Wheel bearing generics

[ventYl]

Hi,
my B4 slightly starts asking for new wheel bearings. I know that there's a possibility to buy SGP bearings straight from manufacturer. But I also know that most of bearings used anywhere are of some generic dimension and made by plenty of producers thus are quite cheapo. I am not very willing to pay let's say 5 times the price of "high quality" (they say it) Koyo bearing for bearing of quality I don't have track of.

Another aspect is that I've read some quite old article in German Motorrad magazine where they dismantled B4 completely after around 50k km and their biggest complaint (apart from gearbox teeth pitting which is fairly normal for vehichles which were ran a lot under full throttle) was lifetime of wheel bearings.

I know the dimensions of the bearings and am able to get Koyo (or whatever would be in the package)  bearings of given types but I am in doubt what exact subtype of bearings to use. While none of bearings is running in external grease bath I think that 2RS (both side double covered) would be okay. The doubt here if to stick with classic bearings (no mark but otherwise C2) or go with bearings for higher loads (dubbed C3) which also have slightly larger play.

So the question is: C2 or C3 bearings? I know that most of you probably use genuine parts or whatever whoever says it is compatible but hopefully someone was already doing any research on this topic. For engine parts there's no doubt that bearings should be for higher loads. I am not sure how much the play is larger and if this wouldn't have negative impact on riding stability or bearing lifetime.

[t6nis]

Does the original bearings have some sort of markings on it? If yes, you could find a datasheet for it, and compare the dimensions, load ratings, etc.

I would go with C3 just to be on the safe side.

[ventYl]

While tram lines in my city is torn apart and getting anywhere is just hell I cannot afford to dismantle the bike just to take a look at the bearings :( While there would be most probably SGP bearings I'm expecting just Suzuki ordering number).  AFAIK according to buddy who changed the bearings on '99 B12 the bearings are of standard play. Some aftermarket suppliers tend to sell C3 bearings.

The datasheets state that if bearing is of standard type then C3 bearing is unsuitable (neither for causes where play after mounting assembly together is important which I assume that motorcycle wheel is that cause) and due to various debates on the interwebs (which magically appeared in my google results only after I posted my own) motorcycle wheel is not far not suitable for using of C3 bearing by RPM nor load.

The dimensions itself are written in suzuki spare parts catalog and cross-checked by their ordering number where standardized bearing dimension is encoded in OEM ordering number. Like right rear wheel bearing ordering number is 08123-63037 with dimensions equal to standard 6303 bearing.

[Squishy]

Any info on what you said "apart from gearbox teeth pitting which is fairly normal for vehichles which were ran a lot under full throttle".

My 400 has a resonance/thumb felt through the footpegs in 3rd gear...

[ventYl]

I've seen this in review of Bandit 400 in some old motorcycle magazine (around year 2000). They dismantled the bike to the last screw and inspected every part of engine and / or drive train. They stated that there was no unusual damage (considering the km on the clock) other than slight gear sprocket teeth pitting. By their words the bike was used to ride on track (presumably under full throttle) a lot so gear had some hard times. Apparently it is nothing unusual to see slight pitting at sprockets under such conditions.

Apart from that, I've been researching my whining 6th gear and the result I've reached is that gearbox sprockets are either inset in groves in shafts or freely floating on bronze bearings. Three (in 6 gear gearbox) groove-seated sprockets (one of them is double-sprocked) are moving providing the shifting ability, the rest of them are freely floating. Both sprockets of 6th gear are freely floating on bronze bearings. If these bearings are off-tolerance it may result in noisy 6th gear but as friend of mine who repairs his own motorcycle and rides for a lot of years told to me - it should not cause any intermittent damage to gearbox. One of his own machines had this condition for more than 50 000 km with no damage.

While configuration of motorcycle 6 gear boxes is usually the same it is likely that other motorcycles will have problems with 6th gear if off-tolerance bearings are present.

[ventYl]

To close this up I went for Koyo 6203 2RS C3 in front and 6303 2RS C3 in rear wheel. Originally there were bearings with signle Z shield (except of rear right which was single rubber sealed) but at least on rear I think this is not the best option given the ability to collect dust.

[Squishy]

To close this up I went for Koyo 6203 2RS C3 in front and 6303 2RS C3 in rear wheel. Originally there were bearings with signle Z shield (except of rear right which was single rubber sealed) but at least on rear I think this is not the best option given the ability to collect dust.

Why did you go for C3 play on the bearings? It's not a crank

[ventYl]

Friend told me that some bikes do have C3 in bearing specs (I did not verify this) and guy at shop also told me that bike wheels need C3 specced bearings. I am not sure it is true but given the price and time needed to replace them I am willing to take the risk.