use the cheaper option of grinding off 2 or 3mm from the inner face of the crank arm.
Cheers d8veh, I guess the downside other than cost of a wider BB is the pedals would be further out and might need a tweek to the hanger to change cogs, but if thats all i think ill do that as i dont have a grinder but do have a bike toolkit that has the BB removal socket.

Is there much advantage of going for the this shimano:
http://www.halfords.com/cycling/bik...shimano-bb-un55-bottom-bracket-british-thread

over the cheaper:
http://www.halfords.com/cycling/bik...x-122-5-square-taper-cartridge-bottom-bracket

My current one seems to be 68 x 113.5
 
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D

Deleted member 4366

Guest
#6
Only time will tell. I've used the cheaper ones without problems
 

John Carnie

Just Joined
Nov 14, 2017
4
1
68
Stratford Upon Avon
#7
As OP says, the longer BB will mean adjusting the hanger, best is to either go the route of grinding or buy a new left (narrower) crank.
 
Oct 20, 2017
208
12
t'North
#8
My YosePower kit was identical - after some heart searching I took 3mm off the back of the crank with a large hand file. Didn't fancy taking power tools to it. Didnt take long.

Swapping crank lengths can be a right pain to sort out

WRT BBs if you go that route, Shimano UN55 are superb, seem to last forever. I wouldn't choose cheaper personally, places like Chain Reaction et al do them at excellent prices, so worth shopping round
 

Jammyb

Finding my (electric) wheels
Jun 30, 2016
24
0
40
southampton
#9
I purchased a new bottom bracket today then got home and after reading all the advice (cheers) though i'd have a go at taking a bit off the pedal crank arm instead. Used a hacksaw to slice about 4mm off then finished off with a file.
IMG_1757.JPG
IMG_1761.JPG
Worked a treat and now all fits without fouling. Will be returning the BB to get a refund - happy days.

Well until the next problem...

I noticed the new wheel had no protection strip running round the inside to protect the inner tube. my original wheel has some nice hard plastic but i had no such thing so ran round it a few times with some electrical tape.

When I went to mount my tyre from old wheel it didn't seem to fit as well. looks like the wheel rim is a bit wider than the existing wheel. my current wheel has a width of 15mm where the inner tube sites, new wheel seems about 20mm wide in the same area. I'd just purchased some new tyres ( Schwalbe Marathan plus 700 x 25 ) Should that size fit on the new rim width?

When I went to inflate it it started to bulge near the valve until the tyre popped out of the rim. Tried resetting and checking inner tub wasn't caught anywhere but had the same problem once pressure was up. I had an old Vittoria randonneur that was 700 x 28 so put that one and it seemed ok, then i noticed it still felt a tiny bit wider near the valve once inflated. 10 seconds later it exploded sending my ear ringing!

So just a bad inner tube ?

Rims need proper protection tape ?

700 x 25 to narrow for the new rim (20mm wide) ?

Was hoping to commute on my new to tomorrow - so close now hopefully resolve this tomorrow eve
 
Oct 20, 2017
208
12
t'North
#10
In my experience rims need proper rim tapes yes, but you can use the one of your old wheel assuming it hasnt perished - some of mine are 20 year sold and work fine, CRC et al sell them cheap enough

The rim width is fine for the tyre sizes you describe - Sheldon can tell you more if you need to go deeper with that stuff

Assuming the insulation tape stayed in the well of the rim and didnt creep in to the corners where the tyre bead settles it should just about work - not ideal but I know people do it. The higher the pressure you run the less ideal insulation tape is. Rim tape is there to keep the tube in the rim and prevent spokes poking up from damaging the tube

What you describe with the bulge sounds it like, either (i) tyre was defective (ii) the tyre wasn't fitted properly, or (iii) more specifically the bulge near the valve suggests you didn't push the valve back in after getting the tyre on and the tube got pinched

Did you use tyre levers to fit the tyre or just thumbs? Have you successfully fitted plenty of tyres and this was a one off?

