Wide Rims, Big Tires, Low Pressures

Everything about building wheels, glueing tubs, etc.
Mr.Gib
Posts: 3215
Joined: Fri Mar 18, 2005 4:12 pm
Location: eh?

by Mr.Gib

So after many hundreds of kms of testing, I have come to the conclusion that the Compass tires in their Extralight casing provided the best ride in terms of comfort and vibration damping, and to the extent that I can tell, they seem extremely fast rolling.

The specific Compass model is the Chinook Pass Extralight - that is their 28mm version. On my 22mm internal width wheels they measure about 29.8mm. Their 32mm Stampede Pass was just a bit too fat for my bike which is a shame as they would have been super comfy.

It is noteworthy that the Chinook Pass did feel better than the Vittoria Corsa g+ 28mm which of course are excellent in their own right. The Compass Extralight tires are noticeably lighter and more supple than the Corsa's. Really an amazing tire.

Perhaps the biggest revelation was the impact of the wide rim on handling. On narrower (17mm internal) rims, I just could not run the tires at 60 psi. Too soft - they would distort a bit too much or fold over somewhat in hard cornering. Same was true for all the 28 mm tires I tried. On 22mm internal width rims and at pressures as low as the high 50's, the cornering and general handling was unsurpassed. Never felt anything even close. Although the Compass seemed best, on the wide rim all of the tires I tried could be run really soft and still felt fast with great handling.

But as with many great things there is a catch. The Compass Extralight tires are so thin that I fear they will not survive the Cent Cols Challenge torture test next Spring. There will be several gravel climbs and perhaps the odd gravel descent. If the sidewalls survive it will be a miracle. In the hand these things feel like paper. Plan is to go with latex tubes with Orange Seal and have a backup set of Corsa G's in my luggage.

The other thing I tried which seems to be helping deal with foot pain due to vibration was to use the thin, cheap Dr Scholl's Air Pillow insole. Much better than more sophisticated options. Knocked out over 200 km last Saturday and between the soft tires and the insoles, the toes still felt pretty good at the end.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

by Weenie


bremerradkurier
Posts: 273
Joined: Mon Jun 13, 2016 4:18 pm

by bremerradkurier

mattr wrote:
Sat Sep 01, 2018 10:05 pm
Zakalwe wrote:
Fri Aug 31, 2018 8:23 pm
Have you tried foam rubber insoles in your shoes as well? Maybe even ride clip pedals, every little helps
we have some sound and vibration deadening rubber sheet we use at work that might help. I can have a word with the acoustics guys and see what the brand/technical name is. (We get it in several different tunes for different frequencies and locations.)

it's a bit like the stuff they use for after market car stereo installs.
The rubber adhesive sheets used on kitchen sinks might work.

http://cofair.com/pdf/Sink%20Silencer.pdf

Mr.Gib
Posts: 3215
Joined: Fri Mar 18, 2005 4:12 pm
Location: eh?

by Mr.Gib

bremerradkurier wrote:
Thu Oct 11, 2018 5:44 pm
mattr wrote:
Sat Sep 01, 2018 10:05 pm
Zakalwe wrote:
Fri Aug 31, 2018 8:23 pm
Have you tried foam rubber insoles in your shoes as well? Maybe even ride clip pedals, every little helps
we have some sound and vibration deadening rubber sheet we use at work that might help. I can have a word with the acoustics guys and see what the brand/technical name is. (We get it in several different tunes for different frequencies and locations.)

it's a bit like the stuff they use for after market car stereo installs.
The rubber adhesive sheets used on kitchen sinks might work.

http://cofair.com/pdf/Sink%20Silencer.pdf
Problem with anything rubber is that it is heavy. I'm rockin' SWorks 6 and 7's. Can't spend all that money and get weighed down. The lightweight foam is working.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

Bigger Gear
Posts: 365
Joined: Fri Mar 27, 2009 6:58 pm
Location: Wet coast, Canada

by Bigger Gear

Mr.Gib wrote:
Wed Oct 10, 2018 5:49 am
But as with many great things there is a catch. The Compass Extralight tires are so thin that I fear they will not survive the Cent Cols Challenge torture test next Spring. There will be several gravel climbs and perhaps the odd gravel descent. If the sidewalls survive it will be a miracle. In the hand these things feel like paper. Plan is to go with latex tubes with Orange Seal and have a backup set of Corsa G's in my luggage.
The ride quality of the Compass Extralight tires is sublime. On my gravel/all-road/winter bike I've been running the 700x32 Stampede or the 700x38 Barlow on HED Belgium+ rims which are 20.6mm width. I think you will be surprised with the durability of the Compass, I used my first pair of Stampede on all sorts of mixed surface including some sharper-edged gravel and even some mellow singletrack and they were bomber. In fact the only 2 flats I suffered were on pavement from sharp debris. The sidewalls, while thin, did seem very durable. I was running them with tubes, anywhere from 55-70 PSI depending on the ride.

