Caliper arm flex... How much is normal? No stopping power!

[drissa]

I've nearly finished my first self-build and I'm worried about the brakes. I've fitted one Miche long-reach dual pivot to the front and I'm getting loads of flex, very similar to that shown in this video (not mine)...


View: http://youtu.be/ZFvJZ1hf1YI


I'm used to v-brakes (which I gather are known for being heavy handed) on a bog standard city bike, which can easily lock my wheels, so I'm prepared for the need to readjust to cantilevers. But I had hardly any real stopping power during my first gentle test ride, going very slowly.

As things are now, I wouldn't feel safe, even with a back one fitted. Yet when I look online, everyone seems to be suggesting this flex is normal...

Any advice? Thanks

 

[jack smith]

Do you have decent pads? Mine flex a little but with some pads i yave no stopping power, others its plenty to skid the wheels i also find if my brake pads are further from the rim and have a longer lever pull they seem to always work better, no idea why

 

[AndyRM]

As above, it's all about the pads.

FWIW I've got those brakes and even with the supplied pads never had any issues with stopping power, though I've never been out in really horrendous conditions.

 

[mrandmrspoves]

If they're new brake pads running on new rims they will improve as they bed in. When new, the rims and the brake blocks are quite.smooth - but after a few trips out, the brake blocks will have started to deposit some of their material onto the rims, which will improve stopping power.

 

[MrWill]

Those Miche brakes are very well known to be absolutely rubbish and flexy.

In descending order, the best long reach caliper brakes:
TRP RG957
Shimano BR650
Tektro R539
Shimano BR451

 

[slowmotion]

I have Tektros on a road bike with "silly money" brake pads (Koolstop Salmons).

As a combination, they are completely and utterly useless.

 

[AndyRM]

@drissa - I kept an eye on my front one on the way into work and even under heavy braking hardly got any flex. Do you have them set up correctly?

 

[drissa]

@drissa - I kept an eye on my front one on the way into work and even under heavy braking hardly got any flex. Do you have them set up correctly?

Possibly not. I've built the bike in a co-op workshop supported by very experienced mechanics, but I'll check it out again with them.

I'm aware the Miche breaks are at the 'budget' end, but I assume the gap between these and the high-end breaks isn't so huge as to mean 'no breaking power at all'. I'll try sanding the pads a little. I got a pair of great Ultergra brakes on eBay, but they wouldn't reach and the 650s seem hard to come by.

The levers have some flex in them, but even grabbing right at the clamp end of the lever, I'm seeing the same amount of flex as shown in the video above.

Thanks for input so far.

 

[AndyRM]

Hm, that doesn't sound right. Have you got the cable tensioned correctly, so it's actually pulling the blocks hard enough towards the rim?

I'll video mine when I get home so you can see what's happening for me.

 

[fossyant]

Those Miche brakes are very well known to be absolutely rubbish and flexy.

In descending order, the best long reach caliper brakes:
TRP RG957
Shimano BR650
Tektro R539
Shimano BR451

I think you will find all Shimano brakes are better than Tektro. I have the BR550 on my Fixed.

 

[djb1971]

As above, I ditched the tektro long drops for the Ultegra long drops. A bit pricey but the fact that they stop you is worth the cost. The shimano calipers are very firm and rigid with almost zero flex, the power from the lever goes to the pads and not up the caliper arms!

 

[John the Monkey]

Another vote for the BR650.

The difference between the Tektros that came with my Giant (even with Koolstop salmon) and the vastly superior BR650 (still using stock pads) is night and day.

 

[Smokin Joe]

Budget brake calipers always suffer from flex, cheap manufacturing mean corners have to be cut somewhere. You don't need to replace both calipers though, 90% of the stopping power is in the front brake and you can pick up a decent 105 or Ultegra front caliper which doesn't cost much, especially online.

 

[Globalti]

Silly video - by the time you're seeing flex, you are squeezing that lever so hard that you'd have gone over the bars and bumped your noggin on the ground.

 

[drissa]

Silly video - by the time you're seeing flex, you are squeezing that lever so hard that you'd have gone over the bars and bumped your noggin on the ground.

If it's anything like mine, this isn't the case. The pads make contact with the rim, but after that, much of the lever force is absorbed by the arm flexing.