Just a data point for anyone interested, I just got a set of Ultegra 6800 wheels and mounted IRC Roadlite tubeless 700x25 tires on them. The front tire measured 26.2mm and the rear 26.5mm.

sup
could smbdy help me with frame selection? huge thanks.

http://www.bikeforums.net/fitting-yo...l#post18358356

Sort of an open ended statement.

I just did a fit. Curiously I wanted to be significantly lower with the bars, and about the same amount closer (so more bent over, more or less).

(Note: I maxed out the reach and I was just getting into increasing reach when the gizmo displayed an error reading, no more movement possible.)

I'm going to start changing my bike one thing at a time to see what happens. Realistically I'm not going to drop the bars the 2 or 3 cm, nor am I going to reduce reach, but I did isolate the sensations that made different positions uncomfortable and now I know to look for them.

I'm also going to test saddles. Didn't have time during the session, which started late in the evening and lasted until almost 1 AM. I'm curious about the twin nose saddles, being shorter in length etc (my saddle nose is well ahead of the BB). I learned a bunch of other things. I bought into the orthotics immediately - it eliminated a significant knee wiggle right away and I felt fine in the 3 or 4 hours I was on the fit bike. I have maybe 2 or 3 more changes to make relating to fit. I want to double check with my spare bars (shallower drop than bars he had), do the saddle testing, and that should set my bike for 2016.

I'll "test" on Zwift, where it's pretty consistent and I'm pretty familiar with what I can and can't do.

out of curiosity, what was the compelling point to go with sram vs another solution? familiarity with the mechanical group?

a friend used it a bunch (his gf was a sponsored tester)--he really liked it, other than some issues with the batteries.

I had 1st generation di2 on that bike. I like racing with electronic shifting, the new di2 would be great too, but what appeals about etap is the operation (right shifter = smaller cog, left shifter = bigger cog) and ease of install (no internal wiring harness).

I'm playing the lottery with hopes of being able to buy an eTap group when they come out.

I think you can program 11 speed Di2 to do that, but no getting around the wiring.

Yes, you can easily program the newer Di2 stuff to work similar to SRAM etap with right/left large paddles for up/down the cassette. I've been running that way for a little over a year. Once you get used to it, it makes much more sense. You can program each paddle/button to do whatever you want and you can also adjust the speed of the shifts.

You can't replicate SRAM's Etap FD shifting (left and right paddles at the same time to shift up and down), but I don't think I'd want to. I programmed the right/left small paddles to shift the FD up/down and this works well and allows you to shift FD and RD at the same time if needed.

I've always had a strong preference for SRAM mechanical groups, but the Shimano electronic stuff works really well and it's a super-clean install with the seat post battery. It just shifts perfectly all the time. The only complaint I'd have is that the paddles have "small clicks" that are not as tactile as I'd like. I wish they were more like SRAM Mechanical upshifts. You can get a complete Ultegra Di2 groupset from the UK for under $1k these days, so the price gap isn't as crazy as it used to be.

I have thought about re-doing the shift buttons so that they do this. I may experiment with it this off-season

cool

i can see plenty of reasons to get it (or not), but the ease of install one makes me scratch my head. running the internal wires on a modern frame takes 30'? 60'? even if it was 2h, it's a 1-time deal.

for me, ease of install would be SUCH a minor point--i'd only go there if a group had my preferred ergonomics. sounds like sram does for you.

all the top groups are so good. i'd be curious to try etap, but shimano is what i'm used to.

i did that on my CX bike but switched it back. i have a 1x setup and figured the separate hands to shift up or down would be nice, esp with gloves. after 1/2 a season, i switched back. i just didn't like it. i was never so panicked that i hit the wrong button when right right shifter controlled both movements -- maybe i wasn't racing hard enough or my gloves weren't big enough. also, for whatever reason i found it easier to brake with my left and and shift with the right -- when set up with the shifting split, there were times when it was more awkward to use the front brake and shift to an easier cog, to set up for a feature.

having to press 2 buttons to effect a front shift is something that would require a bit of convincing for me. maybe it is better.

ymmv, of course.

Do you know if di2 9070 can use a 7870 battery? I am guessing no.

My 2010 Tarmac frame is not set up for internal wiring fwiw, so the existing di2 install uses a lot of tape and zip ties. Functionality has been flawless though. Now you've got me rethinking this.

