Franksx2005 Posted October 11, 2011 Report Share Posted October 11, 2011 I recently sold a set of trialtech forks, the buyer messaged mr to say he thought they look bent so he measured the wheel base then put his old pair of forks back on (also trialtechs) and he says there is 20mm difference. Is this possible? I was under the impression that they would crack/ snap before they do that. You knowledge would be helpful, thanks Quote Link to comment Share on other sites More sharing options...
forteh Posted October 11, 2011 Report Share Posted October 11, 2011 20mm would be a pretty visible bend on a set of forks, it isnt impossible for alloy forks to bend but it is far more likely for them to crack or snap, particularly with forks as stiff as trialtechs. I would guess that the difference in wheelbase could be human error. If they have bent you would typically see stress marks in the anodising. Best way to compare the forks would be to lay them side by side on a flat surface and take a photo of the steerer tubes, that way you can clearly see if they are radically different. Quote Link to comment Share on other sites More sharing options...
Luke Rainbird Posted October 11, 2011 Report Share Posted October 11, 2011 It's not unheard of, though it'd take a bit of a tank to bend a set of Trialtechs. I bought a set of Ashtons years ago, only to put them on and find my 1060 Control suddenly had an 1100mm wheelbase! Quote Link to comment Share on other sites More sharing options...
Mowgli Posted October 11, 2011 Report Share Posted October 11, 2011 Hi All, I am the buyer in question. I only noticed the deformity when I put the forks on and the leg doesn't follow the line of the steerer. When i took the forks back off i layed them next to my trial techs and from the crown down was slightly raked backwards. If i get a chance this evening i shall try and take a photo. I have not noticed any cracks or stress marks on the fork but I will check the top of the crown tonight. Regards Quote Link to comment Share on other sites More sharing options...
Mark W Posted October 11, 2011 Report Share Posted October 11, 2011 I recently sold a set of trialtech forks, the buyer messaged mr to say he thought they look bent so he measured the wheel base then put his old pair of forks back on (also trialtechs) and he says there is 20mm difference. Is this possible? I was under the impression that they would crack/ snap before they do that. You knowledge would be helpful, thanks They changed the geo of the forks a little which might account for some of it, but 20mm seems like a lot... Quote Link to comment Share on other sites More sharing options...
Mowgli Posted October 11, 2011 Report Share Posted October 11, 2011 They changed the geo of the forks a little which might account for some of it, but 20mm seems like a lot... Hi Mark, Do you know what the geo change was? As my original set of trial techs had a cable quide for the front brake yet the ones i purchased of Frank did not. Thanks Quote Link to comment Share on other sites More sharing options...
Franksx2005 Posted October 11, 2011 Author Report Share Posted October 11, 2011 Like, could you measure the rake on the forks I sold you? Quote Link to comment Share on other sites More sharing options...
Mark W Posted October 11, 2011 Report Share Posted October 11, 2011 Yeah, you definitely had the old ones then! They would've been around 45mm. The newer ones are 40mm. Quote Link to comment Share on other sites More sharing options...
Mowgli Posted October 11, 2011 Report Share Posted October 11, 2011 Would you recon the best way to measure the rake would be to lay them on the floor and measure from the floor to the dropout? Quote Link to comment Share on other sites More sharing options...
craigjames Posted October 11, 2011 Report Share Posted October 11, 2011 Would you recon the best way to measure the rake would be to lay them on the floor and measure from the floor to the dropout? You'd have to ensure the steerer was parallel to the floor; measure from the floor to the drop out and then from the floor to the centre line of the steerer. Then subtract that distance from the first and that should give you the rake. Quote Link to comment Share on other sites More sharing options...
JD™ Posted October 11, 2011 Report Share Posted October 11, 2011 (edited) Would you recon the best way to measure the rake would be to lay them on the floor and measure from the floor to the dropout? Just because of you saying this, I thought about it. I can't really see how to be accurate from doing it your way, because of the fact it's gotta be the distance between the extended line from the centre of the steerer to a parallel line going through the dropout. What about... Take a pic of the bike, with forks fitted obv (just frame and forks could work) as side on as you possibly can and as good quality as you can. Take a measurement of something easier to measure accurately, like the headtube length or something, then take that same measurement in pixels or whatever in the picture. Then you can use the ratio between those to measure the rake properly... Overkill much? Edited October 11, 2011 by JD™ Quote Link to comment Share on other sites More sharing options...
Mowgli Posted October 11, 2011 Report Share Posted October 11, 2011 I think I will go by craig's method. I can take my current forks off too and do the same as a comparison. I believe if i posted a photo of both forks on the bike you would notice it without measurements. Due to the time this will take i will have to see if I am able to get this done tonight. It may need tomorrow night also. Quote Link to comment Share on other sites More sharing options...
Franksx2005 Posted October 11, 2011 Author Report Share Posted October 11, 2011 if you had some thin string/ fishing line, tie it to a pen, thread it down the centre of the steerer tube, tie a weight to it, measure from string to drop out?i found a pic, they do look strange Quote Link to comment Share on other sites More sharing options...
onzatrip Posted October 11, 2011 Report Share Posted October 11, 2011 Could it be that your forks are bent and the ones you brought arnt?? Just a possibility Quote Link to comment Share on other sites More sharing options...
JD™ Posted October 11, 2011 Report Share Posted October 11, 2011 I think I will go by craig's method. I can take my current forks off too and do the same as a comparison. I believe if i posted a photo of both forks on the bike you would notice it without measurements. Due to the time this will take i will have to see if I am able to get this done tonight. It may need tomorrow night also. Yea his was is better, it just wasn't there before I typed out my essay! Quote Link to comment Share on other sites More sharing options...
Ali C Posted October 11, 2011 Report Share Posted October 11, 2011 measure the wheelbase as normal, then turn the bars 180 and measure the wheelbase again. If the rake is the correct 40mm then the wheelbase should be 80mm shorter Quote Link to comment Share on other sites More sharing options...
Franksx2005 Posted October 11, 2011 Author Report Share Posted October 11, 2011 measure the wheelbase as normal, then turn the bars 180 and measure the wheelbase again. If the rake is the correct 40mm then the wheelbase should be 80mm shorter Bloody good idea! Just measured my trialtechs and I have 35mm rake Quote Link to comment Share on other sites More sharing options...
Mowgli Posted October 11, 2011 Report Share Posted October 11, 2011 The Picture that Frank has put up is exactly how the forks looked on my bike. My original trialtechs has the crown down to the bend in an axact straight line with the steerer and head tube. Good idea ali, that may be a better way to measure and I can do this with both sets of forks.Hi All, Thanks for your responses to this. Frank has kindly said he would give a refund for the forks. And i am very grateful for this. Regards Quote Link to comment Share on other sites More sharing options...
Franksx2005 Posted October 18, 2011 Author Report Share Posted October 18, 2011 Bloody good idea! Just measured my trialtechs and I have 35mm rake Received the forks back today, I measured the rake the same way I did my existing forks and they come out the same. I also triangulated my forks and the other ones and they come out the same within 5mm. The wheel base is also the same. From the pic I posted they do look strange but the measurements say there is nothing wrong with them and there is no stress marks. Any ideas. Quote Link to comment Share on other sites More sharing options...
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