Brake lever compatibility

[HausFinch]

Hi all,
I've had poor braking on my road bike for as long as I can remember, and I'd like to change that before that changes me. The current setup is Dura Ace 7400 8 speed STI shifter/brake levers paired with Shimano 600 6400 (tricolor era) sidepull calipers. Changing the wheels has made no difference, and putting new shimano (old style ultegra) pads also had little effect. What's my best option for improving the brake performance? New softer pads, or more powerful calipers? Of the newer calipers, which ones would work reasonably well with the old 8 speed Dura Ace STI levers? I hope there's an answer that doesn't involve changing everything.
Thanks!

[P!N20]

It’s probably best to diagnose the problem first. Can you elaborate on what makes the braking poor? Is there too much travel in the levers? Are the levers hard to squeeze? Does it take too long to come to a stop? Does the bike shudder under brakes?

[ValleyForge]

It’s probably best to diagnose the problem first.

Agreed. When were the cables +/- inners replaced? Lubed? How about the pivots?

FWIW I consider Shimano pads akin to Iced VoVos for braking.

[HausFinch]

Thanks for asking. Cables are new, and not the problem. By poor performance I mean it just takes too long to come to a stop. As hard as I squeeze the levers, the pads just seem to rub but not stop the wheel effectively. Granted the rim sides are not machined, and they are older aero profile rims. There's no shudder or squeal. When they were new back in 1990, the mechanic who fitted them, an ex Tour de France team mechanic, said he thought the new 600 brakes had better feel than the dura ace ones, so I went with his rec. But now, despite the "feel", I just notice that it takes a long time to come to a halt. And despite pulling hard on the levers, I'm not able to lock the wheel up, which I know is not the real goal anyhow, but it seems you should be able to manage the full spectrum of wheel flow and friction when braking. I'd like to feel more stopping power with less applied force at the lever. As it is now I need to anticipate stopping well before the point of impact. I have disc brakes on my commuter/mtb bike, and I like what those give, which is probably what made me think the road bike is not adequate anymore. But I don't want to change the whole drive train and wheels to get more stopping power. Any recommendations for better brake pads perhaps?

[10speedsemiracer]

There are so many variables at play here it's hard to be accurate with advice. On a process of elimination basis, knowing that the cables and housing are fresh, I would recommend aftermarket pads.
If that makes little or no difference would recommend newer series Shimano dual pivot calipers (are your calipers recessed or exposed nut fitting).
If that still makes no difference, then the wheels get replaced with something that has a nice braking track with 8/9/10s freehub to suit your cassette.
After all of that there can't be anything else affecting braking. Friction material + clamping + friction surface all replaced. But do it in stages from easiest/cheapest and assess each change.

[10speedsemiracer]

Part of the equation is our knowing which 7400 brake calipers you have now.

Are they the single-pivot calipers like these :


or the dual-pivot calipers like these :


if they are the single-pivot, would be upgrading to dual-pivot calipers. If they are already dual-pivots, and they're operating as they should be, then would try brake pads.

[HausFinch]

Pics are great! However, my current calipers are 600 tricolor single pivot side pulls, while the levers and derailleurs are dura ace 7400. I could look for the dura ace 7400 dual pivots as you suggest. But sometimes those vintage parts cost more than say the newer series Shimano calipers like the ultegra 10 or 11 speed iterations. The older 7400 dual pivots would be a better match for the bike, but I'm prioritizing braking performance over aesthetics, so whatever will work best. But if anyone has a set of 7400 dual pivots surplus I'll buy them to try.

[Duck!]

If that makes little or no difference would recommend newer series Shimano dual pivot calipers.

DO NOT use newer 7900 or later calipers with the old levers! These newer models are designed to work on a longer cable pull than the older models, and will perform very badly with your 7400 levers. Up to 7800 & its derivative generation will be fine, but you'll have to hunt around a bit for them.

