Best gear for gravel? Tire Size? Rim Diameter?



I'm in the process of trying to get a large portion of my commute
home
off of the roads. So far I've found quite a bit of abandoned RR
tracks and such that go pretty much my way. However, I find that in
some areas with very loose gravel or sand I get slowed to a near
walking pace. I'm thinking lower tire pressure and maybe wider tires
would help me float over this stuff. Am I on the right track?

Clearly there would be a penalty on the road portion of my ride, but
if it's the difference between walking speeds and the middle ring for
the slop and gravel portion of my ride it should be a worthwhile
trade.

Since the last large leg of my ride will be on the road, I'm
considering trying very low tire pressure next time, with a couple
extra CO2 cartridges to bring me back up to pressure once I get stuck
back on the pavement.

Lastly, those that love the 29ers sing praise of them "rolling over
anything". In the past I have not put much stock in this since I'm
more the type to come out of the saddle and lift the bike over
obstacles than I am the type to try to roll over them. I'm wondering
though, would the larger diameter tire allow more contact area, and
therefore make it easier to ride through the gravel? If so, how much
easier? I may have to take one of these for a demo @ the next big
NEMBA gathering.

Thanks,

Dan
 
On Mar 19, 11:15 am, "[email protected]" <[email protected]> wrote:
> I'm in the process of trying to get a large portion of my commute
> home
> off of the roads. So far I've found quite a bit of abandoned RR
> tracks and such that go pretty much my way. However, I find that in
> some areas with very loose gravel or sand I get slowed to a near
> walking pace. I'm thinking lower tire pressure and maybe wider tires
> would help me float over this stuff. Am I on the right track?
>
> Clearly there would be a penalty on the road portion of my ride, but
> if it's the difference between walking speeds and the middle ring for
> the slop and gravel portion of my ride it should be a worthwhile
> trade.
>
> Since the last large leg of my ride will be on the road, I'm
> considering trying very low tire pressure next time, with a couple
> extra CO2 cartridges to bring me back up to pressure once I get stuck
> back on the pavement.
>
> Lastly, those that love the 29ers sing praise of them "rolling over
> anything". In the past I have not put much stock in this since I'm
> more the type to come out of the saddle and lift the bike over
> obstacles than I am the type to try to roll over them. I'm wondering
> though, would the larger diameter tire allow more contact area, and
> therefore make it easier to ride through the gravel? If so, how much
> easier? I may have to take one of these for a demo @ the next big
> NEMBA gathering.
>
> Thanks,
>
> Dan


After discussing this over @ RBT I realized I left out a few important
details. I'm currently running 26x2.1 on front and 26x1.9 on the
back. I've tried it on a 20" BMX with 2.125 and it was even harder,
almost impossible. Also, the gravel in question is really just
crushed stone, easily 2" pieces and larger. It's not the typical
gravel you encounter on roads or paths intended for foot/bicycle
traffic, it's way bigger and deeper.
 
Per [email protected]:
>Also, the gravel in question is really just
>crushed stone, easily 2" pieces and larger. It's not the typical
>gravel you encounter on roads or paths intended for foot/bicycle
>traffic, it's way bigger and deeper.


How much doe the stones more around as you go over them?

I've ridden my WTB Mutano Raptors (55/55 size) on what I call
"railroad ballast" a good bit with decent results.

My sense is the bigger the tire and the lower the pressure, the
better.

215# rider, tires at 35-40 psi.

But the stuff I ride on pretty much stays put as I'm going over
it. If the stones shifted around too much it might be a
different story.
--
PeteCresswell
 
On Mar 19, 4:00 pm, "(PeteCresswell)" <[email protected]> wrote:
> Per [email protected]:
>
> >Also, the gravel in question is really just
> >crushed stone, easily 2" pieces and larger.  It's not the typical
> >gravel you encounter on roads or paths intended for foot/bicycle
> >traffic, it's way bigger and deeper.

>
> How much doe the stones more around as you go over them?
>
> I've ridden my WTB Mutano Raptors (55/55 size) on what I call
> "railroad ballast" a good bit with decent results.
>
> My sense is the bigger the tire and the lower the pressure, the
> better.
>
> 215# rider, tires at 35-40 psi.
>
> But the stuff I ride on pretty much stays put as I'm going over
> it.   If the stones shifted around too much it might be a
> different story.
> --
> PeteCresswell


The stone moves quite a bit. Looking back it looks more like someone
was dragging a spade shovel or riding a dirt bike than it does like
someone was riding a bicycle through. I'm ~200 lbs myself. My next
attempt, unless someone convinces me otherwise, will be at 35lbs
pressure. I know I have not ridden gravel with pressure that low, so
it'll be interesting to compare against. I'll post back with results
once I get a chance to try it, which may be a few days with this
weather.
 
Per [email protected]:
> My next
>attempt, unless someone convinces me otherwise, will be at 35lbs
>pressure. I know I have not ridden gravel with pressure that low, so
>it'll be interesting to compare against. I'll post back with results
>once I get a chance to try it, which may be a few days with this
>weather.



Next stop: http://www.flickr.com/photos/mmeiser2/61141473/ ? -)
--
PeteCresswell
 
On Mar 19, 8:43 pm, "(PeteCresswell)" <[email protected]> wrote:
> Per [email protected]:
>
> > My next
> >attempt, unless someone convinces me otherwise, will be at 35lbs
> >pressure.  I know I have not ridden gravel with pressure that low, so
> >it'll be interesting to compare against.  I'll post back with results
> >once I get a chance to try it, which may be a few days with this
> >weather.

>
> Next stop:http://www.flickr.com/photos/mmeiser2/61141473/ ? -)
> --
> PeteCresswell


You know, I'd really like a beach bike too. :) Somehow I think the
salt air, bits of salt water and the sand would be hell on the bike
though. 20mph on loose sand? That's awesome! I'm sure it'd float
over that gravel. I think that's a bike i'd have to try before I buy,
however.
 
On Mar 20, 9:55 am, "(PeteCresswell)" <[email protected]> wrote:
> Per [email protected]:
>
> >  I think that's a bike i'd have to try before I buy,
> >however.

>
> You and me.
> --
> PeteCresswell


I'd love to see some of them for demo at the big NEMBA events. The
big guys usually have a bunch of bikes out, but I don't think I've
seen a Surly tent at all, much less a Surly Demo tent.
 

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