Reached the limit of my brompton..

[cwah]

Finger crossed again. I hope the DP420 can save the game tomorrow morning when I'll go to work...

 

[hech]

Cwah, two hours is a long time drfilling for oil. You don't need a hammer drill, you need a brain surgeon.
Also a cobalt drill bit of various sizes and a fixed drill press, some large leather gauntlets and eye protection goggles. By the way I love your show.

 

[cwah]

My drill bit is HSS Cobalt. Same issue, it wasn't drilling properly.

And I don't see how I can use a drill press on the front side of my brompton..

 

[jackhandy]

Hard luck, cwah (pun intended);
Sounds like the bolt was work hardening as you tried to drill it: I've had bolts do that to me in the past, particularly some grades of stainless seem to do it, if the drill heats instead of cutting proper.

Reading the various metal butchering methods of getting the stub of a bolt out was interesting - I feel better about some of the ways I've tried in the past now: Down here it's known as "Hammer & Drash" methodology

 

[cwah]

Hopefully I have the spare brompton I quickly bring it back to work. (Thanks John )

I think it's probably better to wait 24h to let the DP420 to cure completely (24H at 24C). Will see tonight if the glue is as strong as people says.

 

[neptune]

It is a fact that broken stud extraction is a task that separates the men from the boys. I do not believe that anyone in the history of the world has ever successfully used a stud extractor. I would take the job to a local engineering works to get it done. Cheaper than a new bike. As regards rounded alan bolts, if the head is accessible, they can often be turned with a pair of mole grips.

 

[jerrysimon]

This failure on a Brompton of this part is well recorded elsewhere, so may be worth searching on line.

The front carry block works really well and I know hindsight is an easy thing, but keeping the bolts tightened is important more so if you are carrying heavy loads. If one becomes lose then failure is inevitable.

I tend to use some thread lock to help them vibrating lose but again always check them every six months or so.

PS my original EBrompton is just coming up to three years of my daily commute and 4500 miles

Regards

Jerry

 

[cwah]

Thanks Jerry and Neptune.

I unfortunately already messed up with my thread so only glue can help now...

I haven't cycled with my Direct drive motor brompton since many months now... I'm pleasantly surprised how smooth it is. Acceleration is rubbish, but at the same time it's so quiet and smooth.

Direct drive on brompton feels like taking a train... I can sleep while hearing at the wind music. Whereas with the geared mac 8T it feels like a Kart. More adventurous but also quite tiring.

For long journey the direct drive makes sense actually, just to appreciate the journey and for peace in mind.

 

[morphix]

That's sad news about your Brompton I hope you can fix it. If it can't be fixed, it will have a good scrap/salvage value I bet?

 

[cwah]

I'm sure it can be fixed. Worse come to worse I'll bring it to a car shop and ask them to weld me an extension.

The bike worth too much to me to be sold

 

[eddieo]

I remember your original photos when you started on this, frame looked pretty old as it was,maybe its just fatigue..most bikes don't last forever. Trying to extract a sheared of toughened steel bolt from a soft steel frame not to easy....maybe a heart transplant to fresher and younger doner bike? If welding don't work....

 

[morphix]

I remember your original photos when you started on this, frame looked pretty old as it was,maybe its just fatigue..most bikes don't last forever. Trying to extract a sheared of toughened steel bolt from a soft steel frame not to easy....maybe a heart transplant to fresher and younger doner bike? If welding don't work....

Yeah sometimes the individual parts of high value items are worth more than the sum total in a broken state.. it might be worth dismantling and selling off the parts on eBay and then using the money towards a newer bike if welding doesn't do it.

 

[oigoi]

After thousand of miles, my Brompton finally reached its limits.

The front bloc bolt snapped and the 14kg battery bag was hanging with only 1 bolt remaining. I decided to completely remove the bag and attach it on my rear rack.

It was the most awful journey back home I ever had. 4 miles with winds and uphills (I had to walk when I reach uphills)... I'm now sweating and tired.

Brought my bike to a bike shop and they told me there is nothing they can do because half of the bolt is inside the thread.. I have to bring it to a car repair...

Damn, these bicycle shop have never been useful for anything...


Going to use my drill and re-thread the snapped bolt... Fingers crossed.

CWAH I have had to drill out a lot of sheared bolts, including stainless steel & hardened ones, and I find the most reliable method is to use cobalt drill bits, start off with a 3mm and go up from there until you reach the tapping drill size for the bolt concerned

 

[shemozzle999]

I'm sure it can be fixed. Worse come to worse I'll bring it to a car shop and ask them to weld me an extension.

The bike worth too much to me to be sold

It might still be salvagable Cwah, dependant on how far your efforts enlarged the hole, ask your car shop whether it would be posible to heli-coil the frame (a type of thread insert to repair cross threading ).
Have a look at the block also and see if a larger diameter bolt could be used, that would increase the strength of the repair

 

[Scimitar]

I've never successfully got a broken bolt out with one of those extracters. Each time I tried, the extracter broke, and then it's impossible to proceed because the extractor is hardened and can't be drilled. i think it's much safer to drill-out the broken bolt.

Exactly.
If were to sit down and design a way of leaving a high-carbon steel insert in a hole, the stud extractor would be the way to do it.
Utter, utter, crap. I think I've used them half a dozen times successfully in a lifetime of being careful with them. Well, after the breakages it's easier to just forget about them and go for the drilling-out process every time.
There's only one make I'd trust - Snap-On; every other make is crap. Even the Snap-On ones break sometimes - it's a very hard-won feel you develop for them. And once the extractor is broken in the hole, often the only way out of that fix is spark erosion.
In short - stud extractors - work of the devil.
Forget about them.

 

[cwah]

DP420 doesn't work. It's not strong enough....

Last chance... the car welding shop

 

[shemozzle999]

Heli-coiling video - don't try to do it yourself - get a car shop to do it.

How to Repair Threads With A Heli-Coil Insert - YouTube

or a UK version

http://www.youtube.com/watch?v=sQHRB2ElZJ0&feature=fvwrel

 

[shemozzle999]

Its a shame I did not see this video earlier:

Remove a broken bolt using a left handed drill bit - YouTube

p.s. on re-reading my previous post it might appear I am being a bit harsh but the only reason I wrote it that way is because it might be the last chance for you to reinstate the frame back to its original condition and a feel it might be wise to allow an experienced engineer to carry out the procedure.

 

[Old_Dave]

Another method if the left handed drill doesn't work, is to use a left handed bottom tap.. Then cut the head off a bolt and turn it upside down, weld on a nut or use 2 nuts to lock and wind it down.. But of course it helps if the task hasn't been already got at, lol

If the job frightens your local 'garage' and your willing to pay for the courier then your welcome to send it up to me


Sent from my iPhone using Tapatalk

 

[cwah]

I tried some industrial super glue to see if it works better than the dp420. Will see how it goes.

Next step is indeed the car shop. Welding is required as the level of damage on the thread is quite extended (imagine 2 hours using a hammer drill on a thread...)

Thanks for the proposition old dave, hope I'll manage to do it myself