Conversion kit: Two questions!

[Manalive]

The V2/K conversion is almost done (just waiting for my crankset to arrive, and then need to hook up the gear cables). Two issues have arisen:

• 
  I used an offset-axle fork (the type reccommended against on this website). I like the fact that it retains its angle when reversed - better for off-road obstacles!
  
  However, if I use the central mounting hole for the triangular dropout brackets, there isn't enough clearance between an 11-34 9-speed cassette and the fork for the chain to change gear. If I use the rearward hole, the base of the fork stops the bracket rotating back enough to rest against the fork where the jubilee clips go (see Fig. 1).
  
  Current solution is to run an 11-28 cassette, which is fine around town, and I may find that offroading would be fine with a small-enough chainset (I suppose I can go down to a 22-24-44, but the largest chainring will be too small to make the most of the aerodynamics!).
  
  What do you all think of a spacer block under the jubilee clip? I worry that it may try to crush the fork leg in an unhelpful fashion. The ideal might be a shaped polymer block, e.g. nylon. Or maybe I can use adhesives... I'm guessing that John's design is such that using the rearmost hole won't give too little trail John, this would be so much easier if the three bracket holes sloped up as they went back, thus allowing more clearance around the fork when using the rearmost holes...
  
  Anther advantage of using the rearmost hole would be increased clearance between wheel and fork bridge: it's fine with my 26x1.25 slicks, but the 26x2.0 knobblies have only about 40 thou clearance!

• 
  There is noticeable play in the joint at the rear of the chainstay. Also, the chainstay seems to be a rather 'loose' fit on the triangular bracket: I presume this is so that tightening the bolts doesn't cause the hinge to clamp tight.
  
  Is this to be expected? What do people (specifically John!) think of adding a plumbing-type rubber washer inside the joint, to damp out the play?

Other comments:

• 
  I had to file a small notch in the offside triangular bracket, to clear the end-stop on the rear derailleur! It's a Shimano Deore Shadow.
  
• 
  Is there a reason why bolts to mount the seat to the frame don't come with the V2/K? Seems a bit pointless to use the large jubilee clips I found that M6x15 or M6x20 do the job perfectly (= standard V-brake mount bolts.)
• 
  I like the North Road bars on my first conversion so much that I got an aluminium set of NR handlebars for the V2/K version. My word, but they weigh nothing at all! Doesn't inspire confidence in their strength, but fortunately, you don't feel that when they're on the bike

Regards,

Alex

[/][/][/]

 

[Manalive]

Just looked again at other peoples' posts, and realised that Geoff mentions using half-inch rubber shims under the triangular brackets, which would presumably be exactly the solution! Realise that I could also just not put the wheel completely back in the dropouts, although this would also mean carefully lining up with the brake pads every time I remove/refit the wheel...

Further issues - again as noted elsewhere (e.g. by tmpotter), the rear derailleur mount bolt fouls against the chain in top gear. Simplest solution seems to be to put a washer between the derailleur and the bracket (currently in place: didn't need to be thick enough to stop the derailleur hitting its stop correctly). Happily, the derailleur's cage doesn't quite touch the bracket at fully-back position, as some have found!

Any watch-its or problems with these solutions, or alternative cures?

 

[John Zabriskie]

I ended up rebending the triangular brackets slightly to create greater clearance with parts of the reversed marzocchi fork I didn't want to grind off. This had the added benefit of allowing me to use a 11-34 cassette with no problems.

The 10mm gap is easily accommodated with a nylon or UHMW poly spacer. [Unless the rubber is quite stiff, the deflection under impact load would not be a good thing for the hose clamps.] I would suggest contouring it to fit the fork to spread out the load & matching the angle as best you can to the bracket flange.

You may also find a pair of 1.5mm washers placed on each side of the axle will allow the QR to have enough clamping force to hold the wheel without slipping. [The bracket thickness is substantially thinner than the dropout thickness from your donor bike.] This may also correct your derailleur mounting bolt fouling problem.

 

[Doug Burton]

Hi,

Your kit should have included four nylon washers, two for each side, that go between the triangle adapter brackets and the front chainstay. These are commonly available at the hardware store; let us know if you didn't get them with the kit.

