[mrcodewiz]

I'm having trouble figuring out exactly what reamer I would need for an 18X24 caged needle bearing. Would a 24mm reamer be too big?

The bearing is for a control lever on a motorcycle (foot brake) so it won't see much force.

[txcncman]

Are you a mechanic or a machinist?

[mrcodewiz]

Does that affect the response to my question?

[txcncman]

Yes, it does effect how a response would be worded for best understand by the audience.

Does your bearing require a press fit or a slip fit?

[mrcodewiz]

I apologize - I took your response the wrong way. I am neither a mechanic or a machinist but I am probably closer to a mechanic than a machinist.

I assume the bearing has to be a press fit into the pocket. I attached a couple pictures to give you an idea of what I am doing. The lever itself has a needle bearing in it and a footpeg will run through the lever and mount to the control bracket.

I have one made up but the fit of the lever to the foot peg is pretty loose and I believe it is because the pocket for the bearing was too big (loose slip fit). I loc-tited the bearing into the lever but if I understand correctly, the needle bearing requires some degree of press fit in order to fit the peg correctly (18mm in this case)

[txcncman]

I assume you are not using the hole in the aluminum level as the outer race of the bearing. Measure the outer race of the bearing with a micrometer or quality dial caliper. Subtract 0.02 mm and obtain a reamer for this size. Press the bearing into the reamed hole. If the shaft you are applying the lever to is worn, you will not get a tighter fit until you replace the shaft with a new one. Chances are, the bearing was never the problem.

[mrcodewiz]

I assume you are not using the hole in the aluminum level as the outer race of the bearing. Measure the outer race of the bearing with a micrometer or quality dial caliper. Subtract 0.02 mm and obtain a reamer for this size. Press the bearing into the reamed hole. If the shaft you are applying the lever to is worn, you will not get a tighter fit until you replace the shaft with a new one. Chances are, the bearing was never the problem.

I am not - the bearing is a caged needle bearing so it has its own outer race. I will check the shaft diameter - you may be right on that part.

[mactec54]

mrcodewiz

No reamer is going to do the job for you, the reamer would cost way to much,(a custom 24mm reamer lots of $$$$) normally this hole in the arm would be bored when you are machining it to the correct size for the bearing

Needle roller bearing tolerances, The bore that you machine can make the bearing loose on the shaft or tight, depending on the bearing type & fit in the machined hole

Check with the bearing manufacture for the correct bore size, most likely a H7 fit

If the foot peg shaft is not case hardened were the bearing is on it, it will fail very quickly

This would normal be case hardened or have a hardened bearing sleeve on the foot peg shaft for the bearing to run on

If the shaft is not hardened, or you don't have a hardened sleeve for it, you could use a bronze bushing or something similar, & do away with the bearing, a bushing will do the same job as the bearing, you will need to lube it more offten though

[mrcodewiz]

mrcodewiz

No reamer is going to do the job for you, the reamer would cost way to much,(a custom 24mm reamer lots of $$$$) normally this hole in the arm would be bored when you are machining it to the correct size for the bearing

I guess I will have to work on my boring skills then. That's how I was doing it but my boring head didn't seem to be boring the same diameter over the course of 10 or so those things.

If the foot peg shaft is not case hardened were the bearing is on it, it will fail very quickly

This would normal be case hardened or have a hardened bearing sleeve on the foot peg shaft for the bearing to run on

If the shaft is not hardened, or you don't have a hardened sleeve for it, you could use a bronze bushing or something similar, & do away with the bearing, a bushing will do the same job as the bearing, you will need to lube it more offten though

I wondered this myself but there are a lot of manufactures making a similar setup but without bearings or a bushings - just aluminum to aluminum. I attached an example. Would the needle bearings wear the peg out any faster than those? The movement is only about 15 degrees or so - no more than 45 at the most.

[wildwestpat]

As this pivots about the foot rest on what looks to be a motor cycle or quad bike it is going to be subject to mud and water. Double sealed needle bearings are available but any moisture penetrating the seals will cause problems with the brake release. Since the action is both intermittent and only a few degrees of rotation why even consider using either needle or ball race? As the foot brake bracket looks as if it is aluminium alloy then a brass or bronze bush could cause galvanic corrosion. IMHO use a reinforced plastic bearing (Fiber-Lube or similar all plastic reinforced sleeve bearing) or a pair of stainless steel double rubber sealed bearings with suitable foot rest shaft spacers to take any side thrust for a techno fit. Ball races are readily available in stainless steel - needle rollers are more difficult to obtain particularly when fully sealed and the dimensions are similar when comparing a pair of ball bearings with a double sealed needle roller.

