Re: Re: Re: [RBW] Re: tire pressures

1 Avoiding Tire CollapseThe members who crashed or fell seemed to have pressures 50% below the Berto Pressure.  I chose 25% (or keeping the pressure >= 75% of the Berto Pressure) since it provides margin.  I see it as a Lower Limit I do not wan to be below.2 Supple TiresExperiment with 10% or

Re: Re: [RBW] Re: tire pressures

Thanks for the info and help. This makes an interesting study to see at what percentage underinflation from the Berto recommended pressures correlates with tire collapse. Looks like 25% so far. But I still wonder if Berto chart applies on supple tires with wide rims, as I think I read a BQ

Re: Re: [RBW] Re: tire pressures

LungimsamI would use pressures between 100% and 75% of the calculated F/R pressures. There should be enough room to find a comfortabe pressure John HawrylakWoodstown NJ  On 09/15/16, Lungimsam wrote: So then looks like 75psi front and rear would put me in the zone like the

Re: [RBW] Re: tire pressures

On 09/15/2016 06:45 PM, Lungimsam wrote: So then looks like 75psi front and rear would put me in the zone like the 45psi on the Bleriot would. Trouble is, last time I ran tires that high on a bike bike it made for some harsh riding. I have been thinking of a 650b conversion. The bb's of the

Re: [RBW] Re: tire pressures

The 24cm is measured bottom of bb shell to ground. 24 Bleriot 24.5 Rambouillet. -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to

Re: [RBW] Re: tire pressures

So then looks like 75psi front and rear would put me in the zone like the 45psi on the Bleriot would. Trouble is, last time I ran tires that high on a bike bike it made for some harsh riding. I have been thinking of a 650b conversion. The bb's of the Bleriot and Rambouillet are within .5cm of

Re: [RBW] Re: tire pressures

 Lungimsam28mm 203lb distributed 45%F 55%R and without and with 5lb front load and compared to a current 55psig FNo Front Load    68psig F / 84 psig R Front underinflated by 13psig or 19%.  Rear underinflated by 19psig or 23%5lb Front Load    72psig F / 84 psig R Front underinflated by

[RBW] Re: tire pressures

Ok, so now what if I am: 175lb rider on 27.9 lbs of Rambouillet bike with -~5lb front load on 700c x 28mm Compass Chinook pass tires? I' m currently running them at 55psi, front and rear. Thanks for the info, guys! -- You received this message because you are subscribed to the Google Groups

[RBW] Re: tire pressures

Just FYI. I increased my rear tire to 75psi, but I have left my front tire at 60psi. On Saturday, September 10, 2016 at 9:16:21 PM UTC-7, Don Compton wrote: > > I have been riding 700x28 Grand Bois Cerfs for years. Yesterday, I finally > lowered my pressures down to 60f and 70r. Why did I wait

[RBW] Re: tire pressures

The values I posted, 47/54 psig were INCORRECT for a 38mm tire. I mistakenly used the pressures calculated for a 35mm tire. I apologize. The pressure for the 203lb rider & bike for 38mm are 40psig F, 48psig R, The pressures for the 203lb with 5lb extra on the

[RBW] Re: tire pressures

Berto Tire Pressure App says 38 front, 52 rear. So your 45 AVERAGE is spot on! It just needs to be redistributed. Cheers, GAJett On Tuesday, September 13, 2016 at 6:48:27 AM UTC-7, Lungimsam wrote: > > So if I am 175lbs., on 27.9 lbs. of Bleriot, with 5 lbs. of front baggage, > on 650b x 38mm

Re: [RBW] Re: tire pressures

I remember an rbw employee who said if he ain't bottoming out, he's good. -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to

Re: [RBW] Re: tire pressures

Ron Mc wrote: "The people who were exceptionally low also reported wrecks" Yes, generally their tires were UNDERINFLATED by 25% to 50% of the 15% Tire Drop Calculated Pressure, from my review of the posts. I would recommend maintain your tire pressure at between 75% to 100% of the 15% Tire

Re: [RBW] Re: tire pressures

LungimsamFront should be 47 psig,  Rear should be 54 psig.   This is for a 45%/55% distribution for Rider & Bike and the 5lb load only applied to the FRONT wheel weight.Your 45psig/45psig results in the front at correct pressure and the rear underinflated by 9 psig (17% low).John HawrylakWoodstown

[RBW] Re: tire pressures

Put enough air in your tires. Go for a ride. Let some out or put some in depending on what you think of the ride. Repeat process as/if necessary. There is no absolute. -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from

[RBW] Re: tire pressures

So if I am 175lbs., on 27.9 lbs. of Bleriot, with 5 lbs. of front baggage, on 650b x 38mm Compass Loup Loup tires, at 45psi front and back, where does that put me? -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this

Re: [RBW] Re: tire pressures

on the last tire pressure thread, one of the posters plugged everybody's replies back into the Berto graphs and found out we were all but a couple riding within a narrow error window on those graphs - we have naturally gravitated there. The people who were exceptionally low also reported

