Bike trainer pressure against rear wheel tire?



scorpio012

New Member
Sep 3, 2015
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Hello everyone, I bought a Blackburn mag 3 trainer some time ago and couldn't find out just how much pressure should be applied to the rear wheel tire while it's on the trainer. Could anyone help be with that? Thanks
 

HIPCHIP

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Apr 11, 2009
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Not exactly sure what you are referring to, but on my trainer I run tire pressure at normal road pressures and the roller just pushes against the tire. If yours is adjustable then not sure, but I assume it would be your body weight.
 

CAMPYBOB

Well-Known Member
Sep 12, 2005
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1. Inflate tire to near maximum recommended pressure.
2. Adjust the magnet to the level of maximum resistance you will be training at.
3. Adjust tire contact pressure to where it eliminates slippage between the tire and the driven roller.
4. Test for slippage by grasping the tire and giving it a hard and fast tug. Any slippage at the roller can be seen and/or felt. Higher contact pressure is not necessary and will only increase wear to the trainer bearings and the tire tread.

Blackburn has a couple mag trainer manuals online with similar procedures: https://admin.blackburndesign.com/b...4/10/Blackburn-Tech-Mag-1-Trainer-Manual1.pdf
 
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scorpio012

New Member
Sep 3, 2015
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1
1. Inflate tire to near maximum recommended pressure.
2. Adjust the magnet to the level of maximum resistance you will be training at.
3. Adjust tire contact pressure to where it eliminates slippage between the tire and the driven roller.
4. Test for slippage by grasping the tire and giving it a hard and fast tug. Any slippage at the roller can be seen and/or felt. Higher contact pressure is not necessary and will only increase wear to the trainer bearings and the tire tread.

Blackburn has a couple mag trainer manuals online with similar procedures: https://admin.blackburndesign.com/b...4/10/Blackburn-Tech-Mag-1-Trainer-Manual1.pdf
Thanks a lot for the info and for taking the time to reply!
 

scorpio012

New Member
Sep 3, 2015
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Not exactly sure what you are referring to, but on my trainer I run tire pressure at normal road pressures and the roller just pushes against the tire. If yours is adjustable then not sure, but I assume it would be your body weight.
Thanks for taking the time to reply, but I think "campybob" responded with what I need. Thanks anyway.
 

Froze

Well-Known Member
Jul 13, 2004
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NE Indiana
If after adjusting your tire pressure against the drum and you start to notice tiny bits of black tire rubber after using the trainer than the pressure against the tire is too high so back it off a wee bit at a time till you no longer get those rubber bits.
 

scorpio012

New Member
Sep 3, 2015
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If after adjusting your tire pressure against the drum and you start to notice tiny bits of black tire rubber after using the trainer than the pressure against the tire is too high so back it off a wee bit at a time till you no longer get those rubber bits.
Everyone wants to be a comedian!!
 

CAMPYBOB

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Sep 12, 2005
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I suppose it's possible to get a tire hot enough with enough roller pressure to squirm and deform the carcass and shred itself into small rubber particles...depending on the tread pattern and height and maybe the age/condition of the rubber compound (i.e. dry and age hardened). I've never seen it, but it could happen.

Could it happen at roller contact pressures set with common sense? Ya never know...common sense ain't so common these days.
 

scorpio012

New Member
Sep 3, 2015
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Exactly where was I being funny?[/QUO
FROZE I apologize if I offended you with my saying "Everyone wants to be a comedian" it wasn't my intention. When I read your reply it struck me as being funny was all. If you weren't trying to be funny, but were serious, you must think I'm so stupid that I wouldn't know what to do if I "started to notice tiny bits of black tire rubber"!
 

CAMPYBOB

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Sep 12, 2005
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I think FROZE was just covering all the bases. Trust me...we get folks posting here that need detailed instructions on how to draw their next breath. No. I'm not joking.
 

scorpio012

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Sep 3, 2015
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I think FROZE was just covering all the bases. Trust me...we get folks posting here that need detailed instructions on how to draw their next breath. No. I'm not joking.
I am sorry, but it did strike me as a bit funny and I thought he might have been just fooling around. I've asked for his help in the past(a lot) so I thought we were cool
 

Froze

Well-Known Member
Jul 13, 2004
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I suppose it's possible to get a tire hot enough with enough roller pressure to squirm and deform the carcass and shred itself into small rubber particles...depending on the tread pattern and height and maybe the age/condition of the rubber compound (i.e. dry and age hardened). I've never seen it, but it could happen.

Could it happen at roller contact pressures set with common sense? Ya never know...common sense ain't so common these days.

