Thursday, June 21, 2012

Motor Update

I have been off the road for a little while unfortunately. About a month ago I removed the rear wheel with the motor from the trike to get some broken spokes repaired. Whilst it was off the trike I thought this would be the ideal time replace the seven speed freewheel with a higher quality Shimano one. This is where the problems began as despite the best efforts of my LBS the freewheel would not come off. This is probably due to the fact when I first screwed it on I never greased the threads! In addition my use of the low geared Mountain Drive on occasion would have applied an awful lot of torque to the freewheel ensuring a very tight attachment. So after a substantial amount of effort we gave up on the idea however our attempts caused the threads on the hub motor side cover to strip. So basically when I pedalled the rear wheel did not move - the freewheel just spun around all by itself!

I tried to get a side cover from (who supplied the motor originally) however they were a bit slow to my requests to get one sent (unusual for them but later found out some emails fell through the cracks with staff on leave - it happens!). Being keen to be back on the road as soon as possible I decided to contact Ezee direct and within an hour of my email to them I was told to contact Glowworm Cycles in nearby Sydney who are now an Australian dealer for Ezee gear. They were great and when I explained the situation they offered to remove a side cover from one of their motors and send it to me express post for only $55 and I had it within a few days of contacting them! They even gave me some pointers on how to remove my cover and replace it with the new one.

The side cover was attached with 9 small phillips head screws secured with Loctite. Most were OK to remove with a bit of firm pressure but one needed a hair dryer to melt the Loctite before it would come off. I replaced the 9 original phillips head screws with ones that used an allen key - much better in my view as the head of the screws is less prone to being wrecked when removing or tightening.

It was interesting to take the motor apart and check out the insides -
Drive side of the motor
Internal gear assembly
My previous seven speed freewheel was 11T-32T. However I could not use the 11T cog as it was to close to the frame and due to a fault in the freewheel itself I was also never able to use the 13T cog (the freewheel would just 'ratchet' around and not drive the wheel when pedalling). So in effect I have gone from a 15T-32T 'five' speed to a 14T-34T six speed! I will not have much need for the 34T cog unless I get stuck somewhere with a flat battery and need to pedal up a hill but the 14T will be useful when pedalling on the flats. For the technically minded I have now have a high gear of 72 gear inches instead of 67.2 or to put it another way a cadence of 90rpm will see me cruising along at 31km/h instead of 29 (info courtesy of Sheldon Brown's gear calculator).

My first ride with the new freewheel was going well until I went on to the 34T cog and it all seized up! Looks like I needed a slightly longer chain to use the very low gear. I adjusted the low stop point on the derailleur to lock out the 34T cog until this was installed a few days later. I may also look at changing the current 7 speed trigger shifter to a 6 speed twist. Now that my handlebars come apart in the middle a twist shifter can be installed very easily.

So after all that I am now back on the road and it is all going very well!

No comments:

Post a Comment