Jump to content
Sign in to follow this  
ericmark

Disc Brakes

Recommended Posts

My cheap mountain bike £175 from Halfords 3 years ago has cable operated disc brakes, as new they worked very well, impressed, however they went off, they stopped with exactly the same pressure required on levers as they did from new to retard the bike a bit, but increase pressure, and there was no change in rate of retarding, on inspection it was found an Alan key is required to move the pads closer, they were simply at end of travel, however until one comes to anchor on, one is unaware adjustment is required.

 

Once I was caught out once, I was careful to adjust brakes on a regular basis, however the Alan key needs to go through the spokes, so the took kit with Alan keys I carry will not reach. So holiday to Forest of Dean,  so from Gracelands Caravan site set off to go to Symons Yat view point, then to Monmouth where I would meet my wife and get lift back up the hill.  

 

The was a sign on the route, beware steep decent, on the forest roads, not a problem brakes worked well, then after taking pictures from viewing point used tarmac road to bottom, good job nothing came up, I could stop it going any faster, but realised I could not stop, I had clearly reached end of travel and did not matter how hard I squeezed it would not retard any more.

 

Once at bottom I did stop and tried to wangle in Alan keys to adjust them and caught the disc and burnt my finger, it had clearly got very hot on the way down, anyway adjusted up had a few more rides on the holiday with no problems. On returning home again a few more rides, then applied rear brake and nothing, not even the slightest retardation. On inspection one disc had actually left the calliper, passed two bike shops on way home, neither had replacement discs, so next day to Halfords and they did not have replacement, they phone Clarke who made the brakes, they could not identify the round pad with no levers attached to it, they think they have identified the part, but not sure. They say they will phone me when parts come in.

 

My son had given me a calliper off his bike when he changed to hydraulic ones, but the mountings are different so will not fit, I note with those the pads are held in the calliper and could not possibly fall out. I think the heat going down Symons Yat may have damaged the glue used, and if the brakes had acted on wheel rim, one questions if tyre could have taken the heat, I have considered getting a brush stale and making wooden discs like we did with the Landrovers in the Falklands, being round should be easy enough to make and as long as I don't go down a long hill heat should not be a problem.

 

However the way disc brakes fail worries me, yes had brake block fly out in the past, so I suppose no different, but with discs when they work there very very good, but when they fail they are horrid, just like the girl with the curl. No slowly getting worse, they work one minute then not the next.

Share this post


Link to post
Share on other sites

Many years ago, I worked as a mechanic in a cracking bike shop in Guisborough, and I’ve kept my hand in over the years.  

 

Your first sentence sums it up, ‘cheap mountain bike’. Unfortunately, cable disc brakes are never the most reliable things, there’s no reason they can’t be made to high standards, but the market rightly dictates hydraulic brakes at higher price points and specifications. So cable brakes are cheaply made and fitted. Cost for cost, rim brakes are more efficient and reliable at that end of the market, but marketing insists on discs. When you think of the cost of the bike, and all the parts on it, I’d be surprised if the brakes cost a tenner a set at assembly. Which doesn’t buy a whole lot of quality.  

  • Like 1

Share this post


Link to post
Share on other sites

As far as bicycles are concerned, "cheap" is usually accompanied by "and nasty". Some retailers, who I will not name, sell mainly BSOs, Bicycle Shaped Objects! This is why quality second hand often represents much better value than cheap new, even though it may not be as shiny!

Share this post


Link to post
Share on other sites
32 minutes ago, Stevan said:

As far as bicycles are concerned, "cheap" is usually accompanied by "and nasty". Some retailers, who I will not name, sell mainly BSOs, Bicycle Shaped Objects! This is why quality second hand often represents much better value than cheap new, even though it may not be as shiny!

 

Just like caravans really.

Share this post


Link to post
Share on other sites

On inspection one disc had actually left the calliper??? Disc or brake pad

if you knew you had a problem with the length of the Allen key why did you not get a longer one or are they not available?

 

I don't understand this, I think the heat going down Symons Yat may have damaged the glue used, and if the brakes had acted on wheel rim, one questions if tyre could have taken the heat,

wheel rim or disc?

 

macafee2

Share this post


Link to post
Share on other sites

I have a small bag under the seat with puncher outfit, chain link pusher, and multi-tool spanner and Allen key set, I don't carry a full tool kit, neither do I carry one in the caravan, do have a few more items, but not many, so will adjust brakes before leaving home with idea should not need adjusting while on holiday, clearly not the case in hind sight.

 

It had been my intention to stop on the way down Symons Yat to take more pictures, this would have allowed brakes to cool, however the bike decided this was not going to happen, so yes likely pads did over heat, and it may have effected glue, however I had expected as with car disc brakes backing metal would hit the disc making a sound which alerts you something is wrong, not just pop out leaving one with no brakes.

 

If the mountings for disc brakes were standard I would have swapped them, however the mounting holes are 90 degs out to fit those removed from sons bike when he went to hydraulic, as to if the rubbers in the hydraulic  cylinders can take the temperature is another question? I not disc brakes are not allowed with British road racing I understand due to injuries when they were tried?

 

I accept the is a limit to build quality with cheap bike, however it does not cost much to include service advice in the hand book, there was nothing about how to adjust, never mind how often. I suspect there is a set clearance which should be set with either a feeler gauge or turn until biding and slack off 3/4 turn or some thing. At least there should be a warning that brakes need adjusting regular or they will hit limit, it is a change of practice, in the past if the levers had not touched the handle bars you knew you could pull harder.

 

When adjusted correct they work so well, and there is no warning that they need adjusting only when you want that little extra do you realise it's not there.

 

I want to be able to go out on my bike, and to use a light lock when I leave it, and return to find it still there, as you buy more expensive bikes they don't get any lighter as you end up carrying more and more equipment to lock them up so they are there when you return.   Lock them to a drain pipe and it is only as strong as the drain pipe, lock them to a tree and you need a long lock, so best anti theft is to make the bike look less appealing i. e. cheap so not worth stealing.  

Share this post


Link to post
Share on other sites
Sign in to follow this  

×
×
  • Create New...