monty221pr Posted June 16, 2008 Report Share Posted June 16, 2008 (edited) After riding bmx for a few weeks i have noticed on alot of good bmx wheels the spokes are slightly off set on the rim surely this is stronger as it wud be harder to crush the wheel? (Less flat spots ) Any good reasons why this has not been used for trials wheels? or is it new or something? Sam. Edited June 16, 2008 by monty221pr Quote Link to comment Share on other sites More sharing options...
Bionic Balls Posted June 16, 2008 Report Share Posted June 16, 2008 far as i know...most rims have the spoke holes slightly offset for that very reason... think i've seen a "concept" trial rim on here before with a very distinct offset like you said...anyone else remember? might've been bmx.. they're probably more expensive to make! Quote Link to comment Share on other sites More sharing options...
Greetings Posted June 16, 2008 Report Share Posted June 16, 2008 DOB's have strongly offset spoke holes. This makes the wheel much much stiffer sideways. You wouldn't really benefit from much a rim in normal street use where all the obstacles are horizontal unless you do lots of spins. Quote Link to comment Share on other sites More sharing options...
monty221pr Posted June 16, 2008 Author Report Share Posted June 16, 2008 Loads of people do sidehop gaps n often people are proper sideways when gapping so it would be loads better for trials Sam. Quote Link to comment Share on other sites More sharing options...
psycholist Posted June 17, 2008 Report Share Posted June 17, 2008 Bontrager made some MTB rims with the spoke holes offset to reduce dish back in the 90's. All the spoke holes were to the same side of the rim so the angle between the spokes fro each side of the hub and the plane of the wheel was closer to equal (So the rim was as strong laterally in loading from either side). Most rims have every second spoke offset slightly off the rim's centreline to reduce binding between the spoke nipples and the rim (You lace spokes from the LH flange to the spoke holes offset to the left). To make wheels stronger in side loading a rim with no spoke hole offset will be better because the spokes make a bigger angle relative to the plane of the wheel. There is a wheel building technique known as crossover lacing where the spoke angle is increased by lacing from the LH hub flange to the RH offset spoke holes. This only works in some rim/hub combinations without the spoke nipples binding in the spoke holes (Hubs with the flanges quite close together are best for this - these will be most prone to building wheels that are weak in side loading too, so worth trying if you want a particular hub rim combination but keep turning it into a pringle on sideways landings. Quote Link to comment Share on other sites More sharing options...
jono_misfits Posted June 17, 2008 Report Share Posted June 17, 2008 The Echo rim is also off-set, i bought one about a mounth ago and only just noticed now, it feels a lot stronger than normal rims, as i had a tryall rim previously and compared the echo is more sturdy Quote Link to comment Share on other sites More sharing options...
monty221pr Posted June 17, 2008 Author Report Share Posted June 17, 2008 I dont just mean slightly out of line, like as in one side of the rim then the other so it is easily visable. Example Sam. Quote Link to comment Share on other sites More sharing options...
Echo-Scott Posted June 17, 2008 Report Share Posted June 17, 2008 Some trials rims do have quite an off-set eg: DOB But others have spokes in the middle such as Try-All Quote Link to comment Share on other sites More sharing options...
PaRtZ Posted June 18, 2008 Report Share Posted June 18, 2008 dont forget though, no rim EVER has the spoke holes directly down the middle... how else would you true out a buckle? Interesting to read this though, I had no idea how much the DOB rims were offset Quote Link to comment Share on other sites More sharing options...
psycholist Posted June 18, 2008 Report Share Posted June 18, 2008 (edited) dont forget though, no rim EVER has the spoke holes directly down the middle... how else would you true out a buckle? You can true out buckles because half the spokes pull to each side of the hub. This means a triangle is formed with two spokes for two sides and the space between the hub flanges is the third side. If the spoke holes are offset the triangle sides formed by the spokes don't meet at a point but the principle is the same. Turning the spoke nipple effectively lengthens or shortens the spoke, moving the rim from one side to another. Spoke offset does not affect how easy a wheel is to true (Unless the spoke nipple binds in the hole in the rim because the hole is offset too much). Edited June 18, 2008 by psycholist Quote Link to comment Share on other sites More sharing options...
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