Di2 or Disc Brake

Bikes1234

So going to buy a new bike so basically stuck on what to do.High spec frame so basically its going to be Disc Brake with Shimano Ultergra R8020 or non disc with Di2.If i go disc will have to swap the carbon wheels out as well.What people opinions here

Cee-Jay-Cee

It depends on what you are using the bike for. If your using it daily for commuting and all year round then go with discs but if its going to be 'good' bike for dry/summer use, go with rim brakes and Di2.

gman2k

Go with disc for now as:
1. Frame will then always take disc (make sure it's flatmount)
2. Well fitted mechanical 11spd is very nearly as good as di2
3. You can always upgrade to di2, but you cannot upgrade to disc if it's standard rim brakes.

godtabh

gman2k wrote: »

Go with disc for now as:
1. Frame will then always take disc (make sure it's flatmount)
2. Well fitted mechanical 11spd is very nearly as good as di2
3. You can always upgrade to di2, but you cannot upgrade to disc if it's standard rim brakes.

mechanical is not nearly as good as Di2. Di2 is way better

I've Di2 disk and rim brakes. I'd be happy with either

dahat

Cee-Jay-Cee wrote: »

It depends on what you are using the bike for. If your using it daily for commuting and all year round then go with discs but if its going to be 'good' bike for dry/summer use, go with rim brakes and Di2.

+1

My next winter bike will be disc as for summer use i think a good rim brake set up is more than adeuate.

Bikes1234

Thanks for all your replies the bike is going to be used for racing

Leroy42

I recently treated myself to a cross bike with both discs and Di2.

Both are awesome, but the discs are the standout. The Di2 is a treat, its cool and great but if I had to choose I would go with discs and mechanical over Di2 and rim brakes.

In saying that, I rode rim brakes for years and never had a problem but there is no arguing that discs brakes are much better in the wet.

Lumen

Bikes1234 wrote: »

Thanks for all your replies the bike is going to be used for racing

I would hesitate to use rim brakes with carbon wheels in a bunch containing riders with disc brakes.

Now it may be that pads and carbon braking surfaces have come on enough to make this a non-issue, but I'd want to be quite sure of the specific wheels I was using.

Large bottle small glass

godtabh wrote: »

mechanical is not nearly as good as Di2. Di2 is way better

Why?

The man said well fitted mechanical. The lever activation of a ratchet and pinion system to move a deraileur accurately and repeatedly is a solved riddle for a very long time.

With that in mind and ignoring issues of redundancy and basic maintenance(neither which are in favour of Di2) why is di2 way better than well fitted mechanical?

dahat

Bikes1234 wrote: »

Thanks for all your replies the bike is going to be used for racing

I've done 3 A3 races this year and the amount of disc bikes isn't as big as I thought. I would however expect that to grow over the next 2 years so in your case I'd go for discs for sure.

Currently using rim & alu deep rim wheels for reference.

fat bloke

Go neither. That's where the bargains are. I'll take mechanical Dura ace over ultegra di2 everytime. And lighter rim brakes over heavier disc brakes EVERY time.

Type 17

Some manufacturers are discounting their higher-end rim-brake bikes, so that's the proof that the market is moving to discs. However, it also means that there are deals to be had if you do want a rim-brake bike (with Di2?).

I have both on my good bike - if I had to choose one or the other, I'd go for the discs.

Di2 is is great on the front mech shifting, and 10/11 speed mechanical shifting is pretty precise and reacts badly to dirty cables, meaning frequent cable swap-outs if you ride in poor weather, but if you mind your mechanical-shift groupset, it'll be 90% as good.

(Direct-mount) discs are worth going for, as the confidence makes you a bit quicker (IMO), which beats any minor weight issues and, as mentioned, you can upgrade to Di2, but not from rim-brakes to discs.

Large bottle small glass

Type 17 wrote: »

Di2 is is great on the front mech shifting, and 10/11 speed mechanical shifting is pretty precise and reacts badly to dirty cables, meaning frequent cable swap-outs if you ride in poor weather, but if you mind your mechanical-shift groupset, it'll be 90% as good.

To paraphrase it's 10% better with the proviso that you haven't
*the mechanical sympathy required to trim a front mech
*the good sense to maintain cables on a two precise engineering components on either end of the bike

godtabh

Large bottle small glass wrote: »

Why?

The man said well fitted mechanical. The lever activation of a ratchet and pinion system to move a deraileur accurately and repeatedly is a solved riddle for a very long time.

With that in mind and ignoring issues of redundancy and basic maintenance(neither which are in favour of Di2) why is di2 way better than well fitted mechanical?

Redundancy? Di2 will get you home when the battery is nearly dead. It shuts down the front de raileur. Plenty to get you home.

If you ever need to tune it it’s as simple as pushing a button.

Shifting a hear from big to small ring is effortless. I’ve had di2 for years. Wouldn’t go back

Type 17

Large bottle small glass wrote: »

To paraphrase it's 10% better with the proviso that you haven't
*the mechanical sympathy required to trim a front mech
*the good sense to maintain cables on a two precise engineering components on either end of the bike

It's not the trimming (which I never need because I never cross-chain that far), it's the speed of shifting and the positioning of the hand required to make the shift. Di2 wins hands down (no pun intended).

I have plenty of sense to maintain cables (some of the cables on my daily hack are from 1989, the others are from 1992), but I see customer's bikes with shagged cables most days. 6/7/8-speed stuff is very forgiving with bent hangers, stiff cables, dry/worn chains, etc, but 9/10/11 drivetrains can be very finicky.

triggermortis

I’ve only had discs on my MTB and not a road bike, but my good road bike has Di2 and rim brakes and it’s the best stopping and gear changing bike I’ve ever owned. Di2 works ALL the time (until the battery dies) but the battery lasts forever, and it makes gear changes effortless. I hear what people are saying about being unable to upgrade the frame if you want to go to disc later, but I don’t see disc as the best thing since sliced bread. If I had to pick only 1 it would be Di2. I don’t like the look of discs and I think the relative gain is minimal. Cable shifting works if set up properly and maintained whereas Di2 just works, and keeps working well

gman2k

triggermortis wrote:

I don’t like the look of discs and I think the relative gain is minimal.

I like the look of discs and I think the relative gain of Di2 is minimal.

sin_26

Go with neither.
Personally never heard that someone didn't win race because he had rim brakes instead disc or mechanical grouppo instead DI2.
All theories that you will be faster because more confidence in the braking are well... theories only. DI2 and mechanical at the end of the day will do the same and better rider will win on 105 no problem. Buy cheaper good quality rig which appeals you and spend rest for coaching and training camp or smth.