• For more information on how to avoid pop-up ads and still support SkiTalk click HERE.

Teach me on gravelenture bikes

cantunamunch

Meh
Skier
Joined
Nov 17, 2015
Posts
21,885
Location
Behavioral sink
^ Totally with you on the 8-9-10 sweet spot.

FDs rock for rolling terrain where each climb/descent is half a mile or less. So, yeah, I figured out back when I was building priest bikes that 1x was not for me.
 

Lorenzzo

Be The Snow
Skier
SkiTalk Supporter
Joined
Nov 12, 2015
Posts
2,984
Location
UT
so since its been a spritied but polite discussion, let me throw this option out to you all. I did some investigation and measuring and it seems that I can in fact, put a 32 on the BMC granfondo 01, (as per BMC product video). I think before I go and buy a new bike, i am going to put some Schwalbe Pro One 28's (which will measure closer to 31 on my rims and give it a try. Most of what we have here is not deep, soft gravel but mostly hard pack fine road base and sun-baked dirt. the 28's will also be good on our chip and seal (finer grade). the BMC was originally spec'd with 28's. (I am currently running 25 One's which sit at 27.5 on my rims)

BUT... I also have that superfly, so I am going to put some 2.1 Thunder Burts on that and see how it goes for rougher roads and 2-track stuff.
As you and your LBS probably know, there are generally two clearance dimensions, a somewhat conservative one from the manufacturer and then closer to the actual clearance dimension, the difference being extra room mostly for mud and dirt. On my road bike I tried 32-s which worked fine while the mfr. indicated 30. If I'd had disc brakes I could have gone wider.

However, I developed a preference for my MB in those situations and got rid of the extra tires/wheels but if I were on more compacted road surfaces and weren't looking for geometry relief from my road bike it might have worked.
 
  • Like
Reactions: Ron

skibob

Skiing the powder
Skier
Joined
Jan 5, 2016
Posts
4,268
Location
Santa Rosa Fire Belt
As you and your LBS probably know, there are generally two clearance dimensions, a somewhat conservative one from the manufacturer and then closer to the actual clearance dimension, the difference being extra room mostly for mud and dirt. On my road bike I tried 32-s which worked fine while the mfr. indicated 30. If I'd had disc brakes I could have gone wider.

However, I developed a preference for my MB in those situations and got rid of the extra tires/wheels but if I were on more compacted road surfaces and weren't looking for geometry relief from my road bike it might have worked.
I agree and have a further suggestion for @Ron : You can almost always get more tire than the manufacturer says. Usually 3-5 mm minimum. So, how to find out w/o blowing a ton of money?

Go to a LBS you are sure will let you return unused merchandise. Buy a folding bead tire in a box. IOW, you want something you can return unused to its original package. If it is a wire bead with an adhesive tag around it, you can't do this. Even if you can't find a tire you WANT to put on the bike, you can do this and just consider it a fitting session. Grab a 32 and a 35 and try putting them on your rear wheel. You'll need to install it w/ a tube obviously, regardless of your ultimate plan (and tubeless IS the way to go, although much harder w/ these small tires than MTB).

My point for this is that a 28mm is still a pretty low volume tire, even if your rim squeezes it to 31mm, because it just changes the shape, not the volume. In my above plan, ymmv due to variation in sizing. But I think you will find a 28mm to be entirely inadequate. I have 28s on my road bike and I can tell you that the few times its been off pavement, well, I try to avoid this.

Also, you need to consider the wheel width. A wide array of tires and wheels will FIT together. The Great Sheldon Brown tells us the best fits:

http://www.sheldonbrown.com/tire-sizing.html

Look for a red/green grid near bottom of page. I've found that one, or even two sizes outside of his ideal will work w/o issues if your not doing 1% maneuvers. So, in the above trial sizing, you might find for example that 32 just barely fits and a 35 not quite. If you have say 13mm rims, you'll find that 17s or even 19s might allow that 35 to fit. You can get a decent set of wheels for $200-300, a lot cheaper than a whole bike.

I am building a "gravel grinder" with a steel frame and 35mm tires. But I haven't ridden it yet, so I can't tell you if 35mm will be adequate for non-technical dirt and gravel. But my hunch is it will be.
 
