Lighter weight, or disc brakes, bigger benefit?

ajdobbin

Just to give some background, ive been riding for just under 6 months with a tiagra, rim braked aluminium bike at around 8.8kg.

I live in Cornwall so am becoming quite adept with riding hills, although sometimes the descents can be quite hairy on narrow, dirty country lanes.

I weigh 72kg.

Im looking at a couple of Canyon models, the Ultimate CF SLX with Ultegra 6800, rim brakes and weighing in at 6.7kg (in their outlet)

or

The Canyon Ultimate CF SL 8.0 Disc with Ultegra 8000 weighing in at 7.5kg.

Which bike do you think im more likely to get more of a benefit from? The lighter rim brake model, or heavier disc one?

Be interested to hear your opinions.

dstev55

Disc brakes for me. The confidence they give you on descents outweigh (excuse the pun) the benefit of an 800g weight saving of the rim brake bike. Put some better wheels on it and it'd climb better than the rim brake bike anyway on its stock wheels.

yiannism

Disc brakes from me too, especially if you live in a wet place. Safety and practicality comes 1st for me above a few 2nds on a 5km climb (on descents you will be faster). You can lose those 800g from other places like your belly or from the wheels.

w00dster

Rim brakes for me. And that's from someone who has 2 hydraulic disc brake bikes. I ride in snowdonia where we have mountains, rain and snow.
I like the wider tyre some disc brakes give, but if i was limited to just one single bike, it would be a rim brake bike.....
But then again i change my mind depending on what bike i last rode!!

DeVlaeminck

Wider tyres more benefit than disc braking in terms of confidence descending. Unless i wanted to go with a really wide tyre for off road purposes I'd go with the lighter bike.

kirkee

Both have their benifits. But, as you havent been riding for very long, stick with what you have. Gain more experience, as you get better you will probably find the decents a bit less scary.

joebristol

I think it may depend on the weather you ride in to a certain extent.

If you don’t go out cycling in the rain or when the ground is soaked then take the lighter weight rim brake model. In the dry decent rim brakes are fine.

If however you go out in the wet quite often - and with the mucky roads you mention then I think I’d be going with the disc brake model. 7.5kgs is still a pretty light bike in my mind.

I commute on my racer more than big rides (I use it for fitness training for mtb more than anything else). I’m just in the process of switching from a Boardman Team Carbon (8kgs) with rim brakes to a Cannondale CAAD12 with disc brakes (I think 8.7kgs) because I ride in wet conditions and I want the security of better all weather brakes.

Of course it doesn’t help that both of my mtbs are rocking 4 pot hydraulic disc brakes - the swap to rim brakes each time is a shocker if it’s wet.

fat daddy

I want to say light ...... but seeing that the disc bike is only 7.5kg anyway, then disc 100% .... the difference between 8.5kg and sub 7 is noticable and worthwhile ... but 7.5kg ... I would be happy if a few of my rim based bikes came down to that weight

disc disc disc disc disc .. its a light one !

bendertherobot

Don't forget, the one you're looking at has Exalith rims, which really should narrow the difference between disc and rim (not that there's much in it in the dry).

I assume it's this one?

https://www.canyon.com/en-gb/factory-ou ... s&id=25495

joey54321

Disc for me. Narrow twisty lanes discs would be much more fun, can fit better and more suitable tyres and, having cycled a little bit in Cornwall, might genuinely save your lift one (wet) day.

Though I will say your question of "which will I get more benefit from" isn't really specific enough, there will be a benefit from both but they might be different benefits.

thegreatdivide

bendertherobot wrote:

Don't forget, the one you're looking at has Exalith rims, which really should narrow the difference between disc and rim (not that there's much in it in the dry).

I assume it's this one?

https://www.canyon.com/en-gb/factory-ou ... s&id=25495

A sensible post. If you've used Exalith and discs on a road bike in all conditions then you'll know that there's naff all in it.

bendertherobot

I have to say, as well, there's 300g in the wheels there. The SL version will be a very very nice wheel to ride on. Not that there's much wrong with the DT Swiss disc wheels. But they are quite a lot heavier. The SLX really is a superbike. Very very good for the price.

