Upgrading Giant Defy: endurance or gravel bike?

Cotterend

After a back injury last year, I'm looking at ways of protecting myself from road shock. I have two prolapsed lumbar discs and I don't think they're going to resolve themselves any time soon.

Happily I've been able to keep on cycling, in fact, it's the only sporting activity I have been able to continue, walking and standing upright for more twenty minutes included. Currently I'm back to my usual everyday level of 30 to 40km, 300 to 500m climb. I'm wary of attempting my 'days out on the mountain' though, which would be 80 to 100 km, 2000m +.

I'm not averse to buying a new bike (!) if it can help, but I like my 2010 Giant Defy Composite so I would need to see a real difference. Options to make the Defy safer seem to be to fit larger tyres and a gel saddle.

Does anyone know if larger tyres can be fitted? The 23mm Continentals I have on only just squeeze between the brake blocks.

I tried a gel saddle which I had in my bit box, and found it threw my pelvis back, doing my back no good at all. My normal saddle is quite dished, and holds my pelvis nicely tilted forward. I'm wondering if a gel saddle will, by its nature, never really offer this kind of support.

Moving on from the Defy, Canyon proposed to me a gravel bike, something I hadn't been aware of, their GRAIL CF SL 8.0 DI2. It looks interesting, and certainly scores well theoretically for back care. The modest off-road nature could be useful here anyway, but how much does the on-road performance become compromised?

Their traditional alternative is the ENDURACE CF SL DISC 8.0.

Does anyone have any advice or any experience of these Canyons?

One other minor point is that I have a cassette with a 36t low gear, as some of the local routes have nasty 20% climbs. I would struggle without this low gearing.

Many thanks,

Louise

joe_totale-2

Wider tires run at lower pressures would certainly make a big difference which you'd certainly notice.

Another thing to consider would be the seatpost that you're using. Carbon ones are often more effective at dampening road noise and Canyon bikes do come with a fancy one which is supposedly effective although I have no experience of it.

grenw

I have the Endurace SLX so effectively the same geometry. It feels a little more stretched out than the Alu Defy it replaced but the 28mm tyres vs 25mm do make a difference and is much more comfortable on longer rides. Should be though at more than 3x the price!

I had the same back issues which happened around 8 years ago and was what stopped me running, Mountain biking was my saviour - low impact and a good workout for core muscles. It affects my back a lot less than road biking can do. The constant movement and more upright position helps and the constant battering doesn't seem to have an impact on my back. It's more about the constant crouched over position on the road bike for me.

36t is really low for a road cassette ratio. Depends on what's up front though. 36 is the same as my mtb and far lower than the 32 on my Endurace. Just make sure whatever you get has a compact up front and 32 should be okay.

yiannism

Even with 25mm tires will see big deference on comfort, heck i went from 25mm vittoria zaffiro to continental GP4000 and i saw deference. I have my back problems too (disc hernia), but since i am cycling i never experience something serious, just some soreness from time to time, so my advice is to keep your bike, and change tires, is cheap way to add comfort

singleton

I've got a couple of prolapsed lumber disks - which have recovered about as much as they are going to recover - and have to bear them in mind when doing a number of things.
My bikes are fairly aggressive geometry, so it's not necessarily about buying a specific frame, it's about making it fit and making it right for you. I can ride my CAAD's for multiple hours.

As well as frame geometry, things which may help would include
wide tyres - many newer frames will take up to 28mm
tubeless tyres - means you can run at lower pressures
suspension seat post instead of gel saddle?

tangerineowl

If you decided to stick with your current bike, then I'd seriously look at either one of the best shock-absorbing seatposts or suspension seatpost.

For the first I'd go the Canyon VCLS2.0 / Ergon CF3.

For the second option: the Cirrus Kinekt-Bodyfloat. This will add quit a bit of weight, depending on which model.

I would even consider a Redshift ShockStop stem up front.

I'd stay away from thicker-gel saddles.

