chancelucky

I had an interesting experience today riding what's really a hard-tailed mountain bike with a cousin of Jones bars and 35mm tires. After riding through dirt trails with lots of roots and rocks and unpaved roads without difficulty, I happened
upon a path that consisted of pea-sized gravel that might have been up to three inches deep. i had trouble holding a line going downhill, had to ride in a very low gear on the flat, and had no traction uphill. I wound up riding alongside the trail instead of on it,
then walking the rest of the way up the hill. My tires aren't especially knobby and I happened to be at a fairly high pressure. I imagine that lower pressure with wider knobbier tires might help on this sort of surface, but, how do I put this, can
gravel bikes do actual gravel? This felt closer to riding in sand than anything else.

unterhausen

Deep gravel doesn't stay that way very long, fortunately. It's challenging. I haven't seen any deep small gravel though

obrentharris 

Real gravel, rounded stones ranging from pea gravel to cobbles, is a real pain to ride as you have discovered.

Most of what cyclists call "gravel" is actually crushed rock. Crushed rock has angular faces that interlock with each other to a certain extent. Gravel is rounded and the individual rocks just slide past each other.

Almost all "gravel roads" are actually a mixture of various sizes of crushed rock ranging from about 1 inch in size to dust. This gradation of sizes allows the rocks to interlock even better, giving a nice hard surface when compacted.

Brent

mstateglfr 

yes.


What you described is basically rideable on just a fat bike. Gravel comes in many sizes, so yeah, a gravel bike can ride on gravel.

banana jam 

Gravel Kings 38 TLC 35 rear 30 front I'm 235# this works great. PSI; technique; etc.

Rides4Beer

Fresh, loose gravel can be tough. Bigger tires and lower pressure can help, but even then, sometimes it's just hard to get through. Luckily, as mentioned, most of the time "gravel" is not deep and loose like that, at least around here.

xseal

Also good on fat bike with 29+ (3.0) tires.

Marcus_Ti

Define 'gravel'. Aggregate comes in lots of sizes and shapes. Pea gravel is slow going except on a fat bike.

https://www.wisegeek.com/what-are-th...avel-sizes.htm

unterhausen

This thread is really bringing out the experts on crushed stone. Isn't "pea gravel" actually tumbled? Seems like a weird choice for a road unless they got it on sale.

mstateglfr 

This forum is full of Geologic Engineer washouts. Not everyone can be Fred Flintstone!

chas58

Many of our rail trails have this, and some of our parks. Its rarely deep, unless its on a path more for jogging than riding.

chas58

Well, you don't need any knobs, but you do need volume.
I have sand racing tires that are slicks, but 60mm in size.

I rode one of my gravel routes on 32mm tires once, and running through deep gravel at 20+mph made me really pucker. I was used to doing it on 40mm tires (@25-30psi) and that patch made me pay attention, but wasn't a problem. on 50mm tires, I don't even think about it (same bike).

UniChris

I'm really crushed at the idea that someone would dredge up rounded gravel from a river to use on a path

Marcus_Ti

It is very common in certain counties in Nebraska. For example, here in Lancaster County the DOR loves to use the stuff on MMR roads. They'll dump the stuff out of the truck, spread it a bit fpr coverage and move on....given how little traffic or moisture those roads see, it seldom gets compacted. But, you cross the county line into Gage County, and the pea gravel vanishes and you have fast rolling compacted dirt MMR.

Most unpaved parking lots for churches or businesses have the stuff, too, up here.

chancelucky

The path I was on wasn't necessarily for cars. I'd say that most gravel bikes can ride pretty much anywhere an AWD SUV will go plus some places that have similar surfaces but are too narrow for a motor vehicle. Ironically, I think roads that get used by cars occasionally do help, because the weight of the vehicles helps to compress the road bed.

I'm not sure what it was for exactly. It would have worked for hikers. It might have been the beginning of a road bed of some sort that was waiting to be surfaced. It was very much the sort of thing that makes gravel biking appealing. You can see something and say "Hey, it might be fun to check this out." It's just that it didn't work out in this case.

shoota 

My takeaway from this is why are you using a mtb with 35mm tires?

chancelucky

Because, I have it set up for mixed on road and off road use rather than single track or more serious mountain biking stuff. With 35 mm tires, it's probably closer to gravel bike than mountain bike.
I"m in the midst of converting an old touring bike to gravel use. Once that's done, I'll probably go to wider knobbier tires and use the mountain bike almost exclusively off road.

I'm not completely sure why I"m doing the gravel bike conversion. I live in the RTP part of North Carolina and there's really only one really good gravel trail near me, Umstead State Park. Tennessee and Western Carolina, though,
seem to have a lot more and I guess I'm expecting to do more "Mixed" riding when we visit.

MaxKatt

Same. It’s like a pebble in your shoe.

MaxKatt

Definition of “gravel road” here sounds a lot like Item 4. If so, can I still use a gravel grinder or would I be better off with an Item 4 Cycle?

LesterOfPuppets

Yeah deep gravel is pretty nasty. They over graveled a quarter mile of one of my local gravel routes earlier this year. And it's a spot that maintenance trucks rarely travel so it'll be loose for a long time.

A few years ago I was riding the Palouse to cascades trail and they had recently over graveled a stretch. I was on 1.9" and was riding the edge where possible. I encountered a couple on 32mm and we commiserated for a bit. I asked how much further that way it went. They said a mile. Ugggh. It was towards the end of the day and I wanted to stop already, but figured I should power through the rest of the deep gravel so I didn't have to start my day with it. The rangers drive this route fairly often so I'm sure it was rideable within a few weeks.

LesterOfPuppets

I rode in 2015, and this is a pic from the area in 2018, perfect gravel.

DeadGrandpa

My introduction to riding gravel was the 120 miles on the Denali Hiway on my Jamis Renegade, 700x40 tires with too much air in them. From pavement to reasonably packed and civilized gravel, there was a gradual transition to less civilized aggregate, until there was a section of fist sized pebbles shaped like little pyramids with very pointy tops. Then, gradually it transitioned back to a normal gravel surface. I'm thinking about returning to the legendary Hiway for an encore, and I debate about going with a plus bike. But maybe 700x2.1 is the sweet spot for a mix of gravel and pavement.

shoota 

So how wide of a tire are you going to be able to fit in that old touring bike? I ask because even if you're doing mixed route stuff you should probably be closer to a 38-40. 35mm really isn't great for gravel in general. And nice 38-40mm gravel tires will still feel plenty fast on the road.

chancelucky

I'll probably do 38. I think 40 is pretty close to the limit. Gravel is very much a local thing and where I live the "gravel" roads aren't very technical. That isn't as true in Tennessee or Western North Carolina.

Helldorado

The trails I ride on are mostly small ball-bearings. Usually stainless steel. Let me tell you, it's not easy to ride on that stuff, but I'm pretty skilled and have not fallen once. And I ride fast, usually 20 m/h or faster when descending. My skills are good.