mama-chari: rear wheel = easy?

jdd

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#1
We have two mamas, one used almost daily, the other almost never.

The one in use has major patches of thread showing on the rear tire, so I'm thinking to replace it with a tire off the unused bike. I'm good up to this point, but in putting the rear wheel back on a mamachari is there anything to do (or not), or to watch for or keep in mind?

thanks in advance...
 
May 22, 2007
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#2
The one in use has major patches of thread showing on the rear tire, so I'm thinking to replace it with a tire off the unused bike. I'm good up to this point, but in putting the rear wheel back on a mamachari is there anything to do (or not), or to watch for or keep in mind?.
I repair flats &c. on Jse. utility bikes all the time.

The main issue with re-assembly is to get the wheel aligned straight in the frame.

If it's single speed, or internal-gear hub, then (like with a fixie) take care not to over-tension the chain. About an inch of vertical play is OK.

Before you take it apart, check the order in which all the struts are attached. It's usually (inside to outside): stand, mudguard, rack.

While you're at it, check the chain for stiff links, and pop the drum off the brake to clean out any build-up of brake dust. Look for damage to the sprocket teeth which might indicate an elongated chain; if you have a chain wear gauge, use it.

The little rubber sleeves ("mushi-gomu") in the "ei-shiki" Woods/Dunlop valves cost pennies from LBS and should be changed once a year. Most people don't bother. They're a common source of slow air pressure loss, generating lots of work for bike shops when riders consequently get pinch flats.

If the hub is chrome-plated steel, inspect it carefully. I've seen several cheap ones rust right through, leading to leakage of rainwater into the hub bearings and subsequent bearing failure. Clean off any dirt and rust, and apply rust retarder (sabi-dome) if it's starting to ming.

If you know are feeling more adventurous, it might be worth popping the cones out and servicing the bearings. Clean everything with degreaser. Inspect each of the ball bearings (9 or 10 on each side - don't lose any!) Inspect the ball races for scoring or pitting. When reassembling, use plenty of new grease, and tighten the cones with your fingers just enough that the axle doesn't wobble before tightening the locknut down.

Grease the axle threads and the brake tension arm bolts before you put it all back together - makes it easier to get apart next time.
 

jdd

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#3
Thanks, Mike--maintaining the alignment while tightening the bolts was what I was wondering about, but that other stuff is good to know, too.
 

GSAstuto

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#4
Excellent post, Mike! I absolutely hate working on these as I must do a complete overhaul everytime on the POS. Once you have the wheel off - do EVERYTHING yuou can to avoid having to do it again. BTW -

1) The cheap crap rims oftentimes have the spokes riding up through the rim tape. So - I always check this and grind them down with a dremel. And always use a double layer of the fattest, hardest rim tape you can find. Really helps to prevent flats.

2) After you put on a new tire and tube - then also fill the sucker up with some Stan's or Tufo sealant. This will help guard against flatting for most situations.
 
Sep 2, 2009
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#5
I have stripped down a few mama-chari, so ride as a POS bike to the pub in the rain. Stripping all the stuff off them makes them a damn site lighter than stock (still heavy, of course).

When you take the rear wheel off, just take each part off one at a time, lay it on a piece of white kitchen towel, in the order you took it off, then put it back in the same order.

Most mama-chari I have worked on have had chain tensioners, so you will easily be able to get things in line on the back with the use of small (8mm, if I remember correctly) spanner.
 

jdd

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#6
Done.

Mike, the note to pay attention to how everything is stacked up and attached there was useful. What a mess compared to the simplicity of a normal rear derailleur!

Today was rainy, so daughter didn't ride it, and I got to do this, will have to see what she says about it tomorrow night and in coming days. It only has to last about five more months, she'll be off to uni (hopefully) in april. Burned through any number of latex gloves and still got dirty.

So no, I didn't clean the brake (not squeaking anyway), and I didn't check much else. I did wipe/lube the chain, but that's it, main concern was make this thing work reliably enough for a short while longer. (Once winter really hits she'll be with the wife or me in a car, anyway.)

Thanks all (esp. Mike).

John D.