How bad are really deep drop brakes?

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deejayen
Posts: 48
Joined: 1 Apr 2011, 1:56pm

How bad are really deep drop brakes?

Post by deejayen »

I've got a recumbent which has mis-matched brake mounts and wheel size. However, it does have holes in the front forks and rear tube for mounting caliper brakes. I offered up a deep-drop brake (i think it's a TRP with 73mm drop) from one of my other bikes, but it's not deep enough.

It looks like there are a few brakes with more drop. For example, SJS Cycles list a Dia-Compe 833 sidepull with 68-86mm drop. It seems quite spindly, and reminds me of trying to stop bikes with steel rims and Weinmann brakes. Perhaps the Dia-Compe brakes are even worse!

The optimist in me thinks that if paired with modern day alloy rims, compressionless brake cables and SwissStop brake pads they might not be as bad as I fear...

I just wondered if anyone had experience with this size of brake, if it's possible to set them up to give dependable braking power.

Also, is there any particular caliper you would recommend?
mattsccm
Posts: 5101
Joined: 28 Nov 2009, 9:44pm

Re: How bad are really deep drop brakes?

Post by mattsccm »

I think you know this. Good ones are better than the old pressed steel things of days gone by. Leverage though means that for that for the same construction small drop ones will be better.
Just do your best with quality fittings.
Carlton green
Posts: 3645
Joined: 22 Jun 2019, 12:27pm

Re: How bad are really deep drop brakes?

Post by Carlton green »

I was looking at something overlapping with this topic for my own use. It appears that mostly that for my particular use there isn’t a simple fix and the first action is to optimise cables, outers and pads (which I’ve done, it made a noticeable difference and now the brakes are just about sufficient for my needs). Should I upgrade further then dual pivot calliper brakes would be the next step to try; in theory they should be a simple fit and improvement, but there’s almost always a hidden catch to any change.

Some dual pivot side pull brakes offer deep drop and (relative to single pivot) an increased calliper force onto the rim. SJS sell an e-bike single pivot side pull brake with higher than usual mechanical advantage. IIRC BMX calliper brakes have deep drops, but maybe not enough force onto the rim. Perhaps the arrangement on the OP’s bike might allow the use of drop bolts, which could be significant to the solution. Perhaps there’s some other solution to the mismatch between wheel size and brake mounts.

Photos of the bike would help the ‘brains trust here’. It’s amazing the good solutions that people can come up with.

Good luck to the OP, I hope that something turns up for them.
Don’t fret, it’s OK to: ride a simple old bike; ride slowly, walk, rest and admire the view; ride off-road; ride in your raincoat; ride by yourself; ride in the dark; and ride one hundred yards or one hundred miles. Your bike and your choices to suit you.
Stradageek
Posts: 1657
Joined: 17 Jan 2011, 1:07pm

Re: How bad are really deep drop brakes?

Post by Stradageek »

I await the outcome of this post with interest. At some point I'll need to move to 559 rims on my recumbent to replace the current 571 i.e. another 6mm of drop. The current dual pivot calipers can lock the wheels so I'm hoping an extra 6mm won't be a problem.

Though I'm not a fan of Tektro brakes, I did notice that second hand sets of Tektro long drop dual pivot caliper brakes generally go for pretty near retail price on Ebay. The R559s, in particular, look fairly chunky.
Jamesh
Posts: 2963
Joined: 2 Jan 2017, 5:56pm

Re: How bad are really deep drop brakes?

Post by Jamesh »

I brought one if these as the Shimano long drops weren't long enough.

Haven't noticed any losses tbh.

https://www.condorcycles.com/products/c ... wgp=281345
Glen
Posts: 45
Joined: 5 Aug 2019, 8:13pm

Re: How bad are really deep drop brakes?

Post by Glen »

For a number of years I have been using Tektro R369s on my audax bike. Not as effective as a shallow drop dual pivot but still pretty good. As you might expect, replacing the stock brake pads made a big difference in performance. Regards.
deejayen
Posts: 48
Joined: 1 Apr 2011, 1:56pm

Re: How bad are really deep drop brakes?