On all my kit bikes, I've used a 2mm x 10mm washer to get the derailleur bolt to clear the chain. Not all derailleurs need it, but all mine have.

Thanks,

Doug

 

[Manalive]

Thanks for the replies!

@John - thanks: looks like a spacer is the way to go, and should solve most problems. I can run the bike as it is for the moment, while looking out for the perfect material!

Regarding the derailleur bolt issue, I'm reluctant to put washers on the axle, because (a) it fits beautifully as it is, (b) it's an extra faff when removing/refitting the wheel and (c) the QR grips perfectly well! I didn't actually have a donor - this bike is being assembled out of top-end warehouse-clearance parts from major bike-shop chains.

@Doug - good to know that a washer under the derailleur is not an unusual 'fix'. Yes, I do have four nylon washers, but even with washers either side of the brackets, there's about 1 mm clearance. It's not the lateral play that's the irritation, but a slight longitudinal play: however, I was thinking that if I got rid of the 1 mm clearance with a rubber washer, the longitudinal play would be damped out? I can appreciate that filling the play with thicker nylon washers might cause the joint to 'seize up'.

Regards,

Alex

 

[strubesy]

Because they were sitting right in front of me, I used a set of brake pads from one of my parts bikes for spacers...they work great!

 

[Manalive]

Respect good use of available materials! The 'version zero' Cruzbike conversion had a lovely pair of little-used old-school hard-as-nails pads that will be perfect.

Any other thoughts re. play in the chainstay? I suspect I won't necessarily notice it when riding, but it would still be nice to damp it out so that the chainstay bolts don't needlessly wear the holes in the triangular brackets. I have high hopes of an 8 mm x 1 mm rubber washer in each side! Tinkering time resumes on Wednesday.

I'm STILL waiting for my crankset to arrive, and then I'll be off...

Regards,

Alex

 

[Doug Burton]

Alex,

Is the play in the front chainstay or the rear swing arm?

There should not be any play in the front chainstay or rear swing arm pivots, the ones that use the MTB two-piece "axles" that have the 6mm bolt that goes down inside.

Thanks,

Doug

 

[Manalive]

Doug,

The play isn't in either of those two-piece axles: it's at the rear of the front chainstay, where there is an 8 mm bolt on each side going through a steel washer, through the chainstay, through a nylon washer, through the triangular bracket, through another nylon washer, and into the chainstay again. The play is caused by the 8 mm bolt being ever-so-slightly loose in the triangular bracket. Due to the low torsional stiffness of the fork, this allows the front wheel noticeable side-to-side play relative to the bottom bracket. It may not be a problem when riding, but it feels a little odd to be able to hold the handlebars and wobble the front wheel from side to side!

I think the unsprung steel fork I had on the previous conversion was stiff enough to conceal this play.

Alex

 

[Doug Burton]

Hi Alex.

That connection should be pretty tight.

If it has play, I would add another washer to try and take the play out. It can be a steel washer or another nylon one.

Best,

Doug

 

[Manalive]

THE V2/K LIVES

I put steel washers in alongside the nylon washers (but just to check - I presume the steel washers that came with it are meant to go under the screwhead?), and the play has gone but the suspension still seems to move OK.

I haven't yet moved the triangular brackets to make room for the 11-34 cassette: thought I'd get the bike working first

Rides very smoothly, nice and quick! Also, the rear derailleur is the highest-quality rear derailleur I've ever used, and it's a beautifully quick, quiet shift (Deore Shadow).

Initial issues:

• 
  Being greedy for top-end speed, and being able to lay my hands on it, I put a Tiagra 50-39-30 chainset on. Turns out it can't really work with a mountain-bike FD designed for 48/36/26 or 44/32/22 chainsets! I have to position it so high that it occasionally derails. It's not happy. Think I'll have to get a 48/36/26. Road derailleurs all seem to be bottom-pull? (also, wouldn't work with the MTB shifters)
• 
  The brand-new SRAM chain is only just long enough with the existing gearing! (11-28 at the rear) Even with a 48 chainring at the front, I don't think it will stretch over a 34 tooth cog at the rear. Oh well, no riding crossed-chain then.

