maxants33

I love my crit bike (kinesis Aithein - rim brake). Its super light and I have a great carbon Campag Athena groupset.

I picked up a cheap Kinesis disc fork on eBay - my plan is to put a mechanical disk on the front (keep the frame with a rear rim brake).
It might look a bit funny, but I have all the parts sitting in my part bin, so a front disc addition would be a cheap upgrade. Going mechanical also means I can keep the sweet Athena groupset.

However - has anyone tried mechanical discs in the twisty hairpin context of a crit circuit? I just got back from a holiday and used loads of rental bikes and was really surprised by the poor modulation on the mechanical discs. Would a mechanical disc be any better than a rim brake?

I might try do a side by side comparison, as it wont be too much work to do the swap from rim to disc, and I will report here after!

(btw: hydraulics is not an option, keen to keep my crit bike rolling for minimal cost)

shelbyfv

Surprised to hear that brakes are such a concern for crits! There are only a handful of currently active racers on BF. If they don't respond here, try the 33.

Kai Winters

Either will work well depending on how they are set up, maintained and the conditions of the day. Brakes often see little maintenance...rim brake pads can dry out and are often glazed...disk brake pads are never cleaned and get a build up of dust, dirt, etc. that can affect effectiveness.
I'd prefer disk because they work as well in the wet as dry compared to rim brakes which lose 'bite' when the rim and pad become wet.
I raced through the '80's and '90's on rim brakes and had no problems except when racing in the rain...brakes lose grip so you have to pay a lot more attention to what is going on around you.
That's all I got...take care of your brakes and they will take care of you...

Maelochs

In my experience---which does NOT include racing---mech discs are no better or worse than mech rim brakes of whatever variety. I wouldn't make any changes to a bike which works well if it were not going to be an improvement.

If you ride crits in the wet .... you are nuts, but maybe you might see some benefit. In the dry .... not so sure.

I second the idea to ask the dedicated racers.

maxants33

Now I am asking myself the same thing... I watched video on GCN about discs and improved cornering, and recall others at crit training last year saying similar things. I mostly mountain bike, so discs are naturally the default for me. More disc = more gooder?
However - was just watching rad race and red hook videos - and obviously - no brakes. I am assuming fixed gear though you are using back pedalling resistance for some speed modulation?
I actually used to practice my cornering on the Herne Hill cyclocross course by doing several progressively faster laps - without touching the brakes .This was extremely beneficial for homing technique!

Does anyone know if there is a way to move my question to 'the 33'?

msu2001la

If you're braking so hard into corners during a crit race that the stopping power of disc vs. rim is a factor, you're doing something wrong.

maxants33

Oh yea, naturally - but my interest in discs really came from improved modulation - not stopping power.
I have rim brakes on my crit and commuter bikes - I find they don't do that much when lightly touched, not having any effect on speed until the lever force is a bit higher - when they start to dramatically cut the speed. This to me is not great modulation, at least when compared to my CX and mountain bike hydraulics (shimano SLX and Sram Rival) which have fantastically fine grained modulation by comparison.

I also really like the way on hydraulic discs I can make fine adjustments to speed with minimal hand strength, allowing me to worry less about hand position and how much weight I am putting through the bars, instead of concentrating on putting my hand into the best position for hard squeezing.

I haven't had a good stint on mechanical discs for a long time. So unsure if they have that modulation any better than rim brakes. My holiday rental bikes were mechanical discs, but no name single piston ones. I have a spare flat mount TRP spyre, so expecting better things!

RB1-luvr

one of the GCN racers (a high level junior?) is still racing a rim brake bike. Did you see the video about it?

caloso

Discs don’t provide any benefit in a criterium. As msu2001la said, if you’re having to brake hard into a corner, you’re doing it wrong. I actually open up my front caliper for crits because I want less front braking—I don’t want to accidentally lock up my front wheel if I panic grab my brakes. That’s a sure way to take yourself and everyone around you down.

Plus, you’ll make your front end heavier, possibly affecting handling. You’ll have to get a new front wheel and left lever too. This doesn’t seem to offer any benefit.

maxants33

Also - crit training near me re-starts in April - So I'll definitely do a few classes with the flexy Campag rim brakes, then probably a few with the TRP spyre - and report any differences!
I'm super interested to test this... I have all the parts spare, so nothing needs to be purchased. Only thing is the effort in doing the swap

Jeff Neese

Notice that as long as disc brakes have been around, they didn't become commonplace in pro racing until a few years ago. Pro racers don't like them, didn't want them, and they held out as long as they could. The only reason TDF bikes (for example) have disc brakes is because that's what the sponsors are selling to the consumer market.

Jack Tone 

Try some different pads.

maxants33

Interesting to see the firm support for rim brakes. I definitely like rim brakes and lament their decreasing presence from the bike market. Would be cool to keep my bike sub 7kg, Pretty sure the mechanical disc would tip it over!

TheSilverFox 

There is zero advantage to change to mechanical disk from rim brake. Mechanical disk just doesn’t work as well. Unless it’s something you’ve really wanted to try I’d pass

jonathanf2

Would compressionless cable housing improve modulation on your rim brakes? I know quite a few people using compressionless housing on cable disc brakes to improve brake feel. If I was strictly racing and my courses didn't have any descents with tight switch backs, I'd want the lightest setup possible.

RB1-luvr

My bike with the best braking performance is my RB-1 with circa 2016-ish Ksyrium Elite wheels and Shimano Ultegra brakes. I have to be careful using the front brake it's so strong. I have many disc brake bikes, hydraulic and mechanical.

maxants33

Thats a good point - I had 105 rim brakes before and they were pretty good. The Athena calipers are definitely a bit flexy, but so light. I could upgrade the caliper and also try the compressionless hose.

But I haven't done a crit since last summer. Think I'll definitely ride a bit once it restarts before any medalling.

caloso

Same. I have Ultegra calipers on my race bike (2016 Specialized Tarmac). I can lock up both wheels with one finger--brakes aren't the limiting factor, it's the tires. Get some decent pads. I like the blue Reynolds pads for both my carbon race wheels and my alloy training wheels. Just make sure you swap out pad sets when you swap your wheels. It takes 5 minutes at most.

One more advantage to keeping your rim brake wheels is that when your buddies succumb to the disc fad, they'll be looking to sell off their rim brake wheels. I've picked up a few pairs of really excellent wheels for a song.

maxants33

I've got swiss stop (flash pro) on there. Which I'm sure are good. But the same set has been on there since 2019. I just use the bike for crits in the summer, so they've lasted a long time. But do swiss stops dry out?

msu2001la

Speaking of which, I've got some rim brake tubular wheels collecting dust in my basement right now... I should see if I can unload them soon.
The CX rim brake market is nearing "can't-give-them-away" status.

merlinextraligh

As previously set out, there’s just no need or advantage in a crit.

And while the importance of rotating weight is way overstated, there is a slight disadvantage to accelerating the bit of extra weight associated with discs out of every turn. Admittedly it’s a very small effect, but add up the effect over 100 plus turns, and I’d wager the downside is more significant than advantage in improved modulation.

georges1

Rim brakes for me, the Shimano Dura Ace BR 7800 offers phenomenal power. Even my campy Delta 5th generation brakes work quite well.

tomato coupe

Yawn.

ummed

I didn't read the thread, but if you have to brake to the point where it may make a difference, you are doing it wrong. If you want to put spare wheels in the pit, you probably want rim brakes.

ummed