Post by deejayen »

Thanks very much. My TRP brake seems to be a similar spec to the Tektro and Condor one (around 73 or 75mm drop) and it's not quite there. So, I need a deeper drop. I seem to remember reading of people filing the slots out so that the brake blocks will slide further down the arm, but I'd worry about removing too much material!

As Carlton helpfully says, there are a number of possible solutions to my predicament, but each seems to have a stumbling block, and I'm having difficulty in deciding how to proceed.

The bike was made with canti posts at a height for an obscure 20" rim (a tubular racing\junior rim) which is around 432mm. This wheel size caused me a lot of grief, as available rims were limited to old BMX or wheelchair racing rims, plus decent tubs are non-existent. The rims don't have a good braking surface, and I had problems with them cracking, and even spoke failures due to spoke angles. Also, the tubs were slow and puncture-prone.

The bike also has the aforementioned holes at the top of the forks and rear tube for a caliper brake, but the fork height was set for a 20" 451 rim - not much choice in good tyres nowadays.

It also has IS disk brake mounts, which could be a last resort. However, I don't have disc hub wheels or disc brakes, so anything built around this is going to be quite expensive.

I'm really not sure if I like the bike, but need to give it a good try. I'm just slightly reluctant to throw a lot of money at it, as it's already been a very expensive exercise.

A couple of years ago I had a new pair of 20" 406 wheels built for it. Unfortunately, there was a mix-up in communications, and these ended up having non-disc hubs instead of disc hubs. It's these wheels I was thinking of trying. The bike currently has lightweight KCNC VB1 V brakes which have their own brake posts (shorter than typical canti posts, and possibly a slightly different profile). The wheels are slightly too small for the current brake configuration, even with the brake blocks set as low as they'll go, and the KCNC brakes have really low slots so that the brake blocks aren't much higher than the posts (not good for setting brake block distance or for leverage). I had the idea that buying a set of brake post extenders I could effectively lower the brake posts and hopefully set the brake blocks to the top of their slot, which looked like it might just work. Unfortunately, I've discovered that the brake bosses on the frame have an M10 x 1.0 pitch thread, and the brake post extenders aren't compatible. Also, when the bike shop initially installed the KCNC brakes they've minced the threads by forcing them into the frame bosses. I've spoken to a KCNC dealer and also emailed KCNC but I'm not sure I'll be able to find replacement posts, inc which case I'd need to buy a new set of V brakes. I thought I might be able to find a bolt with a suitable thread in order to fit the extenders to the bike, but I'm struggling to find one as the heads need to be relatively neat in order to sit flush in the extender. I've made enquiries about having custom bolts made, but have been quoted £165 just to set up the machines.

Hence, I started wondering about trying ultra-deep brakes (which would also need different brake levers).

Other options include having a pair of 451 wheels (with disc hubs) built so that I could use either standard calipers or discs. The downside to these is there aren't many tyres available in that size. Also, the cost of new wheels and brakes.

The other, possibly most sensible option, is to have a pair of 406 wheels built with disc hubs. I suppose I could strip down the non-disc wheels I had made and use the rims, but it seems a bit of a waste as they're nicely built and brand new. I'd also need to buy disc brakes etc.

Either of the new wheel builds are probably going to cost £300-£400 with basic components such as SUN CR18 rims and Bitex hubs. A disc brake system could range in price from something like BB5/BB7 upwards.

Having written all that, I'm still undecided on how to proceed. I suppose the 'cheap' options are to get really long drop caliper brakes or try to cobble together a solution to my post extender problem. If money were no object, then a 406 or 451 disc wheelset (or both) might be the best.
hamster
Posts: 4131
Joined: 2 Feb 2007, 12:42pm

Re: How bad are really deep drop brakes?

Post by hamster »

I've run R559 with 1999 Campag Chorus ergos for 4 years for a 27" to 700C conversion. Braking is excellent, if not quite as good as Campag Chorus (shallow) brakes.

