Raleigh Superbe drum brake conversion part 2: First impressions



So on a not so cold Christmas morning in London I woke up, opened presents, ate breakfast,chopped up some brussel sprouts and worked on my bike all whilst the smell of turkey was wafting from the kitchen.  Continuing from the previous night on Christmas eve when I built my wheelset, I had a plan of attack.  Firstly I would have to tension and true the wheels, spread the fork to fit the new wheels, file out the fork ends, fit the rear wheel, fit the brake levers and setup the brakes and then refit the dynamo wiring.


Front wheel:
First step was the front wheel, I wasn't sure how difficult this step was going to be because it required a bit of finesse and brute strength at the same time.  The default front spacing for old Raleighs is 86mm or so, modern front wheels are all 100mm so I had to spread it an additional 14mm which is a fair bit.  Just using two hands pulling the two dropouts apart this was suprisingly easy, the forks yielded to my hands and spread quite easily to 100mm.  Next step was the dropouts, the factory dropouts are keyed to fit the standard front hub which has matching ridges which prevents the wheel from falling out.




The 9mm axle of the XL-FDD front hub is a tad too big for the keyed dropouts, I filed the backside about 1mm or so and it fit perfectly.  I then noticed that now the fork ends were not parallel from the spreading, so a quick go with the pliers fixed this.  Front end now done!






Rear wheel:
Now for the back wheel, one thing I didn't realise until I laced up the back wheel is that the X-RD3 has a bit of dish to it, the drive side flange sits closer in to the center by about 12mm.  Spoke lengths both sides were the same at 270mm and I was able to centre the wheel easily, however the next problem was unforeseen.  I was hoping to not have any of these problems, but you can't predict everything.  What I realised was that the drum actuation arm pivot rubbed on the dropout, so much so that when the wheelnuts were tightened it would prevent the brake from returning... dang!  This occurred because the actuation pivot arm sticks out the same distance as the inside locknut on the axle, and as well because the shape of the Raleigh dropout covers it as well.





I ended up just adding another locknut on top to space the dropout further giving the brake actuation arm about 3mm of clearance, this also had the positive side effect of reducing the amount of dish as well, this set the over locknut distance to about 120mm or so which mean the dropouts had to be spread to fit the wheel in.  Now the brake worked perfectly with no interference.





Brake setup:
Now all there was left to do was install the levers and setup the brakes.  The Tektro FL-750 levers are beauties, they are super minimal and go really well with a vintage bike like the Superbe.  I decided to route the brake cables through the vestigial rod brake guides on the handlebar, this didn't seem to effect the braking at all.  The standard brake cable assembly from Sturmey Archer have a road end on one side which slots into the actuation arm, the other end is a standard flat bar end which goes into the lever.  The FL-750's take road bike ends so I had to use road bike cables with a pinch bolt at the actuation arm end, this allows you to get the exact length for your bike.


First impressions:
The first squeeze of the lever gave a bit of a squishy feel, I put this down to the drum shoes not being worn in to fit the curve of the drum perfectly.  I took the bike for it's first shakedown ride by going down the canals towards Hackney marsh, I brought a fair few tools just in case the unexpected happened; luckily I didn't have to do any adjustments the whole ride.  The modulation of the brake is excellent, second only to discs.  You can easily feather the brake very lightly, if you squeeze harder it will give you a nice progressive increase in braking force.  I rode over and did some practice stops on hardpack with loose dirt covering, you could very easily just feather the brake to the point just before lockup, known as threshold braking - I've never been able to do this with any rim brakes let alone the road brakes that were on it before.



The power of the both the front and back brakes was lacking to be completely honest.  Out of the box they were quite weak, about the same stopping power as a average single pivot caliper brake.  The power was limited by the brake lever hitting the bar though, even when the cable was adjusted to the point just before it was dragging.  I suspect though that both brakes aren't quite worn in yet, that the brake shoes haven't worn into the curve of the drum; I've used the 70mm version of these brakes on someone else's bike that were worn in, and the lever was a lot firmer.  I'll have to do a longer term review as they supposedly take a few hundred km's to wear in; even during the ride I found I could adjust them tighter and tighter without dragging as the shoes slowly were wearing themselves in.

The dynamo worked as advertised, now that the lights were the full 3.0w instead of the 2.0w that the Sturmey Archer AG hub put out the headlight was noticeably brighter.  I honestly couldn't tell the difference in dynamo drag, I have read though that the drag is reasonable, not as good as the top end Shimano units though.



On the way back I stopped for some liquid refreshment, overall I'm very happy with the new wheelset, the initial braking power is a bit disappointing however this should change over time.    I also did a quick weight check, before the upgrade it weighed in at 19.8kg, after the upgrade it's a shade over 20kg.   I'm not 100% sure however as my scales are just cheapies that jump all over the place at around that weight.  Happy riding.

3 comments:

  1. Hi
    I enjoyed reading your articles on the drum brake dynohub,
    And have taken the plunge and bought one to try.
    I am not a wheelbuilder and have left this task to Marcus of Walkers' Wheels in Montmorency.
    I had a Schmidt hub built by him for my 1990ish Raleigh Royal touring bike. They are an Excellent hub but they are pricey and The SA XL FDD
    seemed like a great buy.
    Wheel should be ready in a couple of days, bike has B and M head and tail lights ready for connecting.
    I am looking forward to my first trial of this great looking hub :-)

    ReplyDelete
  2. I had an accident with an ocky strap in the back wheel many years ago and am now very cautious of these!

    ReplyDelete
  3. Yep I've got about 3000 miles nearly on mine now over the past year and it's still very solid. The braking is still fantastic, so far so good!

    ReplyDelete