Descending, Geometry, and 1 bike with 2 wheelsets

Hello All, Ive finally come to the conclusion that I just cant handle a race bike, Giant TCR. I’ve been the slowest descender on group rides for years. I seem to get a little panicked around 30mph, even on roads I know. I’ve had the bike 3 years and ridden more than 7,500 miles outside on it, and had a bike fit just before I bought the bike.

However, the fit and handling on my TCX feel amazing, 40 mph downhill with no fear. It just feels right. Ive ripped CX races, gravel, Single track, and pavement. After comparing the geometry below it looks like the TCX has a much longer rear end, slightly slacker HTA, and slightly shorter/higher front end.

Geometry comparison…

2016 Giant TCR SL, Conti 5k’s in 25c tubeless, ~78psi, 155lb rider
2018 Giant TCX SLR, Maxxis Ramblers 40c, ~30psi

I’m considering selling both these bikes and buying the 2021 Giant TCX Pro and running 2 wheelsets, one for gravel and one for road. Am I missing a less obvious solution? Thoughts?


I actually like your solution.

You’ve identified the frame geometries that suits your riding style, so it makes sense to carry those learnings over to your next purchase. It makes sense that the TCX’s longer wheelbase and slacker head tube increases its stability on descents. The TCR in (M) also has a 57mm trail which is race-y and twitchy, compared to the TCX’s stabler 65mm.

Having two wheel sets & tires to optimize for traction vs rolling resistance on a single frame you’re comfortable with sounds like a great consolidation plan…


Do what works. I have an Emonda H2 fit which is very similar to the TCR, only a 5mm longer chainstay, and I feel awesome descending with it, but everyone likes what they like. I’m wondering if more of the difference has to do with a smaller harder tire. 25c at 75psi vs a 40c at 30psi is not even comparable IMO

I would definitely be going with a 28 or a 32c for the road wheelset. I doubt my TCR can fit any bigger rubber. I wonder how much of that safe feeling vs the fear come from the tire. I had thought it might be the noise of higher speeds, but the gravel tires definitely have more noise at speed and I use the same helmet and hit, so Im not sure whats up.

Why can’t you just apply the “2 wheelset” solution to your current TCX?

Unless you up just want to get a new bike, which I completely support.

Good idea! Don’t tell the “minister of finance.” Current TCX is a dog. Its a super hear aluminum bike that I bought for a few cyclocross and gravel races every year. After riding a high end TCR for a few years Id like to get something as close as possible to that quality of spec, frame, and wheelsets. The new 2021 TCX has the same frame weight that my TCR SL from 4 years ago has. I may keep the heavy alu bike as a permanent trainer bike.

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I find your analysis good and in my opinion, you come to the right conclusions for you. Maybe because I did something similar :). Here is my personal n=1 experience of the past year:

I went from my endurance road bike with 25mm Conti GP 4000 (with latex inner tubes) to my gravel bike with 2 wheelsets (GP 5000 TL 28mm & WTB Venture 47mm). I love it. This is my one bike to ride everything outside and the old bike is now permanently on the indoor trainer.

Regarding the descending, I never really had any issues with my old bike (endurance, not race geometry), BUT my new setup gives me soooo much more confidence. Not surprisingly, given disc vs rim brakes and the different tires.

Since I’m about the same weight like you, I rode my 25mm (latex tubes) with 70psi front, 75 psi back. The 28mm TL I ride with 55psi/60psi. The wider tires and the drop in pressure make them feel just so much more connected to the street when cornering / descending - no ‘bouncing on the tarmac’, it feels like you are on rails. So with your concerns, I would recommend you going even wider for the 32mm GP 5000 TL. No real harm in doing that (besides minimal aero penalty).

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Just curious as to your height and inseam length? I have a long inseam and tend to find bikes with longer chainstays to handle a bit better. I run more seatpost length and sit high and a long way back. I also usually ride a size smaller frame than manufacturers recommendations as my shorter torso and larger saddle setback requires a shorter top tube.

I used to ride a TCR but moved away from Giants as they tend to have short chainstays (even on the larger sizes, which I’ve never understood). I definitely feel more centered and balanced on my current bike.

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Regardless of that, I’d try your current tcx with road tyres, just to make sure it’s not just the tyres that make the difference. But even if, you could run fat wide slicks on a tcx frame even on the road.

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I think you’ve hit on a decent solution. FWIW I always found my TCR a bit twitchy and a nervous descender, and my current Emonda isn’t much better.

Though you probably have identified your best way forward, if you’re in the market for a do-it-all bike, I’d seriously recommend a Mason Definition. Tremendous reviews, which it deserves, and with the right wheels/tyres it can do most things. Not cheap, but it’s also bombproof and will last you a long time.

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Do it. I loved my TCX for road riding

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I have wondered about my position over the back wheel. Im 5’10 with a 31" inseam, riding a medium. I also err on the side of a smallish frame. Just looking at the bike, the seat definitely seems to hover over the back wheel.

I am definitely going to put some road slicks on the current TCX and see how that feels keeping up with the road group.

Ive also thought alot about the disc vs rim brake… issue. I got the TCR at a BIG discount, so I never thought twice about the disc vs rim, but the rim brakes on carbon at just OK with very little initial bite, so they dont inspire much confidence.

As one of my riding friends put it “on the road bike, everything happens in slow motion, so your brain has time to thing about the worst that can happen going around the next curve.” I thing thats definitely the case for me. On gravel or MTB Im totally focused on the feel of traction, not on the next “what if.”

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I noticed this on my first outing with the Trek; I felt like I couldn’t get ‘over’/on top of the pedals properly on a steep climb. I’d be intrigued to know if someone with some detailed knowledge of bike geometry could explain this.

With regard to sizing, I am a very similar height and inside leg to you and the Trek is a 54; by their sizing chart, I should be a 56, but 56s feel big under me and the reach can be an issue.

Cervelo R3/S3 geometry in a 54 looks spot on for me, but it’s a brand I’d be pretty nervous about buying after all the QC stories. The other manufacturer whose numbers look right is Cannondale (Supersix/CAAD), but same story with QC (albeit not as bad).

I’m in the same “could ride a 56 but prefer a 54” boat and my Emonda fits me well I think, though I do run the longer mast and 110mm stem vs 90. Here’s an over exaggerated aero tuck

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