BB Cups Just Won't Thread

[Bob Loblaw]

So I'm building up a bike for a friend, a Litespeed Xicon.

The bottom bracket cups are used SRAM cups, but they turn smoothly and appear to be in fine shape. However, they just won't thread in to the BB shell. If I fiddle with them long enough, the threads catch, but after 3/4 of a turn or so it stops cold. Application of torque increases resistance so that within an additional 8th of a turn I lose my nerve.

I've confirmed that the BB shell is 68mm, and the cups are reverse threaded on the one side, so I am pretty sure I'm not trying to thread Italian into English or vice versa. I've cleaned the threads thoroughly but haven't chased them (no machine shop tools...I'd have to farm that job out). The cups are labeled drive- and non-drive-side, and I've triple checked I've got that right.

For the life of me it seems like there's a thread compatibility issue, but I can't imagine what I could be dealing with.

The frame is brand new, but not in great shape. The dropouts are bent so badly that right now I can't even get the rear wheel in.

Ideas?

TIA

BL

[AngryScientist]

sounds like you need the threads chased. Ti can be tricky...

[AngryScientist]

edit: just re-read the last bit.

why are the dropouts bent???

it's certainly conceivable that if the frame was mishandles to the point of bending dropouts, the BB could have been flexed to the point where it is now out-of-round, torqued, or out-of-parallel, this could definitely lead to a no thread match situation.

[Bob Loblaw]

Beats me. The frame still has the warehouse tag on it. I'm sort of concerned that it's been abused as you suggested. Even if the threads need to be chased, the BB should thread in farther than this, at least on one side, but both sides seem uniformly mismatched. It definitely seems something is amiss.

edit: just re-read the last bit.

why are the dropouts bent???

it's certainly conceivable that if the frame was mishandles to the point of bending dropouts, the BB could have been flexed to the point where it is now out-of-round, torqued, or out-of-parallel, this could definitely lead to a no thread match situation.

[ultraman6970]

That the frame has tags on it, doesnt mean it was chased. Many frames back in the day were not chased again after the paint job.

Find a shop as close as posible and take that to be chased because to have a BB shell busted is not funny thing.

[CNY rider]

So I'm building up a bike for a friend, a Litespeed Xicon.

The dropouts are bent so badly that right now I can't even get the rear wheel in.

Ideas?

TIA

BL

I wouldn't let my one of my friends ride this thing.

[salem]

I wouldn't let my one of my friends ride this thing.

First, I'll second that, at least not without having the alignment checked. I wouldn't waste time with the BB before you address the bigger issue. At that point, if the person doing the alignment says the BB threads are the wrong pitch (not sure how that would happen, but I have seen it), you could salvage it will a threadless bottom bracket--it threads on itself for use in damaged frames. Usually, these are square taper only, but this system worked very well for years and still does.

[oldpotatoe]

So I'm building up a bike for a friend, a Litespeed Xicon.

The bottom bracket cups are used SRAM cups, but they turn smoothly and appear to be in fine shape. However, they just won't thread in to the BB shell. If I fiddle with them long enough, the threads catch, but after 3/4 of a turn or so it stops cold. Application of torque increases resistance so that within an additional 8th of a turn I lose my nerve.

I've confirmed that the BB shell is 68mm, and the cups are reverse threaded on the one side, so I am pretty sure I'm not trying to thread Italian into English or vice versa. I've cleaned the threads thoroughly but haven't chased them (no machine shop tools...I'd have to farm that job out). The cups are labeled drive- and non-drive-side, and I've triple checked I've got that right.

For the life of me it seems like there's a thread compatibility issue, but I can't imagine what I could be dealing with.

The frame is brand new, but not in great shape. The dropouts are bent so badly that right now I can't even get the rear wheel in.

Ideas?

TIA

BL


Have a good bike shop chase the threads. I use dish washing liquid soap when I chase titanium..prevents galling and sticking. It is titanium? Or aluminum?

[fourflys]

I'd be taking the frame back to where it was purchased... sounds like something happened to it... I have Xicon and had none of the issues you're speaking of...

[Bob Loblaw]

Thanks all, for the replies.

I tried three different BB's, none of them would thread farther than half a turn or so, so I took it to a shop to have it chased...they couldn't do it either. Their assessment was that the threads are incorrectly cut, so the frame is on its way back to Litespeed for an RMA.

Apparently my friend bought it from some guy on eBay for a "very good price." My guess is the seller was dumpster diving outside Litespeed or buying factory seconds or something and eBaying his finds. We'll see what Litespeed has to say.

Caveat emptor...if it sounds too good to be true, it probably is.

BL

[GuyGadois]

Well, there is always the Mavic BB solution which doesn't need threads at all. But, with the dropouts bent, I would be hesitant to ride it all unless the fix is simple...

Gadois

[Bob Loblaw]

Yeah exactly. That's pretty much the only way I can see this bike becoming road-worthy.

I'm betting the poor guy is going to end up shelling out some cash to make this right, or selling it for a loss.

Well, there is always the Mavic BB solution which doesn't need threads at all. But, with the dropouts bent, I would be hesitant to ride it all unless the fix is simple...

Gadois

[fourflys]

any idea what the guy paid for this? I know I paid $1500 (MSRP) for my frame/fork/HS...

just curious...