Anyone know how to reduce spring tension in Dia Compe 610 Centerpulls

[Sam Krueger]

Hi,

I bought a bike that came with these. I took them off as they were too stiff. They seem to brake well, but the spring tension is so stiff it makes it not enjoyable. I experienced the same thing with RH centerpulls.

It seems strange they make the spring tension so strong, as it should just be strong enough to safely and quickly keep the pads off the rims.

I never had that issue with any dual pivot brake.

So, is there a way to lower the spring tension? Different springs, maybe flex or bend the springs that are on there? I have another bike they could work on if this could be remedied.

Appreciate any feedback, thank you.

[travi...@gmail.com]

Can you share a picture of your braze ons? I wonder if the hole is in the wrong place. I haven't noticed excessive tension with the RH centerpulls.

[ThermionicScott]

Do your brake levers also have return springs in them?  Old-school brake calipers had strong enough springs to not only re-open the brake calipers, but to pull the brake levers all the way back open.  Shimano's SLR system used weaker springs in the calipers and additional springs in the levers to achieve each goal independently.  If you mix-and-match parts you can end up with too much (or not enough) total spring tension.

If your brakes are mounted to posts, there's the possibility of having another hole added for the spring end, like those old MTBs with two or three holes on the post for adjusting spring tension...

- Scott

[JohnS]

Hello,

Maybe it's your brake levers? I have Gran Comp 610's and old school Shimano 105 brake levers (aero, non-brifters) which work very well together for me on my Surly Pacer. I don't see anyway to adjust the tension. You may want to consider Paul Racer or Racer M brakes. They have adjustable spring tension. I have Paul mini-motto's on the front and touring on the rear of my Crust LB-Canti. Work great.

JohnS

[Sam Krueger]

Hi,

Thank you Scott and John, and everyone else, for your thoughtful response.

I"m using Shimano 9 and 10 speed brifters, and really like them, so I wouldn't want to go to an old fashioned lever. 

It's interesting that this is never mentioned in how these brakes are described and hyped up. I also found it interesting that the modern RHerse version suffers from the same thing, they were really hard to close.

It's a shame they don't offer a different spring tension for modern brake levers, that would seem to be a reasonably attainable fix.

Well, I guess these will be going up for sale when I get around to it.

Tailwinds,

Sam

[lena...@gmail.com]

Hi Sam,

I noticed this too with Compass (RH) centerpull brakes. Modern levers with high mechanical advantage help to mitigate this. SRAM levers (no return springs) work well with these brakes. TRP RRL levers with the return springs removed are another option.

Since you like the brifters you have, a different lever may be out of the question.

On the opposite end, I discovered brakes with weak return springs can pose problems too. The Juin Tech F1 rear brake with less-than-perfect full housing vaguely returns a Tektro lever without a return spring. On another bike where the full housing had less friction, the brake worked better and had a light touch.

Lena

[satanas]

IMHO it's worth trying to bend the springs to change things, and while I've never had a reason to attempt this with centrepulls or dual pivots it works fine with cantis, V-brakes and single pivot sidepulls. Usually one needs to increase the return force, but I see no reason why the opposite shouldn't be doable. If you decide to do this, proceed carefully and do not apply the maximum possible brute force at first.  ;-)

It's also possible that the levers you have might have reduced MA (7900 onwards for 10 speed), and that might be the problem rather than just the spring tension; the difference between say 7800 and 7900 is quite noticeable.

Later,

Stephen

[Sam Krueger]

Thanks Stephen.

Interestingly, I dug out the brakes and hand flexed them along with a standard Tektro brake. They felt very similar, even though the Dia Compe has two enormous springs on each side.

But when I looked at my bike carefully, they aren't quite long enough (they came with 700c wheels, I've since converted to 650b on my Nordavinden but had already changed brakes). 

So they are for sale. I won't post them yet but if anyone is interested, lmk. Great new near condition, all of the hardware.

Cheers.