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Sparky
Joined: 08 Dec 2003
Posts: 19083
Location: PDX3/13/14 10:29 PM |
Sandi, how is that Tandem rolling ?
You guys got that sucker rolling regular like?
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sandiway
Joined: 15 Dec 2003
Posts: 4902
Location: back in Tucson3/14/14 12:29 PM |
Good weather, good times
Weather has been exceptionally kind here. Well since you asked, you're gonna get a bit of spam here...
Last significant thing we did was a well-known Gates Pass loop at the edge of the city, see e.g.
http://emol.org/tucson/gatespass/
. I think it was about 45-50 mins of climbing from downtown and then a plunging descent after the top.
Our first time with the tandem on this route, I took it easy on the descent, instead of blasting down. It's narrow and twisty with lots of cars. The disc brakes are great.
We're at the top of the climb. Tucson is somewhere in the far background.
Hope everyone is riding!
Sandiway
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Sparky
Joined: 08 Dec 2003
Posts: 19083
Location: PDX3/14/14 12:45 PM |
So loving it, both of you?
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sandiway
Joined: 15 Dec 2003
Posts: 4902
Location: back in Tucson3/14/14 3:07 PM |
yup...
We're definitely having fun on the tandem. And I haven't upgraded anything on it yet!
We have a few local loops that we can do in our neighborhood just riding out of the front door. All of them involve some climbing but I'm careful not to ramp up the distance and difficulty too much. Our fitness is improving, one of the toughest short climbs is the last stretch to our house at the end of a ride, I've noticed we're surviving that better and better these days.
Sandiway
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Sparky
Joined: 08 Dec 2003
Posts: 19083
Location: PDX3/14/14 3:19 PM |
Any comments about the gearing in function worth a mention. The setup is intriguing, very curious about how it is as far as day to day...
Bob
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sandiway
Joined: 15 Dec 2003
Posts: 4902
Location: back in Tucson3/14/14 3:32 PM |
Tandem shifting
The daVinci setup is quite unique in a couple of ways.
#1 Since I have four chainrings, and a 11-32 on the back, the range is huge. We get to use the biggest gears at least once per ride (because what goes up must come down). Haven't really used the smallest chainring yet. But we haven't tackled the longest climbs yet in the area.
#2 The independent coasting/resync bit. It's great at traffic lights. I don't always manage to click in immediately but it doesn't matter. Each of us can adjust the cranks the way we want. Climbing feels a bit weird when we're out of phase; but it's easy to adjust phase.
Having said all that, the SRAM cogset itself can be a bit finicky in just a couple of gear combinations. Not sure if it's true for most tandems or if I need to adjust the cabling a bit. It's a very long run from the front brifter to the rear derailleur. It's never gonna be as crispy as a single. Maybe a electronic rear derailleur would have been better, but I don't know if they work with 9-speeds.
I'm not sure my seatpost would raise high enough for you, but if you ever come this way, you guys are welcome to test the tandem on our local roads.
Sandiway
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Nick Payne
Joined: 10 Jan 2004
Posts: 2626
Location: Canberra, Australia3/15/14 12:10 AM |
quote:
the SRAM cogset itself can be a bit finicky in just a couple of gear combinations. Not sure if it's true for most tandems or if I need to adjust the cabling a bit.
On our Co-Motion, which I built up using 9-speed Shimano with bar-end shifters, the shifting isn't any worse than on my own bikes. I would think, other things being equal, that SRAM shifters/derailleurs would be less sensitive to a long cable run than Shimano, as the amount of cable pulled per gear change is about 60% greater, so any elasticity in the cable would have less of an effect.
OTOH, the cable run for the derailleur cables on the Co-Motion is more direct, as they run straight along the internal lateral to the rear BB before heading off to the rear derailleur, whereas they obviously can't do that on your frame as there is no internal lateral...
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Sparky
Joined: 08 Dec 2003
Posts: 19083
Location: PDX3/15/14 12:19 AM |
We may take the IBIS out tomorrow, Elaine's first ride of the year...
Speaking of this, What rack set up are you doing for Transport?
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PLee
Joined: 08 Dec 2003
Posts: 3713
Location: Brooklyn, NY3/17/14 6:31 AM |
quote:
I'm not sure my seatpost would raise high enough for you
According to Wayne Lim, you only need a 1/4 inch or so . . . ;-)
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dan emery
Joined: 11 Jan 2004
Posts: 6890
Location: Maine3/17/14 7:09 AM |
Congrats Parkin
Nice run yesterday in the NY Half. Brisk, eh? I was checking the results for my niece and checked you too. Recover well.
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Sparky
Joined: 08 Dec 2003
Posts: 19083
Location: PDX3/17/14 12:01 PM |
No Tandem, we took road bikes instead. Elaine's first ride of the year, 26 miles. New seat too! ;)
Kudos Parkin...
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sandiway
Joined: 15 Dec 2003
Posts: 4902
Location: back in Tucson3/17/14 12:13 PM |
quote:
I would think, other things being equal, that SRAM shifters/derailleurs would be less sensitive to a long cable run than Shimano, as the amount of cable pulled per gear change is about 60% greater, so any elasticity in the cable would have less of an effect.
The da Vinci runs Campy Chorus shifters in front and a modified SRAM rear derailleur. I'm not sure what the amount pulled per gear is in this setup...
Sandiway
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sandiway
Joined: 15 Dec 2003
Posts: 4902
Location: back in Tucson3/17/14 12:34 PM |
quote:
Speaking of this, What rack set up are you doing for Transport?
No rack. The tandem fits in the back of my RX with just the front wheel off.
