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• #1252
I like my BB low. Nothing wrong with that. I am just saying 270 aint that high. Also depends on the wheel base. My cargo bike suffers badly from pedal strike, but it isn't a problem if you know it's a thing
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• #1253
My cargo bike suffers badly from pedal strike
Those flat MTB pedals need a lot of clearance don't they. Now you'll know for the next one!
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• #1254
Yes for sure. BB is at 265mm I think. Turning with such a long wheel base seems to mean I get quite close to the ground. SPARKS have been made ;-)
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• #1255
AS @PhilDAS says, I think if I find a correctly dimensioned 4130 straight tube I should be able to make it work with some off the shelf headset parts. The trouble with a 44mm HT is that it doesn't leave much room for the rear brake hose to wrap around the steerer.
I asked a Chinese CNC company and they quoted me $220 for a fully custom machined headtube which will just take the drop-bearings. Not crazy expensive once you factor in the cost of headset cups etc. Obviously, it's expensive if you fuck it up and have to order a second one... -
• #1256
A second one would be cheaper if you ordered them at the same time though... Half the cost is in the set up
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• #1257
Yes, most definitely. Time for a list ;)
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• #1258
haha im keen, sounds cool
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• #1259
Haven't properly dimensioned it, but it'd be something like this.
1 Attachment
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• #1260
Had a call with TBA yesterday to discuss my course which was generally positive, as in they're willing to help with my ideas but not take responsibility if they don't work (fair enough).
I might abandon the wishbone in favour of concentrating on the headtube as the key feature and not messing that up.
As a backup headtube option, I was looking for just some plain gauge tubing that might come in a suitable diameter and wall thickness, i.e. 58mmOD, 2mm wall. Anyone know of a good source? -
• #1261
What's your vital dimension?
LASAero don't do 4130 that large, Aircraft Spruce do 2 1/4" or 2 1/2" but choice of wall thickness is pretty limited at that diameter.
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• #1262
Ideally, the finished piece should have 62mm OD, 55.95mm ID at the ends. I can machine the outside to remove some weight in the middle of the tube.
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• #1263
2.5" x 0.12" wall thickness from Aircraft Spruce is pretty damned close?
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• #1264
Talking headtubes, what's the deal with mitreing a downtube to meet a tapered headtube?
Having only done straight headtubes it seems like doing a tapered one will be hella difficult but maybe I'm over thinking it?
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• #1265
yeah they look awkward. Ive wanted to do one for a bit but havent got round to it. Also are there tapered heatsinks out there for tiggin?
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• #1266
Is it boric acid that some people use as flux?
I knows its something acid!
I tried it a while ago and wasn't overly enamored but fancy trying it again just for dipping my rods in.
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• #1267
Yep, that's the stuff. Matt swears by it. Never tried it myself.
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• #1268
Cheers.
Just grabbed some off ebay.
I remember when I was trying to make a paste with it it just didn't want to go where I wanted it to. Hopefully it sticks to a hot brass rod ok!
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• #1269
A drop of washing up liquid helps.
I find it a right faff to wash off. Not sure if money saved on it, works out cheaper than time trying to get it off. I probably bake it on a bit much.
If this is correct Merckx's bike at that time was on 265. If that's good enough for cornering when racing, with clearance required for wide pedal and cages, does a rando bike really need a higher BB (I understand it'll be just fine)?