Front triple on CrossCheck
 

I recently bought a CrossCheck. It has the QBP build with the exception of the wheels. It has a double on the front. I think, in order to have the gearing for loaded touring, I have to go with a triple. What is needed to do this conversion. It looks as though a triple could be done the way it is without swapping BB's or buying a new crank. Would a new derailleur be needed front and rear or would the stock ones work. I have had differing opinions on this and need to know. Thanks in advance for your help

I switched my Tricross from a double to a triple. Depends on what's already on the bike. If a standard/cross double, then what you'll need is a triple crankset (Shimano LX trekking), front derailleur, possibly rear derailleur (long cage, I'd go with a Shimano LX model), and possibly a new bottom bracket. I use a 68x118 on my Trek 520. If you have Tiagra or 105 shifters, they should work with a triple. So would down tube shifters. Ultegra and higher won't. I did my conversion for about $150 off ebay.

Good news, bad news.

The stock Cross Check has two chainrings, but the crankset is drilled for three rings, so you don't need a new crankset. Just get the small chainring of your choice, as long as it has a 74mm Bolt Circle Diameter (BCD). The cranks have a 110/74 BCD.

You will, however, need a new bottom bracket, a 68 x 118 (the 118 is the spindle length, the stock bottom bracket has a 113mm spindle that is too short for the triple setup on the Cross Check).

You will also need a different front derailleur. The stock front derailleur won't shift to all three rings, not enough range even with the limit screws turned all the way out. Most any bottom pull front derailleur will work with with the friction bar end front shifter, it just needs to be a triple compatible front derailleur.

I just did this conversion a couple of days ago on another person's bike.

Yep, well biked is correct. Different BB, different FD, same crank.

However, according to Surly you can also set it up as a compact double. It won't be quite as low, but with a wider cassette it might be low enough for your purposes.

Well biked is right-- but here's a couple of things to think about. First, I'd try adding a couple of 1 mm spaces to the stock BB. It might work fine-- or not. Most likely not. The 118 mm BB is 100% sure to work.

Look for a cheap/free front derailer. Older MTB derailers should work fine of they are bottom pull. In fact, these older derailers mightl work better than anything you can buy new.

Does this mean the rear derailleur will still work? I'm in the same boat, and I've already got a Deore LX front derailleur kicking around.

that's a good question peterbc-- the answer is, sorta. The short cage Tiagra is a very good derailer (Surly spec's their bikes with the absolute best parts at a certain price point) As long as you don't cross chain, the rear derailer will work. Only use the small chainring with 3 biggest cogs in back and you're golden.

I should have elaborated on that in my earlier post. Yes, the stock Tiagra rear derailleur has plenty of chain wrap capacity to handle the triple setup as long as the stock cassette is used. The cassette is 12 x 25, so even if you were to install a 24t small ring on the triple to go along with the stock 48/36 setup, you'd have a max. chainwrap requirement of 37t, which is Shimano's official spec on the stock Tiagra GS rear derailleur. I installed a 26t chainring on the Crosscheck I worked on the other day, so no problem for the Tiagra RD.

However, for loaded touring, 12 x 25 almost certainly isn't going to cut it. A mountain cassette, something like an 11 x 32 or 11 x 34, would be more in order, and to do that you're going to need an mtb rear derailleur, both for the chain wrap capacity and for the ability to use a largest cog of that size and not have the upper derailleur pulley bump into the cog-

well biked is right about touring, you'd want a MTB cassette and rear derailer. But I've always wanted a touring triple (46-36-26 or so) hooked to tight road casette (12X25) That way I'd have tight, fast gearing on two chainrings...and a bailout gear for steep urban climbs.

And you made a good point in your earlier post about not cross chaining (small chainring to smallest few cogs) to keep from running into a chainwrap capacity problem with a rear derailleur that's not really designed for a certain drivetrain. Or to keep from wearing drivetrain parts unnecessarily fast, for that matter.:)

I have a 2005 CrossCheck. I did not change out my bottom bracket to add a small chain ring. Perhaps Surly is using a wider bottom bracket now ... I doubt it but I'm not sure.

Either way, for me to get the best possible gearing on my CrossCheck with as few changes as possible, I:
1- added the small front chain ring; from the invoice: Salsa 26t 74mm 5-boltinner chainring $15.42
2- changed the cassette to 11x32
3- due to adding a chain ring, I had to change the front derailleur to one that would handle the larger shift; from the invoice: XT Traditional Frt 31.8 Bottom Pull $28.99

I don't remember how much the cassette cost.

Also, I had a little bit of trouble installing the front derailleur, but I was able to make it work. If you're not mechanically inclined, get one through your LBS so you can be sure to get the right one.

Again, I have an 05, maybe specs have changed...

I used the stock Tiagra rear derailleur when I upgraded with a 26 tooth small ring and and 11x32 cassette. Initially I was concerned I'd need a long cage rear derailleur, but in almost 4000 miles I have had no problems.

According to the specs on the surly sight, the rear derailleur is "mid cage", so as long as you avoid cross chaining, you should be fine. There's really no need for cross chaining anyway, that's why God gave us front derailleurs. :)

I also have the mid-cage Tiagra on my 05 CrossCheck. Just now, I went downstairs and put the rear in the largest (my aftermarket SRAM 11x32 cassette) and front on the largest stock chain ring. I did it just to see if I could. The stock mid-cage Tiagra handled it just fine.

That being said, I NEVER do this due to wear-and-tear on the drive train. It's nice to know, however, that if I did it by accident, it wouldn't cause me any immediate mechanical problems.

On my touring bike, I use a double chainring setup that has almost the same range as you're looking for: 26 and 42 tooth chainrings on the front (using the inner and middle positions of a triple crankset), plus a 12-26 cassette (SRAM) on the rear. The top gear is not huge, but when touring I prefer to conserve my energy when going downhill rather than trying to break any speed targets. Even with the strongest tailwind, I've never needed anything more than the 42-12 on the flats. Any rear derailleur should be able to handle the chain wrap needed, I use a short cage Ultegra. The front derailleur really needs to be a mountain bike version so that the curve matches the biggest chainring (42 teeth), I use a Deore LX. Using a MTB FD would cause a problem if you're using drop-bar STI integrated brake/shifters because they're designed for a road FD, which needs a different cable pull than a MTB FD; I avoid this problem by using a down-tube shifter to control the front derailleur (while still using an STI for the RD).

Isn't the front shifter friction? If so couldn't I install the inner ring and adjust the limit screws? I have an 11-34 mtb XT cassette but would it be needed?

The claim in post #3 above is that the there isn't enough side to side range of motion in the stock front derailleur to accommodate the triple. That may be true, but if it were me, I'd give it a try. Buy the inner ring and bolts first, and install them, and check to see if you can get the range of motion you need out of the front derailleur. Worst case you'll just have to buy a new one.

The question of whether you'll need the 11-34 cassette is something only you can answer. Being a proto-geezer I need all the help I can get up hills, so I would go for it. But that's just me.

Speedo

Well, I am a fat proto-geezer, so I will probably need it as well;)

It's been a while since I did this, but I seem to remember that the cage on the stock FD isn't wide enough to accomodate the chain as it moves around on the cassette. Not a big deal if you're into micro-adjusting your FD every shift or two of the RD.