Transcontinental Race No. 7 - TCR7 - #TCRN07 - 2019

I'm trying to get 30/46 but it is a pain in the arse as trying to keep stages pm. First attempt was absolute black rings but pm doesn't work properly with them. Am now fiddling around with a 105 triple (with just an inner and middle) but it needs spacers and faff to get the chain line. I don't think I cba, so may reorder the ab rings I returned last week. PM not exactly critical.

Interesting to hear about your power meter not working. That must be because of the oval ring and nothing to do with Absolute Black? I Googled and found this, https://powermetercity.com/2016/07/24/power-meters-oval-chainrings/

I have tried running a triple as a double with an Ultegra 6703. So many things going on there to sort out. Like for example the axle is longer and has a spacer that goes on the drive side. That spacer is not not really the ideal width. The chain angle was worse than the AB sub compact rings with an MTB cassette on a road free hub body and a short chain stay. Some really noisy cross chaining was going on there without actually cross chaining. If you follow that. So I abandoned that project.

Where I ended up was the Rotor 3D cranks with the one piece 46/30 chain ring. Love that setup. No power meter though. I don't make enough power to merit measuring it, lol.

anyone else volunteering this year?

Ok so another session of Joy of Baik Tech with Bob Thod ;)

Disclaimer: It's been a couple years since I went through so please accept some inaccuracies in what I'm sharing. I dont have time to redo maths and re-research before typing.

If I remember right the more distance the mech pully is away from the cassette, the slower the shifting and the wear is accelerated on the cassette + chain. This then wears the front rings faster.

Shimano doesn't "support" a bigger cassette than a 34T for the 11spd Ultegra. When doing the math explained at the Wolftooth RLDM website on rear mech capacity, the numbers also indicate this doesn't/shouldn't work. But yet it works. It shifts fine. Why? Well, one example could be when running a 46/34 at the front, there is a difference of 12 teeth instead of 16. This makes the rear mech happier. Maybe that is the key?

Back when I went through all this I reached out to Wolftooth support, which was fantastic btw. They helped me understand what was going on, why and what I needed for the solution I was looking for. Because I wanted to run an 11-42 cassette on the back and front chainrings with a 16 tooth difference, such as 46/30 or 50/34, the only option is to use an 11 spd XT GS rear mech because it's the only one with enough capacity to handle that amount of chain slack. The WT Tanpan is then necessary to change the pull ratio of the road shifters to make the XT mech move the correct amount.

The body of the Ultegra and XT rear mech are pretty much the same dimensions. This allows the Ultegra to step up to the larger rings such as up to 40 without the pully colliding with or riding on the biggest ring.

So why does the WT RLDM exist? I don't know. Because WT need to make money? Or maybe there is a good technical reason, but as we see from the rig that got @Skinny through Italy with no issues, on there was an 11-40 rear, 46/34 front and no RLDM. So to sort of repeat his words on the Terravail tires and Petervary, if that setup works for @Skinny, then it will work for the rest of us mortals. If for some reason it doesn't, then try a RLDM.

And as @Skinny said, get the RX series with the clutch.
Part numbers for reference:
RD-RX800-GS for cable
RD-RX805-GS for Di2

This is kinda my point - my setup shifts into every gear - why do I need a WT, unless it had some magic way of making shifting better?

I would like better shifting but it's pushing the limits of the RD so I'm happy to have ok shifting and big fuckoff gears at the back. The only difference with mine is the 50T big ring that I could probably drop to 46T but would that make much difference? It might improve shifting a little since I could run a slightly shorter chain but is it going to be enough to justify another chainring?

I really enjoy the 46 front ring because it expands my useable range of the rear cogs. I've swapped all my bikes to 46 on the front. On a 50 tooth I don't touch the smallest 3 cogs. With a 46 I have more choices but still don't use the 11. For me a 46 makes a huge difference.

I'm curious about a 44 so i'm working on a project with a Force 22 crank, a 2x North Shore Billet (NSB) spider with an MTB 104 BCD, and 44/28 rings. The Ultegra 8000 front mech is happy with that small of rings on the frame I am experimenting with. But there are some serious chainline and front mech interference issues I'm trying to sort out with spacers. It is not looking to promising at the moment but if I nail it then this will be my new off-road setup. The Force cranks can be quite flexible by changing the spider but these types of projects are not for everyone. Lots of time and money spent experimenting but I like that sort of thing.

