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Discussion Starter #1
I wasn't going to post this but then I saw how much a new brake disc costs and thought if someone else gets into the same predicament, they may be able to save a bit of money.
I suppose it depends on how bent the disc is, mine was about .030" (.76mm) in one spot

I would be interested to know if people have found brake discs and pads for significantly lower cost than the OEM one.
 

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I wasn't going to post this but then I saw how much a new brake disc costs and thought if someone else gets into the same predicament, they may be able to save a bit of money.
I suppose it depends on how bent the disc is, mine was about .030" (.76mm) in one spot

I would be interested to know if people have found brake discs and pads for significantly lower cost than the OEM one.
A quick google and eBay search will reap results... I just fitted this





You can go box standard cheaply as well..



Hope this helps..

Chris


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I wasn't going to post this but then I saw how much a new brake disc costs and thought if someone else gets into the same predicament, they may be able to save a bit of money.
I suppose it depends on how bent the disc is, mine was about .030" (.76mm) in one spot

I would be interested to know if people have found brake discs and pads for significantly lower cost than the OEM one.
That was an interesting approach to straightening out a warped disc, sort of the way someone would have approached it in 50 years ago when labour was cheaper (if disc brakes had been routinely fitted to production motorcycles in those days). I quite liked it myself, but with a new part only costing about 拢50 it probably wouldn鈥檛 be worth doing, and taking the risk with one鈥檚 safety.

Good post though.

Alan


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I hadn鈥檛 read the post properly or I鈥檇 not have posted about replacement.
Good job with the truing, have you felt any pulsing through the lever?



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Discussion Starter #5
I did want input as to where everyone had found better prices on discs, so thanks.馃槉
I did have a quick look on ebay and found some prices not quite as low as Chris posted (exchange rate is currently 拢1 = $1.333 us). Trade war effect???
Not a fan of ebay, but I may have to become one.

There was no pulsing thru the foot lever that I could tell, just the normal solid feel, even with that .030" bend.
That final spin of the wheel was after I had applied the pads back to the disc, so it wasn't grabbing once per rev like it did before.

And yes Alan, well spotted, I am from the older generation and as I am retired, my labor is free. I'm not pulling myself away from stock trading or running a business, where there would be some cost perhaps.

Got the DTI and holder thru Amazon for $26. And I think I will be using them again on my sons car soon, as his brakes are pulsing a little. Mostly to either prove or disprove my theory that the pulsing happens when the pads wear thru the thin hardened layer created when the discs are initially ground. Then you get into the cast iron, which does not have uniform properties causing thickness variations around the disc, rather than warping as it is mostly put down to.
Brakes on cars are of course much cheaper <--Link to RockAuto
Interesting spec on this performance disc about runout and thickness variation (final bullet point). Implies perfection is not required.o_O

Rich
 

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I did want input as to where everyone had found better prices on discs, so thanks.
I did have a quick look on ebay and found some prices not quite as low as Chris posted (exchange rate is currently 拢1 = $1.333 us). Trade war effect???
Not a fan of ebay, but I may have to become one.

There was no pulsing thru the foot lever that I could tell, just the normal solid feel, even with that .030" bend.
That final spin of the wheel was after I had applied the pads back to the disc, so it wasn't grabbing once per rev like it did before.

And yes Alan, well spotted, I am from the older generation and as I am retired, my labor is free. I'm not pulling myself away from stock trading or running a business, where there would be some cost perhaps.

Got the DTI and holder thru Amazon for $26. And I think I will be using them again on my sons car soon, as his brakes are pulsing a little. Mostly to either prove or disprove my theory that the pulsing happens when the pads wear thru the thin hardened layer created when the discs are initially ground. Then you get into the cast iron, which does not have uniform properties causing thickness variations around the disc, rather than warping as it is mostly put down to.
Brakes on cars are of course much cheaper Interesting spec on this performance disc about runout and thickness variation (final bullet point). Implies perfection is not required.o_O

Rich
Hey Rich,

So I鈥檓 thinking your discs should be made of martensitic stainless steel (not cast) and this is why you were able to cold work them back to true. If they were cast, stressing them until they strain would probably cause crack propagation (possibly unseen) as the elastic region of cast is quite limited.
EBay is great but you have to be fairly careful ...
It鈥檚 a good feeling truing something (did a fair amount when I was serving as an Armourer) and it sounds as though you have done a cracking job mate, nice one!

Chris.


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Hi Rich,

I thought it was a really good post, and a good video also. My point about this being the way we might have approached the problem 50 years ago was really pointed towards the maintenance industry: I don鈥檛 think one would be able to persuade a bike shop to attempt a repair like it today, but in the 1970s truing up things with a hammer and a punch would have been common fare for a mechanic. In one respect that is a great pity because we mostly replace rather than repair stuff now, but on the other hand manufactured parts have become so cheap it is possible (and safer) to replace rather than refurbish.

I like your approach of fixing stuff that can be fixed - like you I鈥檓 retired (not old age retired - but could afford to retired) and enjoy fixing stuff. I often buy bikes that need fixing, even though it hardly ever makes any financial sense - it is quite satisfying to take something that is beyond economic repair and produce something serviceable (usually for a fairly small outlay but a huge amount of my time). My 1976 Suzuki Bloop is a good example, bought for 拢200 as a barn find that had not run for 30 years and now runs like a top (although it certainly looks 43 years old:



It probably only cost about 拢200 to (oily rag) renovate the bike, but if I accounted for my time it would probably be charged at about a shilling an hour.

