TREK Domane disc

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Trkorb
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Joined: Sat Jan 19, 2013 1:17 am

by Trkorb

We have two Domane Disc 4 series bikes in stock at our shop right now, decided to check them out to see if there was rub - Both of them missing paint due to the rotor...

Not such a great start to this whole disc brake thing by trek...

Spoke to the warranty guys in the UK, am awaiting a response from them next week as to the solution. They did acknowledge it was a problem on some models.

Seems a 140mm rotor would work fine, it seems like the only fix right now bar a redesign of the front fork.

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Benno
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by Benno

Trek have been doing this for years by over spec'ing front rotors on their mountain bikes as well.
Though many can and do argue this, I am perfectly happy with the performance of the 140mm rotors on my Defy.

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netromsa
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by netromsa

I checked it again yesterday and put some new tape on the fork. White putting the wheel back in I automatically scraped the fork(tape) and these rotors are so sharp, it directly sliced a piece of the tape. Maybe it's just this wat causes the damage.
@ oliverrb, please report back what the warranty guys come up with!

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fletch62
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by fletch62

I'm pretty sure the rubbing has come during use. a credit card won't fit between the fork and rotor. I measured the card at .77 of a mm. The rotor is too close, especially on a bike with a fork designed to give and flex. The stupid thing is Trek recommend a max. of 25c tyres, when there is clearly room for at least 32c. Would this be to avoid tyre rub?
I dont think a 140mm rotor is going to make a lot of difference either, as that only reduces the height by 10mm and the clearance will still be suspect.
I must say i have been underwhelmed by disc brakes so far. I've also had issues with air in the lines(no brakes), the new Shimano levers have no reach adjustment so they pull back extremely close to the bar, and the braking while being great doesnt seem worth the trouble. If had my time (and money) again, i think i would rather a Domane with the Bonty direct mount EE copies. Dont think they make them for that model yet.

netromsa
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Joined: Fri Jan 17, 2014 9:21 pm

by netromsa

Mine has a reach adjustment screenshot, You have to pop the hood of to be able to reach it tough

bombertodd
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by bombertodd

Fletch is sounds like you need a lesson on Shimano road disc brakes. Bleeding the air out is easy. They have reach adjustment too.

fromtrektocolnago
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by fromtrektocolnago

I'm a bit of a Luddite and a slow adapter of new technology. For me to switch, the product has to solve a problem I already believed I had, not for some problem others including marketers would like me to think I have. I've had no issues with my 6800 Ultegra brakes except in extreme wet conditions and there is some incremental maintenance that comes with hydraulic disc brakes(how much can be debated, along with a weight and cost penalty.

I'm from Missouri, I'll need more convincing. Perhaps after UCI gives full approval it will mature more standardize more and prices come down a bit. For weekend rides in good weather I see no benefit at this time.


Edited note, I'm slow down on descents when the roads are not optimal so will try out 25 mm tires. This is my example of trying out new things when there's a problem to solve such as descending faster on rough terrain.
Colnago C-59 (Dura Ace)
Firefly(Ultegra)
Colnago C-64 disc(ultegra) with Bora 35 wheels

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fletch62
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by fletch62

@bombertodd: I havent used Shimano since about 2006 and zero experience with disc's. The bike came from Trek head office and then the local dealer with the air in the lines. With the new levers it is apparently harder to get pressure into the line as it relies on gravity feed.
Its not the reach adjustment that concerns me, more the lack of a stroke adjustment which is supposed to be present. My levers are the newer ST-RS685 which has no adjustment that i can see. The first model had both adjustments via screws in the lever body. You should be able to see in the photos there is nothing to adjust.
ImageImage
The other photos show how close to the bar the lever pulls back for full pressure. If you are descending in the drops with fingers on the bar and brakes, you can get your fingers caught between the lever and the bar leaving you with no braking at all.
ImageImage
I have been on Campag with KCNC & Planet X calipers, so not the best brakes, but always ran them with as little play/lever pull travel as possible.

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Benno
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by Benno

Most people still bleed Shimano from the bottom up with a syringe, gives a better bleed. It is possible to adjust the stroke by adding a tiny bit more fluid to the system and pumping the pistons out a bit more. It's a little tricky, like adjusting a derailleur without a barrel adjuster, but easy with a little experience.

bombertodd
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by bombertodd

Fletch do you have the bleed block, Shimano mineral oil and the bleed funnel? If so bleeding is a piece of cake. Install the bleed block be replacing the brake pads with the bleed block. Just take out the bleed screw and attach the funnel. Add oil to the funnel then repeatedly squeeze the lever and gently tap it until no more bubbles come out also make sure you tilt the bars down about 30 degrees to get air out of the reservoir. When finished put the plug back in, remove the funnel, and replace the bleed screw. Once you bleed them a few times you'll be a pro.


You can also fine tune the engagement by changing the block thickness by sanding it smaller (quicker engagement what you want) or making it thicker (slower engagement). You can make it thicker by adding material such as business cards or old credit cards.


The freestroke screw is located on the top side. While the reach adjustment screw is underneath (you might need to move the lever over to see it). I recall them both being small 2mm allen screws.

wcroadie
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Joined: Fri Mar 16, 2007 6:58 am

by wcroadie

After being MIA from this site for years, I am glad I decided to stop in today, I am contemplating getting either an Emonda or Domane and was considering getting disc brakes, after reading this thread I think I will stay away from disc brakes for now. Love them on my MTB.

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Mr.Gib
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by Mr.Gib

I think disc are completely unnecessary for nearly all road applications. The one useful exception is for winter training in the Pacific Northwest. You can eat a set of rims in one season if you train on hilly terrain. I have a disc bike for this application. Everything works fine but the complications, additional weight etc. do not deliver any real dividends save for extending rim life. I do admit that if you must have carbon clinchers then disc is the only option IMO, "but that's not my bag baby".
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

Trkorb
Posts: 146
Joined: Sat Jan 19, 2013 1:17 am

by Trkorb

So, Trek got back about the disc brakes on our shop bikes...

They are sending us new forks because of the paint damage - and also supplying a different spacer kit for the swappable dropouts to stop it happening again.

I did ask about smaller discs in the future but they did say this kit will stop the problem so no need for smaller discs - once the kit is in ill take one of them out and see what happens, what do you guys think the best test for this would be? How can i flex it as much as possible to make sure its ok??

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fletch62
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by fletch62

Someone will correct me if i'm wrong, but wont adding a spacer at the dropout mess up the alignment with the rotor & caliper? Or is there a side-way adjustment for the caliper?
As for testing the new fork, i would try a 20% climb going up, or a sharp descent with a tight corner at the bottom going down.

by Weenie


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Trkorb
Posts: 146
Joined: Sat Jan 19, 2013 1:17 am

by Trkorb

There is a large amount of sliding adjustment for the caliper but I don't see that being an issue. I'm off work for a couple days, so will see any effects of the spacers the beginning of next week.

Hmm, not many 20% climbs around! I'll just have to hit some corners hard and see what happens.

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