I think I have heard that this can be done with a little wire splicing. Checkout this site: CarltonBale.com » Shimano Ultegra and Dura-Ace Di2 Electronic Shifting ? Everything You Need to Know this dude has alot of great info on Di2.

Great link, thanks!

More questions now. This will be an interesting project to puzzle over for the next month or so.

My 2010 Tarmac frame is not set up for internal wiring. But, the frame was recently broken, repaired, and stripped, so I would be willing to experiment with drilling it out. Shimano even makes grommets for retrofitted holes. I'm thinking I would drill out the cable stop rivets. It's appealing as a tinkering project.

Or, stick with the etap plan.

i'm not 100% sure as it has been a while since i had 7970, but i'm fairly sure the battery itself is compatible between 7970 & the external battery versions of 6770/6870/9070. however, i think the external battery is sold with the e-tube battery mount. the wire exiting from that mount is different for e-tube vs 7970.

2 options are:
1) buy only a new battery mount (i suspect this may be possible--either through an official source or ebay)
2) use one end of an e-tube wire and splice it to your existing battery mount. it's not hard work to do the splicing--it's just that the wires are very narrow gauge. i've coached 1st timer solderers (is that a word?) through it.

shimano's grommets are, well, just grommets. depending on where/how you drill, you may find it easier to use other grommets. sometimes i have found the shimano grommets don't work all that great, even in a frame designed for it. one spot on my tarmac comes to mind.

if you're careful, drilling the frame is NBD. if you are willing to keep some wires exposed, it would be fairly trivial, but if you want to sink all of them it is harder as you will need a larger opening to fit the b-junction.

One easy example would be to drill at the top of the DT and a single hole near the bottom, then run the RD connector externally along the underside of the CS. The FD & battery leads will be short and external as well. 2 small holes, very easy.

Another thought that comes to mind is whether you can drop wires down the ST and get them to run up to the front of the DT and back to the RD (you'll have to drill rather at the back or along the CS). If your Tarmac is "open" at the bottom bracket, this would be trivial. Many (most I've seen) have a metal shell, though. If you can get those wires routed, you can then drop a B junction down the ST without having to drill a larger hole in the BB.

You'd then need 2 small holes for the FD & battery wires.

Some frames I've drilled (a Cannondale Scalpel) had internal plugs in the down tube used during the molding process. I have yet to see a Specialized bike with that, but it could happen. I was able to drill through the plugs but it gets a little awkward due to how you have to reach the plugs with a drill (through the BB shell and the HT opening). Very unlikely, though.

I'd give it a shot. You like Di2. It's proven. You can get deals on it. It's available now. And, while I've drilled a brand-new frame, your attitude toward THIS frame means a bit lower risk.

Also, give Shimano a quick call (the 949 area code #). They have some very knowledgeable people there, and they can definitively answer whether the old battery itself will work in a new mount. They have been remarkably helpful.

(Hm...last thing that comes to mind is I know the new internal batteries have the firmware built into the battery itself; there is no mount. I wonder if this could be a problem for the external batteries--if they can accept new firmware or have some limiter I don't know about. It is possible the FW is built into the external mount, not the battery.)

One more way to test: Order/borrow/find a new charger from your shop/a friend/backcountry, and see if your battery charges. You then know that at least all the leads/connectors match up.



(As I thought about it, there may be a way to

I was just looking at the frame, which is conveniently bare. There appears to be an internal carbon shell around the BB spindle. I don't know if that can be easily removed and put back in. I do recall once popping out one of the external flanges of that shell when I was pulling a bearing, which makes me hopeful the shell comes out.

If I were to do this project, I'd want to go with an internal battery too, no point in drilling holes in a frame and then bolting stuff on the outside of it.

Even if the BB shell doesn't come out, I think the fully internal wiring would be possible with a lot of fiddling. I'd drill out the cable stops on the down tube and chain stay, and one more hole at the FD. Then run fishing line or similar from each of the three holes up through the seat tube. Wire up the B junction completely, tie the proper lines to the wires coming off the B junction, and drop it down the seat tube, hanging on to the battery wire. Then pull the A junction, FD, and RD wires through.

