Motorized Bicycle Engine Kit Forum  

Sponsors



Go Back   Motorized Bicycle Engine Kit Forum > Motorized Bicycle > Board Trackers and Vintage Motorized Bicycles

Board Trackers and Vintage Motorized Bicycles Vintage enthusiasts share your board trackers and other vintage motorized bicycles ideas, builds and replicas here

Reply
 
Thread Tools Display Modes
  #161  
Old 04-17-2017, 08:38 AM
wret's Avatar
wret wret is offline
Motorized Bicycle Elite Member
 
Join Date: Feb 2014
Location: Maryland
Posts: 306
Default Crunch!

I never really liked the sheet metal anchor arm of the AV88 rear hub I've been using, particularly since I had to extend it to reach a stud on the frame. It worked though and I've ignored it. Saturday it came loose, wrapped about 360 around and dragged the chain guard into spokes. It sheared off several spokes, and actually ripped a couple out of the hub flange before the inertia ceased and I skidded to an abrupt stop from about 25 mph.

Lesson learned: don't ignore these nagging little things. Now I'm faced with a dilemma, or maybe a challenge depending on how you look at it. I don't really want to use another AV88 hub but the think I liked about it was that the spoke mounting diameter was similar to 21" dirt bike drum hubs so that it can be transplanted into a wheel using the existing spokes. I have a complete drum hub (1970's Suzuki I think) that I took out when I put the wheel together. I've been thinking of a way to bolt a sprocket to it and use it as a rear hub. I've seen disc conversions but I don't think I've seen anyone mount a sprocket to one. I know longer need the sprockets on both sides as the crank pedals are long gone and I don't think they will be returning. I'm not really out anything but my time if it doesn't work. The next thing would be to get a rear wheel drum hub, already designed to attach a sprocket, though I don't know if there are any obstacles to making one fit such as width and sprocket spacing.

Here's what I noticed about breaking down on a motorcycle: in less than a minute a motorcycle rider stopped and offered help with tools. I was only a block or so from my house and had to walk back to get some tools to cut the chain guard out of the spokes so it would roll. When I got back to the bike, another motorcycle/rider was waiting to see if he could help, and one or two others in cars stopped to offer help. A couple of weeks ago, while several miles from the house, I threw thew the chain. Within seconds, before I even had time to think about repair options, a guy with a pickup, ramp, and straps stopped, loaded the bike, and had me home in a few minutes. I am amazed how motorcycle riders look out for each other.
Reply With Quote
  #162  
Old 04-17-2017, 11:28 PM
Harold_B's Avatar
Harold_B Harold_B is offline
Motorized Bicycle Elite Member
 
Join Date: May 2012
Location: Grand Rapids, MI
Posts: 895
Default Re: Starting to look like something

Glad you kept it upright! I had the brake arm shear and wrap around the hub on a Shimano coaster and decided I'd be building with drum brakes going forward. I'm using the Sturmey-Archer with the thread-on sprocket though I'm not using a chain (belt drive). The spacing is wider and I'm not sure they'd have the stopping power you'd need for your heavier bike.
Reply With Quote
  #163  
Old 04-18-2017, 07:32 AM
indian22's Avatar
indian22 indian22 is offline
Motorized Bicycle Elite Member
 
Join Date: Dec 2014
Location: Oklahoma
Posts: 1,020
Default Re: Starting to look like something

Wret I'm also glad you stayed on the bike 'cause often all goes atumble when these things come apart. It sounds the wheels a mess, but know you have it sorted out with your outlined plan.

Harold did I understand you correctly, that the coaster lever sheared and would you mind describing where it gave way? Generally the flimsy band holding the lever arm breaks or the lever strap fastener bolt falls out. If it was the lever itself breaking I'll need to give this some design consideration as I use coasters on all my rear hubs. Actually the coaster works pretty good in my bikes under 100 lbs. but I always run a front brake as well on all bikes, pedal chain failure isn't uncommon and then no brakes from the rear!

Get her up and running Wret as she is really looking good and needs lots of riding this Spring. Rick C.
Reply With Quote
  #164  
Old 04-18-2017, 07:35 AM
wret's Avatar
wret wret is offline
Motorized Bicycle Elite Member
 
Join Date: Feb 2014
Location: Maryland
Posts: 306
Default Re: Starting to look like something

Thank Harold. Yes it occurred to me we could all use some skid practice.

I do like a good solid drum hub. I considered putting my original Puch hub back on. It has a great solid, antiquey look, but it's not worth the effort (or expense of custom spokes). That hub didn't have enough stopping power.