I always fit by hand, finishing at the valve, with a few psi in the tube to prevent pinches, and push the valve back inside the tyre after finishing the initial fit as the tube can get caught. Then go right round the tyre on both sides to settle the bead. Then I put 15 psi or so in and spin the wheel. Then round the tyre again on both sides to settle the bead higher/lower to get the tyre to run perfectly. Then up to max pressure to force everything in to place, check again before dropping to my working pressure and finally checking again - All the Schwalbes I have used have been very well made and seem to settle in perfectly quite nicely, though any tyre manufacturer can make the odd rogue
 

Jammyb

Finding my (electric) wheels
Jun 30, 2016
24
0
40
southampton
#11
Thanks DynatechFan it sounds like i made a few school boy errors from reading your advice. The tyre is almost new i'd fitted them to the bike pre elec conversion about 2 weeks ago.

I did inflate the tube a bit to fit and took time making sure the tyre looked in place correctly on both sides before pumping up to full pressure. The school boy error might have been that i didn't push the valve back into the tyre but instead pulled it through the hole and put the nut down on the valve to hold it all the way though, I understand now that might have caused it to pinch. (made that same mistake on both tyre's i tried!)

Watched a couple of youtube vids on fitting now so will try again with a new inner tube tonight. Think ill get so rim tape at the same time as i pump the pressure up to about 110 psi on the rear.

Might pick up a couple of bigger inner tubes to fit my old tyre's that came with the bike just in case i do have more trouble (there 700 x 40 originally, removed them as there thread pattern is loud and there slow for road use - narrow tyres made such a difference)

Found some advise on the net suggesting 20mm width rims should be used with a min of 700 x 32 so maybe i'm pushing it a bit with the 700 x 25. Considering my errors on mounting them though its got to be worth another go.

Really appreciate all the advise, fingers crossed ill be able to make first commute on it tomorrow - did i mention i'm a tad excited! ;-)
 
D

Deleted member 4366

Guest
#12
Marathon Plus tyres are notorious for that problem. It's nothing to do with the rim tape. They don't like to be stretched, so it's best not to use tyre levers on them, though you probably need levers to get them off, but you must use the correct technique. You have to push as much of the tyre rim into the well in the rim before levering, then, while holding a bit of lever pressure, work every possible bit of the tyre rim into the well before pulling it over the rim.

Once the bead has stretched, the tyre will keep popping off. Only a new one will solve it. Some rims are worse than others. I'd try one more time before condemning the tyre. Once on, put a small amount of pressure in the tube, then make sure that the tyre sits evenly on the rim. Push the valve in to make sure that the adjacent bits of the tyre can go down onto the rim.
 

Jammyb

Finding my (electric) wheels
Jun 30, 2016
24
0
40
southampton
#13
thanks guys, I decided to get some wider tyres today so went for a set of marathon 700 x 35. fitted them carefully and all is well - first ride out tonight was great! The kits really good and had no problem wizzing me along at a max of 23mph ish. With the new cassette though I think I need a new chain I can see it slip not between cogs but actually slip forward with a little click under load. Could see it clearly when i got back with bike upside down. Take it you don't need a specific chain for freewheel vs cassette ? Just a standard 9 speed chain?

Only thing I'm not sure about is when i spin it up unloaded ( bike upside down ) there seems to be a sort of uneven rhythm / slight grind noise. difficult to explain so hopefully my link to a video uploaded to youtube will work. It sounds a bit like an uneven engine - is this normal ?

 
D

Deleted member 4366

Guest
#14
The pulsing noise is just the unbalanced weight of the tyre.
 

Jammyb

Finding my (electric) wheels
Jun 30, 2016
24
0
40
southampton
#15
The pulsing noise is just the unbalanced weight of the tyre.
Ah thanks nothing to worry about there then [emoji106]

Enjoyed my first commute today normal 20 mins today took 16 [emoji3]


Sent from my iPhone using Tapatalk
 

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