I suspect you will find your dial gauge invaluable many times in the future, I bought one a decade or so ago (with a magnetic retort stand) for one particular job, and have probably used it a couple of times per year. Tools are nearly always a good investment.

Your thesis about excessive brake run out being the result of differential wear through the hardened surface is interesting. Why not treat yourself to a digital micrometer (they are remarkably cheap, you will find one for less than $10 on eBay (I鈥檓 an eBay fan)) and find out whether the thinness varies? You know you need a digital micrometer (every man does).

Anyway, good article.

Alan


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Hey Rich,

So I鈥檓 thinking your discs should be made of martensitic stainless steel (not cast) and this is why you were able to cold work them back to true. If they were cast, stressing them until they strain would probably cause crack propagation (possibly unseen) as the elastic region of cast is quite limited.
EBay is great but you have to be fairly careful ...
It鈥檚 a good feeling truing something (did a fair amount when I was serving as an Armourer) and it sounds as though you have done a cracking job mate, nice one!

Chris.


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... that is a really good point that I thought about whilst out walking Bob (the dog) but forgot to mention to Rich. Cast iron would be too brittle to cold work with a hammer and punch. I agree that Rich did a good job though, and that it was good of him to share it with us.

You are right about eBay being a great resource as well Chris, I use it most days.

Another thing I forgot to mention to Rich was to congratulate him on changing his own tyres. I do as well, and it really isn鈥檛 difficult, but most riders I know entrust that job to the bike shop. The cost saving isn鈥檛 really the significant point, rather it is about having an intimate knowledge of one鈥檚 bike (or car/pushbike/other machine).

Best wishes,

Alan


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My front brake has signs of owner dementia(taking off with the disc lock in place..) probably very slightly bent, it hardly pulses with a finger on the lever, my plan is to just insert a breaker bar in the hole the lock was in and bend it right back, using the caliper as indicator. But with this method i can fix the first disc i bent馃槃
 

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Another thing I forgot to mention to Rich was to congratulate him on changing his own tyres. I do as well, and it really isn鈥檛 difficult, but most riders I know entrust that job to the bike shop.
Everybody should learn how to change a tyre for emergencies, but why would you do it by choice when a motorcycle tyre supplier will give you fitting, dynamic balancing and old tyre disposal all for free? Mind you it took me 45 years to work this out. Big shout out to Pablo's Motorcycle Tyres in Melbourne, Australia.
 

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Discussion Starter #11
Everybody should learn how to change a tyre for emergencies, but why would you do it by choice when a motorcycle tyre supplier will give you fitting, dynamic balancing and old tyre disposal all for free? Mind you it took me 45 years to work this out. Big shout out to Pablo's Motorcycle Tyres in Melbourne, Australia.
I have to say changing tires (tyres) on a steel rim is easier than an aluminum one, due to the tires sticking to the rims. I just screwed up...
Tire changing - I think I can still get tires cheaper on line, even after delivery fees and do the install and balance myself. Cycle gear for example charges full MSRP for the tire and then some. Plus I do a 2 stage balance - wheel rim first, mark the heavy spot, then mount the tire with the tire mark at the heavy spot (not where the valve is). Usually end up with fewer balance weights. I will check again for the next set on my MT-09, I do scratch aluminum rims with the tire levers. Have not taken the plunge for the harbor freight changer yet, looks cheap to me.

As for the discs, I did change out a pair of front discs on my old 1100G and getting the retaining screws out was scary. The loctite they used was too much - I thought the thread was going to strip
 

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Everybody should learn how to change a tyre for emergencies, but why would you do it by choice when a motorcycle tyre supplier will give you fitting, dynamic balancing and old tyre disposal all for free? Mind you it took me 45 years to work this out. Big shout out to Pablo's Motorcycle Tyres in Melbourne, Australia.
I think it is unusual for tyre factors to offer free fitting, balancing and disposal, here in England the normal charge is 拢25. Unfortunately, if I booked my bike in for a new tyre at Pablo鈥檚 Motorcycle Tyres in order to take advantage of the free fitting, the new tyre would be worn out by the 12,000 mile back home and so would negate the saving.


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Unfortunately, if I booked my bike in for a new tyre at Pablo鈥檚 Motorcycle Tyres in order to take advantage of the free fitting, the new tyre would be worn out by the 12,000 mile back home and so would negate the saving.
Bring some extra wheels... and a snorkel. It's going to be 40C here tomorrow so you will enjoy it.

Each to their own but I've changed enough tyres and done enough pretend balancing to happily pay the pro's to do it.
 

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I think it is unusual for tyre factors to offer free fitting, balancing and disposal, here in England the normal charge is 拢25. Unfortunately, if I booked my bike in for a new tyre at Pablo鈥檚 Motorcycle Tyres in order to take advantage of the free fitting, the new tyre would be worn out by the 12,000 mile back home and so would negate the saving.


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Yes, a lot of us dont live near enough to a motorcycle tire specialist for that to be possible. I have to get my tires in the mail, and car tire guys.. nah, rather change and balance myself. Its always three times cheaper as well.
 

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Bring some extra wheels... and a snorkel. It's going to be 40C here tomorrow so you will enjoy it.

Each to their own but I've changed enough tyres and done enough pretend balancing to happily pay the pro's to do it.
If you do pretend balancing you probably should never have replaced a single tire to begin with馃槄
 

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Bring some extra wheels... and a snorkel. It's going to be 40C here tomorrow so you will enjoy it.

Each to their own but I've changed enough tyres and done enough pretend balancing to happily pay the pro's to do it.
... if I leave now I should be there by about April :)


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