Disc Brakes on Vendetta V20

[RojoRacing]

Ok so I absolutely torching my carbon wheel friendly brake pads on my Vendetta because of the extra speed it gains between corners. I thought I could get away with some new calipers and maybe try the newest version of Swiss stop pads but it seem disc brakes is going to be the only thing that solves my problem. I also just so happens I'm about to order new wheels so I can choose disc compatible hubs on the new wheels.

Standard road hub spacing of the drive wheel is 130mm but all disc compatible road hubs are 135mm. That's only 2.5mm of .100" per side and long alloy forks and chainstays on the V20 should flex more then enough to fit the extra 5mm of width. The question I have is that ok to do and are there any ill effects with lining up the caliper and rotor? I don't imagin there would be any issues but I figured I'd ask someone who has disc brakes on their Vendetta like @BentAero. I know you don't have the V20 version of the bike but I don't think the any of the disc brake mounting tabs have changed at all. Maybe @Robert Holler can chime in in regards to disc brake mounting changes through the generations of the Vendetta.

Robert mentioned the possibility of clearance issues between the caliper and spokes when running 140mm rotors. Are the V20 post mounts compatible with 140mm disc brakes to begin with and do the guys feel 140mm discs are powerful enough to stop a speeding Vendetta? I know 140 in the rear would be more then enough power to skid the tire at will but the front has a lot of weight and can grip the ground quite well under heavy braking.

I'm planning on using TRP Spyre SLC calipers per the recommendation of a well trusted friend who really likes his on his CX bike. https://www.trpbrakes.com/category.php?productid=1200&catid=206&subcat=0

Anything else you guys can contribute would be appreciated.

Thanks

 

[ratz]

If you are going for the Sprye's make the jump to the Hy/Rd. They are cable actuated hydraulic. The self centering pads feature is worth the prices of admittance. The only thing you have to remember with them is to lock the brake open (there is an integrated screw, three quick twists) to prevent the pads from death clamping with the rotor removed and forcing you to bleed them.

For the 24 hour stuff you do; not having to ever worry about your pads rubbing is the benefit; braking force and feel is great but a secondary benefit. As point of reference we have 3 bikes with avids that I have to adjust all summer long. In 2 years I have never had to adjust the Hy/Rd's (and that's why they are on dad's bike)

 

[RojoRacing]

In a 24hr race I never even use the brakes so I don't think uneven wear leading to potential dragging issues is even a variable. I would think the true dual piston actuation of the mechanical TRP would eliminate most of the constant pad adjusting. Hydro Pistons can get sticky over time and no longer return at the same rate making them hard to dial in a perfect drag free ride. Sticky pistons is probably more a muddy MTBing issues though.

I like the price point of the full mechanicals as well as the lighter weight because after all I'm only getting discs in the first place because I climbing big F**king hills :lol

How many sets of pads have you gone through on the semi hydro setup and have you had to mess around with bleeding them at all?

 

[ratz]

How many sets of pads have you gone through on the semi hydro setup and have you had to mess around with bleeding them at all?

Bled once, was trivial because all the fluid is in the brake (kid walked by and squeeze brake level while I was work on it and froze the pads in the locked position *sigh*. Still the first set of pads about 1500 miles on that bike; I don't brake much either unless I have 100 lbs of kids in the trailer; then I tend to have to brake a lot on the hills; while in the back the kids are yelling go faster. Bike doesn't really see rain but it sees it's fair share of puddles. New house on top of hills, brakes are going to get a lot more work.

Sounds like the SLC are the way to go for you; a least a couple people here have reported mounting them. Not sure about 140mm and spokes; Robert is usually dead on + conservative (as expected) the V20 fork you have should be 132mm spacing to work with 135mm and 130mm.

 

[LMT]

I have the mechanical TRP's on my bike and they work really well.

The only drama I had with mounting was that the rear rotor (120mm) is very tight against the frame. So much so that I had to file about 1mm from the weld as the screws that held on the rotor were brushing against this.

I have the 140 rotor on the front and this is more than enough braking power.

 

[RojoRacing]

Where do you even get a 120mm rotor seriously I don't know anything smaller then 140mm existed.

 

[Robert Holler]

The TRP Spyre will not work on the rear of the V20. The placement and width of the unit will contact your spokes. It MAY work with your wheels IF they have a smaller flange on the hub.

It depends on that and the cross pattern of the spokes for clearance.

Just a heads up.

Robert

 

[Bill K]

I have a V20 with the TRP HY/RD calipers.
The rear wheel has a 140mm rotor. It barely clears the frame (same as leetaylor55 mentions above). A 160 rotor would not fit unless you modify the frame and flatten the bulge at the weld.
My wheel has a Sram X7 hub (32-spoke, 2-cross lacing) and the caliper clears the spokes by about 1mm or so.
I cannot use the front wheel from my DF bike because it does scrape the spokes. It has a SON 28 ISO dynohub laced to a 700c rim.
Curiously, I have another wheel from my Bacchetta with a SON 28 dynohub laced to a 26" rim that works fine and the caliper does not scrape the spokes.
So, the tolerances are pretty tight but I am happy with it. Just choose your hub wisely.

The front wheel will easily fit a 160 rotor (I switched from 140 to 160 so I can more easily swap wheels). Both sizes work fine.
160 front / 140 rear is a good combination and likely improves brake modulation.

I have just under 2000 miles on the V and am on the second set of brake pads.
The first set that came with the calipers (resin) wore out rather quickly in all the January rain.
If you are considering the HY/RD, the self-adjust feature is definitely nice, but it stops self adjusting when the pads are about half worn. It's not a big deal, but when I first noticed it I thought the calipers needed to be bled.

