ULtrialsguy Posted October 25, 2012 Report Share Posted October 25, 2012 So guys I recently got fed up with my old frame, an onza t-rex, who wouldn't like. Anyway I saw a neon bow frame for sale on here and promptly bought it for a good deal I must say. Thank you Seabasss for that. So I then also had to get snail cams as my old one had a tensioner. This was fine as I knew I needed one. Then when it arrived I realised that my old frame had an internal headset and the bow needs an external one so I had to buy a new headset and I bought a new stem at the same time to compensate for the different geometry. Sooo today I finally got round to putting everything onto the frame and when putting on my expensive middleburn cranks I found that the crank hits off the frame on one side and barely clears it on the other side. This clearly isn't going to work. Also I just bought a new BB a few weeks ago when my old one snapped and the new axle is pretty much as wide as you can get. So am I going to have to get new cranks to make it work? I really don't want to because I've pretty much spent all my money on everything else. Advice please.. Quote Link to comment Share on other sites More sharing options...
ChrisTrials2012 Posted October 25, 2012 Report Share Posted October 25, 2012 I reckon selling or trading those middleburn/ bb combo for an ISIS modern system would be a good idea. Middleburns are quite sought after so you should have no problem selling. Quote Link to comment Share on other sites More sharing options...
Blake Posted October 25, 2012 Report Share Posted October 25, 2012 You could grind off some of the crank, just a few mm to get it to clear. Quote Link to comment Share on other sites More sharing options...
ChrisTrials2012 Posted October 25, 2012 Report Share Posted October 25, 2012 You could grind off some of the crank, just a few mm to get it to clear. But what if under pressure during a rotation it bends and hits, plus grinding a crank seems a bit risky. Quote Link to comment Share on other sites More sharing options...
Blake Posted October 25, 2012 Report Share Posted October 25, 2012 I don't think your middle burns are going to bending much. . . Picture of where it's hitting, and will be able to tell you if it's safe. Quote Link to comment Share on other sites More sharing options...
ULtrialsguy Posted October 25, 2012 Author Report Share Posted October 25, 2012 Ok the grinding idea might work but I'll just check again and try and get a pic or two. I think quite a bit would have to be removed to make it clear. Quote Link to comment Share on other sites More sharing options...
ChrisTrials2012 Posted October 25, 2012 Report Share Posted October 25, 2012 I don't think your middle burns are going to bending much. . . Picture of where it's hitting, and will be able to tell you if it's safe. They're not mine, just thinking in terms of you could grind the cranks, reduce resale value, then find it hasn't solved the problem. Quote Link to comment Share on other sites More sharing options...
Martin Reynolds Posted October 25, 2012 Report Share Posted October 25, 2012 i had a similar issue on my born running tensile cranks. I got around it by putting a small washer between the crank and where the crank buts up on the bb. Quote Link to comment Share on other sites More sharing options...
Blake Posted October 25, 2012 Report Share Posted October 25, 2012 They're not mine, just thinking in terms of you could grind the cranks, reduce resale value, then find it hasn't solved the problem. Well you wouldn't do it unless you know it's fixed the problem. And a lot of problems like this have come up since people started going high BB. Quote Link to comment Share on other sites More sharing options...
ChrisTrials2012 Posted October 25, 2012 Report Share Posted October 25, 2012 Well you wouldn't do it unless you know it's fixed the problem. And a lot of problems like this have come up since people started going high BB. how does the BB rise affect it ? Quote Link to comment Share on other sites More sharing options...
Martin Reynolds Posted October 25, 2012 Report Share Posted October 25, 2012 how does the BB rise affect it ? Moves the cranks closer to the brake cylinders 1 Quote Link to comment Share on other sites More sharing options...
ULtrialsguy Posted October 25, 2012 Author Report Share Posted October 25, 2012 Right here you go, had to use my phone so probably not great quality. First of all heres the clear side. Then heres the side thats catching. From above. And with crank below. Quote Link to comment Share on other sites More sharing options...
