Search results for:

aha, the plot thickens -> Di2.
An expensive experiment that may not work.
The path to a new crankset starts to appeal when comparing the costs innit?
If you did take that on, you might be the first person ever.
Mixing an 11/46 with a 2x front is already quite an uncharted territory.

ah you want to try the 11/46 cassette. If you have a 12 tooth difference on the front like a 46/34, then I think you can push the 1x GRX rear mech to do 46 with the mod I mentioned on page 1 of this thread. The point of the long cage XT mod is to take up the chain slack. The body of that GRX should handle the jump to 46.

As per my last research and testing extravaganza, there were no solutions for a 5x110 BCD that went lower than a 33 tooth. And I think that 33 came from one of the French chain ring manufacturers, TA Specialities maybe? It is not possible to go smaller than 33 with a 5x110. Praxis works did something that went down to 32, but that is only with their cranks.

46 tooth 5x110 rings are often paired with a 36 or 39 tooth inner ring (for cx). All the ones I've tried work fine with a 34 inner.

How did your experiment with the 11/40 cassette go? Is it enough or you looking for more?

Ditto on the park boots not sticking but so far only needed to try them on TL tires. Read/heard somewhere that the innards of TL tires have a different compound that is pro slime, anti stick. Tested it with the gorilla tape and was ok-ish. But maybe the glue on the boots and maybe even the tape is starting to fade? Ended up gluing a big and rather tough tube patch to the inside of the tire. I start to think about carrying flexy plastic bits again.

Something else I came across. The fit on some of these new TL tires with certain rims, is so tight that it goes well past Conti tough and into the realm of nearly impossible to mount unless cool ,calm, collected and in the shop.

for sure, makes a huge difference during the few seconds a year it gets used. For those hardcore analog embracing measuring sprints, I pull the battery too and read the calliper manually.

Tire update

Continental GP4000 28, 270g on 17mm = 31mm
Continental GP Urban 35, 350g on 17mm = 33mm
Continental GP5000 32, 300g on 18mm = 32.2mm
Continental Travel Contact 37, 520g on 19mm = 34mm
Challenge Strada Bianca 36, 350g on 20mm = 37.2mm
Panaracer GK Slick 38/40, 330g on 20mm = 38mm
Vittoria Terreno Zero G2.0 35/37, 435g on 20mm = 36.2mm

Pics of Travel Contact, GP Urban & Terreno Zero

FYI to those looking for more gearing capacity at the rear.
There is a hack possible with the Shimano GRX RD-RX812 rear Mechs.
The body of these mechs are the same as the XT. Compare the shape of clutch housing.
As per the specs the RD-RX812 have a low capacity (31T) due to a medium sized cage and thus are intended to be limited to 1x.
However by changing to the long cage of the XT, you get the same capacity as the XT RD-M8000-SGS of 47T.
Running a 16T difference on the front and an 11/42 on the rear is no issue. Shifts fantastic.
Pic of the XT SGS cage parts below.

The real issue with franks post is the age of the farming equipment. It's clearly older than 50 years.
:)

One way of looking at the race is of a group of highly privileged people parading their affluence in a masquerade of suffering in front of people for whom suffering is a quintessential part of life.

Quality meme material here. If I knew how I would have a go at making one but instead you'll have to imagine it. Spoken from the perspective of the locals:

Oh you think riding your fancy expensive bikes in my back yard is hard? Try living here you snowflakes. :)

Klaus had a dispute with Kevin. Sounds pretty serious! ;)
https://youtu.be/Q4BveTSlwrY

I’d guess Bob_Thod has a muscle balance that’s more suited to oval rings.

Correct, or from the other perspective, a muscle imbalance where the oval provides some compensation.

My issues stem from trauma caused by injuries and not taking the recovery therapy seriously. Decades ago the chain snapped while climbing out of saddle. On the power stroke the pedal came round and snapped the fibula on the opposite leg. Years later add a couple 2nd degree foot sprains. Voila issues.

Words of advice, never underestimate the power and importance of recovery therapy. Take it seriously & work on every little muscle you don't know about. They all need to be strong because they function together enabling us to do the amazing things we can do. Even if, or, especially if, we sit in an office all day.

I first stepped into oval with a 50/34 and still have that on a bike.

The oval takes the edge off at top dead centre and bottom dead centre. Take a 50T ring for example, at the largest point of the oval the size is like a 52T. What the oval does is like switching the size of the chainring quick from 52 to 48 at the smallest part of the oval. It makes the transition from the upstroke to the downstroke easier. For me this was a dramatic and noticeable difference in reduction of pain. You might experience something totally different.

The switch to oval for me was clear. It helped me a ton but not while climbing. Especially when grinding or getting slammed to a near halt. When my knee acts up, I need to cut the power asap. The only way to do that is with granny gears. With this limp mode option I don't put myself out of commission for weeks.