Wierdagger

So, we have to choose from total weight 78.7kg with rim brakes and 79.5kg with disk brakes.
Difference in 1%. I'd rather take disk one. :roll:
Romet

sloppyschleckonds

Wierdagger wrote:

So, we have to choose from total weight 78.7kg with rim brakes and 79.5kg with disk brakes.
Difference in 1%. I'd rather take disk one.

Have you ridden exalith rims?

sloppyschleckonds

thegreatdivide wrote:

bendertherobot wrote:

Don't forget, the one you're looking at has Exalith rims, which really should narrow the difference between disc and rim (not that there's much in it in the dry).

I assume it's this one?

https://www.canyon.com/en-gb/factory-ou ... s&id=25495

A sensible post. If you've used Exalith and discs on a road bike in all conditions then you'll know that there's naff all in it.

Another thumbs up for exalith rims. I haven't tried the Campag coated rims but i would imagine they are the same quality.

joebristol

I haven’t tried Exalith rims, but a quick google suggests they can in some cases be noisy, and if they get a lot of certain types of dirt on them you can wear the coating off the wheels quite quickly. Going back to my previous point, if the wheels are going to get used in the wet on really muddy / gritty roads then this could be an issue. I’ve also heard that exalith rims can eat through brake pads.

On that basis discs still hold an advantage for frequent wet weather riding for me.

Back in the day I had various Mavic ceramic rims with v brakes and although they were good, when discs came in they mashed them for performance, albeit there’s a lot more mud with mtb than road.

lostboysaint

Joebristol wrote:

I haven’t tried Exalith rims, but a quick google suggests they can in some cases be noisy, and if they get a lot of certain types of dirt on them you can wear the coating off the wheels quite quickly. Going back to my previous point, if the wheels are going to get used in the wet on really muddy / gritty roads then this could be an issue. I’ve also heard that exalith rims can eat through brake pads.

On that basis discs still hold an advantage for frequent wet weather riding for me.

Back in the day I had various Mavic ceramic rims with v brakes and although they were good, when discs came in they mashed them for performance, albeit there’s a lot more mud with mtb than road.

Still fascinates me that people would rather spend money on a disposable wheel rim in order to achieve the same braking performance rather than just occasionally have to change some pads.

joebristol

Indeed - discs brake pads are like £10 probably for Shimano and discs themselves last a long time.

I’m happy with a slight weight penalty for this consistent braking with cheap running costs vs having to buy really expensive wheels with a special coating that will wear away and require a new rim to replace (unless there is some way of recoating them).

thegreatdivide

Joebristol wrote:

I haven’t tried Exalith rims, but a quick google suggests they can in some cases be noisy, and if they get a lot of certain types of dirt on them you can wear the coating off the wheels quite quickly. Going back to my previous point, if the wheels are going to get used in the wet on really muddy / gritty roads then this could be an issue. I’ve also heard that exalith rims can eat through brake pads.

On that basis discs still hold an advantage for frequent wet weather riding for me.

Back in the day I had various Mavic ceramic rims with v brakes and although they were good, when discs came in they mashed them for performance, albeit there’s a lot more mud with mtb than road.

To clarify some internet myths, because that’s what your quoting, not real world experience like the guys on here:

1. It’s not a coating it’s a treatment.
2. The squeal that a few ‘reviews’ mention comes from pad set up - but once the correct toeing in process is used they make a lovely ‘fzzzzz’ noise.
3. Disc brakes can make a horrendous noise.
4. If you treat Exalith rims well they will last you for years and years with little wear. My own pair of Exalith2 RSY-SLRS bought in Autumn 2013 have done tens of thousands of miles in all conditions including treacherous descents down Cols in the pi$$ing rain and look as good as new. If you’re a cack handed fud, full of the fear, who drags their breaks on a 1% hill and doesn’t look after their toys then yeah – you’re going to screw the rims.
5. For fast wearing pads see point 2. I haven’t changed my last set of pads since late 2016 and I climbed over 125k meters last year – so that’s a lot of down too.

joebristol

TGD - Probably quite a lot of riders will drag their brakes on a variety of hills so will wear stuff out quicker than you do. We’re not all expert descenders on the road (although I’d consider myself pretty reasonable off-road - without being the next Aaron Gwinn).

