How long do disc rotors last?

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simonhill
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How long do disc rotors last?

Post by simonhill »

How long do disc rotors last?

OK, a bit of a piece of string question, but I wonder how often, with any given sort of use, they need to be replaced.

I do have an ulterior motive. It is often said that rim brakes wear our rims, which they do. But you rarely hear people criticising disc brakes for wearing out rotors.

With rims costing about the same as rotors, could there be little difference in the respective running costs.

My last Rigida Sputnik rear rim lasted over 40,000 kms when replaced with wear line showing. Front is still OK, a further 5,000 on. Mainly touring and day rides - but I do try to avoid the wet.
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Heltor Chasca
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Re: How long do disc rotors last?

Post by Heltor Chasca »

Can’t answer directly, but bent/broken rotors make the best wind chimes.

Here to help.
Brucey
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Re: How long do disc rotors last?

Post by Brucey »

IME the piece of string is of a length that is usually shorter than 25000 miles.

But then too, most rims wear out well before that, anyway.

cheers
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fausto99
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Re: How long do disc rotors last?

Post by fausto99 »

simonhill wrote:With rims costing about the same as rotors

I didn't know that. :shock: :shock: :shock: Why?
fixedfixer
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Re: How long do disc rotors last?

Post by fixedfixer »

Changed a pair of BB5 rotors that had done approx 12,000 miles on the daily commute bike. They still worked fine but did have noticeable wear on them.
amediasatex
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Re: How long do disc rotors last?

Post by amediasatex »

With rims costing about the same as rotors, could there be little difference in the respective running costs.


Depends whether you can build/re-rim your wheels yourself or not ;-)
If you can't then then the labour cost of rebuild is often greater than the cost of the rim itself. Not to mention possible time off the road, disc rotor change takes all of 5-10mins and can be done by anyone with a allen key/torx wrench/cassette tool depending on your fitting type.

Also, cheap (and perfectly serviceable) disc rotors can be had for under £10, most 'cheap' rims are double that. Mid range rotors are ~£20, and only the very top end ones are over £40, rims normally vary from £20 -> £80+ so even if you can find a expensive rotor that costs more than a cheap rim it's not the norm.

There are myriad reasons to prefer one breaking system over another, but I think the 'disc rotors cost the same as rims' angle is a fairly weak argument.

However, back on your original question of 'how long do they last?'
That is indeed a piece of string style question, but I've only ever worn out one pair of disc rotors and that was on an MTB ridden in adverse conditions, so not really representative and I didn't keep track of the mileage but it probably wasn;t very high. I've worn out many more rims, on-road and off-road.
simonhill
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Re: How long do disc rotors last?

Post by simonhill »

fausto99 wrote:
simonhill wrote:With rims costing about the same as rotors

I didn't know that. :shock: :shock: :shock: Why?


Just to answer this, and a few others who doubted me.

I looked at disc brake rotors on wiggle and got prices from £16 upwards. Lots were about the £24 mark with some going much higher.

I then Googled my rims (as specified in my OP) and.find Spa do them for £18.

Also, I never said this is the only argument for disc v rim, merely that it is regularly cited ass case against rims.

Please keep 'em coming.
rjb
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Re: How long do disc rotors last?

Post by rjb »

Anyone tried to recycle a large cassette sprocket as a rotor ? a 40 tooth sprocket is approx 160 mm diameter.
Just thinking outside the box. :wink:
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gloomyandy
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Re: How long do disc rotors last?

Post by gloomyandy »

I'm not sure what sort of disc rotor you looked at but this one (on Wiggle) is only £4.74 (to me as a Gold price)....
http://www.wiggle.co.uk/lifeline-one-pi ... 1245541262

Looks like a pretty reasonable one to me. So a disc can be considerably less expensive than a rim.
simonhill
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Re: How long do disc rotors last?

Post by simonhill »

I looked at what I thought was an average price for a named brand. Below your £4:50 disc are three more in my price range.

I don't know anything about rotors, but if most are £17 upwards I would wonder why one was only £4:50.
nomisp
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Re: How long do disc rotors last?

Post by nomisp »

Hi, this thread seems to have moved into a rim / disc cost question . Should not the cost of pads also be taken into account, especially as I hear stories of pads being worn out very quickly especially in wet or muddy conditions compared to shoes,. Nomisp
Mr Evil
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Re: How long do disc rotors last?

Post by Mr Evil »

The design of the rotor matters; I had some where the holes drilled into them were arranged into two circles. Of course the greatly reduced surface area around those two circles wore a lot faster than everywhere else, ending up with two grooves in either side of the disc after only about 4k miles. I changed those for some with no holes at all, and they have no noticable wear after a similar distance (whereas I can wear through a rim in that time with rim brakes).
Stevek76
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Re: How long do disc rotors last?

Post by Stevek76 »

simonhill wrote:With rims costing about the same as rotors, could there be little difference in the respective running costs.


Yes but there's an order of magnitude or more difference in the time taken to replace them, so that largely depends on how much you value your own time. Not to mention that building a wheel is a level or three up in bike maintenance ability than changing a disc rotor.
The contents of this post, unless otherwise stated, are opinions of the author and may actually be complete codswallop
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Si
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Re: How long do disc rotors last?

Post by Si »

nomisp wrote:Hi, this thread seems to have moved into a rim / disc cost question . Should not the cost of pads also be taken into account, especially as I hear stories of pads being worn out very quickly especially in wet or muddy conditions compared to shoes,. Nomisp


also the cost of the wheel rebuild and new spokes if appropriate. Most home mechanics can change a disc easily but those who can build their own wheels are in a minority.
iandriver
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Re: How long do disc rotors last?

Post by iandriver »

+1 for how longs a piece of string. Miles don't wear rim brake tracks or rotors. The life they've had does.The average rotor does seem far more resultant to the average pad compared to a brake block on an aluminium rim.
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