Home › Forums › Bike Forum › Replacing HTII BB bearings, help please.
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Replacing HTII BB bearings, help please.
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toys19Free Member
I duuno which alloy the KTM engine casings are made of so I can't comment, but I know that some shimano cups are 6061 t6 and some raceface ones are 7050 T736. Heat them to 200 degrees and you will lose a good deal of the yield strength. Don't do it kids.
neilnevillFree MemberThe shimano cups have an annoying lip (in one side at least) that hides the bearing from any socket that you try to use and drive the bearing out with. You can get to it with a flat bladed screw driver and although its a fiddle, it will come out with patience (it isn't all that tight a fit) Once out, I filed a couple of flats out of the lip to make it easier to use the screw driver to drive the bearing out next time. i thought about taking the whole lip off to allow a socket in, could see no reason for the lip….but bottled it and just put a couple of flats for the screw driver access.
Oh and note that the shimano cups are NOT all the same. XT, XTR and Saint (I think) have a slightly larger external diameter bearing than lx, hone etc. The different thickness in the outer wall of the cup is easy to see if you compare the two types. So choose your replacement bearings carefully.
banjowhackerFree MemberHeat them to 200 degrees and you will lose a good deal of the yield strength. Don't do it kids.
Really? You can safely powdercoat 6061 t6, which means heating it up to 200 degrees for an hour or less. In order to help pop some bearings i would have thought they'd only need to be in an oven for 5-10 mins. Sounds messy though with all that plastic and grease…
bigyinnFree MemberCould just be a thicker cup shell to cope with the higher loads likely to be exerted on the cups in Hone and Saint. AFAIK they all use 6805 / 618052RS bearings.
toys19Free Memberbanjowhacker – Premier Member
Heat them to 200 degrees and you will lose a good deal of the yield strength. Don't do it kids.
Really? You can safely powdercoat 6061 t6, which means heating it up to 200 degrees for an hour or less. In order to help pop some bearings i would have thought they'd only need to be in an oven for 5-10 mins. Sounds messy though with all that plastic and grease…
Banjowhacker I would prefer to say that you cant safely powder coat 6061 T6, see this thread. If you want to know more send me an email address in profile. I think your right about the mess though, hadn't thought of that…
neilforrowFull Memberanyone got a picture of the betd / goldtech press… I want to see one before I buy it… (I have phoned them and the fella said he would text me a photo.. hasnt turned up)
could someone either post it up here or email it to me… neilforrow(at)hotmail.com
cheers
toys19Free Memberneilforrow
– mine arrived this morning. It doesn't have the collet thing to get in behind any bearings the have the same id as the bearing cup inner id.But betd supplied me with a little clip that kind of helps, but I needed to use a screwdriver and hammer to make a gap between the bearing and cup, just pushed the bearing out by 0.5 mm or so and then the clip fitted in behind fine, then using the press tool on the clip a quick bump with the rubber mallet and the old bearing popped out. Fitting new bearings went easy. I'll post some picks when I get home tonight.neilforrowFull Membertoys19 – cool, thanks.. is it a quality tool, ie worth the money?
toys19Free MemberOk here is the tool, left to right starting at the top:
1)new bearing tool for pushing in new bearings. Smaller dia of this is near 24mm so that the enduro bearing sits nicely on it.
2) Cup holder. use your imagination..
3) old bearing extract tool.bottom left to right
4) clip thingy only needed if you have a 25mm id bearing and bb cup like 5) below
5) race face bb cup, inner dia of cup is close to 24mm so the edge of the bearing is nearly hidden. so use a small screwdriver and hammer to shift the bearing enough to get the clip in there, then put the cup in the cp holder and using the extractor tool and rubber mallet push on the clip and bearing pops out..
6) is an fsa mega exo bb with a much larger bb cup inner dia so you can see lots of bearing inner edge, so just use the extractor part , with cup in the holder and rubber mallet application.next foto is an angled shot of the bearing cups to show the difference, you can clearly see the raceface cup on the left where the bearing id is really close to the cup id which makes pushing it out a bit tough until there is a big enough gap to get the clip in. FSA one will be a dream…dunno what shimano or other cups look like maybe someone could post piccies?
I've had acouple o shandies so spelling and syntax might be wide of the mark.
carlphillipsFree Memberivebeen using my betd tool for ages, its very handy and has saved me loads of money
bigyinnFree MemberHad a try at getting the old bearings out of their shimano cups yesterday. Didnt fancy oven baking the cups to get the bearings out, so i put them in an old baked bean tin and boiled them for 5 mins!
