vosyer

I have two tandems - both with 145 rear spacing, I've come across a deal on a Hope 40 hole Big Un without the disk setup, but with 140 spacing. Can I make this work somehow? thanks

merlinextraligh

sure, if you've got a steel frame, you can just clamp it down or cold set the frame to 140

ricardo kuhn

actually even easier make a 5mm longer spacer for the left side of the Big-Um and then add two 5MM spacers to you calipers... less stress on the frame that is for sure, (remenber when you "Compress" a frame the drop out follow the tubes, ergo they become mis-aling in reference to each other,,,aka not paralel anymore..)


PS: if you don't want it I will buy it in a second, those hubs are heavy but super strong and also they can be build 4 cross, what else you want,,,,,!?!? I have five of them my self and I want even more..
also remenber they feature a Five bolts type rotor that is only availalble from hope... so try to get the rotor with the hub if possible

vosyer

Thanks Richard,

I think I'll buy it, I am told this is a Big Un without the rotor set but for an arai drum, if I can't make is work for a tandem I'll make it wotk for my loaded touring bike which current has 135 spacing. Again thanks for for your endorsement that this is a good hub, I hadn't seen one for a while.

ricardo kuhn

I'm glad I can help, I never see one in use with a Arai drum, but i'm sure will last you a few bikes.

stapfam

If you contact Hope, or a Hope dealer, They can supply the relevant spacers to space it out to 145mm. It will require a retrue/ rebuild on the wheel though, as if you just add a spacer on one side, it will put the dishing of the wheel out.

Leisesturm

I agree with stapfam, the spacers should go on both sides of the hub. There should be no need to re-dish the wheel then and the amount that the caliper needs to be spaced is only 2.5mm. Some trikes take advantage of a wide dropout spacing to have equal dish on both sides of the wheel i.e. no dish at all. This makes for a stronger wheel and this might have been where Ricardo was headed. It comes at the price of an offset rim, however, and don't think that kind of misalignment is appropriate for a single track vehicle. Spreading 135mm dropouts to 140 is IMO just as problematic as squeezing in 145 dropouts, there is always the danger that one side will move more than is neccessary and the final spacing although accurate enough in terms of dimmension will be inaccurate because of the failure to achieve a 50/50 re-size. Would a less than 2mm misalignment be noticed? I would have thought not until I read the thread about crank length...


H

stapfam

Hate to say it, but you have the sprocket to think of. The spacer will go only on one side of the hub, to keep the sprocket alignment correct,. This will mean a redishing of the wheel, but need not be that expensive. Incidentally- I have just sent my first set of Hope Bigun wheels for a strip and rebuild. Hubs were stripped, and Freehub taken apart. All put back together with original parts, and the only maintenance necessary was replace one spoke that had a bend in it from taking a branch a few months ago. Not bad for a pair of wheels that have taken some abuse for 4,000 miles. On the puting a 140mm hub in 145 spacing- It is possible, but you will cause misalignment of the chain/sprocket or even the straight line alignment. Far better to get the frame proffesionally tweaked to 140 - or take the course of rebuilding the hub to take 145.

On the disc realignment- Hope amd I dare say others, make a spacer to bring the disc outboard from the hub. The norm is that from 135mm spacing, to 145- a 10mm spacer will be required. I did not follow this route, but made a spacer to bring the caliper inboard to the disc. Which is the better method is anyones guess, but either way works.

ricardo kuhn

I much rather see all the Spacers on the None drive side because,,
first as you mension the issue of the triangulation of the hub rim and spokes, in ideal conddiccions you want even angles at the spokes, that makes for the strongest structure since the tension are far more even plus will be great is the spokes are separated at the hub as much as possible to increase the triangulation, also the issues of the chain line and the compativility with the other wheels already available (the two original wheels),
just think about it,, tandems already have pretty wide Q- factor and ussually also wide Bottom brackets,Ergo the chainring are already farde out that Optimal (midde ring in perfect line with the middle cog) if you make the cogs even closer to the center or away from the right drop out, that angle on the chain will increase even more, plus maybe the derraileur can not even take the extra travel require(since the cogs will be farder inwards) and even the set screw maybe will be at the end of the travel, on that same note just imagine how complicated will be to re-aling all the shifers, cables and derreileurs, etc, every time that you change to another wheel.

actually i was thinking about this dicotomy last night and i think I found the ultimate solution,,so the ipotesis is that you don't even need to re-space the caliper, maybe will be far easier to space the rotor to make it closeer the the left drop out,(what ever distance is require so you don't need to reajust the caliper making the 3 wheels totally compatible and interchangable),, I done stuff like this On motorcycles(bolts with spacers) for years with out any trouble, if the bolts are propertlly torque they will not bend or fail at all..

also I assume we were discussing this problem with people that know what they doing so I did not even think about the need to mension wheel dish since is something so ovius,, i guess the next time i do it, just to make sure we are on the same page...

if you don't need to don't mess with the Aligment, I spend many hours working aligment frame tables and I can tell you Cold setting is not as easy as you may think, first of all you need to have a reference line(center of the frame) and move each of the drop outs a certain amount,, if you move on of them fardar than necesary creating a diferent poligon (even if you achive the dimension you want, ) the frame will ride crucket...since the angle of the wheel will not be in reference with the center line of the frame,,, i hope i make sense on this one..

ricardo kuhn

I agreee with your observations stapfam, maybe next time i read your comments first so i don't need to type them my self.

vosyer

Thanks for everyones comments. Just to let everyone know I don't mind redishing tor even rebuilding the wheel and I have a friend who has the tools to spread my frames. Many of my steel classic single bikes have been spread numerous times (120,126, to finally be be 130. Its one of the beauties of having a steel frame. I have never yet had call to spread or decrease the spacing on a tandem though. It appears from everyone's comment that these are good hubs and for that reason alone I am buying them because good tandem hubs are to find. Again thanks for everyones comments.