Last edited:
  • Like
Reactions: Ron
Thread Starter
TS
Ron

Ron

Seeking the next best ski
SkiTalk Tester
Joined
Nov 8, 2015
Posts
9,282
Location
Steamboat Springs, Co
I just emailed BMC for clarification. yeah, i measured the stays and they are 36 so using 3mm clearance per side, the 30 should work just fine. height is also good. i run Bontrager D3 TLR's which are 19.5 internal fwiw
 
Last edited:

skibob

Skiing the powder
Skier
Joined
Jan 5, 2016
Posts
4,268
Location
Santa Rosa Fire Belt
I just emailed BMC for clarification. yeah, i measured the stays and they are 36 so using 3mm clearance per side, the 30 should work just fine. height is also good. i run Bontrager D3 TLR's which are 19.5 internal fwiw
I'd be interested in knowing others thoughts on how much clearance is necessary. If your wheel is true, its only deflection you need to worry about (and mud maybe, but I am of the opinion that it will scrape itself off, one way or another).

And if it were me, I'd still investigate at least a 32. I've measured and then put tires on that I thought wouldn't fit, and they did. Maybe you are as bad at measuring as me . . . :huh:
 
Thread Starter
TS
Ron

Ron

Seeking the next best ski
SkiTalk Tester
Joined
Nov 8, 2015
Posts
9,282
Location
Steamboat Springs, Co
i used calipers. According to a BMC product video, they state you can run 32's but, I am still using this bike for 90% road work. I talked to my neighbor last night about this and he's actually running a 25 equiv tire. His wife is running 28's. They work fine on the hard pack stuff but he does need to be careful. He really feels 30 will be fine; not the absolute best but just fine. I did used to run my 28's on rails to trail, trail and they were fine, you did have to be careful on loose sand and fresh cinder. If I can get by without a new bike, its worth some performance sacrifice. Afterall, it is a GF frame, .

Here's my bike BTW. BMC Video

http://www.bmc-switzerland.com/us-en/innovation/tcc-high-tech-in-the-hell-of-the-north/
 

scott43

So much better than a pro
Skier
Joined
Nov 12, 2015
Posts
13,549
Location
Great White North
A few comments..
I do prefer suspension forks on dirt roads here as the washboard is severe at times and at speed is a serious issue. YMMV..

I understand the comments on carbon..I have some similar feelings but I think if you have the cash it's not a huge issue. You simply buy more often and inspect more often. I haven't seen a lot of failures and most of the pro failures seem to involve and accident first. Having said that, what's a lifespan on a carbon part? 5 years? Dunno..I'd be careful to inspect personally.

Depending on the road, I think 28c is too narrow. 38c is more reasonable. Once you get up to 45c or more you are in better shape for some loose dirt for sure.

I can see drop bars for gravel roads..especially for longer distances..comfort.
 
Thread Starter
TS
Ron

Ron

Seeking the next best ski
SkiTalk Tester
Joined
Nov 8, 2015
Posts
9,282
Location
Steamboat Springs, Co
Just did about 15 on the rural roads. Its a mix of hard pack, some washboard, a little loose on the corners , 6" wide, 2-3" deep divots and ruts. I didn't really want to call these gravel roads because they aren't true, loose gravel. They are more like classic Gran fondo :) I let some extra air out of my tires ( I normally run 90F/95R) and although I certainly see how a 33-35 would be ideal, I really didn't have any issues. The GF carbon frame,bars and wheels really do a solid job of vibration mitigation and it a stable bike. Keeping a light touch on the bars is key too. I am looking forward to getting the Pro One 28's which should run at just about 30.5. I suspect running these at about 75-80 will make for a pretty decent ride which would be a good thing.


BTW- Moots is located here in Steamboat and their Gravel adventure bike is called the Routt (our county and play on words) This was really designed for exactly what I was looking for and it max's out at 35 tires. I would love to have one of these bikes! the "cheapo" build is $7,200 they also make a Routt 45 with corresponding tire clearance.

http://moots.com/bike/routt/
 
Last edited:

Lorenzzo

Be The Snow
Skier
SkiTalk Supporter
Joined
Nov 12, 2015
Posts
2,984
Location
UT
Would this be a good time to bring up the inflammation/disease link and how various exercises play into it?

