Project Katmandu: GS rebuild
- Thread starter pete.keys
- Start date
It would work for as long as the weld held out - same as the other methods. However if the weld failed then the remaining section wouldn't have the torsional strength required and it would fail too.
Bugbear
Registered user
Shep is right and welding a shaft in the middle of its length, however well done, can never be as strong as a new shaft, of the required length, splined (or interference-fit) and welded into the original ends.
IMHO, of course.
IMHO, of course.
Two alternative approaches that I've seen (probably on advrider).
1. Machining a larger diameter, longer spigot and corresponding couterbore on the mating half and then drilling the assembled shaft through the counterbore/spigot, make a tightly fitting pin which is a pressed in and then countersunk at each end and welded over. Once the alignment of the shaft is checked then the joint is fusion welded.
2. Internally splined sleeve which is fitted onto the original shaft using a pin as above and the splined end from a second shaft cut and fitted into the sleeve and bevel drive (left floating). There may be a BMW part from a previous model that can be used or modified to make this sleeve as it would be a difficult one off machining job.
No idea if these were more reliable.
1. Machining a larger diameter, longer spigot and corresponding couterbore on the mating half and then drilling the assembled shaft through the counterbore/spigot, make a tightly fitting pin which is a pressed in and then countersunk at each end and welded over. Once the alignment of the shaft is checked then the joint is fusion welded.
2. Internally splined sleeve which is fitted onto the original shaft using a pin as above and the splined end from a second shaft cut and fitted into the sleeve and bevel drive (left floating). There may be a BMW part from a previous model that can be used or modified to make this sleeve as it would be a difficult one off machining job.
No idea if these were more reliable.
Re. 1
I think that's how Pete's was done originally. The problem is that the cross-pin doesn't contribute much (if anything). The drive-shaft is not, as you know, of a great diameter so by the time you've allowed sufficient wall thickness to get a decent weld you end up with a spigot/counterbore diameter of 9 or 10 millimetres. If you then cross-drill the spigot for a pin, then what diameter pin are you going to fit? Certainly nothing that'll contribute to strength. What appears to have happened here is that the weld failed and the spigot tore in half around the cross-pin. IMHO whatever you do, with this basic method, if the weld fails the shaft is going to fail. Nothing else you do will save it.
Re. 2
Now this sounds like a good idea and it would certainly be fun to try. The problem with Pete's current modified swing-arm is that there just isn't room in it for any extra components. If there were, a simple sleeve, welded over the join, would probably solve the problem anyway.
Canuck
Registered user
Does moorespeed have any left... I know he just had a lot fabricated as I got one. SUrely the time and effort gone into getting it wrong just isn't worth it?!?
1000 miles up on project Katmandu
1000 miles of commuting are now under the belt of project Katmandu and I must say the bike is absolutely brilliant, and I am thoroughly enjoying riding her every day.
The engine that Richie built is just puuurfect. I had some low rev lumpyness that was infuriating around town in traffic. After a few attempts balancing the carbs with a vacuum gauge, with no improvement I eventually used the "shorting" method and now she runs much much better. Low down torque is awesome. At tick over she will quite happily run up the quite steep ramp between floors in the car park and will pick up smoothly from tickover to full rpm.
With the +10% gearing, quite happily sits at 85mph at 5,000rpm and I've now seen 120mph flat out
Handling is excellent and inspiring.
I have ridden a modern GS800 recently - project Katmandu is much much better and I wouldn't swap her for a new GS1200
Outstanding jobs..
- Headlight frame wobbles a bit and needs more rigidity
- Thinking of getting a talon 19inch front wheel built
- front brake upgrade of some sort
1000 miles of commuting are now under the belt of project Katmandu and I must say the bike is absolutely brilliant, and I am thoroughly enjoying riding her every day.
The engine that Richie built is just puuurfect. I had some low rev lumpyness that was infuriating around town in traffic. After a few attempts balancing the carbs with a vacuum gauge, with no improvement I eventually used the "shorting" method and now she runs much much better. Low down torque is awesome. At tick over she will quite happily run up the quite steep ramp between floors in the car park and will pick up smoothly from tickover to full rpm.
With the +10% gearing, quite happily sits at 85mph at 5,000rpm and I've now seen 120mph flat out
Handling is excellent and inspiring.
I have ridden a modern GS800 recently - project Katmandu is much much better and I wouldn't swap her for a new GS1200
Outstanding jobs..
- Headlight frame wobbles a bit and needs more rigidity
- Thinking of getting a talon 19inch front wheel built
- front brake upgrade of some sort
And lastly..
- Ride it to Katmandu
.
... In the meantime, how is like to ride around town?
I have the Moore speed pistons in my city r100, and find them great. Grunty and smooth, and in no way a stressful race engine.
But you have the full works engine with valve changes + taller suspension.
Saw your comment on the carbs, and am interested to hear more about how it feels as a daily commuter
Now I have sorted the carb balance out so that the bike is smooth from low revs she's great. She was a bit of a handful before that though. The torque of the engine is such that in top gear at 1500rpm if I open the throttle she'll put smoothly all the way... so she really is rideable. richie did all the right things, this isn;t a peaky top end race engine, its built for low down torque. My only remaining issue really is the clutch thats a bit too heavy. At some stage I'm going to put a lower 1st gear in and then I'll lighten off the pressure plate slightly at the same time.
I thinks that's a Nocandu
LOL: waiting for my mate to ride again before we go .. he got on a bike for the first time after his accident a few weeks ago but found it really painfull. he's an all year round, 30,000miles a year on a bike type of bloke and being off a bike for so long is killing him!!
And lastly..
- Ride it to Katmandu
Will be next year now I think, realistically. Should have ironed out all the issues and got a good few thousand miles on the clock by then so she'll be well bedded in..
bits go on ebay
Hiya
I blitzed my shed yesterday in spring cleaning mode and sorted all the stuff out to make way for, and contribute to my next project.
http://www.ebay.co.uk/sch/peterjkeys/m.html?_nkw=&_armrs=1&_from=&_ipg=25&_trksid=p3692
listed here on ebay, but make me a sensible offer, or if you need something to get you bike back on the road urgently and I'll remove
cheers Pete
Hiya
I blitzed my shed yesterday in spring cleaning mode and sorted all the stuff out to make way for, and contribute to my next project.
http://www.ebay.co.uk/sch/peterjkeys/m.html?_nkw=&_armrs=1&_from=&_ipg=25&_trksid=p3692
listed here on ebay, but make me a sensible offer, or if you need something to get you bike back on the road urgently and I'll remove
cheers Pete
I'd like the crash bars, oil cooler guard and the
Ignition control unit please Pete.
In a real rush right now, but give me an idea
of price you'd like and postage please.
Back in contact this evening!
Cheers
Roger
Ignition control unit please Pete.
In a real rush right now, but give me an idea
of price you'd like and postage please.
Back in contact this evening!
Cheers
Roger
I'd like the speedo please, how much?
Iv'e put a bid on the carbs
OMG what have i done - I put 32 items on ebay and now i've got messages on here and ebay coming thick and fast, so i don't know what to do and I don't want to piss anyone off....but I fear I will what ever I do 
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Probably best to leave 'em on Ebay, unless no current bids 
I'll outbid Mav anyway
I'll outbid Mav anyway
Probably best to leave 'em on Ebay, unless no current bids
I'll outbid Mav anyway
ohh yeahh!! I have £20 and not scared to bid all of it
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