Pictures to follow (probably next week, though)[/]

 

[Manalive]

THE V2/K CONVERSION LIVES

Other notes:

• Having experienced both, a conversion with a threadless steerer is SO much stiffer than the quill stem adaptor! Much more positive to ride, when pulling on the handlebars.
• The V2/K frame didn't come with bolts to fit the conversion kit's seat base to the frame. John: this would be useful! Given the convenient threaded holes, it seems a bit pointless to use the conversion kit's Jubilee clips to mount the seat. V-brake mount bolts seem to be perfect for the job - to anyone else building a V2/K, ask your LBS for a couple of M6x15 or M6x20 bolts with low-profile heads.

[/]

 

[Doug Burton]

That bike is beautiful.

 

[Manalive]

Thanks A tribute to the design.

The lock has now migrated onto the front tube, over the front derailleur (on what I feel I should call the seatpost, except that it's a couple of feet in front of the seat...)

Commuted to work & back on Friday, and two other cyclists independantly commented on how fast it was (conveniently, the traffic lights enabled them to catch up to make such comments )

Regards,

Alex

 

[Manalive]

Two steps forwards, one step backwards...

First step forwards: the Deore 48/36/26 crank works perfectly with the Deore front-derailleur, unlike the Tiagra crank! Perhaps not so surprising...

Second step forwards: brake-pad spacers enable the triangular bracket to mount in its rearmost hole, so that even with an 11-34 cassette, the chain never fouls the front fork

Step backwards: with an 11-34 cassette, if I change more than a single gear at once, the chain jams on the triangular bracket itself.

I've put the 11-28 back on, while I resume thinking... Suggestions?

More pictures of the bike to follow - it's getting a Topeak A-type beam-style rack shortly...

Regards,

Alex

 

[Doug Burton]

Alex,

I notice in your photos that the axle is all the way to the rear of the axle slot in the triangle bracket.

You may need to move it forward in the slot to allow the chain to clear the bracket when it rides up on the top of the cog to change gears.

The handling should be insensitive to the resulting small change in trail dimension.

I usually try to run my axle in the middle of the slot. This also makes the relationship between the derailleur upper pivot location and the axle centerline close to or identical to what was intended by the derailleur manufacturer.

Best,

Doug

 

[Manalive]

Hi Doug,

Thanks: very helpful. In the light of that, I've put the brackets back into the middle holes!

At the office garden party on Thursday, various people were trying the Cruzbike, in various stages of inebriation! Some (including a man who can ride a unicycle) managed extremely well, some (including a keen road AND mountain cyclist, who can perform trackstands) couldn't manage two yards before falling over...

Unfortunately, at some point in the falls, the rear derailleur cable got a little damaged! More significantly, somehow, a knock partially closed up the mech-side dropout (just by 1.5 mm or so), as I discovered when I tried to remove the wheel and it jammed. I levered the dropout back to its proper shape, and it seems OK!

The cable damage was an excuse to redo all the cables 'properly' (they were quickly fitted to get going, and were a mess). I'm now a lot happier with the look of the bike! Much tidier. The remote lock-out for the fork is now next to the stem, out of the way of everything, but convenient to use.

OUTSTANDING ISSUES:
- I've not yet fitted the 11-34 socket (I'll put that on when I leave London and need it as a mountain bike proper, after August), but Doug has shown the way!
- It's not shifting to the smallest sprocket: the rear derailleur doesn't adjust far enough out. Looks like I need a slightly thicker washer under the rear derailleur.
- The handlebars (60 mm rise, 45 degree sweep) are maybe a little bit of a stretch, but not so much that I could reverse them! The stem is as short as I can find (60 mm). So, I'm looking out for handlebars with a similar sweep but a smaller (ideally no) rise. There are plenty of very nice bars out there of the right shape, but in road-lever diameter. Annoying.

Attached are photos, with the new Topeak A-type rack...

God bless,

Alex

 

[Doug Burton]

Hi Alex,

Absolutely beautiful.


Based on side view comparisons between your V2K and mine, you might be able to bring the seat base forward one by one more hole set - this might get you the reach you're looking for without replacing the bars.

You could then adjust the seat post to restore the seatback angle if you wanted to.

Just an idea...

Best,

Doug