Cycling UK Forum

Thanks for all the replies, it's much appreciated. I have added photos of the replacement rack I have fitted but still with the old calipers. I did try the new calipers but the cable guide points straight at the rack support still. I can probably move the support to the right a bit, I am thinking long bolt and spacer between support and p-clip. I have to admit I am concerned with how this will route the cable outer too far right.
Other options are:
a) just mount the rack to the right stay - but less rigid support
b) stick with original single pivot caliper which is not releasing fully at the moment
Regarding option b the cable is sticking in the rear cable outer. I am getting about 2mm clearance between pad and rim but if I tweak it by hand it is more like 4mm. I have replaced the outer but this did not help. Does anyone know if the spring loses its springiness? I know everything is coated in mud but it gets a good clean when it rains (about 5 days ago now).
I also note the comment regarding dual pivot brakes and mud so may not be the best option to go down this route.
I have included a photo of my homemade mudguard using plastic milk bottles and an old spoke stiffener, it works really well!

I am trying to replace the brakes on my giant speeder with dual pivot ultegra (br6500). Unfortunately the cable wants to go through the rack support! I have just changed to a different rack but have the same problem. On the old single pivot brakes (motion exage brA250 ) the cable is further outboard and comes out near to vertical. The ultegras have the cable guide further inboard and seems to point inboard at about 20degrees.
I hoped for a straight swap between calipers but they seem incompatible. I have included photos (hopefully) showing the new caliper without the cable and the old one which I have put back showing a good 3cm clearance to the rack.
The ultegra just doesn't look right, am I doing something wrong? Everything is from the 90's so I thought compatability would not be a problem. My other bike (a giant kronos also from the 90's) has dual pivot 105's with loads of clearance to the rack support although the seat stays are nearer.
Any thoughts gratefully received (sorry but first photo is upside down).

Your toes will be 1cm nearer to the front wheel so this may be an issue, depends on frame size and shoe size.

For those of us who have a limited number of hands I find the levers which hook onto the spokes really useful with difficult tyres. I currently use vittoria tyres which do seem easy to remove. I can manage to remove tyre completely (both beads) plus inner tube without levers, on a good day. Warmer temperatures help, also getting as much air out of the inner tube as possible then tightening the valve.

I have had similar issues a few years back and what helped me was changing the glasses I use for cycling to ensure I could see clearly through the top part. This then means you do not have to tilt your head quite so far back. It seems a small change, but can make a big difference.

Brucey wrote: ↑9 Jul 2024, 3:11pm

bluespeeder wrote:..... I have got lateral movement down to 0.5mm and the radial trueness has about 1mm variation. ....

that is probably a tolerable result, given the nature of the build and your lack of experience. Good job!

Thanks, I'm pleased with the result. I do wonder whether a lot of us ride with wheels which are out by this much radially after hitting a pothole but never notice.

531colin wrote: ↑9 Jul 2024, 12:57pm It may not be obvious, but radial truing requires a lot more nipple-twisting than lateral truing.
The thread pitch of the nipples is probably about 1mm, so to pull a section of rim towards the hub by 1mm requires putting a whole turn on a number of spokes.
In contrast, you can usually see a difference truing laterally making quarter turn adjustments.

I counted the number of turns removing the spokes, 39 half turns on one side. As the threaded part is about 1cm this is more like 0.5mm per thread. This means correcting 1mm of trueness would be 2 turns, putting a lot more tension on those spokes making overall spoke tension very uneven.
It is possible as you tighten the high points the low points get pushed outward so maybe 0.5mm of movement would be enough?
Correcting lateral trueness seems much easier, I found tightening 2 spokes on one side and loosening 2 opposite worked well.

slowster wrote: ↑25 Jun 2024, 12:10pm I have Tektro RL520 levers on two bikes, one with full size Shimano v brakes and the other with Avid BB7 MTN disc brakes. I find the low force/large cable pull to give a lighter lever action, which to me feels better than NSSLR STI levers with Tektro Spyre calipers or dual pivot calipers with Shimano or Campagnolo road levers. I have never felt that I have not had enough braking power when braking from the hoods

If there are any downsides of the RL520 lever, they are the consequence of designing a drop bar lever from scratch to provide the longer cable pull of linear pull brakes. Firstly, the main body is a bit larger in length (forward projection) than most other brake only levers, i.e. more like a brifter body. Secondly, the lever blade is also a bit further away from the drop where they are closest compared with an STI lever - only by about 5mm-7mm, but for someone with small hands that might make all the difference.

