HELP NEEDED! ... FIRST TOURING BIKE BUILD

[DGULL]

Hi Guys,

I plan to build a multi purpose touring type bike and i'm looking for some advice/guidance on drivetrain.

The bike will be used 5x/week for a flat 8mile ew commute with 10-15kg of luggage. It will also be used for 2-4 day touring trips mainly within the UK (wales, peaks, lakes) with a medium weight load.

I'd like to use STI shifters but with components offering a lower/wider range of gear inches than a road groupset would offer.

I've been looking at Tiagra 4700 10 speed STI shifters with a Shimano XT M785 10 speed dbl chainset (24.38t) and 10 speed MTB cassette (11-36t).

I've read about the ability to cross over road and MTB components given the correct capacity derailleurs. Are there derailleurs out there that would allow me to combine the above components?

If the above combination is ridiculous could anybody suggest a drive train combination using STI shifters (and preferably a double chainset) that could provide gearing in the region of 18" - 100" (700 x 32 wheels).

This is the first time i will be building a bike from scratch so my expertise / knowledge is limited.

THANKYOU!

[hamster]

You would need a 9 speed MTB derailleur for that. 10 speed MTB uses a different cable pull ratio, road rear mechs don't like the 36T cassette much.

[TrevA]

Id consider a triple if I were you. All of my 3 bikes have triples and I don't normally use the granny ring on any of them, but it's nice to have it there in case, and I do use it if I go up into the Derbyshire Peak District. There are some steep climbs where you'll appreciate a low gear. Crowdicote, Winnats, Mam Nick, Kirkdale, Longstone Edge, Curbar Edge and Rowsley Bar are just a few that spring to mind, where I would used the granny ring.

[hayers]

+1 for a triple.

I run a 10sp 105 triple with ultegra 12-30 cassette. I've replaced the 30t granny ring on the triple with a 26t from spa, which rarely gets used on day rides, but was low enough to pull 5 days luggage up the long myndd last year but a "road" high end for fast club rides. I use down tube shifters, but sti would work as road front and rear mech - both 105.

Of course, a myriad of other options are available, but that works well for me.

[TrevA]

Having re-read the opening post, I see you are going for an Alpine double 24/38 chainset. In that case ignore what I said about triples, your gears should be plenty low enough for anything you are likely to encounter, even loaded up. Bottom gear on my tourer is 26 front X 34 rear and I can get up pretty much any hill on that, even with a load on. You may find you are lacking a top gear - 38x11 gives 93 inches according to my maths, but it's not really an issue unless you are doing fast group rides.

One problem you may have is your front mech fouling the chainstay. You'll have to use a road front mech if you are using STI's, so you may struggle to get it low enough. My Tiagra triple front mech just clears the chainstay with a 26 ring.

[531colin]

First bike build and looking at making up your own drivetrain? this may not be a good idea.
Why don't you read up a few threads currently on the boards looking at front mechs, chainline, etc.?
http://forum.cyclinguk.org/viewtopic.php?f=5&t=111766
http://forum.cyclinguk.org/viewtopic.php?f=5&t=111697
http://forum.cyclinguk.org/viewtopic.php?f=5&t=111377

[recordacefromnew]

First bike build and looking at making up your own drivetrain? this may not be a good idea.
Why don't you read up a few threads currently on the boards looking at front mechs, chainline, etc.?
http://forum.cyclinguk.org/viewtopic.php?f=5&t=111766
http://forum.cyclinguk.org/viewtopic.php?f=5&t=111697
http://forum.cyclinguk.org/viewtopic.php?f=5&t=111377

+1, I do appreciate that's why you are asking here, but be aware that not all the answers are correct all the time.

Another thread you should read due to your interest in the 4700 is at viewtopic.php?f=5&t=111237

I think only sram can give you a truly self consistent double drivetrain mixing road and mtb for low gears with sti, although other workable mix and match options exist.

[DGULL]

Thank you all for the help / advice.

I have gone for a more straightforward setup consisting of

Shimano 105 5700 10sp Shifters
Shimano FC-R460 chainset (46.34t)
Shimano 105 FD
Shimano XT M771 10sp MTB cassette (11-36t)
Shimano RD-M592 Deore 9sp RD

If anybody sees any reason why this would not match together (sufficiently) please let me know where i've gone wrong!

Thanks,
Dan

[landsurfer]

Surely with the amount of cycle companies extant at this time any combination of components you can think of can be bought ready built .... with a warranty ???
Your individual components will have a warranty .. but sub para 1.2, page 6, article 7 .. will say the warranty is subject to assembly by a professional cycle builder, wearing a ballet tutu, 6 days a week, matinees Wednesday, Sing God save the Queen . ...!!

[DarkNewt]

Hey,

well done, I did the same and learned so much that was useful to me on the road. You can see the various trials and tribulations on my blog thedarknewt.blogspot.com. I wanted something that was built for me and there didn't seem anything off the shelf, you will find the team on here brilliant for advice and ideas!

I went for an M780 groupset that has been absolutely rock solid and gets me up any hill, great deals on it too!

good luck mate!

[cycleruk]

I'm not sure if the Deore 9 speed RD will suit a 36T max cassette? Perhaps someone can verify this.
I do have a Deore 9 one that works a 10 speed 11/34T cassette.

I would also consider a granny ring a fair bit lower than the 34T you propose. I would be looking to get a gear as near to 20 inch as I could. Especially for loaded touring.
Your 34T / 36T x 27= about 25.5 inch.
My 26T / 34T x 27 = 20.6 inch.
How much difference those 4 inches make

[531colin]

Thank you all for the help / advice.

I have gone for a more straightforward setup consisting of

Shimano 105 5700 10sp Shifters
Shimano FC-R460 chainset (46.34t)
Shimano 105 FD
Shimano XT M771 10sp MTB cassette (11-36t)
Shimano RD-M592 Deore 9sp RD

If anybody sees any reason why this would not match together (sufficiently) please let me know where i've gone wrong!

Thanks,
Dan

Have a look at the cycle parts spec. here....http://www.spacycles.co.uk/m1b0s21p3552/SPA-CYCLES-Elan-%28105-triple%29
You can substitute this chainset http://www.spacycles.co.uk/m2b0s109p3052/SPA-CYCLES-TD-2-Touring-Triple-Chainset-with-Zicral-Ringswith 24/34/46 chainrings and the appropriate BB unit.....giving a much lower bottom gear.
If you must have a double chainset, this one http://www.spacycles.co.uk/m2b0s109p3383/SPA-CYCLES-TD-2-Super-Compact-Chainset-with-Zicral-Rings works down to 24/40. But if you start at 24 teeth, an extra 16 teeth is a big percentage increase. 28/44 would be a compromise between a lower gear and closer ratios, or you could use 24/38 which you started with....but with a road chainline.