The best read of the topic of oval is a study called:
Comparative biomechanical study of circular and non-circular chainrings for endurance cycling at constant speed.

The PDF file is:
Biomechanical study chainrings - release 2

Link:
http://www.noncircularchainring.be/pdf/Biomechanical%20study%20chainrings%20-%20release%202.pdf

It's a heavy read but in conclusion, the Rotor and similar shapes are crap, not enough oval, the Osymetric shape is the best. TA Specialties started making a shape very similar. But neither offer a sub compact solution. I'm hoping that one of them make rings for the new GRX. I'll be all over that. In the meantime, the Rotor and Absolute Black 12% oval rings do me fine and allow me to ride more. Your milage may vary.

You pull me into another tech talk with this post :)

Have knee issue, have hills, choose to climb, which drives me to experiment with these types of drivetrains. Can do only high cadence with low power. No grinding else it's time off the bike.

I am a believer in the oval chainrings because I have a noticeably happier knee(s). I just picked up the newish one piece Rotor 46/30 oval chainring that fits only the new ALDHU & VEGAST. Looking forward to that. I really want the Osymetric or TA but don't get the 46/30 combo.

Since my last writings on this I've come further with the topic and also setup a Shimano 1x with a 50T Sunrace cassette. Some unpleasant chainline issues that were solved by shimming the cassette outboard and the crank inboard. It's sorta happy now but I'm disappointed in 1x. It's not as trouble-free as I thought and it is not smooth. Tried chains of KMC, Shimano and SRAM all at DA/XTR level. Conclusion, SRAM chains are made to like 1x. The others not so much.

The devil is in the details with this stuff. I'm willing to hash them out with anyone thinking about this but need to know exact model of shifters, F&R mech, and what you are willing to change.

A 46T or 50T in the rear is designed for a 1x.
2x could only work if front rings are very close in size, like CX 46/39 close.

Spent much time on this website comparing gear ratios of what I have to where I want to go. Then reading, buying and trying different stuff.

http://gears.mtbcrosscountry.com

Punch in what you have, then compare it to an 11spd Shimano 11/42(or 40) rear and 46/30 (or 48/31) front.
That is a very solid functioning and achievable setup that doesn't squak or grunt.

hmm another XX1 casualty? I have this crank on my MTB. I keep it because of the great 156mm Q-Factor.

Anyone read somewhere what exactly happened? Would like to know the cause of failure.

Enough use cases out there where carbon cranks don't survive knocks and collisions with objects. Attached a couple examples found via google.

180km on one leg is hardcore. That leg with no pedal must be dead from keeping it steady on the BB/CS.

FYI
https://srmr2019.maprogress.com/

from https://www.dotwatcher.cc/post/7rCM8b5EetgmXfevXxr7mL

"TCRNo7 winner Fiona Kolbinger is currently on the road after stamping in at the Loudeac checkpoint around an hour ago. She rode from Brest (the finish of this year's TCR) to the start-line of PBP, and joked that she was riding her own BBPBP (Burgas, Brest, Paris, Brest, Paris)"

Coolest ever!

Is that an ice cream cone? if yes, what did you consume first? the ice cream or the beer? and how did that go down the tubes?

in my experience those two together are a no go. would not do again.

Maybe after doing the Silk Road race, you view that sort of terrain with different eyes, and maybe it's a little Silk Road training?

Could this type of event be done with any reasonable efficiency without the help of any technology?
To have to think and calculate routing while racing . ouch.

posted at https://dotwatcher.cc/race/transcontinental-race-2019

haha thats funny, I'm with Bagoly. It's a harmless joke like when we were kids and crushing on a girl. Hope he does't get burned at the stake it from it.

It would be an honour and privilege to be dropped by Fiona.

View from the beginning of the parcours from Google Street view.
Some sun between the clouds there now, so view should be alright.

Does "Changed position" mean you tried slamming those cleats as far back as possible?

If possible, consider cutting the holes (with a chain saw file for example) so you can put the cleats back even further. You can find this file in the garden section of hardware stores next to the chain saw chains. They are the right diameter of the cleat holes and can munch up carbon good enough.

The theory is that with the cleat towards the back, the calf muscle is less stressed, therefore pulling less on the Achilles tendon.

Power to you!

Welcome to the club ;) pretty soon you'll be doing maths!

Wish y'all no mechanical issues and a puncture free experience.

Looking forward to living another TCR vicariously through watching your dots and scavenging the webs for pics and info.

all the best !

Will the GRX RD-RX810 work with a large cassettes at the rear and a large tooth difference at the front.

Based on the data and experience we know from ultegra, and doing the maths, that answer is no. But lets leave the "maybe" door open for now.

Looks like Shimano want you to do one or the other. Large range at the rear, or at the front, and then buy into the components that get you that. Those of us that want/need both, still have to deal with wolf dohickeys.