Mr.Gib
Posts: 3215
Joined: Fri Mar 18, 2005 4:12 pm
Location: eh?

by Mr.Gib

Well, thanks for that info. I was pretty much committed to leaving the Compass tires at home.

Those "first Stampedes" of which you speak - were those Extralights?

I always carry a boot with me so I can survive a torn sidewall as long as it doesn't lead to a crash.

I suspect I'll be right on the edge at various points on this trip and am hoping to avoid any roadside delays. Those extralights are scary thin.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

mattr
Posts: 3823
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

Mr.Gib wrote:
Fri Oct 12, 2018 12:36 am
Problem with anything rubber is that it is heavy. I'm rockin' SWorks 6 and 7's. Can't spend all that money and get weighed down. The lightweight foam is working.
If they are cheap and lightweight, the foam will pack down very quickly at the pressure points, ball of foot basically, so get a few spares in stock/wedged into kit bags if you go anywhere. Then you can swap immediately, rather than having to go shopping.

They might also suffer with sweat/rain if they are very cheap.

They probably aren't designed for heavier cyclic loading either, probably ok for standing around, walking to the shops, but running will knacker them quickly and 90-100 rpm for 200km a day for a month will soon put paid to the damping they are providing!

Bigger Gear
Posts: 365
Joined: Fri Mar 27, 2009 6:58 pm
Location: Wet coast, Canada

by Bigger Gear

Mr.Gib wrote:
Wed Oct 31, 2018 5:39 am
Well, thanks for that info. I was pretty much committed to leaving the Compass tires at home.

Those "first Stampedes" of which you speak - were those Extralights?

I always carry a boot with me so I can survive a torn sidewall as long as it doesn't lead to a crash.

I suspect I'll be right on the edge at various points on this trip and am hoping to avoid any roadside delays. Those extralights are scary thin.
Yes they were Extralights. I currently have another pair plus a pair of Barlow in 38. Pricey but addictive. I've ridden the 38s on some pretty rough stuff as well and never had a problem. For just regular gravel riding I think you will be fine, so long as you are not the kind of guy who just bashes over stuff. I grew up riding and racing motorcycles, so I'm pretty good at picking a smooth line through most terrain and I think that has always helped me with tire and wheel damage in all forms of bicycles.

mattr
Posts: 3823
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

FWIW, it also depends on how your roads are made and what gets washed onto them.
My tyres last no time at all round here compared to where i used to live. But base stock for the roads is much much harder, more abrasive and sharper than what they use in the UK.

basilic
Posts: 701
Joined: Wed Jan 05, 2011 8:05 am
Location: Geneva, Switzerland

by basilic

Gib - at some point, won't they send you route details? on paved roads, even in bad condition, the Compass EL will be perfect. On uphill unpaved roads (eg Finestre from Susa), same. I did gash a sidewall once going downhill on a rocky path, had to boot it (that was on 14 km of up and down between cols of Arpettaz and Aravis). Why not ride the ELs most days, and change to something sturdier on the 1-2 days when it's needed. You'll bring spares anyway.

Mr.Gib
Posts: 3215
Joined: Fri Mar 18, 2005 4:12 pm
Location: eh?