As Shimano have fiddled around a lot recently with braking cable pulls, correct matching with levers is more critical nowadays and may be part of the reported problems of deep drop brakes.
LuckyLuke
Posts: 374
Joined: 10 Jun 2010, 11:54am

Re: How bad are really deep drop brakes?

Post by LuckyLuke »

Hi, I recently used a pair of Dia Compe Mx 1000 deep drop BMX callipers, for a pal’s 650b conversion. They are 73-92mm drop. IIRC Dia Compe make another BMX calliper brake with a little less drop.
I brought them from here:

https://www.tritoncycles.co.uk/componen ... ake-p11902

I combined them with Kool Stop pads and decent compressionless outer cable, (Jagwire KEB SL). Plus good brake levers; Shimano R550 flat bar brake levers.

I was pleasantly surprised by the performance as I was anticipating crap braking. It was perfectly adequate. Caveat: I’m 70kg and it was an unloaded bike. I rode it 11 miles across London. Pretty flat, but quite stop-start, and I was late (and enjoying the ride), so I rode briskly. The brakes definitely were used in anger.
Best wishes
Luke
LuckyLuke
Posts: 374
Joined: 10 Jun 2010, 11:54am

Re: How bad are really deep drop brakes?

Post by LuckyLuke »

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Dingdong
Posts: 966
Joined: 22 Apr 2022, 4:59pm

Re: How bad are really deep drop brakes?

Post by Dingdong »

+1 on the Tektro, cheap and cheerful and quite effective.
Dingdong
Posts: 966
Joined: 22 Apr 2022, 4:59pm

Re: How bad are really deep drop brakes?

Post by Dingdong »

And definitely flat bar brake levers, if you want to get any effective braking grunt out of it.
Carlton green
Posts: 3645
Joined: 22 Jun 2019, 12:27pm

Re: How bad are really deep drop brakes?

Post by Carlton green »

This topic reminds me of the experiences of Dawes Kingpin owners who find a need to change rim sizes, so maybe some overlapping experience there to research.

Looking on the Diacompe web site I see their various brakes plus drop range and plus expected rim width. I’m not sure how important rim width is but it’s something to be aware of.

Matching the cable pull length of brake and lever is important, whether accidentally or not I’ve always used the levers that came with the brakes - such things used to come as a set.
Don’t fret, it’s OK to: ride a simple old bike; ride slowly, walk, rest and admire the view; ride off-road; ride in your raincoat; ride by yourself; ride in the dark; and ride one hundred yards or one hundred miles. Your bike and your choices to suit you.
deejayen
Posts: 48
Joined: 1 Apr 2011, 1:56pm

Re: How bad are really deep drop brakes?

Post by deejayen »

Thanks very much.

It sounds like one of the Dia-Compe brakes might work. I hadn't thought to check their website, but see they have a range of models which might work, but not sure how they compare in terms of stopping power. They even have the DC808 for e-bikes, and say "better stopping power with long caliper arms", but not sure how it differs from their other models.

There's also the DL800 which is actually a dual-pivot brake with 61-79mm drop, and there's a possibility this might work.

I'll need to measure up - do you have any tips on measuring the bike and rim to ascertain the exact required brake drop?

Also, what's the actual pivot bolt length for front and rear brakes - ie the bit which goes through the frame and forks? I think the frame at the rear of my bike is probably a bit deeper than most front forks, so I'll need to make sure the bolts are long enough.
drossall
Posts: 6115
Joined: 5 Jan 2007, 10:01pm
Location: North Hertfordshire

Re: How bad are really deep drop brakes?

Post by drossall »

My understanding is that the design of a brake can affect its mechanical advantage and therefore effectiveness - not just the depth as such. For example, there's some overlap between a medium brake with shoes at the bottom of their adjustment, and a deep one with shoes at the top. The latter will often give better performance, because mechanical advantage decreases as you lower the shoes. But it does depend on design.

Someone better at this may come along soon and say more.
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