However, most of our rides have been out of the front door. I'm particularly proud of the one we did last Friday late afternoon. It's not a long tandem ride. But this is what we did:
1. Rode out of the front door just before 5pm. Did part of our usual loop backwards. And then extended it to a friend's restaurant. A bit over 30km (about 19 miles). This was the training part.
2. Ate dinner. Chatted with friends. Sun went down.
3. Switched on the lights. Rode a bit over 8km (5 miles) home.
(See route
http://dingo.sbs.arizona.edu/~sandiway/blog/cheng's%20beijing.png
. Home is starred. Restaurant near 30 km marker.)
It was kinda satisfying because we didn't use the car to go out to have dinner.
We got a 19 mile training ride in. Total included about 500ft of climbing. I've resisted putting on a bike computer on the tandem. But I noticed also, with quiet satisfaction, despite the climbing and some stop lights we covered the 19 miles in under 55 minutes. That means we're beginning to gel on the climbs and move a bit faster.
Sandiway
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Nick Payne
Joined: 10 Jan 2004
Posts: 2626
Location: Canberra, Australia3/17/14 1:52 PM |
quote:
The da Vinci runs Campy Chorus shifters in front and a modified SRAM rear derailleur. I'm not sure what the amount pulled per gear is in this setup...
Presumably the amount of cable pulled by the shifter. Campagnolo 11-speed shifters pull the same amount of cable as Shimano 9-speed, and Campagnolo 10-speed shifters pull the same amount of cable as Shimano 8-speed, and both of those are perfectly viable combinations to use on a bike. One of my bikes is using the 11/9 setup - Chorus 11s shifters with the FD and RD and cassette all being Shimano 9s MTB components. The shifting is essentially perfect, and compared to S, the Chorus shifters have more trim positions available for the FD to banish chain rub. And I know people who are using the 10/8 setup with equally good results.
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PLee
Joined: 08 Dec 2003
Posts: 3713
Location: Brooklyn, NY3/17/14 3:56 PM |
NY Half - yeah, it was brisk. And I really haven't had a good chance to get in the training given this miserable winter we've had. So I kept it slow and easy. I pretty much nailed the time I was aiming for. Temps got into the 30s!
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dan emery
Joined: 11 Jan 2004
Posts: 6890
Location: Maine3/17/14 5:20 PM |
Poor training etc.
Yeah that's exactly what my niece said before the race. I think she ran pretty well, though slower than her best. But she assured me she will be prepared to kick butt in Brooklyn in May. Are you running that one? I'd like to hop down and watch it, bit I'm outta town.
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PLee
Joined: 08 Dec 2003
Posts: 3713
Location: Brooklyn, NY3/18/14 8:56 AM |
Yes. I'm running Brooklyn in May. It's in my 'hood!
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sandiway
Joined: 15 Dec 2003
Posts: 4902
Location: back in Tucson3/19/14 2:58 PM |
quote:
Campagnolo 11-speed shifters pull the same amount of cable as Shimano 9-speed
That's it! But I wonder why they use the SRAM rear derailleur. Obviously, they need to modify the SRAM so the cable pull matches.
I'm going to put the tandem on the bike stand and adjust the derailleur to see if I can get it shifting better.
Sandiway
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Sparky
Joined: 08 Dec 2003
Posts: 19083
Location: PDX3/19/14 4:17 PM |
Sandi, clean and lube that last section of housing too!
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sandiway
Joined: 15 Dec 2003
Posts: 4902
Location: back in Tucson3/21/14 12:09 AM |
shifts fine on the stand...
It shifts mostly fine on the stand. It seems to ride the middle cog a bit. Maybe the cassette is a bit funky. Tweaked the adjuster a bit. Wiped the cables. And put the tandem in the back of the RX for a short trip to San Diego.
You see it fits in diagonally with the rear seats down and the front wheel off.
Sandiway
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dan emery
Joined: 11 Jan 2004
Posts: 6890
Location: Maine3/21/14 7:43 AM |
Awesome
That is totally cool the way it fits in back. Did you have that figured out, or was it a pleasant surprise?
One of my criteria for a car is that a bike fit in the back without even taking the front wheel off (yes I'm that lazy) but for a tandem I'd gladly make an exception. I've wrestled with a tandem roof rack in the past, and it's doable but throwing the bike in the back is way better IMHO.
Have fun in San Diego, great riding (as well as other stuff) out there.
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Kramer
Joined: 12 Jan 2004
Posts: 121
Location: Richmond, VA3/21/14 9:39 AM |
SRAM Cassette
The not so smooth shifting could be attributed to the SRAM cassette. They aren't know to be the best shifting or smoothest/quietest cassettes. A Shimano cassette could fix the issue.
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Sparky
Joined: 08 Dec 2003
Posts: 19083
Location: PDX3/21/14 11:02 AM |
That is ultra convenient how well that fit in there.
I got a new rack due to the carbon bike. Did not like hanging them from the top tubes. The wheel loops on the new one stop that.
Anyway, out Ibis has to have both wheels off and still encroaches into the front seats in the Equinox. It is hugs between the 60 Capt and the 700c wheel I guess.
I spent last night out in my shop modifying the old rack, which is a super HD Thule. The bike will be vertical with the front end slightly above the roof.
Tomorrow is test mount day. Can pop on some pic if anyone like to see 'Rube Engineering' in action...
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sandiway
Joined: 15 Dec 2003
Posts: 4902
Location: back in Tucson3/22/14 8:40 AM |
no racks for me
I guesstimated it would fit with wheels off when we visited the da vinci factory in Denver. Yes, it was a requirement. I don't like racks unless absolutely necessary for many reasons.
But it was a pleasant surprise to see it would fit with only the front wheel off (a 5 second job).
Sandiway
P.S. I'm going to email da vinci but I might try a Shimano 9-so cassette next time...
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