Thanks for all the comments and good advice!
Originally Posted by
shelbyfv
Aren't the 4700 shifters the newest ones, not compatible with much other 10 speed stuff? I'd double check whether that RD will work with them.
Originally Posted by
mstateglfr
No go on that rear derailleur with the shifters you want.
But with the gearing you list, you can just use the Tiagra 4700GS rear derailleur.
4700 shifters need 4700 derailleurs. Same with current 105 shifters- they wont work with mtb or lower # derailleurs. Its what Shimano has steadily moved toward with any current STI shifters that have cable routing under the tape.
Originally Posted by
bradtx
masterchief, With an 11-34T cassette you'll have a range of ~20-93 GI, certainly do-able. If you can find 4600 generation STI levers and FD, you can use your desired RD. If you are not going to load the front of the 520 too heavily, 32 hole rims will work with the 36 hole rears.
Brad
Okay so I've done some more research and it seems you guys are right, the st-4700 will not work with the T610 rear derailer. I was under the impression that up to and including 10 speed, Shimano road and mtb shifters and derialers were interchangeable (except from the dyna-sys mtb range, which the t610 is not part of, as far as I know). This is almost correct, as bradtx says if I would use the older 10 speed Tiagra 4600 shifters, it would work, BUT Shimano has used the cable pull ratios of the new 11 speed on the 4700 Tiagra (and maybe also the R3000 Sora) group, so the st-4700 will not work with the t610 rear derailer. Thats a bummer, as I was opting for the t610 to be able to use a 34t cassette if I wanted to. With the Tiagra 4700 rear derailer im limited to a 32t cassette, which may be fine, but I like having options. Anyway,
thanks for making me aware of this, that was exactly the reason I posted here.
Originally Posted by
Tourist in MSN
Are you sure that a 38T chainring is big enough (with 11/32 cassette) for flat riding or shallow downhills? I use a 11/32 cassette on several bikes, my derailleur touring bike has a big ring of 46T (triple, 46/42/24) with that cassette.
Not sure if the fenders will fit under the mini-V brakes. I have mini-V brakes on my folding bike, but that is the only bike I do not have fenders on so my experience with mini-Vs is limited. My other rim brake bikes that have fenders have full size V or cantilever brakes.
Originally Posted by
robow
Can you purchase just the 520 frame and fork from Trek and may I ask your cost if you don't me poking my nose in here?
Btw, your 38x11 at 90 rpm's is maxed out at 25 mph which may or may not be fast enough for you. I would want at least a 42 big ring up front and that can easily be done with a mountain bike crank, of which you can remove a chainring if you want to maintain a double up front.
Best of luck with your build.
I've been comparing gear inch ratios of my current commuter triple setup with this build, and it looks like the 38-24t will cover my needs, although I did think of it as vey small to begin with. I will have to see, and if its too low a 40 or 42t is available online. 25 mph is plenty for my commuting, I don't mind coasting at those speeds. I actually think a lot of peoples bikes a way over geared for their purpose. How often do you find your self commuting/touring at 25 mph? For me thats not very often, so I would rather have a wide range for the cruising and climbing speeds.
Regarding the mini-v's and fenders it wont be an issue. I have the same setup on my road bike for spring and autumn weather, see the attached picture. The tire is the Panaracer Gravelking 32c (file tread version) on a DT Swiss R460 rim, and there is plenty of clearance for road riding.
After the 520 caught my attention, I emailed the four Trek dealers in my town, and they would all be able to make a special order and supply it within a week. The price is 3800 danish kroner for a frame with fork, which with current exchange rates is $543. I have no idea if that sounds expensive to an american, but the build in total should land around $1500, which is within my budget.