When you say myths - I’m quoting people on some forums who were talking from personal experience - so much he same as you are.

I’m about to get my first road discs - but my mtb discs rarely squeal wet or dry - unless you get biblical amounts of mud on them.

Without wanting to seem stupid, but the difference between a coating and a treatment?

lostboysaint

About £50/rim

mamil314

Coating is a substance applied on top while treatment would mean a special method of preparing surface (like bead blasting). Both can be, and, usually, are rubbed off if exposed to grit.

In OP's stead i would buy disc brake bike, replace heaviest parts (wheels, crankset, saddle) and enjoy sub 7kg ride.

pilot_pete

thegreatdivide wrote:

Joebristol wrote:

To clarify some internet myths, because that’s what your quoting, not real world experience like the guys on here:

1. It’s not a coating it’s a treatment.

Exalith is a super-hard, 10-micron thick rim coating...since the Exalith is just a coating, it is possible to damage it and have the aluminum rim underneath show through. from a VeloNews review with quotes from Mavic.

PP

svetty

Purely based on the OP's reference to 'narrow dirty country lanes' I'd probably go with the disc. The R8000 groupset is also a factor...

bendertherobot

mamil314 wrote:

Coating is a substance applied on top while treatment would mean a special method of preparing surface (like bead blasting). Both can be, and, usually, are rubbed off if exposed to grit.

In OP's stead i would buy disc brake bike, replace heaviest parts (wheels, crankset, saddle) and enjoy sub 7kg ride.

He could buy a used Equilibrium disc for that money, and use it on the bad days

ajdobbin

kirkee wrote:

Both have their benifits. But, as you havent been riding for very long, stick with what you have. Gain more experience, as you get better you will probably find the decents a bit less scary.

Probably sensible advice, but I REALLY want a new bike lol. I wouldn’t say I was finding some of the descents scary, but I would say a few times it’s felt like the brakes were pretty much working at their limit

bendertherobot wrote:

Don't forget, the one you're looking at has Exalith rims, which really should narrow the difference between disc and rim (not that there's much in it in the dry).

I assume it's this one?

https://www.canyon.com/en-gb/factory-ou ... s&id=25495

Yeah that’s the one. As a bit of a noob, am I right in assuming Exalith rims are decent then? I’ll do a bit of research on them.

joey54321 wrote:

Though I will say your question of "which will I get more benefit from" isn't really specific enough, there will be a benefit from both but they might be different benefits.

Yeah fair point

Wierdagger wrote:

So, we have to choose from total weight 78.7kg with rim brakes and 79.5kg with disk brakes.
Difference in 1%. I'd rather take disk one.

When you put it like that it does seem a bit silly to worry about 800g. But I will say, when I’m riding with 2 full water bottles, my god can I feel the difference once they’re empty, and thats just over a kilo (although I imagine at that point fatigue has kicked in too!)

bendertherobot

Yes, very good wheels, and normally retail for about £1k.

lostboysaint

ajdobbin wrote:

kirkee wrote:

But I will say, when I’m riding with 2 full water bottles, my god can I feel the difference once they’re empty, and thats just over a kilo (although I imagine at that point fatigue has kicked in too!)

You really can't.

ajdobbin

lostboysaint wrote:

ajdobbin wrote:

kirkee wrote:

But I will say, when I’m riding with 2 full water bottles, my god can I feel the difference once they’re empty, and thats just over a kilo (although I imagine at that point fatigue has kicked in too!)

You really can't.

Silly me, of course you know better than I do how and what i feel when im riding my bike.....

joey54321

You can feel that difference.

Though just because you can feel the difference does not mean it's significant.

alex222

In my experience there was considerable step up in performance between the Tiagra (4600) and the Ultegra rim brakes. So I wouldn't let your current experience with rim brakes influence you hugely.
That aside I would go for the rim brake bike.