I still have the 46T on retired bike. I could probably use that ring and put a 50+ on the turbo one but I'm lazy and the 50T up front is good for fat people like me that will ride the descents some times.

Rabies jab done. Sounds like one of you lot got there before me? CityDoc, Wimpole Street.

Also Teravail sound quite promising.
Think I’ll order some once the bank balance recovers.

What size are you getting?

Probably 32, apparently run true to size. Are you considering them?

I was considering them but initially could not see in 32, although I can now. Have just ordered 4 seasons in 32. Not sure have made the right choice but I think there is only around 70km of gravel in total. I may still be convinced!

There's 80km in Serbia, which doesn't look too bad, some more in France, which we should find out any day now, plus the bits you don't know about yet which you will have routed onto without realising.

According to the Serbia parcours I have drawn on Komoot (which, of course, is quite likely wrong), it is about 50km of gravel the rest is not. Then I thought it would be less than 20km of gravel for the Alpe d'Huez parcours in France. Not completely sure if I have made correct tyre choice so may take one rear spare of a more gravel friendly tyre.

Maybe I'm late to the party with this one. I just learned about the new Shimano GRX groupset.

https://bikepacking.com/news/shimano-grx/

The new RD-RX810 or 815 rear mech has capacity to run a 11-42 cassette. No roadlink, no tanpan necessary. Compatible with everything road.

The ultegra level FC-RX810-2 crank is a 48/31.
The lower level FC-RX600-11 is a 46/30.

I'm not sure about availability. Some items are appear in stock at some online shops like bike24. Some have a lead time of September.

Attached the rear end compatibility table.

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Yeah, it's been discussed in the groupset chat.

there is a groupset chat?
what about a tire chat? I'm gonna share a few more bits about tires when I get to it.

Yes, there is also a tyre thread.

Charliebikemonger should have the 32 Rampart durable in soon for those interested

After the tire talk I was going to pull the trigger on the Continental GP Urban because I know what I would be getting. Will be about 35mm wide, black chilli, poly x. Familiar puncture protection level. However the mystery of the Panaracer was too strong to resist. That and I'm a rubber junkie.

Strada Bianca:
• Measures about 37mm on a 20mm internal width dt swiss rim.
• Has a thick and dedicated puncture protection layer just under the chevron ribbed tread pattern.
• Sidewall is cloth like.

Gravel King Slick:
• Measures about 38mm on a 20mm internal width dt swiss rim.
• In my opinion it has no dedicated puncture protection layer under the knurled and chevron ribbed tread pattern. There is less rubber/thickness there than other tires I'm familiar with. The Conti Grand Sport, GP4 and 5k have more meat in the middle section than this tire.
• Sidewall is covered in the same grippy rubber (anti flat) coating as the tread area and appears/feels more robust than the Bianca.

After 3000+km on the Bianca, no puncture. So far it never met an object that compromised the sidewall. It’s one of only two tires that never punctured. The other being Conti Contact Travel.

The lack of meat in the middle of the GK Slick leaves me uncertain. Makes me think this tire might be its happiest off road, in an area without thorns, and with sealant inside. The fun factor will be really high though.

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Parcours are on a Komoot!

https://www.komoot.com/collection/887208/-tcrno7

I damaged the sidewall on both my Strade Bianca tyres earlier this year and got a huge sharp stone through the tread. Wouldn't buy again but only because of how hard they are to get on.

I used spring clamps for woodworking as extra hands to try and keep the bead in the rim as I worked around the rim. Didn't work. Also ruined one of their latex tubes in the process. Horrible experience, like the pain of giving birth.
A friend who's been riding tubular and challenge tires since ever, says he doesn't know what I'm on about. He explained something about slow, patience and finesse and they just slide on. For me it was like fitting a square peg in a round hole.

Took mine to the LBS after wasting an evening on it and ripping two tubes. Cost me 10e to get both tyres fitted.