Shimano BR-R650 cable pull compatibility question

[Samuel D]

Hello, all.

The Shimano BR-R650 brake calliper is pretty old and designed for Shimano’s shorter cable-pull standard. How does it perform with Shimano’s new brake-levers/shifters that pull more cable?

Presumably the lever effort would be increased for a given braking force, but by how much? Worth worrying about?

And do you think Shimano will eventually replace the BR-R650 with another 57 mm drop calliper designed around the new cable-pull standard? Even though bicycles with wider tyres are becoming more popular, disc brakes seem to be taking over.

Thanks.

[Valbrona]

I wonder irather than anything else.f the new Shimano actuation ratio has more to do with the advent of direct-mount calipers

[Brucey]

I think you will have to pull about 20% harder for any given retardation level. This is about the same (maybe less) vs the variation you will get with any one caliper by simply moving the brake blocks up and down.

If you choose different brake blocks you can get more variation than that too.

The 'new' cable pull standard predates direct fit calipers BTW.

cheers

[Samuel D]

I think you will have to pull about 20% harder for any given retardation level.

That doesn’t sound too bad.

I found a Shimano compatibility document (link leads to PDF download) that tends to back that up. It says the combination of BR-R650 and current STI levers is officially supported, albeit with the caveat: “Braking power is slightly less than standard combination”. Since Shimano is pretty conservative about these things, that’s good enough for me.

A pair of BR-R650 callipers should last for many years, so it’s reassuring to know they would work with new STI levers in the future.

I ordered a pair, after a couple of years of wondering whether I should. Am curious to see how the vaunted “thrust bearings” (are there really tiny ball/roller thrust bearings in there?) improve braking compared to my low-end Tektro callipers.

[Valbrona]

I am not sure whether micro bearings in my Super Record brake calipers gave more power, but they make for a smoother action and a nicer feel.

I wonder how using levers with differing pull ratios impact on the functioning of disc brakes.

[Samuel D]

I spy a BR-R650 calliper on this Paris–Roubaix bike (the brake is described as “low-end” by the BikeRadar writer, who of course didn’t recognise it – and might have thought it low-end if he did!). Looks like the braking force with current levers is good enough for pro racers.

Valbrona: I think bearings would reduce the friction (or stiction) incurred when the brake is on hard and the pivot is under load as the rim tries to drag the pad around with it. They would improve the feel under low load too, though that’s less important to me.

[Samuel D]

Well, I tried to install these. Unfortunately, the cable ferrules (capping the external cable housings) on my Dawes Clubman are wider in diameter than the ferrules Shimano expects me to use. They slot nicely into the barrel adjusters on my Tektro brakes, but wouldn’t fit into the BR-R650. Of course I only noticed this after installing the front brake.

I put the Tektro calliper back on for now. Any idea what kind of cable ferrules I need for the Shimano brakes? I haven’t encountered this particular problem before!

[keyboardmonkey]

I had the exact same problem. Not sure it helps, but I just went in to a bike shop, bought something else (handlebar tape I think) and the nice chap gave me FOC the ferrules and a Jagwire inline cable adjuster for the rear mech. LBSs, eh?

[Samuel D]

I had the exact same problem. Not sure it helps, but I just went in to a bike shop, bought something else (handlebar tape I think) and the nice chap gave me FOC the ferrules and a Jagwire inline cable adjuster for the rear mech. LBSs, eh?

They’re useful places when they work like that!

So you just removed the old ferrules and put the new ones on? They fit okay? I had envisaged having to get new Shimano cable housings, and new handlebar tape for after installing the new housings, and the whole thing being a bit of a job …

[The Mechanic]

I have BR-650 brakes on my audax bike. They are operated by Ultegra 6700 STI levers. I have not noticed any change in the brakes since changing from 6500 STIs

[Samuel D]

I have BR-650 brakes on my audax bike. They are operated by Ultegra 6700 STI levers. I have not noticed any change in the brakes since changing from 6500 STIs

I’m glad to hear that. Thanks for posting. It doesn’t affect me now, but who knows what sort of shifters I’ll use these with these callipers in the future.

[CREPELLO]

Well, I tried to install these. Unfortunately, the cable ferrules (capping the external cable housings) on my Dawes Clubman are wider in diameter than the ferrules Shimano expects me to use. They slot nicely into the barrel adjusters on my Tektro brakes, but wouldn’t fit into the BR-R650. Of course I only noticed this after installing the front brake.

I put the Tektro calliper back on for now. Any idea what kind of cable ferrules I need for the Shimano brakes? I haven’t encountered this particular problem before!

Well it seems that you just fit the housing directly into the brake cable adjuster. That is how I fitted my 650's some years ago, and I would have checked up on this, because it does seem a slightly odd arrangement (weight saving, no doubt ). I've had no performance issues with the housing or brakes. The housing isn't going to spread like an unferruled gear cable housing would.

My other road bike uses RX100 long drop brakes, the 650 predecessor. That cable adjuster does allow for a standard ferrule. Though having just googled images of the RX100, I see that other people are NOT using a ferrule

[keyboardmonkey]

I had the exact same problem. Not sure it helps, but I just went in to a bike shop, bought something else (handlebar tape I think) and the nice chap gave me FOC the ferrules and a Jagwire inline cable adjuster for the rear mech. LBSs, eh?

They’re useful places when they work like that!

So you just removed the old ferrules and put the new ones on? They fit okay? I had envisaged having to get new Shimano cable housings, and new handlebar tape for after installing the new housings, and the whole thing being a bit of a job …

Well, I did all that - so it wasn't the exact same problem - but if there were any ferrules supplied with my new shifters c/w int & ext cables they did not fit. I have Shimano 105 (5703) brake levers btw. Happy with the set up, but obviously not the most recent version of 105.

[Samuel D]

Well, I did as recommended, removed the ferrules, put the cable housings directly into the callipers, and off I went. The fit could be a bit snugger, but it will do until I replace the housings in the future (which I think might also improve performance; the Dawes-supplied housings look cheap and nasty).

The new brakes are a significant improvement over the old ones, especially from the hoods where braking force is limited – in my case at least – by finger strength. Pleased with the upgrade.