i am gutted. i have an On One titanium frame for years that i love dearly. the left side Hope BB threads are part worn and the corresponding threads on the frame are similarly worn. it must have been loose in the shell. i thought titanium was supposed to be a tough material but it looks as if the titanium and aluminium threads have worn equally. has anyone any rescue remedies ? i spoke to Enigma who were very helpful, but said the shell could not be repaired. I tried a new BB in the shell but it has no grip and just pulls out

One option (though not for HT2 cranks) is this:

Zenith Threadless Bottom Bracket for Damaged Frames
http://www.velosolo.co.uk/shopchain.html

Replacement model for the older YST model stocked previously. These are a brilliant ‘get out of trouble’ product if you have a frame with damaged or stripped bottom bracket threads. Instead of the usual threading, the cups have tapering sides to fit snugly into the BB shell. One side of the BB threads onto the other side pulling the two halves together within the frame.

These are a much better quality than the YST with very smooth 6002 sealed cartridge bearings. Install with a standard Shimano splined BB tool (tool section 26BB-2A). Suitable for 68mm BB shell. Two choices of length at 110mm or 113mm. JIS taper. Note: some photos show older YST – the Zenith appear at the top

Otherwise, helicoils are available.

if you had an early Hope BB you may find that it came with fibre washers and they’ve ‘collapsed’…, mine did and have done the similar damage to my 456Ti 😥

Hope did replace the BB cups, and I bought new ceramic bearings (at cost).

I’m now using Deore BB’s as sacrificial items although have a Saint to put in next as they’ve longer threads (on the drive side).

FWIW Also occurred to a friends alloy frame and totally sha99ed his BB.

Can you not put something that’s totally servicable in there and bond it in?

Helicoils as nemesis said. There’s a couple of frame builders lister Ti repairs on the below list.

http://www.framebuilding.com/custom_uk_bicycle_framebuilders.htm

And BETD do helicoil repairs http://www.mountainbikecomponents.co.uk/items.asp?CategoryID=236&Name=Frame+repairs

I’d check the frame threads are gone, ti is way harder than alu.

I had exactly the same issue, I installed a Velo Orange threadless BB which has a square taper axle (so needs a new chainset). This worked ok for a while, but does tend to loosen. The real fix is a helicoil. I spoke to Bet’d and they said they could repair it with a helicoil, and this costs around £120…I ended up selling the frame on ebay with these faults mentioned…too much hassle.

thanks very much for the help guys. yes the threads on the frame are gone ( on one side only ), i found this amazing as i thought the strength of titanium would trash the aluminium treads first , but not so. i don’t completely understand the helicoil. have any of you direct experience of either of these options, the thread less bb is cheap to start but becomes dearer when i add the cost of 2 nd hand middle burn cranks

i don’t completely understand the helicoil

You have the Bb threads re cut slightly larger than normal with a special tool that cuts threads slightly larger diameter but with the same pitch. Then a coil is threaded into the new threads. Should be as strong if not stronger than the original threads.

I had the same thing in an aluminium Prophet frame. Threads on the drive side Hope BB cup and frame stripped.

Had the frame helicoiled by BETD who did a great job, I would definitely use them again.

thanks very much, helicoil it is then !
might get the frame polished at the same time

Let me know how it goes, I have an old ti frame this has happened to and it’d be nice to resurrect it!

Which bike is that Schmiken? You’ve not buggered the kingdom have you?

Another possible option would be a Saint BB. They have longer threads than most BB’s so may do the job

This [/Another possible option would be a Saint BB. They have longer threads than most BB’s so may do the job]+ get the remnants of the existing threads chased (recut) I’ve seen many frames brought back to Life this way

No Nath, it’s an old road frame at my mum and dad’s. Would be cool to get it working if it’s not too expensive though!

Just an update.
saint bb have longer threads on the drive side – therefore no use if the problem is non drive side.
nobody can thread titanium frame bottom brackets for helicoils
i bought one of these – ‘First threadless square taper bottom bracket’. it cost £40 from vernon barker. it appears to be a really well engineered, solid piece of kit, i applied loctite to the threads, it takes a bit of grunt to tighten completely home but now seems very secure. time will tell how it performs !

FWIW, the RaceFace 100mm Bottom Bracket (available for Fatbikes) has very long threads on both drive and non-drive sides. You’d have to leave off the plastic tube in the middle, or shorten it to suit, but it’s another potential solution

The Saint has now gone into mine, as the previous Deore BB gave up.

Are you sure the ti threads aren’t just bunged up with ali swarf?
APF

I think I would just bond in a hope bb and change the bearings.

As above I used loctite to bond a hope cup in and also removed the bottom bracket spacer to get a bit more purchace.

Bolt

Are you sure the ti threads aren’t just bunged up with ali swarf?

This. Failing that I’d sooner helicoil than start bonding BBs in.

What andyl says its no different to Tha alloy cups bonded into carbon frames a bb shell is 24tpi which is a pretty fine thread for its diameter and a properly designed helicoil wont have much meat on it tbh

In very expensive CNC machines where spares are unavailable fix is to remove/machine the old thread and put the housing centred around the thread, inject replicating epoxy around it this recreates the threw and pitch to microns and is used for years after ,its a leadsctew so is designed to resist wear, its also a technique we use in composites/bikes for forming bearing fits and threads in carbon