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My wife adores her 15 year old Giant TCX Composite (size 44!). Arthritis means no getting out of the saddle for hills.

We've got the standard 52/38 up front and a slightly larger 11/26 at the back. A lot lower gearing is needed.

I had SRAM PG990 (I think) on the back of mine, that had (I think) a maximum 34 , which was great . I don't recall if this required a new rear derailleur cage. I think so.

The wife doesn't mind MTB components, as long as they're around Ultegra spec. I'd rather invest money in a bike she loves, than spend $5k (Aussie) on a equivalent replacement.

How low can we go?

Argenti Apparatus
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Henry Barber
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    Which components are installed? If you can’t get us the names, take some photos. If it’s really 15 years old it would be the Ultegra 6600 10 Speed groupset. – Michael May 04 '20 at 05:50
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    Is she being "bike-snobby" about the groupset name? If you end up with something from the lower groupsets, then use acetone to remove the name. If you match the part colour (black/silver) with the rest of the parts, it will not stand out too much. – Criggie May 04 '20 at 22:04
  • How worn is the current groupset ? – Criggie May 04 '20 at 22:05
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    Simplest would probably be to replace the rear cluster with something with more teeth. Might require upgrading the derailer, but that would not be a deal-breaker. – Daniel R Hicks May 04 '20 at 22:57

2 Answers2

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Switching the rear derailleur to a 9-speed Shimano mountain and the cassette to an 11-34 is the most straightforward in terms of minimal parts changes. It's not the lowest you can go. It leaves you with the high gears you've already got, i.e 52/11, which is not useful for most people, but one of the questions here is exactly how much you're happily willing to take off from the high end of the range. (For most people in this situation, but not everyone, the answer is a lot.)

Switching the crank to a compact 50/34 was the next fashion after standard doubles like she has finally fell out of favor for normal people road bikes. You could do so with or without also doing the above rear end change. The FD and shifter you have should be fine. Most compact cranks you'll find are nominally 10 or 11 speed. To make them work with 9, use tiny chainring spacers. There are many posts here about this.

So-called super-compact cranks with ranges like 30/46 have finally started to become mainstream in the last few years. The nice thing about them is that for many people, 46 represents around the biggest big ring that's actually useful, i.e. in many cases everything beyond that is wasted. They'll work acceptably with your FD. A lot of them are external bearing cranks with chainline specced to work with 135mm rear ends, which isn't a dealbreaker for putting on her bike but is a minor drawback. To avoid this you could get a square taper one like Herse, VO, or IRD. Some of these cranks come in variants with big rings smaller than 46, but these won't play nice with your existing FD and shifter setup.

Nathan Knutson
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    There are many 8 or 9 speed cranksets. Just go for Sora instead of Ultegra. The OP wrote "as long as they're around Ultegra spec" Well, one can always buy an old Ultegra, if there is a compact one, but a lot has changed in 15 years and new Sora might not be that bad in comparison with an old Ultegra. After all, we are talking about a crankset, no movable parts, no bearings or bushings... – Vladimir F Героям слава May 04 '20 at 09:03
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    I've switched my road bike to 46/30 and 11-32 and I think that's pretty ideal for road riding. There are many "gravel" cranks on the market now and your current rear derailluer can easily shift an 11-32 with a WolfTooth Roadlink. – Fred the Magic Wonder Dog May 04 '20 at 16:55
  • I think this era of Shimano components may have had an FD specific to the compact cranks. At this time, I think manufacturers had not come up with one cage curvature that worked well across chainring sizes. If so, the OP's FD won't shift as well as a stock setup. That said, it should be acceptable. FDs are cheap, anyway. – Weiwen Ng May 04 '20 at 19:22
  • @VladimirF actually, I think Sora is square taper. The OP could see about a Tiagra or 105 crankset; if it's 105, it can be from a previous generation of cranks (i.e. the 5800 series; I can't recall if a 5700-level compact existed). That way, the OP wouldn't have to change the bottom bracket. – Weiwen Ng May 05 '20 at 16:26
  • @WeiwenNg No, new Sora and Claris are Hollowtech Ii and even use the modern hollow chainring shape. Older versions are Octalink. Square taper is perhistoric for Shimano groupsets. – Vladimir F Героям слава May 05 '20 at 16:45
  • I stand corrected, then. – Weiwen Ng May 05 '20 at 16:48
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Depending on the amount of wear in the current groupset, you might consider replacing some of it to work better together.

The main limiting factor could be the width of the freehub, which will either limit you to a 10 speed cassette, or may allow the use of an 11 or even 12 speed. Depends if there are spacer in the back or not.

One upgrade set might be Rear mech, Cassette, Chain, Shifters. The rear mech would probably be a long or perhaps medium cage that can take a 32 or 34 tooth big cog.

If you want, could also replace the crankset and front mech with the same groupset, keeping pedals though. This would give the option of a super-compact where the inner is about 30 or 32 tooth. Combined with a 32 or 34 this is a sub 1:1 ratio and goes great up most grades.

Off-tangent - I've known a couple riders with Arthritis and while they do have good days, there are always bad days too. It never goes completely away. So with an eye on the future, is it worth exploring an ebike to help her up the slopes? It may be worth broaching the subject. Whether you can install a retrofit kit or if a complete replacement is a better answer. Something to consider anyway.

Criggie
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