This is what I had in mind. Plenty of meat in the flanges of this hub to support sprocket bolts. Sometimes an idea seems great until you put it together. Actually I had questions about this one, but going together, it seems solid.


Attached Images
File Type: jpg front hub conversion1.jpg (177.6 KB, 68 views)
File Type: jpg front hub conversion2.jpg (140.8 KB, 69 views)
Reply With Quote
  #165  
Old 04-20-2017, 06:48 AM
Harold_B's Avatar
Harold_B Harold_B is offline
Motorized Bicycle Elite Member
 
Join Date: May 2012
Location: Grand Rapids, MI
Posts: 895
Default Re: Starting to look like something

Now that's a beefy looking hub! Nice.

Rick - the arm itself let go or more specifically the anchor bolt hole tore through. It was an after market arm made by Ridley for the Shimano 110 spline hub for use with sprockets. To be honest I'm not aware of anyone else having had this issue but I'm not interested in a repeat! Here's a link to the old thread showing a couple of pics: http://motorbicycling.com/showthread...=43392&page=18
Reply With Quote
  #166  
Old 04-20-2017, 07:06 AM
indian22's Avatar
indian22 indian22 is offline
Motorized Bicycle Elite Member
 
Join Date: Dec 2014
Location: Oklahoma
Posts: 1,020
Default Re: Starting to look like something

Thanks Harold and glad you survived the incident without bodily injury. I'd think not common, but like you said...Often the "strap" breaks or the bolt works loose, but I've not heard of the lever itself failing on a coaster, it happened so they do.

Wret that hub looks the deal and the standoffs stand out as a simple, yet robust and attractive solution to spacing. Back on the road with lacing soon no doubt.
Rick C.
Reply With Quote
  #167  
Old 04-20-2017, 07:07 AM
wret's Avatar
wret wret is offline
Motorized Bicycle Elite Member
 
Join Date: Feb 2014
Location: Maryland
Posts: 306
Default Re: Starting to look like something

Yes Harold, there are some similarities there to my incident.

After taking everything apart, I think it would be unfair to blame the issue on the AV88 hub. The stamped sheet metal brake plate/arm are actually pretty stout, though I'm not a fan of the tin-can thin sheet metal that form the rest of the cover. I'm sure it was my modification of the arm and being insecurely fixed to the frame that caused the failure.
Reply With Quote
  #168  
Old 04-20-2017, 07:23 AM
wret's Avatar
wret wret is offline
Motorized Bicycle Elite Member
 
Join Date: Feb 2014
Location: Maryland
Posts: 306
Default Re: Starting to look like something

Thanks Rick.

I should disclose another "doh" moment when preparing for lacing the new hub to the rim. I've laced a few wheels now and it gets easier and less intimidating each time. But, most of my reference material came from the bicycle world, in particular Sheldon Brown's excellent tutorials. After reviewing some lacing tips related to motorcycle wheels I learned (and this may be embarrassingly well-known to most) that typically all the spokes in a wheel are not the same. I looked closely when I took my wheel apart and sure enough I had "mild acute" and "mild obtuse" spokes installed randomly.
Reply With Quote
  #169  
Old 04-20-2017, 09:42 AM
indian22's Avatar
indian22 indian22 is offline
Motorized Bicycle Elite Member
 
Join Date: Dec 2014
Location: Oklahoma
Posts: 1,020
Default Re: Starting to look like something

So Wret I'll just confess to being somewhat similar in mental acuity to motorcycle spokes: ranging somewhere between mildly obtuse & acutely obtuse at my best ...can't see acute used in a positive manner that would apply to meself except as result of mental or physical examination.

As to spokes: I know you are in the process or have corrected the errant positioning. It all comes back to having a nice, safe Spring ride. Rick C.
Reply With Quote
  #170  
Old 04-22-2017, 02:36 PM
wret's Avatar
wret wret is offline
Motorized Bicycle Elite Member
 
Join Date: Feb 2014
Location: Maryland
Posts: 306
Default Re: Starting to look like something

Well it's a lovely rainy Saturday so I can get some wheel work done and don't have to feel bad about shirking yard work

I tried out a lacing tip I read about: inserting all the spokes in the hub first and tieing them in pairs. It actually worked quite well. This keeps the spokes close to their correct orientation and as a bonus, holds them in away from the wheel so it doesn't get all scratched up.



This wheel went together easily


And ballanced nicely
Attached Images
File Type: jpg wheel spokes.jpg (123.1 KB, 32 views)
File Type: jpg wheel whole.jpg (223.2 KB, 32 views)
File Type: jpg wheel bal.jpg (229.0 KB, 30 views)
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 05:43 PM.


Sponsors

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
MotorBicycling.com