Araya RM-20 wear indication?

[StevieBob]

Hello all,

Turning to the knowledge available here. So I have two old Giants (1990 Terrage and 1989 Super Sierra), both with their original Araya RM-20 rims. Now after I took a closer look it seems like they are smooth, no wear indicator groove. Now since they are old...sorry...vintage I have no clue wether they are completely worn out or that there never was a wear indicator. If the latter is the case, how do I know if they have some braking/life in them left.

Thanks in advance,

Stephen

 

[k-rod]

I'll bet there is some sort of rim wall thickness measure, beyond which a rim becomes dangerous ... but one would need know that measurement, and have a caliper with which to measure it.

 

[itscervo]

If you look closely, no :!: , a bit closer than that :roll: . You should see that a small part of the rim braking surface has no lip on the inner or outer, this is where the rim was welded & ground flat. So by looking at this flat part you will see how much wear has occured.

 

[StevieBob]

Re:

If you look closely, no :!: , a bit closer than that :roll: . You should see that a small part of the rim braking surface has no lip on the inner or outer, this is where the rim was welded & ground flat. So by looking at this flat part you will see how much wear has occured.

Ooooh, that is THE solution!! Feel very dumb now because that makes a ton of sense XD Any idea to what degree the rim will be useable, as in no: aaaaah crash and burn, pain, agony...death?

 

[itscervo]

Well, I have 2 bikes with RM20 rims, 1985 - 1986 & they both still have that flat spot. So I guess I'm never going to find out in this life time .

 

[M-Power]

Re:

I was never a big fan of these rims as they tended to wear out much faster than Mavics and when they split from brake wear, which they always did after around a year of commuting, it was usually late at night in driving rain

 

[cmjc]

The front Araya CV-7 on my 1991 Panasonic did finally wear through this year after sterling service.

But, I noticed it going concave long before I rode it to death.

My point in posting, is that I had ample time to see, before the rim became unusable, and even with an open "crack" on the rim due to wear I still felt safe. Mind you I did go easier on the front brake going downhill from then on

In contrast I bought a new Alex Ace-19 rim, used on the back wheel, and that wore through in only two years of riding. Much more flimsy manufacture.

Araya CV-7 would be my choice for longevity. But since I couldn't get one, I put a Mavic X139 rim on the back wheel.