Bill

 

[Freygeist]

...180mm on the drive wheel works fine (Shimano Di2 hyd.)! 140mm on the back - would take 160mm also, but it rubs a bit on the weld, you'll have to file it off! (as i had to do with the 140 also....)

I'm quite happy with the 180 in front because of long and steep descends in the Austrian Mountains....!

Manfred

 

[LMT]

Where do you even get a 120mm rotor seriously I don't know anything smaller then 140mm existed.

Might be wrong on this. I know that the rear rotor is smaller than the front. I think it might be 140mm, but it is tight to fit. I'll check tonight.

 

[RojoRacing]

View attachment 2420 View attachment 2421 ...180mm on the drive wheel works fine (Shimano Di2 hyd.)! 140mm on the back - would take 160mm also, but it rubs a bit on the weld, you'll have to file it off! (as i had to do with the 140 also....)

I'm quite happy with the 180 in front because of long and steep descends in the Austrian Mountains....!

Manfred

The rear wheel locks up so easy as it is right now the small the better to reduce overall bite and increase the modulation. Right now I'm having to plan ahead to far back before tight hairpins I can't even see yet because if I wait till I see the corner I'll overcook my front pads even more then I already am or risk blowing the corner. I imagine a 140 is fine in the front and probably a massive improvement over what I have now but I think I'll give the 160 a shot to start. After I have lots of rotors options from the mtbs.

Any chance you could post a few pics of the important clearance areas that were in question? How about some close ups from behind both calipers looking with the rotor to see frame clearance and spoke/hub flang clearance.

I ordered my new wheels last night after another risky ride on the current rim brake setup but it'll be 6 weeks before they arrive. My friend with the TRP brakes said I could pillage his wheels and brakes off his bike to try out on mine so I maybe give that a shot while I wait for my stuff to come in.

 

[RojoRacing]

@Freygeist was your hyrdos rear brake hose long enough from the factory or did you need to buy a longer hose?

 

[DavidCH]

after another risky ride

Why risky?

 

[RojoRacing]

Well I never do anything conservatively and tend to ride that fine line all the time simply by instinct, it's a way of life after years of motorsports. The high winds last night combined with lumpy chip seal road surface and at least a dozen 40+ mph to 10mph hairpin corners plus random gravel from rock slides make the Hamilton DH risky by default. Then you add in the twitchiness of the Vendetta along with brakes that are literally melting and peeling away and you have a situation that makes me feel like I could lose it at any point. I like riding that edge but would rather my equipment not be the reason why.

 

[Bill K]

I did a bit more testing of the back wheel.
On my V20, the 140 mm rotor clears the frame by less than 0.013 inches (the smallest spark plug gap measurement gage I have).
For fun, I put my DF front wheel in, and it's 160 mm rotor barely touched the frame. If I sanded the paint off the frame, it would not rub.
With the DF wheel (SON 28 ISO dynohub), the HY/RD caliper rubs the spokes with the 140mm rotor, but clears the spokes with the 160mm rotor.
Here is a picture of the 160mm rotor in the frame:


Here is the 160 rotor with the HY/RD caliper mounted:


As a side note (off topic), my DF front wheel is a HED Belgium tubeless with a Maxxis Re-Fuse 700 x 32 tire. It actually fits, with about 1mm clearance between the tire and brake bridge.
If I wanted to file down the unused brake bridge, I could ride it like this. But I'm not going to, and if the tire stretches (it is brand new) it would not fit.

Bill

 

[RojoRacing]

Well I went ahead and ordered all sram red 22 hydro so Tuesday I'll be installing all that stuff from scratch. Filing 4 years worth of taxes makes buying a few bike parts a little easier on the wallet

 

[LMT]

I've checked and the rear rotor is 140mm. The number that Bill quotes is about right for the clearance between the rotor on the rear wheel and the frame - it is very tight.

No spacing issues for the front wheel running a 160mm. My wheels are Ksyrium SL pro disk FWIW.

 

[RojoRacing]

View attachment 2420 View attachment 2421 ...180mm on the drive wheel works fine (Shimano Di2 hyd.)! 140mm on the back - would take 160mm also, but it rubs a bit on the weld, you'll have to file it off! (as i had to do with the 140 also....)

I'm quite happy with the 180 in front because of long and steep descends in the Austrian Mountains....!

Manfred

Did you have to buy replacement hoses for your disc brakes? My red 22 hydros just showed up and the front hose is like 6" short for proper routing. It looks like I'll have to cut the compression nut off the rear hose to route it through the frame but it's also looks to be about 6" too short as well. I'm wondering if the 2m long replacement hoses is even going to be long enough for the rear. Really sucks to have to buy 2 hoses strait away just for install.

 

[1happyreader]

Really sucks to have to buy 2 hoses strait away just for install.

Ask them if there is a tandem kit for Red 22 hydros or sell in bulk ?
Just don't use the evil R word. (recumbent).
Feel your pain ,had to give up on a polar computer because it was designed to be mounted on a drop bar stem REALLY close to the sensor on the fork.
Later,,, bye

 

[marshall2389]

I've got an extra Avid 160 mm G2CS disc brake (http://www.chainreactioncycles.com/...zv1Nk9RjN_j4h-xlJynQIaAjtC8P8HAQ&gclsrc=aw.ds) with bolts.

New, never used, $10 + shipping if anyone wants a backup.