Ultegra brakes question for the roadies

I want to swap my current non-series calipers with Ultegra 6700 (to work with 10 speed 105 shifter/brake levers). Would I be right in thinking the only difference between the front and rear calipers is the length of the bolt – ie the front being longer to go through the for? If that’s the case can I buy 2 x rear and cannibalise the bolt from the front caliper into the Ultegra? Rears going v cheap at the mo.

You’ll need to remove the brake shoes and turn them round.

I’d not be 100% certain that the bolt would be the same with the new Ultegra calipers. There are a number of different types used on Shimano’s newer brakes. You can buy a replacement bolt from SJS though if it doesn’t fit. And if your current one does then excellent.

http://www.sjscycles.co.uk/shimano-ultegra-br-6700-pivot-bolt-assembly-front-525mm-x-125mm-8g6-9803-prod29956/

Thanks munrobiker.
BUT £15 for a bolt! That’s half the cost of the 6700 Ultegra caliper!

Buy 105 5800s instead of old ultegra,bit more powerful due to the dual pivot.

Buy 105 5800s instead of old ultegra,bit more powerful due to the dual pivot.

(Shameless plug). I have an unused set for sale, in black. Email in profile…

105 or Ultegra?

You’d best not look at the Dura Ace ones then 😉

105 or Ultegra?

5800 series 105. They’re more powerful than Ultegra 6700.

Bump for the evening crowd.

Does anyone know best source of info for whether the main attachement bolt on non-series front caliper can be put in a rear 6700 Ultegra caliper to make that into a front? Looked on Shimano site but not conclusive.

You mean the nut?

A nut’s a nut. If it’s long enough it’ll be fine. Old Trek Madones use a very deep nut for some reason, but there’s nothing special about each groupset. Just buy a pair of rear brakes and re-use your existing nut on the front one (having swapped the pads over).

Pretty sure he means bolt.

No idea OP, unlikely IMO.

But the bolt is integral to the brake. It’s a nut you need surely? I’ve never seen a Shimano road brake with a separate bolt.

Maybe I worded it wrong.
The front and rear caliper bodies are they same (apparently) – the only difference between them being the central bolt which will be longer on the front than the back as it has to go through the fork. Obviously a nut is a nut but the bolt lengths are different.
What I need to know is if I bought 2 6700 rear caliper bodies, can I take the bolt out of one of them and put the longer bolt from my current front brake in it to effectively convert the 6700 rear to a 6700 front?
Pretty sure that makes sense now if it didn’t before 😉

Just gone to take front brake off to see if the bolt will pull out.
Can’t undo the allen key – nightmare!
It’s rounded on the outer and recessed into the fork itself – it won’t budge and I don’t want to force it.
Think I’ll be back in touch with CRC as it hasn’t been touched since I bought it from them in Feb last year.

That does make sense, and yes, you should be able to if you can sort this issue!

Email just sent to CRC – they checked it before it was sent and it’s been untouched until tonight.
Hopefully they can help out in some way (crosses fingers)

Think I’ll be back in touch with CRC as it hasn’t been touched since I bought it from them in Feb last year

Rounded off on it’s own did it?

Funny.
Nothing has been ’rounded off’ in the sense you mean it.
I mean it isn’t a conventional nut – it’s round and recessed into the frame with the hex on the inside.
This hasn’t been forced but not sure of next move hence email to the point of purchase.

http://www.sjscycles.co.uk/shimano-caliper-brake-mounting-bolt-each-prod28697/

one of these,

That’s the badboy.

FWIW, I bought a pair of ultegra 6800 brakes from eBay a while back. Didn’t check them and when it came to building up my new frame I’d been sold 2 rears. The bolt was not removable and I ended up buying a new front.

The amount of water the front bolt/nut sees can make it seize

Thanks al – been doing some reading up.
I’ll see what CRC say first but guessing if I tip the bike upside down and wd40 subtley that might release the bond. FWIW the bike hasn’t really got wet.

scott – that was a bit naughty by the seller. Are you saying categorically that the bolts are NOT interchangeable then?

Just as an aside, how good are Swissstop brake pads compared to the ones that come as stock with 6700?

You might like to try jamming an allan key in and turning the front brake to undo rather than turning the bolt. You’ll have to remove the cable first, obviously. Never seen a rounded inner bolt before.

6700 stock brake blocks are just fine on alloy rims with DA9000 levers. Mine have stopped me in dramatic fashion.

The 6800 bolts appear to be pressed through the body of the brake. They feel and look loose / removable and that you could get them out, I couldn’t see a reason it wouldn’t come out however I couldn’t get it to budge. I spoke to my LBS and they said they weren’t removable. I didn’t buy the new brake from them so they had to reason to tell me that if it wasn’t correct.

Each and every part number for 6700 brakes

“Email just sent to CRC – they checked it before it was sent and it’s been untouched until tonight.”

Not touching it till now isnt a good thing. Thats the cause rather than the defence

That said i always used anti sieze on that bolt when building customers bikes. I doubt many shops/crc do.

Take something thin like a spoke and clean out all the mud before pushing the hex key back into that recessed nut. It will go quite a long way in and find fresh flats; you have probably not inserted it far enough due to the mud inside and you’ve rounded off the flats.

ultegra 6800 parts diagram

Semmed you can’t get just the bolts for the newer 6800

you won’t need swissstop pads.

SJS Cycles (who sell loads of Shimano spares) say the bolt is the same so it can be done…waiting to get another mechanic second opinion first though 😉

The ‘other’ mechanic says it’s doable….but a massive pain in the hoop.
Lots of potential to lose tiny grub screws, round off tiny grub screws and mess up spring tension big time.

Sounds like a disproportional amount of hassle for a relatively nominal saving TBH so will
be giving it a miss.

The next thrilling installment follows:

The bolt that wouldn’t undo last night came away fine earlier with a) proper daylight b) a squirt of GT85 and c) a better allen key (ironically from CRC who did get back to me with some suggestions).

I can confirm the the centre fixing bolts do come out of my non-series calipers with some faffing.
I can also confirm that after reassembly it does not work as well as it did previously even though I had an untouched rear caliper as reference (I was pre-warned about this).

I’m surprised how small the bolts are – the rear’s threaded bolt only protrudes out of the back of the caliper body by 13mm and the front is 26mm which threads into a 41mm(!) long mounting bolt which is recessed into the back of the fork.

If I can get a longer mounting bolt I could use 2 x rear 6700 calipers, or still get away with these calipers if the rear bolts are closer to 26mm long rather than 13mm. I think I might even be confusing myself now.
I’m off to investigate 😉