It might take a lot of fiddling to get the lines around the BB shell, but I have got all winter.

that shell isn't meant to be removed. the trickiest part will be getting the wire from the RD up and over that shell. there is a slight chance that there may not be enough/any space on your frame to accomplish this. It can be very tight, even on a frame designed for internal wiring. it's a tricky thing to get right, but since you have the frame it is very much worth doing, IMO. you actually may have an easier time because you are just trying to go up from the RD, not up, over, around the BB shell and then down.

what i would do is take a length of brake cable. mark a point on it about equal to the length of the ST. insert it down the seat tube so it hits toward the rear of the shell--and see how far you can keep pushing. mark the spot where it stops, then when you pull it from the frame, compare it to the ST + CS length.

if you get the cable down there, you could then slip on some brake housing and see if it passes through. if it does, you are pretty much golden as cable housing is ~5mm....about the diameter of the e-tube connector.

unfortunately the e-tube wire connector is a little rigid, but if the above test worked you will be able to get it through, i'm pretty confident.


i'd definitely go internal battery, but i figured you were trying to save costs/reuse parts; hence your external question.

Success, I got the housing all the way from the seat tube to the back of the chainstay. I know a lot of the appeal of this project is just how tinkery it is.

I measured out all the wires:
shifters to A junction: 350x2
A junction to B junction: 1000
B junction to FD: 200
B junction to RD: 700
B junction to battery: 550

Those are best guess at the actual distances. I'm sure I should add something to each for safety margin. 50mm? 100mm? More?


BTW I used a borescope to help get the housing through. I use this tool about once every 2-3 years. Every time it is like "hey I have exactly the right tool for this!" and I am so glad I have it.

seems a bit on the long side. that's usually enough to go from handlebar area to bottom bracket.

nice work. yep--perfect tool!

as for measurements....yes, those seem right. most peoples' b-junction will be in the DT whereas yours will likely end up in the ST (don't know that you'll be able to stuff that into the DT....nor should you bother; people only put it there as that is where the access point often is) so they might use a shorter DT cable.

the challenge you might face is this: unlike someone who has a hole near the BB shell where all the wires can exit, then you connect them to the b-junction and stuff it back in the DT near the BB shell, unless you drill that out (you probably won't/shouldn't), you'll have to get all the wires to exit the frame at a point where you CAN connect the b-junction.

the most logical thing would seem to be to have all wires exit at the top of the ST, then you connect the b-junction and stuff it back down. as a result, you might need a substantially longer RD & DT wire--basically you'd have to add the length of the ST to your measurement.

you could do some creative stuff to get around this (e.g., sink the DT wire and have something tied to the end so that after connecting it, you could pull it partially back out the top of the DT....but then if you ever have an issue the b-junction is not easily accessible.

if i were you, i'd probably go with something like this:
1400mm DT (longest available; after you connect the b-junction you could pull it out a bit as there is always slack between the DT & junction A)
350x2 for the shifters (common)
800 or 900 for the RD (i'd probably err on the longer side...maybe even 1000)
~550 for the FD
~350 for the battery

in case you are curious, the difference in weight between a 350mm wire and a 700mm wire is almost nothing--single digit grams. so, in this case i'd forego any effort to nail the length exactly right and instead overdo it.

for the DT wire, take into account the height & length of your stem and where the A junction will be. also keep in mind that you'll turn your bars.

for a typical 56cm specialized, i'll use:
2x350
1000 DT
800 battery (long, but when i pull the post for travel i like to have the cable hang out of the ST and not fall back in)
700 RD (b junction is ahead of the BB, so it has to go up, around, over, and down to get to the DT)
350 FD

a little extra length allows me to pull the b-junction out and have some room to work on the rare circumstance that i need to.

Thanks for all the advice. I had thought about the wiring challenge you mention, I described how I planned to install it in post #2892 above. But it would be simpler just to use very long wires, both to install and in case I ever need to fish the B junction back out, as you said.

I ride a 54cm race frame and mine is 550mm.

I've ordered 2 complete di2 kits (internal battery) and they both came with the following wires:
2x 350 (shifters)
300
600
700
1000

I've installed them on 2 specialized frames, both 56's (a tarmac and a roubaix). Lengths worked well, nothing was tight.

some factors to consider:
CS length
amount of wire you want outside the frame, near the RD
where the junction sits (above the bb? in front of the bb?)
length of DT wire (if it is short, the junction might be further up the tube)
whether one wants some slack in case the junction box has to be pulled from the bike.