Blake Posted October 25, 2012 Report Share Posted October 25, 2012 grind off that corner maybe? Quote Link to comment Share on other sites More sharing options...
ChrisTrials2012 Posted October 25, 2012 Report Share Posted October 25, 2012 what about the brake cylinder? will that catch if he grinds the corner? Quote Link to comment Share on other sites More sharing options...
Martin Reynolds Posted October 25, 2012 Report Share Posted October 25, 2012 grind off that corner maybe? I found that even on my born frame, with a stupidly stiff back end, my cranks wouldnt hit if you rode normally, but when i put the power down i could flex the back of the frame and hit the cylinder with the crank. I expect he'd have the same issue considering they run that close. I'd advise selling your burns and get new cranks. Burns are sought after, and to be honest you could be left with money in your pocket if you sell them and buy some cranks with more offset 1 Quote Link to comment Share on other sites More sharing options...
N.Wood Posted October 25, 2012 Report Share Posted October 25, 2012 Cranks do bend. My Try-all CNC's have about 3mm of clearance fronm the brake cylinder and I ground off about 2mm from the crank and under heavy uphill run ups on grass / shit it still hits. What bb do you have? Quote Link to comment Share on other sites More sharing options...
Martin Reynolds Posted October 25, 2012 Report Share Posted October 25, 2012 Cranks do bend. I always thought it was the frame that flex'd? Quote Link to comment Share on other sites More sharing options...
ULtrialsguy Posted October 25, 2012 Author Report Share Posted October 25, 2012 I have a trialtech BB with 127.5mm axle. Also does anyone know if the middleburn cranks have changed at all in the last few years so I could check the offset as mine are fairly old. Quote Link to comment Share on other sites More sharing options...
bike_dummie Posted October 25, 2012 Report Share Posted October 25, 2012 File the crank like the try-all crank below (at the end near the pedal thread) Quote Link to comment Share on other sites More sharing options...
Martin Reynolds Posted October 25, 2012 Report Share Posted October 25, 2012 I have a trialtech BB with 127.5mm axle. Also does anyone know if the middleburn cranks have changed at all in the last few years so I could check the offset as mine are fairly old. I dont think they've changed at all. They were designed ages ago, so they dont have much offset compared to trials oriented cranks Quote Link to comment Share on other sites More sharing options...
BradJohnson Posted October 25, 2012 Report Share Posted October 25, 2012 i have some Tryall Cranks for sale £40 posted mate. Quote Link to comment Share on other sites More sharing options...
ULtrialsguy Posted October 25, 2012 Author Report Share Posted October 25, 2012 (edited) i have some Tryall Cranks for sale £40 posted mate. Aren't they £40 on Tarty anyway? Unless they're the expensive version but they only have 3mm of extra offset whereas echo cranks have 6mm of extra offset. Edited October 25, 2012 by ULtrialsguy Quote Link to comment Share on other sites More sharing options...
Martin Reynolds Posted October 25, 2012 Report Share Posted October 25, 2012 Aren't they £40 on Tarty anyway? Unless they're the expensive version but they only have 3mm of extra offset whereas echo cranks have 6mm of extra offset. im pretty sure he means £40 for a pair of the expensive ones, whereas its £40 for one on Tarty Quote Link to comment Share on other sites More sharing options...
BradJohnson Posted October 25, 2012 Report Share Posted October 25, 2012 Aren't they £40 on Tarty anyway? Unless they're the expensive version but they only have 3mm of extra offset whereas echo cranks have 6mm of extra offset. They're the expensive one's you burke. Quote Link to comment Share on other sites More sharing options...
Rockman Posted October 25, 2012 Report Share Posted October 25, 2012 They're the expensive one's you burke. He thought you meant these.. which are £40.. http://www.tartybikes.co.uk/cranks_pair/tryall_expert_isis/c514p11216.html 1 Quote Link to comment Share on other sites More sharing options...
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