Gravel Inadequacy

[JimF22003]

I have a very, very heavy Specialized Tri-Cross, about 8 years old, that I’m trying to adapt for gravel-grinding duties. Besides how heavy it is, the gearing is currently quite inadequate for me any way. It has a compact crank with an 11/26 cassette, using Shimano 105 shifters with Ultegra RD.

I can do OK on grades up to 10% or so as long as the surface is pretty smooth, because I can standup on the pedals. I can’t keep seated for those grades. If there’s a lot of very loose or coarse gravel however, I can’t keep the rear wheel from spinning out if I stand up, even if I keep leaning way back over the rear wheel.

As an example, I had to walk several times on Old Waterford Road coming out of Leesburg.

I’ve ridden these roads on a mountain bike with some extremely low gearing, and I was able to avoid having to get off and walk. I’m looking for similar gearing on the Specialized. I could use some advice from among any of these options:

1) increase rear cassette range to at least 32 and preferably 34 or 36 teeth. I think I’ve seen some people switch to a mountain bike RD for this without having to swap the shift levers.
2) Smaller crank with a 46/30 or something. Need a recommendation.
3) I’m not a huge fan of this bike in the first place, so i could be convinced I need a whole new bike. Lay it on me

Anybody who works for a bike shop, don’t be shy about recommending your wares. PM me if you want.

[mstone]

Swapping the rear derailleur for MTB one is generally easy (though you can run into problems with 10 speed MTB, I would guess that’s not an issue). You can’t swap the front der, so MTB front crank can cause shifting difficulties. With a 30 small that shouldn’t be an issue either. Probably cheaper to start swapping out the rear components and see if you need to go further, unless you’re in the market for a new crank anyway.

[Phatboing]

@JimF22003 82967 wrote:

1) increase rear cassette range to at least 32 and preferably 34 or 36 teeth. I think I’ve seen some people switch to a mountain bike RD for this without having to swap the shift levers.

This might be possible while keeping the Ultegra RD. I’m running a 11-32 on the Fargo, with the Ultegra RD (medium cage, I believe), and it’s totally fine and wonderful. I’ve taken it MTB-ing in Lake Fairfax, and the new gearing eliminated all the issues I had with the wheel spinning out on climbs.

Two minor issues: The jockey gear hits the cog when in the highest (11t) gear, and it also hits the cog in the granny-32 combination (but not in the middle-32 combo). The former isn’t a problem because hey, it’s a Fargo, and I have no need to go that fast, and the latter is similarly not a problem, because hey, it’s a Fargo, and I’m not climbing trees with it.

[83b]

On my road/cross bike I’ve got old 9 speed Ultegra (6500 or older). The rear derailleur is a medium cage and I can run a 34 tooth cassette by flipping the b-screw around so that the screw’s head rests on the derailleur hanger. The shift range is somewhat limited; I don’t cross chain within the last two gears, which takes some attention. Basically the same setup and problems as Phatboing above.

With a compact crank that gets me a 1:1 low gear, which is occasionally very useful.

[Kaboose]

What size tooth combination do you have for your crankset?

I’m also in agreement with the previous two posts, if you know for sure that your rear derailleur is a mid-caged length, a bigger cassette is the best and cheapest option. If you have a short cage, then you don’t necessarily have to get a mountain derailleur to get a much bigger gear range, just get one with a longer cage. Depending on the size of the front crankset, you could do a medium cage 11-32 to get a larger range. If you don’t know if you have a short or medium cage, you can either go to a bike shop and ask what size it is, or google the part number on the back of the derailleur.

[JimF22003]

Thanks for the advice. I think I could go to a 28 on the back without changing anything else, but I don’t think that would buy me too much. Truthfully I’m looking for an excuse to buy a new bike, but I’m just not sure how much of this kind of riding I’ll actually do. I’m mainly a road person, and will probably always be one.

[Phatboing]

@JimF22003 83098 wrote:

Thanks for the advice. I think I could go to a 28 on the back without changing anything else, but I don’t think that would buy me too much. Truthfully I’m looking for an excuse to buy a new bike, but I’m just not sure how much of this kind of riding I’ll actually do. I’m mainly a road person, and will probably always be one.

I must admit, I had me a good larf upon reading this.

Presented for your consideration:

If I hadn’t gotten such a good deal on my Colossal, I’d have gotten this: http://www.ninerbikes.com/RLT9 (the excuse to get one being that it ticks many boxes for both roading and off-roading)

[83b]

I think that Niner looks amazing!

[JimF22003]

A lot of the new bikes I’m seeing for sale tend to come with an 11/30 cassette and what I think is called a “mid-compact” crank with 46/36 teeth. I’m wondering if a 36/30 low gear would cut it? I imagine I could put a 34 on the inner ring, since that’s what works on regular compact 50/34 setup.

I may have to see if I can wrangle a bike to try for a couple of hours to see how it works. Maybe I can get away with a little bit more of the He-Man gearing.

[Greenbelt]

Don’t you just need a triple front chainring (granny gear)?

http://www.bianchiusa.com/bikes/road/steel/volpe/

[mstone]

@Greenbelt 83176 wrote:

Don’t you just need a triple front chainring (granny gear)?

http://www.bianchiusa.com/bikes/road/steel/volpe/

That’s an expensive change. (Swapping out the cassette and maybe the rear derailleur doesn’t cost much, putting on a triple basically means replacing the whole drivetrain. You need a new brifter, which really means a new pair of brifters–who wants one new one and one crufty one? So you’re looking at new brifters, new crank, new front derailleur. At that point, might as well upgrade to a larger cassette also. And then do you really want to use the old rear derailleur with new everything else?) Now if you’re looking to buy a new bike, go for it.

[Greenbelt]

@mstone 83178 wrote:

That’s an expensive change. (Swapping out the cassette and maybe the rear derailleur doesn’t cost much, putting on a triple basically means replacing the whole drivetrain. You need a new brifter, which really means a new pair of brifters–who wants one new one and one crufty one? So you’re looking at new brifters, new crank, new front derailleur. At that point, might as well upgrade to a larger cassette also. And then do you really want to use the old rear derailleur with new everything else?) Now if you’re looking to buy a new bike, go for it.

I was thinking n+1, of course.

[DismalScientist]

@mstone 83178 wrote:

That’s an expensive change. (Swapping out the cassette and maybe the rear derailleur doesn’t cost much, putting on a triple basically means replacing the whole drivetrain.

Bah… You just need a nice new friction bar end (or better yet downtube) shifter.:rolleyes:

[consularrider]

@DismalScientist 83197 wrote:

Bah… You just need a nice new friction bar end (or better yet downtube) shifter.:rolleyes:

Worked for me on my old 1985 Raleigh.

[vvill]

@JimF22003 83169 wrote:

A lot of the new bikes I’m seeing for sale tend to come with an 11/30 cassette and what I think is called a “mid-compact” crank with 46/36 teeth. I’m wondering if a 36/30 low gear would cut it? I imagine I could put a 34 on the inner ring, since that’s what works on regular compact 50/34 setup.

46/36 is more of a CX specific crankset, where the range of gears is closer together because a CX course doesn’t have long climbs or descents (or long anything really). “Mid-compact” is 52-36 (aka in between 53/39 standard and 50/34 compact).

My gravel bike is a CX bike so it has a taller bottom gear than my road bike with a compact crank but I do still use a 11-28 in the back. I think if I was sure I had low gearing issues I would go with a triple – then the bike could be also used for cargo, light touring, etc. But a 34/30 would be pretty low already at around 30 gear inches with a 700×32, so that may work.

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