by Mr.Gib

mattr wrote:
Wed Oct 31, 2018 7:56 am
Mr.Gib wrote:
Fri Oct 12, 2018 12:36 am
Problem with anything rubber is that it is heavy. I'm rockin' SWorks 6 and 7's. Can't spend all that money and get weighed down. The lightweight foam is working.
If they are cheap and lightweight, the foam will pack down very quickly at the pressure points, ball of foot basically, so get a few spares in stock/wedged into kit bags if you go anywhere. Then you can swap immediately, rather than having to go shopping.
Yup, I have purchase and cut to size 4 pairs. I will travel with inventory. It is my view that cycling is much easier on foot beds and footware in general than being on foot. How much easier can easily be determined by adding together how much your ass and hands hurt.
Bigger Gear wrote:
Wed Oct 31, 2018 9:03 am
Yes they were Extralights. I currently have another pair plus a pair of Barlow in 38. Pricey but addictive. I've ridden the 38s on some pretty rough stuff as well and never had a problem. For just regular gravel riding I think you will be fine, so long as you are not the kind of guy who just bashes over stuff. I grew up riding and racing motorcycles, so I'm pretty good at picking a smooth line through most terrain and I think that has always helped me with tire and wheel damage in all forms of bicycles.
This is very encouraging. I should be OK then. I pride myself on my smoothness - I am always focused on my line out of necessity. My battered old body just can't take any hard hits. I am easy on gear for someone my size. I have never dented a rim.
basilic wrote:
Wed Oct 31, 2018 2:46 pm
Gib - at some point, won't they send you route details? on paved roads, even in bad condition, the Compass EL will be perfect. On uphill unpaved roads (eg Finestre from Susa), same. I did gash a sidewall once going downhill on a rocky path, had to boot it (that was on 14 km of up and down between cols of Arpettaz and Aravis). Why not ride the ELs most days, and change to something sturdier on the 1-2 days when it's needed. You'll bring spares anyway.
Yeah we'll get gps files I assume. I have seen the route and checked out some of it on Google Steet View. It's the Appenines so a real mix of surfaces, a lot of it quite rough. The Compass tires will of course be great on the rough chip seal and broken pavement. For the gravel sections there will be some Strada Bianchi type surfaces but also other sections on major climbs that look a bit nastier. Hard to tell exactly what the gravel is like. And Google of course has not been to the worst bits so they remain a mystery. Love the suspense.

I should probably chance it. The ride is so nice. It'll will be an all in commitment. I won't be changing any tires I don't have to. They either survive or they die, and then I'm changing tires that night.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

calleking
Posts: 131
Joined: Sun Sep 13, 2015 3:20 pm

by calleking

I run my Panaracer GravelKing 42mm at 30/25 PSI. Silky smooth, lefty fork, SAVE seat post. 72kg. 😎
S-Works Tarmac SL6 Sagan Superstar DA Di2 + ENVE SES 4.5
Cannonndale Slate 17 Ultegra

Retired: Aeroad CF SLX 8.0 DI2

mattr
Posts: 3823
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

Mr.Gib wrote:
Wed Oct 31, 2018 10:15 pm
Yup, I have purchase and cut to size 4 pairs. I will travel with inventory. It is my view that cycling is much easier on foot beds and footware in general than being on foot.
Compared to running, yes. Compared to standing around or walking to the shops i'm not so sure.
Typically 90-100 pedal strokes a minute for 3-4-5 hours, i'm not convinced!

Mr.Gib
Posts: 3215
Joined: Fri Mar 18, 2005 4:12 pm
Location: eh?

by Mr.Gib

calleking wrote:
Thu Nov 01, 2018 7:30 am
I run my Panaracer GravelKing 42mm at 30/25 PSI. Silky smooth, lefty fork, SAVE seat post. 72kg. 😎
Thanks for joining the party but the application here is for 200 km and 5000 meters per day for 10 days on roads with only occasional gravel. With 42 mm GravelKings and the bike that they require, I doubt many "normal" people would survive the 10 days. I must be fast, I must be light, I must be reliable.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

spartacus
Posts: 45
Joined: Mon Apr 04, 2011 6:53 pm

by spartacus

What about trying a more compliant frame? I’d think 25c tires on wise rims at -60psi should be as good as you could ask for if they’re supple tires.

by Weenie


jlok
Posts: 712
Joined: Tue Jun 30, 2015 3:30 am

by jlok

I run 28c tubeless tires on 25mm int width rims, which make it to 31.8mm effective tire width at 50psi. I'm 73kg. All high frequency vibrations are very muted with this setup but still have plenty of feel. High speed descend no problem. Very planted.
Giant Propel Advanced SL Disc 1 / BMC TM02 < Propel Adv < TCR Adv SL Disc < KTM Revelator Sky < CAAD 12 Disc < Domane S Disc < Alize < CAAD 10

Post Reply
  • Similar Topics
    Replies
    Views
    Last post