Regards - Pat

[mrcodewiz]

As this pivots about the foot rest on what looks to be a motor cycle or quad bike it is going to be subject to mud and water. Double sealed needle bearings are available but any moisture penetrating the seals will cause problems with the brake release. Since the action is both intermittent and only a few degrees of rotation why even consider using either needle or ball race? As the foot brake bracket looks as if it is aluminium alloy then a brass or bronze bush could cause galvanic corrosion. IMHO use a reinforced plastic bearing (Fiber-Lube or similar all plastic reinforced sleeve bearing) or a pair of stainless steel double rubber sealed bearings with suitable foot rest shaft spacers to take any side thrust for a techno fit. Ball races are readily available in stainless steel - needle rollers are more difficult to obtain particularly when fully sealed and the dimensions are similar when comparing a pair of ball bearings with a double sealed needle roller.

Regards - Pat

Surprisingly, adding bearings to this connection really improves the feel of the controls. I will have to look into the plastic bushings. That may be better than having no bearings. I originally intended to use regular sealed ball bearings but I couldn't find any in the appropriate size. I want to keep the peg diameter at 18mm so that factory pegs can be used and that seems to be a fairly odd size for normal ball bearings.

[mactec54]

mrcodewiz

If your pegs are aluminum, they would of been anodized, so this would give you a hard surface, but with the needle bearing working on it, the life would still not be very long, for the peg or the bearing, Yes the movement would be smoother with the bearing, but there are many very good plastics that you could make a bushing to do the job as well, It would still want some kind of seal to keep the dirt out

wildwestpat
You can get needle roller bearings double sealed & with hardend inner sleeve
Standard from most bearing suppliers, So no problem with that part

Its being able to use a bearing will be the hardest part, without changing the peg, & putting a hardened sleeve on it, for the needle bearing to run on, It will not last very long at all, without the hardened sleeve

[txcncman]

Looks like we have run into an entire engineering redesign problem, not just a machining or mechanic's problem.

[mrcodewiz]

It certainly could be problematic.

[mrcodewiz]

Looks like a pair of 17X26X5 deep groove sealed bearings are the closest I can get. I wonder why something like that isn't made in an 18mm.

[wildwestpat]

Hi Mactec54

If you have found a stockist for stainless steel needle roller bearings that are sealed both ends i.e. have both inner and outer ground sleeves then I would be interested. My previous hunts for this type of bearing have proved fruitless.

Thanks - Pat

[mactec54]

wildwestpat

No they are not SS, if they are sealed they would not need to be SS for this application, but if you did need ss needle roller bearings, here is one of many
http://www.asiabearings.com/Bearing-...ealed-2RS.html

I think mrcodewiz has found the solution with the 17X26X5 Bearing just make sure they are 2RS for the seals

He will only have to modify the peg were the bearing is fitted by turning 1mm off it for the bearing to be fitted, the bearing would want a shoulder on the Peg anyway, & bore the lever bearing bore to the 26mm when it's being made

[mrcodewiz]

Weird - looks like I lost a couple posts for some reason. I was already going down the path of redesigning the pivots so I researched a little this morning and I found that there are actually several (some big-name) makers of controls that are doing exactly what i did - caged needle bearings riding directly on the peg. I don't know if they are using double sealed but it would seem likely because I can see how riding in wet/dusty conditions would foul the non-sealed ones up pretty quickly.

I do like the idea of sandwiching two roller bearings in, though. It seems it would make it easier to take the play out of the lever without having to worry about the tolerances as much. The biggest drawback is that I would have to make the pegs either smaller or bigger and then not be compatible with OEM and other big brand pegs.

I may run one side with deep grooves and the other with needle bearings and see what they look like at the end of the season.

[keebler303]

If your bearing ID is larger than the peg, a sleeve could be used without modification to the peg.

Matt

[wizard]

There is little doubt that a roller bearing of some sort would work to advantage and would feel great new. The problem is contamination and the likely need for frequent lubrication. Witha roller nearing you also run the risk of a lock up if grit or contamination gets into the rollers. In this regard even oil lite bushings will need lubrication.

Synthetic materials, for example roulon type bushings might provide better performance and do so without the need for excessive lube. However here is the flip side, lube will protect the shaft from rust if it is steel. A rusted shaft will lock up even a synthetic bushing.

As you can see many trade offs here. Consider this you could also make use of shaft seals to keep out contamination (installed backwards). However then you loose some of that nice feel of a roller bearing.

In any event back to needle bearings, in most applications I'm familiar with outer races are not heavily pressed fit, being more of a tight slip fit. Note however most of my experience here is with industrial machinery where plain old ball bearings are most common. As someone has already mentioned if the shaft is soft you really should be using a sleeve on that shaft suitable for the needle bearing. Even something as simple as foot pedals will generate wear on a plain shaft.

So my approach would be this: use a reamer sized for the bearing with the goal of a tight slip fit. Take an effort to provide for lubrication and shaft seals. Have both needle bearings and shaft seals riding on sleeves to reduce the fast wear seen on a soft shaft.

Surprisingly, adding bearings to this connection really improves the feel of the controls. I will have to look into the plastic bushings. That may be better than having no bearings. I originally intended to use regular sealed ball bearings but I couldn't find any in the appropriate size. I want to keep the peg diameter at 18mm so that factory pegs can be used and that seems to be a fairly odd size for normal ball bearings.