I don't about the heat thing, all I know is that on other forums when a question comes up about trainers you'll get responses saying to use dedicated trainer tires so you don't get that bits of rubber, when the real problem is tension of the drum against the tire. I use nothing but retired tires off my road bikes and I never get shredding. By the way, if you use a tire that's been on the road you must clean the tire off real well and pick out any bits of debris in the tire, failure to do this could wear a groove in the drum.

No, I wasn't offended, just trying to figure out where the funny part was! LOL
 

scorpio012

New Member
Sep 3, 2015
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I don't about the heat thing, all I know is that on other forums when a question comes up about trainers you'll get responses saying to use dedicated trainer tires so you don't get that bits of rubber, when the real problem is tension of the drum against the tire. I use nothing but retired tires off my road bikes and I never get shredding. By the way, if you use a tire that's been on the road you must clean the tire off real well and pick out any bits of debris in the tire, failure to do this could wear a groove in the drum.

No, I wasn't offended, just trying to figure out where the funny part was! LOL
Froze I am sorry~! You have always given me sound advice so I shouldn't have doubted your sincerity. Thank you for your advice. I still haven't bought that seat I had asked you about. I don't know if I told you that I had to send the first trainer back due to some malfunction, but they sent me another.
 

Froze

Well-Known Member
Jul 13, 2004
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NE Indiana
With lower end trainers you're bound to run into one that will malfunction out of the box, but the next one you get should be fine for a very long time because there is very little to go wrong with those things.. If I recall correctly you bought it from Performance or Nashbar, either one has a lifetime customer satisfaction with it not to mention the factory warranty so you'll be fine with it.
 

scorpio012

New Member
Sep 3, 2015
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With lower end trainers you're bound to run into one that will malfunction out of the box, but the next one you get should be fine for a very long time because there is very little to go wrong with those things.. If I recall correctly you bought it from Performance or Nashbar, either one has a lifetime customer satisfaction with it not to mention the factory warranty so you'll be fine with it.
Hi Froze, I bought it online from the Sun & Ski website. The second one was a couple of bucks cheaper because I got a discount for buying the first one from them, only ten bucks, but still ten buck is ten bucks. One of the problems was that I never rode on a trainer before so I didn't know what type of sounds they make normally. The second one is a little quieter.
 

One speed

New Member
Aug 7, 2006
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I suppose it's possible to get a tire hot enough with enough roller pressure to squirm and deform the carcass and shred itself into small rubber particles...depending on the tread pattern and height and maybe the age/condition of the rubber compound (i.e. dry and age hardened). I've never seen it, but it could happen.

Could it happen at roller contact pressures set with common sense? Ya never know...common sense ain't so common these days.

Yes. It is possible to get the tire hot enough to shed little bits of rubber which then stick to the back of the seat tube. If the tyre/rim runout is too much, then the wheel will skid on the roller at one point and be too tight, ie too much pressure at the high point leading to the aforementioned overheating. Mind you, the one I have almost discarded has been in use for 10 years, so fits the category of dry and age hardened, and has only recently started to disintegrate. I thought that the high spots would wear off but the wear has been almost insignificant. It is only an issue when on the high load settings and very high equivalent road speed. I use normal air pressure, about 100/110 psi and set up for minimal skidding as described above. Common sense really.
 

CAMPYBOB

Well-Known Member
Sep 12, 2005
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Most trainers use a spring-loaded roller. That will compensate, to some degree, for an out-of-round wheel or a tire that is incorrectly seated or one that has a slight bubble or hump. The key words are: to some degree.

A badly out-of-round wheel or one with a lot of side-to-side wobble may cause excessive tire wear at high speeds/efforts.

I used a sew-up a couple/three years ago on the trainer and rollers that had a broken carcass from road use pothole abuse. It had a pronounced 'S' profile as it turned. I got over a year's use on the trainer out of it with no harm to the trainer or bike. Even with it on a fixed gear track bike the only time the busted carcass was noticeable was during extreme efforts. Despite age, the tread did not lose rubber flakes or leave marking on the trainer's roller...in this case. Again, I only used enough roller contact pressure to eliminate slipping under acceleration.
 

One speed

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Aug 7, 2006
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My trainer is a Blackburn Trackstand with a screw adjusted roller. The tyre is actually a sewup Vittoria Competition Rally and is now down to the carcass in spots. Maximum usage of a tyre no longer safe to ride on the road!!! The problem would not have arisen had the roller been spring loaded.
 

CAMPYBOB

Well-Known Member
Sep 12, 2005
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I'ld say you got your money's worth out of that tire. I like those old Vittoria's. They are great tires for road training.