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Shimano R550 wear indicators.

freehubfreehub Posts: 4,258
edited February 2010 in Workshop
Hi.

I looked at my front wheel and I notice on one side the wear indicator appears to be almost gone, which would indicate the wheels have reached the end of there life, thing is, the rims are hardly concave.

Would it be safe to keep on using them until they're pretty concave?


Thanks
Will.

Posts

  • softladsoftlad Posts: 3,587
    I'm guessing the wear indicators are there for a purpose.....
  • John.TJohn.T Posts: 3,698
    softlad wrote:
    I'm guessing the wear indicators are there for a purpose.....
    Mainly to sell more wheels. You can safely go double the depth of most indicators.
  • softladsoftlad Posts: 3,587
    John.T wrote:
    softlad wrote:
    I'm guessing the wear indicators are there for a purpose.....
    Mainly to sell more wheels. You can safely go double the depth of most indicators.

    how do you know when you have gone to 'double' the depth..?
  • John.TJohn.T Posts: 3,698
    Many years experience, keeping a close eye on the concavity and getting it wrong on 2 occasions. Both these only resulted in brake judder and a quick lowering of tyre pressure before riding home. I have also used a 'pointed' micrometer to measure the wall thickness. You need to do this in several places as it does vary. I changed the rim at 0.7mm.
    As a rough guide 1mm concavity is worn out.
  • John C.John C. Posts: 2,113
    John.T wrote:
    Many years experience, keeping a close eye on the concavity and getting it wrong on 2 occasions. Both these only resulted in brake judder and a quick lowering of tyre pressure before riding home. I have also used a 'pointed' micrometer to measure the wall thickness. You need to do this in several places as it does vary. I changed the rim at 0.7mm.
    As a rough guide 1mm concavity is worn out.

    Are you saying if I put a steel rule across the rim and there is more than 1mm gap in the center it is worn out ? If so, I have a worn out pair of wheels.
    http://www.ripon-loiterers.org.uk/

    Fail to prepare, prepare to fail
    Hills are just a matter of pace
  • freehubfreehub Posts: 4,258
    softlad wrote:
    I'm guessing the wear indicators are there for a purpose.....

    It was a sensible question.

    My R550's are hardly concave, yet my Open Pro rims are pretty concave, and apparently open pro rims have a hole appear in the rim when they wear out, and that's not happened yet.
  • John.TJohn.T Posts: 3,698
    Are you saying if I put a steel rule across the rim and there is more than 1mm gap in the center it is worn out ? If so, I have a worn out pair of wheels.
    They are getting that way John. Rims such as OPs do not have much more than 2mm in the wall between the bead section and the clincher lip. If you are worried about them either beg, borrow or steal a point micrometer and measure them or blow the tyres up to about 150psi and leave for a while. If they are getting dangerous you will find the brakes judder as a section will be forced out. I had the latter happen to me the other year when I put 110 psi in my front tyre then took the bike in the car to the YRC reliability trial at Tadcaster. When I got on the bike the front brake was juddering badly. I did the ride at 90 psi with no front brake, and binned the rim asap. Far safer to measure the rim but point micrometers and/or point verniers are not easy to find.
  • John C.John C. Posts: 2,113
    These were a pair of Mavic Cosmos wheels that I used with standard Shimano pads. Living in the same area as you you will appreciate the use of brakes, I tend to use mine a lot. I now use Koolstop pads and after 2 seasons my Shimano 550s are showing no sign of wear. I've binned the mavics after 1 season, I cried.
    http://www.ripon-loiterers.org.uk/

    Fail to prepare, prepare to fail
    Hills are just a matter of pace
  • John.TJohn.T Posts: 3,698
    Now using Ambrosio Evolution rims and Koolstop blocks on the winter bike. I get about 4000+ miles from the rear and about 6000 from the front. It does depend on how mucky a winter it is. The Evolutions have a bit more meat on them than OPs.
  • rakerake Posts: 3,281
    or get a trekking rim for winter. thicker in all the right places and not too heavy.
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