The old-style 6400 pads from memory are a pretty hard compound, which will be a fair part of the problem. Replace the pads with the newer style holders & replaceable inserts, which will open up a greater range of pad options. Shimano's current pad compound, which comes stock in the pad & holder kits, is vastly better than the old 6400 compound.

[10speedsemiracer]

Thanks Duck, was aware and probably would have suggested a set of br5700 depending on frame and tyres, while maybe swapping pads as well.

[HausFinch]

Thanks Duck for the specifics about what calipers my current levers will work with. That's what I was aiming to learn. But first I'll switch to the newer version cartridge pads as you suggest and see how much faster I can slow down. Then maybe shop around for some older dual pivot calipers.

[10speedsemiracer]

Thanks Duck for the specifics about what calipers my current levers will work with. That's what I was aiming to learn. But first I'll switch to the newer version cartridge pads as you suggest and see how much faster I can slow down. Then maybe shop around for some older dual pivot calipers.

Sorry, I completely missed the 600 single-pivot as being on there already. The other issue to consider is fitting, i.e. are the existing calipers exposed nut or recessed nut, and also brake drop/reach.

[HausFinch]

Thanks 10speed, it's a racing frame so definitely not long reach. Nut fitting is recessed, late 80's hand built frame. Not sure whether it is short or normal reach, but that won't matter for first step switching pads.

[10speedsemiracer]

OK, so these calipers:


which as far as single-pivot go, were actually not too bad (and thankfully should be recessed nut) but as Duck said, the OE pads were hard. Dual-pivot will be an incremental improvement, but I would try the pads first and work from there.
In terms of pads, these:
will make a nice difference to braking performance, and also give you the option of then trying aftermarket inserts.
https://www.pushys.com.au/shimano-dura- ... e-set.html
If you were going to fit dp calipers, wouldn't bother with the 7400, just go straight for something newer whilst remaining compatible. I've used 5700 series 105s on a couple of bikes, the most recent with 500ex levers, and 5800 105 on a couple, and even with the stock Shimano pads (5800) they both worked very well.

[HausFinch]

Yes, thems the ones, the last of the single pivot 600 calipers. I'm happy to stick with them if stickier pads are all they need. They are the only parts not Dura Ace on the bike, as I said because my mechanic felt they were better than the DA ones of that year. So I'll start with pads. I see that Shimano makes ultegra level cartridges with the same rubber compound as the DA ones, at $15 less per set at Pushys, so that seems the go. Thanks so much for your detailed recommendations. There are so many choices when it comes to pads, and I've already bought new ones that didn't improve the braking at all, so getting real experienced advice in this area helps narrow the field. Thanks again! I'll try new pads and post the result.

[10speedsemiracer]

Yes, thems the ones, the last of the single pivot 600 calipers. I'm happy to stick with them if stickier pads are all they need. They are the only parts not Dura Ace on the bike, as I said because my mechanic felt they were better than the DA ones of that year. So I'll start with pads. I see that Shimano makes ultegra level cartridges with the same rubber compound as the DA ones, at $15 less per set at Pushys, so that seems the go. Thanks so much for your detailed recommendations. There are so many choices when it comes to pads, and I've already bought new ones that didn't improve the braking at all, so getting real experienced advice in this area helps narrow the field. Thanks again! I'll try new pads and post the result.

Yeah, I've messed around with different pad inserts (Ashima, Jagwire, Miles Racing) and had varying experiences, but have found the current gen Shimano pads to be fine on alloy wheels, especially when factoring in $s.

[Duck!]

I see that Shimano makes ultegra level cartridges with the same rubber compound as the DA ones, at $15 less per set at Pushys, so that seems the go.

To be frank, the difference between the Dura-Ace & Ultegra units is likely to just be the material of the pad holders; Shimano use the same pad compound in all models of brakes within a particular generation, usually giving the compound a tweak with each successive Dura-Ace series.