Probably not.
 

scott43

So much better than a pro
Skier
Joined
Nov 12, 2015
Posts
13,549
Location
Great White North
I think he's shooting at extreme endurance and its tendency to increase inflammation response. As opposed to moderate exercise, more resistance, less endurance and having appropriate rest time between. There is a train of thought as well that the true risk for heart disease is inflammation, not fats or cholesterol.
 
Thread Starter
TS
Ron

Ron

Seeking the next best ski
SkiTalk Tester
Joined
Nov 8, 2015
Posts
9,282
Location
Steamboat Springs, Co
oh, well, I hardly consider a 22 mile ride with 1200 vert even "endurance" let alone extreme. it just keeps my hip loosened
 

scott43

So much better than a pro
Skier
Joined
Nov 12, 2015
Posts
13,549
Location
Great White North
And you have to kind of factor in ANY exercise versus none. It's a balancing act..I got stuff to do..I do what I can when I can. Moderation..
 

Lorenzzo

Be The Snow
Skier
SkiTalk Supporter
Joined
Nov 12, 2015
Posts
2,984
Location
UT
I think he's shooting at extreme endurance and its tendency to increase inflammation response. As opposed to moderate exercise, more resistance, less endurance and having appropriate rest time between. There is a train of thought as well that the true risk for heart disease is inflammation, not fats or cholesterol.
Well since Scott brought it up.

There's been strong evidence for some time that inflammation links with heart disease, cancer and a variety of other maladies. Studies were originally done on things like smoking, excess weight, LDL and other risks that have been known to correlate. There were also studies done suggesting a link with oral diseases but it wasn't really taken all that seriously.

Now there's mounting evidence that many other forms of inflammation can bring about disease, including endurance exercise. There is now strong evidence that dental inflammation is a significant trigger. My doctor recently explained this stuff to me but I haven't as yet done much web research.

Most doctors now check for inflammation markers in blood tests for many or all adults.
 

Bill Talbot

Vintage Gear Curator
Industry Insider
Joined
Nov 9, 2015
Posts
3,166
Location
New England
oh, well, I hardly consider a 22 mile ride with 1200 vert even "endurance" let alone extreme. it just keeps my hip loosened

Hell I don't even consider 65 mile, 8000 vert 'endurance'... just my yearly stress test :huh:
 
  • Like
Reactions: Ron

scott43

So much better than a pro
Skier
Joined
Nov 12, 2015
Posts
13,549
Location
Great White North
Watched something on PBS about cholesterol versus inflammation, specifically as a result of carnitine (amino acid from red meats) being processed by gut bacteria and producing trimethylamine (googled that bit..). Byproduct, inflammatory response and atherosclerosis. So I'd avoid the red meats, don't beat yourself up on your cholesterol numbers, don't take statins, stop doing 15 mile runs 6 days out of 7 and do more yoga, moderate weights, moderate cardio.

It's funny, in the old days when you worked hard to eat, you wore out early and died young. Now we want to replicate beating ourselves up! :D Sitting on your ass isn't good..neither is 10 marathons a year, apparenly.
 

Bill Talbot

Vintage Gear Curator
Industry Insider
Joined
Nov 9, 2015
Posts
3,166
Location
New England
Watched something on PBS about cholesterol versus inflammation, specifically as a result of carnitine (amino acid from red meats) being processed by gut bacteria and producing trimethylamine (googled that bit..). Byproduct, inflammatory response and atherosclerosis. So I'd avoid the red meats, don't beat yourself up on your cholesterol numbers, don't take statins, stop doing 15 mile runs 6 days out of 7 and do more yoga, moderate weights, moderate cardio.

It's funny, in the old days when you worked hard to eat, you wore out early and died young. Now we want to replicate beating ourselves up! :D Sitting on your ass isn't good..neither is 10 marathons a year, apparenly.


It's not the red meat, it's what they are fed that is causing the problem. Get high quality grass fed or organic meats and enjoy. :beercheer:
 

Sponsor

Top