Re: [RBW] Re: tire pressures

But werent Bertos calculations on stiff tires? Much stiffer than the sidewalls many use today? Compass, GB, etc. Also on narrower rims than used today? So does his table really apply anymore? -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch"

Re: [RBW] Re: tire pressures

Thanks again for this. I'll try 55/65 or so, though because my only high pressure (ie, > 30 psi) gauge is the doubtful one on the pump, I'll have to get another one. The other day the pump gauge said 20-25 for the 51 mm F Freds, but the low pressure gauge showed ~ 15 in front; and indeed it felt

Re: [RBW] Re: tire pressures

Patrick 15% TDC pressures for a 32mm El Pass for YOUR 200# Total Weight (175+25) is 52/64 psig F/R. So YES 65/70 psig F/R would be HIGH 13 psig high in F 6 psig high in R. The rear is reasonable. The front probably could lose 10 psig. >From the responses in another post on Tire Prressure,

[RBW] Re: tire pressures

Fortunately or unfortunately, I have another new Grand Bois 28 Cerf,so it will be awhile until I need to purchase new tires. When I finally wear them out I am going to buy some Compass 700x32 extra lights. Some complain about the price of Grand Bois and Compass tires, but I get my money's worth

Re: [RBW] Re: tire pressures

Thanks, John. I read Berto's article -- was it published in Bicycling? -- years ago, but I've never bothered to be as exact as the method entails. My thumbs and forefingers are pretty well educated by now, and I am thinking that even 65/70 for the Elk Passes is a wee bit high for my taste, unless

Re: [RBW] Re: tire pressures

Opps , hit something & it got sent unfinished Patrick Here are the tire pressures for the 15% tire drop method for the weights and widths you specified: 175 Lb + 20 lb = 195 lb total weight 45%/55% distribution 23 27 29 F 89 69 61 R 112

Re: [RBW] Re: tire pressures

Patrick Here are the tire pressures for the 15% tire drop method for the weights and widths you specified: 175 Lb + 25 lb = 195 lb total weight 23 27 F R On Sunday, September 11, 2016 at 5:26:41 PM UTC-4, Patrick Moore wrote: > 175 rider + bike at sub 20 and another sub 25.

Re: [RBW] Re: tire pressures

I find that even good bike shops pump tires much too hard; there is a "too hard" even for cheap Kendas. When I pump tires for customers or friends, I try to leave a wee bit of cush -- the sweet spot is vanishingly small with cheap, thick-sidewalled tires. Odd: I used otherwise very decent 559 X

Re: [RBW] Re: tire pressures

Ok, what is the actual width.  I interpolate on the slope and intercept of the published curves to get the curve for say a 29.5mm width.  tell me the actual width and I can get the 15% TDC pressure.John HawrylakWoodstown NJ   On 09/11/16, Don Compton wrote: Berto's old method

[RBW] Re: tire pressures

On a side note, I took my sister in law to a few shops to test ride a bunch of bikes and found that a common complaint she had was they were too harsh. Well, the tires were all pumped up to rock hard!! Not to mention most stock tires on the hybrids we were looking at are not the supple ones

Re: [RBW] Re: tire pressures

175 rider + bike at sub 20 and another sub 25. Elk Pass tires, measuring ~27 and ~29 respectively; run at ~65-70. I don't sweat digits f/r, but I do use the pinch test to get front a wee bit softer. In fact, were it not for the gauge on the pump, which for all I know may be defective, I'd just go

[RBW] Re: tire pressures

Berto's old method does not take into consideration the benefits of wider rims. On Sunday, September 11, 2016 at 9:06:17 AM UTC-7, John Hawrylak wrote: > > Don > > 28mm tires at 60psig F & 70psig R supports a TOTAL Weight (rider & bike) > of 175 to 180 lb for a 15% Tire Drop (Berto's method)

[RBW] Re: tire pressures

I got ~175lbs rider + ~27.5 lbs bike + ~7 lbs.bag on both my Rivbikes at any given time riding on Compass rubber: Bleriot with 650b x 38 Loup Loup- 45psi front and rear Rambouillet with 700c x 28 Chinook - 55psi front and rear -- You received this message because you are subscribed to the

[RBW] Re: tire pressures

With the 700x38 Barlowe Pass on the Hilsen and the 650x42 Babyshoes on the new MAP and the lowest pressures I can get away with, I INTENTIONALLY ride on rumble strips because even after riding these supple Compass tires for a couple of years I still can't get over how damn comfortable they are.

[RBW] Re: tire pressures

Don 28mm tires at 60psig F & 70psig R supports a TOTAL Weight (rider & bike) of 175 to 180 lb for a 15% Tire Drop (Berto's method) assuming a 45%F and 55%R weight distribution (typical Rando).. John Hawrylak Woodstown NJ On Sunday, September 11, 2016 at 12:16:21 AM UTC-4, Don Compton wrote: