Tramlining !!!! - Avon Road Riders

[Onder]

Maybe I missed it but how much do you weigh all kitted up? I run all my bike tyres Avon and Doomlaps at
28 rear and 26 front. Maybe bump that up two pounds each to see if it changes things. It does, it makes the
bike feel lighter and roll more easily.
However, mind you that I weigh less than most by a fair amount. 130 pounds full kit and I wear a lot of duds.
So if it were me I'd do the cheapest thing and change the tyres one at a time and see.

 

[robs ss]

Yesterday we were out for a ride that included about 20 miles of newly laid grooved concrete road. At 60-70 MPH the bike was so squiggly that I thought some suspension component had broken or the swingarm bushings had suddenly gone missing!

Mike - have you checked with any other riders you know to see if the road may be the issue?

 

[YING]

I've only had problems with tracking on grooved roads with tt100s
I have a 90/90/19 roadrider on the front and I think a 410/19 roadrider rear (I'm not near the bike and I can't remember)
I put 35psi in the front and 42 psi in the rear and I have no problems at all

Baz,
How much do you weigh and does anyone think that has something to do with that. I have 100/90 tires on both ends and have never had MexicoMikes problem running 32lbs rear and 28lbs on the front.Just asking. I weigh about 130lbs.
Thanks,Mike

 

[baz]

Baz,
How much do you weigh and does anyone think that has something to do with that. I have 100/90 tires on both ends and have never had MexicoMikes problem running 32lbs rear and 28lbs on the front.Just asking. I weigh about 130lbs.
Thanks,Mike

I weigh just under 16st so something around 220lb I guess in stockinned feet

 

[MexicoMike]

I weigh 170lbs kitted; bike is totally stock Commando - whatever they actually weigh! I don't carry any additional gear - just me on the bike. Both wheels are properly balanced - no vibration on "normal" road surfaces at any speed.

I've done a lot of "research" since yesterday, which included bringing it up at the local motorcycle club meeting yesterday - 14 guys/2 gals. Two of the attendees are motorcycle shop guys. Here is what I "learned:"

1. One shop guy said the tram lining is due to the rear tire direction being wrong; other shop guy says, no way the tire direction matters re the tram lining.
1.a. Avon says, if I understand correctly, that the directional tread is mostly about water displacement and also improved wear. No mention of any issues as far as vibration/road surfaces or other factors.

2. Nobody else has any trouble on the same road - at least not to the extent that I did. One rider says he notices it a bit but it's not objectionable.

3. One shop guy says tire pressures should be as per original; other shop guy says pressures should be higher!

4. Re #3, general discussion resulted in the observation that modern tires (like the Road Riders which are tubeless if mounted on appropriate rims, have stiffer sidewalls than the original tube tires and therefore it SEEMS like they would not require more pressure. "Since the sidewalls themselves are stiffer Shouldn't the opposite - original or even lower pressure - be appropriate?" was one opinion.

5. Everyone else is riding relatively current bikes so they are not dealing with the question re "old" tire pressure vs new tire pressure.

6. Comic relief: One of the members rides a V4 Panagali his suggestion was, "Just wheelie for the extent of that road! With only one tire on the ground it should be less of a problem!"

Absent his wheelie ability (both rider and bike), today I'll have the tire reversed on the rim. Then my plan is to air up the tires to "Baz pressure" and take it out on that road. Then I'll stop several times and reduce the pressure a few psi each time until I get down to "original pressure" and see what happens.

 

[baz]

I weigh 170lbs kitted; bike is totally stock Commando - whatever they actually weigh! I don't carry any additional gear - just me on the bike. Both wheels are properly balanced - no vibration on "normal" road surfaces at any speed.

I've done a lot of "research" since yesterday, which included bringing it up at the local motorcycle club meeting yesterday - 14 guys/2 gals. Two of the attendees are motorcycle shop guys. Here is what I "learned:"

1. One shop guy said the tram lining is due to the rear tire direction being wrong; other shop guy says, no way the tire direction matters re the tram lining.
1.a. Avon says, if I understand correctly, that the directional tread is mostly about water displacement and also improved wear. No mention of any issues as far as vibration/road surfaces or other factors.

2. Nobody else has any trouble on the same road - at least not to the extent that I did. One rider says he notices it a bit but it's not objectionable.

3. One shop guy says tire pressures should be as per original; other shop guy says pressures should be higher!

4. Re #3, general discussion resulted in the observation that modern tires (like the Road Riders which are tubeless if mounted on appropriate rims, have stiffer sidewalls than the original tube tires and therefore it SEEMS like they would not require more pressure. "Since the sidewalls themselves are stiffer Shouldn't the opposite - original or even lower pressure - be appropriate?" was one opinion.

5. Everyone else is riding relatively current bikes so they are not dealing with the question re "old" tire pressure vs new tire pressure.

6. Comic relief: One of the members rides a V4 Panagali his suggestion was, "Just wheelie for the extent of that road! With only one tire on the ground it should be less of a problem!"

Absent his wheelie ability (both rider and bike), today I'll have the tire reversed on the rim. Then my plan is to air up the tires to "Baz pressure" and take it out on that road. Then I'll stop several times and reduce the pressure a few psi each time until I get down to "original pressure" and see what happens.

I'll be interested in your findings

 

[Fast Eddie]

130lbs ?

In riding gear ??

You’re supposed to put BOTH feet on the scales chaps…

 

[concours]

130lbs ?

In riding gear ??

You’re supposed to put BOTH feet on the scales chaps…

That's "free horsepower" compared to the rest of us....

