Spec. Tricross Gears

[mpeter]

First post, so go easy on me . I've recently purchased a Spec. Tricross Sport and really loving it. I've got a couple of queries about the gears though. The bike comes with Tiagra shifters and front derailleur but Deore LX rear derailleurs.

First question, the Deore are mtb derailleurs I believe. What is the difference, if any, between road and mtb derailleurs?

I mainly ride on the road and although I don't do any real rough stuff, I do sometimes veer off into the muddy stuff. Bearing this in mind, would there be any reason not to swap out the Deore for a Tiagra derailleur to match the front? Or would another mtb derailleur be a better option? One reason I'm thinking of swapping it out is that on a couple of rides, when going uphill, I'll be going along happily when it jumps up a gear without warning - much to the distress of my legs Would I be wasting money swapping because of this, or is it just a case of tuning? Shifting is quite smooth, despite the surprise jumping, but reading around, the Deore LX doesn't get a particularly good rap on the mtb forums.

 

[l4dva]

Welcome!

I got the same bike about a year ago, and if i remember right it used to do the same thing with the gears occasionally jumping, i took it back to the bike shop I got it from and had them look at it. Turns out it was just down the the cables stretching a little, this happens with new bikes they did a few adjustments and its been bang on ever since!

I'm not a technical expert but the difference between MTB and road derailleurs won't be a very noticeable. From what I under stand rear road derailleurs are shorter to suit the short range in road cassettes, seen as we have mtb cassettes (ie 11-32 as opposed to a typical road cassette that would be 11-25 for example) our derailleurs would need to have a longer arm for it to work. So I guess a road derailleur wouldnt be suitable unless if you change the cassette to a road cassette as well, only problem with that is you loose the lower end gears for the big hill climbs, it's all down to personal preference though, when i first got the bike i used to use the lower gears on the hills all the time, nower days i don't so when it came to replacing the cassette i got a 11-28, but i've kept the decore derailleur as it still works well and dose the job!

 

[Norm]

Welcome, MP.

I think that the mtb stuff is on there to give increased spacing between the gears and a much larger big-ring. Road bikes usually have closer ratios on the rear than mtbs.

If you look at the size of the gear rings on the cassette of the Tricross sport compared to something like the Secteur Sport, you can see the difference in the number of teeth and you can see the increased bulk of the LX derailleur compared to the Tiagra kit fitted to that Secteur.

I also think that the jumping should be curable by a bit of tuning. It would certainly be cheaper and possibly easier than swapping the rear derailleur, which might require a change of cassette as well.

BTW, I've got the Tricross Sport too and love it.

 

[potsy]

Welcome, MP.

I think that the mtb stuff is on there to give increased spacing between the gears and a much larger big-ring. Road bikes usually have closer ratios on the rear than mtbs.

If you look at the size of the gear rings on the cassette of the Tricross sport compared to something like the Secteur Sport, you can see the difference in the number of teeth and you can see the increased bulk of the LX derailleur compared to the Tiagra kit fitted to that Secteur.

I also think that the jumping should be curable by a bit of tuning. It would certainly be cheaper and possibly easier than swapping the rear derailleur, which might require a change of cassette as well.

BTW, I've got the Tricross Sport too and love it.

Looking at those pics norm,the derailleur's look the same size to me,I have the secteur sport triple and am thinking of putting on a larger cassette 12-28 maybe instead of the 12-25 it came with.
I'd have thought the deore mech would be similar standard to tiagra,just one is mtb spec and the other road spec.

 

[Norm]

Looking at those pics norm,the derailleur's look the same size to me.

They looked different to me, so I've just been down to check (it helps these long winter evenings fly by!)

Whilst I didn't take my vernier with me, the Tiagra cage (I think that's the name for the arm) on the Secteur has about 8cm from centre to centre of the pulleys, whereas the LX set up on the Tricross is close to 9cm.

I think that the cassette on the Tricross is 12-30, although it was cold and dark and I can't reliably count that high without taking my shoes and socks off.

 

[mpeter]

Thanks for the answers folks. I'll probably take it in for a tune up this week then and see how that goes.

 

[Brandane]

I have the poor-mans version , the standard Tricross. Although I am very happy with the bike overall, I have recently had a problem with the rear hub, as posted in this thread....

http://www.cyclechat.co.uk/forums/showthread.php?t=55545

I don't know if the hubs are the same on the Sport, but might be worth your while keeping an eye on it, especially if, as you say, you like to veer off into the muddy stuff occassionally. More likely that I have just been unlucky, as it should not fail after 3 months!

 

[cyberknight]

Sounds like a simple tweak of the rear mech shifter barrel is needed .All cables stretch a bit from new so they need a tweak.

Handy hint stand behind the bike and turn the barrel adjuster on the rear adjuster the way the gear needs to go .

Eg if its not shifting down turn left or if its not shifting up turn right.


http://bicycletutor.com/adjust-rear-derailleur/

 

[mpeter]

I have the poor-mans version , the standard Tricross. Although I am very happy with the bike overall, I have recently had a problem with the rear hub, as posted in this thread....

http://www.cyclechat.co.uk/forums/showthread.php?t=55545

I don't know if the hubs are the same on the Sport, but might be worth your while keeping an eye on it, especially if, as you say, you like to veer off into the muddy stuff occassionally. More likely that I have just been unlucky, as it should not fail after 3 months!

Looks like the hubs might be the same fro reading the spec. I'll keep an eye out for that.

Thanks

 

[Steve Austin]

Nothing wrong with LX mechs. If you want to upgrade, you should for for an XT or SLX. A lot of tourers/cyclocrossers use MTB mechs as they are better able to handle knocks. Road mechs can't handle as large a gear range as well as you can't get them with a long enough cage.

 

[bottombracket]

Hi mpeter,
I'm new here myself and no-one's offered me 'to come outside' yet!

My touring bike also has the Tiagra shifters/Deore mech combo...
Although you could upgrade, I personally think there's not much point.
I've got a 15 year old Deore mech on an ancient MTB which has only ever had the jockey wheels replaced.
It does, however, remain to be seen whether the new ones are built as well as that...

The long cage mech is indeed to accomodate a wider range of gears.

The gear skipping is almost certainly due to cable stretch - it happens on all new bikes (if you've ever fitted a new string to a guitar the same thing happens - although that wouldn't make your gears skip of course! )
Some shops offer a free tune-up a month or so after purchase to sort this out.