I have these levers on the bike I use in the warmer months ( I am not going to say summer, this year). I am very pleased with the shape and feel of them. The only downside I find is they are slippery in the wet, especially with full finger gloves. I tend to ride on the hoods and use middle and ring fingers to brake which occasionally slide off in the wet. I need some kind of tape to give them more grip.

For me, not having my size 48 feet hit the front wheel improves handling immensely.

I have taken Brucey's recommendation of prioritising equal tension over roundness and now have what will be a useful winter wheel. Tension of the spokes is close to that of a newish wheel I have (same model) and the spokes sound fairly equal in tension. Dish measures 10mm each side to the chainstay. I have got lateral movement down to 0.5mm and the radial trueness has about 1mm variation. No doubt this may change a bit after it has been ridden but I will tweak that if necessary.
I may have made things difficult using a used 24 spoke rim but this is the type of wheel I usually use (I could have chosen the rs21 wheel I am using as a summer wheel with 20 spokes!)
It has been a good learning experience and thanks for all the advice.

SprokenBroke wrote: ↑8 Jul 2024, 12:12am I've only built a couple of wheels so I'm not an expert by any means. But there's something that people haven't mentioned. Did you initially set up the spokes so that they were all the same? What I mean is, screw on the nipples so that the thread is just covered on all the spokes, then go around the wheel, starting and finishing at the valve hole, tightening each nipple by the same amount. The reason I say this is because your tension has ended up very uneven and doing it systematically this way helps to keep it about right.

This is the technique I used. I think it came out uneven because the rim has been used. I have now gone around the spokes tuning them by ear to be the same and the result is much improved. Very little lateral movement and less than 1mm of radial so I may accept this. I have tried to improve the radial movement but it is not responding to tightening spokes at the high points. It is possible the rim is slighlty distorted radially from hitting a pothole or small rock. There seems to be 3 high points so I have a triangular wheel! As mentioned this is less than 1mm so will not be noticeable.

531colin wrote: ↑7 Jul 2024, 12:52pm You know the advice provided by the village idiot when asked for directions....."Well, I wouldn't start from here!"

Like Brucey, thats how I feel about your choice of a first wheelbuild: however, you are where you are, and if you wish to proceed the first thing to do is to get the spoke tensions on the driveside closer matched.
(note this will, essentially, tend to rotate the hub within the rim, so you need to keep a check on what you are doing to the NDS tensions)

Then go for roundness, then lateral true

Thanks for that, it confirms what I thought would be the best order to do things.
It may not be the easiest way to learn to build a wheel, but it is what I have and should result in a useful spare at the end. I am also treating this as a learning exercise for truing my existing wheels should they need it.
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Thanks for that, it confirms what I thought would be the best order to do things.
It may not be the easiest way to learn to build a wheel, but it is what I have and should result in a useful spare at the end. I am also treating this as a learning exercise for truing my existing wheels should they need it.

This has crossed my mind although not for that reason! I did tape the "new" rim to the old so no foul ups with the lacing. It is an assymetric rim and is the right way around. I now wonder if wear on the spoke holes (both hub and rim) of used parts means that it may make things more tricky. I was surprised by how far out roundness it is seeing as I started with each nipple just covering the threads and added equal turns to each (allowing for offset between DS and non DS).

The wheel has 24 spokes so that may be making it more challenging. The tension ratio DS to non DS is about right as the dish is pretty well spot on. When I twang the spokes they sound quite varied, especially on the drive side, my concern is this may affect the strength.