 

[baz]

That's "free horsepower" compared to the rest of us....

Yep a quick Google shows 1hp per 2-3lbs rider weight
I feel really fat now

 

[possm]

"a. Avon says, if I understand correctly, that the directional tread is mostly about water displacement and also improved wear. No mention of any issues as far as vibration/road surfaces or other factors."

It is also about the direction that the belting / rubber is applied in the manufacturing process!

 

[Fast Eddie]

That's "free horsepower" compared to the rest of us....

Indeed !

 

[Torontonian]

I thought we were talking about suddenly hitting grooved concrete road surfaces at speed. Motorcycles don't enjoy that .

 

[marshg246]

Maybe I missed it but how much do you weigh all kitted up? I run all my bike tyres Avon and Doomlaps at
28 rear and 26 front. Maybe bump that up two pounds each to see if it changes things. It does, it makes the
bike feel lighter and roll more easily.
However, mind you that I weigh less than most by a fair amount. 130 pounds full kit and I wear a lot of duds.
So if it were me I'd do the cheapest thing and change the tyres one at a time and see.

So, fully dressed you're around 150 - you're making me jealous

Many, many years of K70 and K81 Dunlop tires on Triumphs, I followed the owners books. Most say 24 Front and 25 Rear but if you have a passenger 28 Front and 31 Rear. Never having a passenger I set to 26 Front and 30 rear (I'm heavy).

I kept that when I went to Avon but then read the Avon recommendations - MUCH higher! And when I went much higher, the tires were much better, IMHO. Because other smaller people sometimes ride my bikes, I have those that have Avons at 35 Front and rear. If I were going out for a long ride on Avons (those days are over ) I would want at least 38 in the rear when cold.

BTW, the 1974 T150 Owners says that a average rider is 168 pounds (76kg). Most of the manual just say "average rider".

 

[Onder]

No wonder I have the fastest bikes in town. All that added horsepower!

 

[Mark Savage]

I’ve never strayed much from what Avon recommends (I emailed them years ago) 29 psi front 34 psi rear. When loaded for touring I put an extra couple of pounds in. I noticed it was a bit wayward on those German rain grooved motorways, didn’t like them much and also there’s a section of road not far from where I live that was badly scraped when it snowed years ago that it’s tracks strangely over. I’m used to that bit now and found it’s better the quicker you go.

 

[robs ss]

I’ve never strayed much from what Avon recommends (I emailed them years ago) 29 psi front 34 psi rear. When loaded for touring I put an extra couple of pounds in. I noticed it was a bit wayward on those German rain grooved motorways, didn’t like them much and also there’s a section of road not far from where I live that was badly scraped when it snowed years ago that it’s tracks strangely over. I’m used to that bit now and found it’s better the quicker you go.

I'm going to change from 30/30 to what you're doing!

30/30 is easier though! (for us "small of brain")

 

[MexicoMike]

Had hoped to make the tests yesterday or today but I'm not going to be able to get out until Tuesday... But will advise here when I find out whatever I find out!

This added a few minutes later... Just found that Avon's suggested pressure for "classic bikes" is 25F 28R. I couldn't be more confused re this issue. Oh well, when I get the testing done I'll know what works best for my Commando - at least for tram lining with Avon RRs. Of course, it may turn out that best pressure to reduce/eliminate the tram lining is not the best pressure for general riding!

 

[Elfix]

As we all learned from the Ford Firestone/Explorer debacle, the concern of low pressure is heat build up. Tire construction, tube or tubeless, road surface, weight, and speed all contribute to heat buildup in a tire as it flexes when rolling, so the “ideal” running pressure can vary widely.

I was taught at some point to compare cold to hot pressure and to target a change of 2-4 psi as a general rule- but I’ve read lately that it is really more a matter of adjusting to ride dynamics and rider preferences. I find the suggested pressures in some of the factory manuals of my older machines to be disturbingly low and I wonder if this has more to do with rider comfort than actual tire performance, given that most early suspension systems were unable to react to small bumps. My 1972 Yamaha RT2 lists 18/16… and I confess I’ve never run it that low.

My track bike, on Dunlop slicks, runs at hot pressures of 31f and 22r. Dunlop recommends higher rear pressures for the smaller section slicks used on the supermotos and 250’s….. all useless data when talking vintage bikes, but suffice to say “correct” pressures vary a lot.

 

[Fast Eddie]

As we all learned from the Ford Firestone/Explorer debacle, the concern of low pressure is heat build up. Tire construction, tube or tubeless, road surface, weight, and speed all contribute to heat buildup in a tire as it flexes when rolling, so the “ideal” running pressure can vary widely.

I was taught at some point to compare cold to hot pressure and to target a change of 2-4 psi as a general rule- but I’ve read lately that it is really more a matter of adjusting to ride dynamics and rider preferences. I find the suggested pressures in some of the factory manuals of my older machines to be disturbingly low and I wonder if this has more to do with rider comfort than actual tire performance, given that most early suspension systems were unable to react to small bumps. My 1972 Yamaha RT2 lists 18/16… and I confess I’ve never run it that low.

My track bike, on Dunlop slicks, runs at hot pressures of 31f and 22r. Dunlop recommends higher rear pressures for the smaller section slicks used on the supermotos and 250’s….. all useless data when talking vintage bikes, but suffice to say “correct” pressures vary a lot.

What are you running slicks on ?

 

[Elfix]

This old thing- a Ducati 848.

It’s done 10 seasons under me now- but it’s won the AK championship 4 times.