Cotterend

GrenW wrote:

I had the same back issues which happened around 8 years ago and was what stopped me running, Mountain biking was my saviour - low impact and a good workout for core muscles. It affects my back a lot less than road biking can do. The constant movement and more upright position helps and the constant battering doesn't seem to have an impact on my back. It's more about the constant crouched over position on the road bike for me.

I had only thought of mountain biking as rough and dirty: I'm a road cyclist! Clean and fast.... But I cannot deny the truth of what you say: road cycling is not good for core musculature. I had even wondered if this contributed to the back problem. Strong below the waist, strong shoulders and arms, but a gap in the middle.

I now do a lot more standing to try to promote core development. It has made my cycling faster and more fun.

It is time to get hold of a mountain bike though, and see how it goes.

GrenW wrote:

36t is really low for a road cassette ratio. Depends on what's up front though. 36 is the same as my mtb and far lower than the 32 on my Endurace. Just make sure whatever you get has a compact up front and 32 should be okay.

The 36t is perhaps less about the brute climb but the issue of clipping. On a 20% grade I find it really hard when I need to pause to un-clip safely, and even harder to get re-clipped. Fighting the hill, which feels like a roofside, its hard even to stand on 20% tarmac in cleats, and so little time in low gear to get the clip in. 36t lets me do a granny crawl all the way to a slightly flatter bit.

tangerineowl wrote:

If you decided to stick with your current bike, then I'd seriously look at either one of the best shock-absorbing seatposts or suspension seatpost.

.....

I'd stay away from thicker-gel saddles.

I have learned my gel-saddle lesson

Today I'm taking the bike to a Giant store to see what tyre sizes will fit and ask if they have any sprung seat posts. It's a carbon non-circular section that I assume is specific to Giant.

grenw

Cotterend wrote:

Today I'm taking the bike to a Giant store to see what tyre sizes will fit and ask if they have any sprung seat posts. It's a carbon non-circular section that I assume is specific to Giant.

If it's the D-Fuse post I don't think there are any after market alternatives that fit into the frame. Giant may do something. It's pretty good at damping road noise but nowhere near as good as the VCLS one on the Endurace

kingdav

Sounds to me like over time, core strengthening exercises might offer you at least as much comfort as the bike upgrades. I was advised to do some pilates and yoga which made a huge difference to how my back felt.

I realise the gel saddle thing has been done to death already, but if you're interested in a rational explanation why a big cushion like saddle isn't necessarily more comfortable you might like to read this article:
Cervelo don't make saddles but did some research and came up with this paper which is some independent guidance.
https://www.cervelo.com/en/engineering- ... ad-saddles

Good luck getting a comfy set-up!

dj58

GrenW wrote:

Cotterend wrote:

Today I'm taking the bike to a Giant store to see what tyre sizes will fit and ask if they have any sprung seat posts. It's a carbon non-circular section that I assume is specific to Giant.

If it's the D-Fuse post I don't think there are any after market alternatives that fit into the frame. Giant may do something. It's pretty good at damping road noise but nowhere near as good as the VCLS one on the Endurace

It won't be a D-Fuse seatpost on a 2010 Defy, it will be a composite aero Vector depending on the bike model.

OP you may be able to fit a 28mm tyre on the rear if you have adequate clearances, and a 25mm to the front fork, if you fit brake calipers with clearances for those sizes. e.g. Shimano 105 5800.

Poppa Wheelie

Have you heard of the YouTube channel Global Cycling Network? They have a couple of videos that compare gravel bikes to road bikes that you might find of interest.

For what it's worth, if you like the 2010 Defy you'll probably find a new Defy to your liking. As far as I'm aware they come with 28 mm tubeless tyres and a 32 tooth cassette as standard.

The point here is that a bike with a 28 tooth rear mech is usually supplied with a short cage rear mech, whereas a 32 tooth cassette needs a long cage rear mech. Because the bike is already fitted with a long cage rear mech your dealer might be able to change the cassette for something even lower fairly cheaply.

Cotterend

kingdav wrote:

Sounds to me like over time, core strengthening exercises might offer you at least as much comfort as the bike upgrades. I was advised to do some pilates and yoga which made a huge difference to how my back felt.

I realise the gel saddle thing has been done to death already, but if you're interested in a rational explanation why a big cushion like saddle isn't necessarily more comfortable you might like to read this article:
Cervelo don't make saddles but did some research and came up with this paper which is some independent guidance.
https://www.cervelo.com/en/engineering- ... ad-saddles

Good luck getting a comfy set-up!

Interesting read on saddles, thank you. Mine isn't bad, it turns out, a bit more hollow wouldn't come amiss. It is good to be able to analyse it, and having read th article, it all seems obvious now!

I'm very wary of yoga. In the context of sport, generally your body tells you when something is getting stressed. I find the straining into unusual positions out of context with any sporting activity in a yoga session disables the normal feeling for what is good and what isn't. It is all too easy with a lot of twisting to put some very high loads on joints not used to them. Pilates is a no-no, according to my physio, bouncing movements are very dangerous in the context of slipped discs.

Update:

I went to the Giant bike shop and asked if the Defy would take a 28mm tyre. I was told it would, but they had no GP4000s in stock. I Wiggled some and fitted them. They don't fit The front is OK, the back fouls the brake arch. Only a bit, but that' a bit too much. Other than that, the ride is certainly smoother, but at low seeds, choppy. This adds to the problem rather than resolving it. Dropping down a bit from the recommended 7 bar eased the choppiness but the contact band on the tyre becomes wide. This afternoon on a damp downhill where service braking is never an issue, they began to slide. They are new, which could explain it, but I suspect they have too low a surface pressure and too large a surface.

No shock absorbing seat post is available for it.

I've ordered a Canyon Endurace CF SL disc 8 to try which is the first in the range with the split sprung saddle stem. It also has 28mm 4000GPs so a good comparison with the Defy now. At the price, I'm needing it to be a lot better than the Defy: it will take a bit of paying for!

I've decided against looking any further at mountain bikes, I don't want to get into a whole new raft of kit and expertise. Instead, once a week, I'm going fell-running (well, fell run-walking!!) on a nearby mountain, which should achieve the same for core strength. The first was a couple of days ago, the usual Delayed Onset Muscle Soreness set in this morning, always a hazard when recommencing eccentric muscle loading after a lot of pure cycling!

Cotterend

DJ58 wrote:

OP you may be able to fit a 28mm tyre on the rear if you have adequate clearances, and a 25mm to the front fork, if you fit brake calipers with clearances for those sizes. e.g. Shimano 105 5800.

I have Shimano 105s. Shimano say they are compatible with 28C tyres (https://bike.shimano.com/en-EU/product/ ... 10-RS.html). But the tyres don't fit.

Any ideas?

Louise

devonboy

Tyre width can vary with internal rim width.On Zonda two way fit wheels GP4000s measured 31mm wide rather than the advertised 28mm.

On the other hand Schwalbe 30c tubeless tyres measured 30mm on the same rims suggesting tyre make can also play a part.

On my winter bike swopping wheels from 21mm internal to 17mm internal rims resulted in a
2 mm reduction in width but an increase in tyre height.

dj58

Cotterend wrote:

DJ58 wrote:

OP you may be able to fit a 28mm tyre on the rear if you have adequate clearances, and a 25mm to the front fork, if you fit brake calipers with clearances for those sizes. e.g. Shimano 105 5800.

I have Shimano 105s. Shimano say they are compatible with 28C tyres (https://bike.shimano.com/en-EU/product/ ... 10-RS.html). But the tyres don't fit.

Any ideas?

Louise

Unfortunately you have chosen the brand/model of tyre that sizes up larger than the stated size. I can only suggest you try another brand of tyre. What is the internal dimension of your wheel rim? Also try running lower pressures e.g. 70 - 85psi.

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