This expanded them enough to hammer the old ones out reasonably easily. I can see the tool would do it better though!
One thing i am going to do before i press the new ones in, is to file the internal shoulder down in the cups at 90 degree intervals to make getting the next set of bearings out easier…nedrapierFull MemberNeeded new HT2 bearings, looked on betd site as per advice on here.
Ticked the "yes, I'm sending my cups for free fitting of bearings" box.
Posted my cups with seized bearings to them on Tuesday lunchtime, they've just arrived at my desk now with the new bearings fitted.
Yay for betd. Cheers!
Edit: for people reading this much later, that's less than 48 hours since I posted them.
cookeaaFull MemberI’ve just ordered some cheap ebay bearings to do my spare BB…
It struck me though how ironic it is that I’m having to do this at all pissing about with bearings on what is apparently the apex of MTB Crank/BB technology…
Correct me if I’m wrong but don’t the current HT2 Road cranks use a 19mm (3/4”) axle? In fact doesn’t the DXR (Shimano’s massively expensive BMX HT2 Cranks), I Don’t own either of these but I can’t imagine that crap bearing life would go down well with serious roadies, are Road HT2 cranks similarly harsh on their bearings?
I seem to remember seeing pic’s of Nicco’s bike from the mega a couple of years ago, equipped with road cranks, or am I mistaken?
Why the fudge do we actually need a 24mm axle on all HT2 MTB cranks?
toys19Free MemberIf the cups are the same size 37mm and the spindle is smaller 19 down from 24 then the bearing will be bigger and likely to last longer…
neilforrowFull MemberI have now swapped out the bearings, (and the betd tool is spot on) however…
the 6805's i have a 7mm wide, the ones that came out are 6mm wide…
have done some googling and cant seem to find any (apart from ceramic uber pricey ones) and my bearing supplier doesn't do them.
It means the plastic cover doesn't seat properly and I cant get the 2nd seal to seat…
Anyone else had this prob..??.. can I just do away with the plastic cover?
DelFull MemberNeil,
the shimano system relies on the 'top hat' bits not only to provide additional external seals, but also to space between the inner race of the bearings and the crank axle. if you try to fit the cranks without it, you will find you have about 3mm play in the assembly 🙁
good luck fitting with the top hats. i'm sure it can be done though. the enduro bearings are sized so that they fit directly to the crank axle. ( they're probably the same width as the shimano ones too i expect ).DanFree Memberif the bearing is 7mm wide instead of 6mm, just remove 1x 2mm spacer from the system and all should be the same except the plastic covers will stick out from the shell a wee bit more. I have no idea if this will cause issues in the long term but it seems to make sense.
bigyinnFree MemberIIRC the older HT2 BB bearings were 6mm, newer ones, i think, are 7mm.
will need to check tonight as my bearings turned up on monday and i havent even looked at them properly yet!neilforrowFull MemberDel:
"if you try to fit the cranks without it, you will find you have about 3mm play in the assembly" – Ass.
Oh (you probably guessed) Hannah 'popped' 2 weeks ago… hense not out on the bike… dont think I will be doing Wed night rides for a few weeks yet! FYI – Baby Boy – 7.4lbs called Torr. Enjoying every minute.
Bigyinn, could let me know if the new ones are 7mm that would be great…. if not it looks like I will have to shell out £20 for the enduro bearings.
JengaFree MemberIIRC the older HT2 BB bearings were 6mm, newer ones, i think, are 7mm.
Spot on old bean. There are two different depths of cups out there. Enduro bearings fit both, but most shop bought ones are 7mm thick and don't fit the older cups, without standing proud. Not a lot you can do if you have the older cups.
Also, Enduro bearings are a closer tolerance and don't need the top hat. And they do seem to last longer, at least they do on my very un-scientific research.
neilforrowFull MemberLooking into this a bit closer, I can get the enduro bearing kits for around 9.80 each. But there is postage on top… (about £10 per order)
Anyone fancy a group buy to keep the cost down? ie get several sets for £10 each.
I have 3 bikes running this system, so it is worth while in the long run.
DelFull MemberNeil,
congratulations mate! i'll pass the word!
i think 'well done' is the term…. 🙂does that £10 include the external seals? if so you can put me down for a few sets. EDIT – that's 3 off pairs.
we'll need to talk about those seatposts when you have time too, assuming that's still a go-er. give me a week or so to talk to everyone and get firm numbers.neilforrowFull MemberDel, yep its the whole set, seals en' all. Will get a final cost once I know numbers.
seat posts are still a goer, I just got one in for will and several for my brothers mates… let me know.
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