Rim Brakes, Motorized Bicycles & Miles -a cautionary tale

Re: Rim Brakes, MBs & Miles -a cautionary tale

happycheapskate said:
I've never seen that before! (drums actuated by the same levers as v's). I've seen "drag brakes" on tandems, though.
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They aren't actuated by the same lever. One lever controls the drums, the other controls the V-brakes.

If your drum brakes aren't doing it for you, have you cleaned them out and adjusted them? Are there any other shoes available for you?
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The simple fact here is that the 70MM drums aren't strong enough to stop 300lbs of MaB and man downhill on a hot day in a fashion that doesn't make the rider's sphincter pucker. Gravity is a pain in the ass.

What do the white v-brake pads do differently?
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They're softer, hopefully they don't take the black off my rims.

I have used the black ones and red ones.
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Me too. Many times.
 
Re: Rim Brakes, MBs & Miles -a cautionary tale

Alloy rims are dangerous. Get good rims with heavy duty spokes(14 gauge). I've used rim brakes and they've always worked well for me. Even when wet. Never had a problem. Alloy will bend and break very easily. Aluminum will bend quite a bit before breaking. I had warped wheels once from so doing so many jumps. Gotta have strong aluminum rims with heavy duty spokes to keep that from happenin' to ya.
 
Re: Rim Brakes, MBs & Miles -a cautionary tale

re: take the black off the rims. That's probably why they don't stop!
I have black Alex rims on my mb, and the black paint is slicker than snot!
I sanded the brake tracks with 80 and 100 grit sandpaper. They look like record grooves, but smaller tracks, like most "machined rims". Now they work really well, even with common black pads and 2 finger lever.


41bAtDWIhCL._SS500_.jpg
http://ecx.images-amazon.com/images/I/41bAtDWIhCL._SS500_.jpg
trials/mtb heavy duty wide rims by Alex.
 
Re: Rim Brakes, MBs & Miles -a cautionary tale

happycheapskate said:
re: take the black off the rims. That's probably why they don't stop!
I have black Alex rims on my mb, and the black paint is slicker than snot!
I sanded the brake tracks with 80 and 100 grit sandpaper. They look like record grooves, but smaller tracks, like most "machined rims". Now they work really well, even with common black pads and 2 finger lever.
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Good for you, but you seem to be confused about my setup. My drum brakes being too small was the problem.
I didn't have rim brakes on my bike before. How does black anodizing on the wheels of a drum brake-equipped bike affect stopping distance? ;)

The V-brakes with soft pads work better than drums. They also work better than V-brakes with hard-compound pads.
Working in tandem with my drum brakes, I think my bike stops equivalent to something with large discs now.
 
Re: Rim Brakes, MBs & Miles -a cautionary tale

Ah they figured it out :) The world is dirty, rim brakes don't like that. Every few tanks of gas spray your rims with a good dish washing soap 50/50 with water and a brush clean them. Both sides. Take a rag and do the same for the break pads. It's your life, so just do it! (c)
 
Re: Rim Brakes, MBs & Miles -a cautionary tale

Hmmm never even entered my mind that something like that could even happen!!! I have to inspect my bikes......thanks for the headsup!!!
 
Re: Rim Brakes, MBs & Miles -a cautionary tale

Yeah, that's a good idea, to check with the flat ruler or something, but shouldn't be the only way use to check.

It's possible also that using tires much wider than the rim, or wider than intended, may leverage against the walls of the rim with dramatic force. Running wide tires is very popular on motor bicycles.

machiasmort said:
Good thread, excellent illustration and reminder! I like the flat edge refference point... Newer Chinese rims might be thinner!
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Re: Rim Brakes, MBs & Miles -a cautionary tale

happycheapskate said:
Yeah, that's a good idea, to check with the flat ruler or something, but shouldn't be the only way use to check.

It's possible also that using tires much wider than the rim, or wider than intended, may leverage against the walls of the rim with dramatic force. Running wide tires is very popular on motor bicycles.
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I don't think that theory holds water? As the O.P. had run of the mill wheels....they were not extra wide or anything to such a point.

It is easier to mount road bike spandex rider type tires to a rim they were more designed for on the road type repairs I think? My experience with mountain bike type wire bead tires is they run tighter tolerances to the rim than that of typical road bikes and can take incredible abuse!



When reading here they suggest a way better tool than a run of the mill plastic tire spoon for such tires. http://www.parktool.com/blog/repair-help/tire-and-inner-tube-replacement



I always peddled mountain bikes with touring road gear sets AKA work slacks/jeans were always perfect attire for me no spandex. Then when I showed up at work all I had to do was eat breakfast and lock the bike. I just never saw any need for those myself but that's truly just me..I throw that comment in as I am a different breed of rider than a tradition road bike and I do have mountain bikes with as much as 20,000 ''all'' peddled miles on them!

I have just begun to use Large Marge rims. Will have to report back.

I mean a guy can run different gears and get a 30 mile work out with out having to go 30 miles lol. My route to work errands etc were not allways 30 miles away.

Just the gutter in the cities streets is brutal on the average road bike! That's why you see many spandex attires blocking the road at times. Because the gutter will quite simply destroy their wheels! ''Warps flats etc'' Those wheels are designed to be light and easily serviceable as a road bike guy wants the least amount of exercise.. they want competitive racing speed and the skinniest tires they can achieve. . In loo of some of that with cutting weight being the major objective and even some of the carbon fiber creations I don't see those as more durable?

In my Humble opinion I think a larger tire has some inherent flex that I think could very well prove more forgiving on a rim. As the tire easily gives takes the abuse and not the rim. The new going craze about solid tubeless tires would be very hard on spokes as the weight would be centrally located at one region of the spokes and not shared on a distributable pad of air.
 
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Re: Rim Brakes, MBs & Miles -a cautionary tale

The tires used on those rims have always been the standard wire bead 26x1.95, same as was equipped stock & run at 40-45psi BTW
 
Re: Rim Brakes, MBs & Miles -a cautionary tale

Very nice and very , very informative thread BarelyAWake. I for one would have never EVER thought to check the tolerance of rim wear due to brake pad wear just never even though of it and your 100% right there must be 1000% more stress on these rims now that we are using motors VS pedaling.

As it is on one of my bikes I have a 2" tire on a rim rated for no more than 1.5" tire but hey "It Fit" & when my 295 lb azz is taking a corner @30 mph I'm always thinking "What if that tire rolls off the rim" OH well I say to myself and dip a lil more Now I have to worry about the rim just exploding altogether . I like the idea you used for checking the wear simple yet ingenious As you can tell I throw caution to the wind when I'm riding.

However .... on a safer note my Niece and Nephew like to come over and fire up one or both of my bikes and take them out So it's them I care about & I thank you for bringing this potential catastrophic situation to my attention "I see now" after using your straight edge tech, that I indeed "need new rims" My brother & I bot thank you for this thread again! Seriously
 
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