prelit

Hi guys, I've just fitted a Gremica 125mm front hub to a Bantam to try to improve the braking power over the previously fitted Montesa 110mm hub. The hub had very little wear, max dia was measured at 125.5mm and surface was free of any damage, I used a new NOS brake plate and cam assembly with oversized shoes arched to to fit the hub. The lining material was recommended by Villiers Services to be the best for trials. I also opened the brake plate spindle hole 0.020" to allow the plate to centralise with the brake on before tightening the spindle. Now what I expected was a significant improvement in braking power but in fact the braking is no better! New wheel bearings. New cable. Domino levers. Now I've only been up and down the road dragging the brake on but I expected more. I quickly dropped the wheel out and looked at the linings, it looked as if the contact area was good judging by the shine on the shoes as the material was matt after machining down to size. So I chalked the linings and repeated, sure enough the contact area was good with 100% contact. A few more trips up and down the road dragging the brake on to try and bed in resulted in no better performance. I was also alarmed at how cool the hub was too the touch. The lining material is a grey colour, very soft and when machined produced a fine dust. It machined real easy and I just had to keep the tool dressed to produce a nice finish. The hub surface has been bead blasted. Anyone else used this lining material? Is there any better material available? I have the NOS shoes that came on the brake plate, these obviously aren't arched to the Hub Dia. but maybe they will be better. They look a more course lining and are brown. Any other comments? Thanks, Prelit.

Hi Guys, Does anyone know to a uk supplier of the Tubliss system? Thanks in advance. Prelit

Hi Guys, Tried every thing!!! Left to soak in paraffin for 3 days, twatted the end of the studs every day whilst in soak, heated stud/boss as hot as I dare. Never had anything this stubborn before. Well I gave up and had to machine out on a dividing head & re tap. It looks as if they were just normal studs, after I machined the core out then the thread could be picked out. After I re tapped the threads look ok and I'm happy enough to use on my Bantam project as this hub will give me a right foot back brake. Thanks for you help, Simon.

I can add a few tips... I play with loctite!!! It does denature with heat... the temp is about 150-160 deg C for most products they have for thread locking. How you apply the heat can make a big difference. For example if the thing its connected to is a giant heat sink or transfers heat really well you may have to apply a little more heat than first thought. A small butane torch can be invaluable for denaturing loctite in a controlled and concentrated fashion. The pic below is me denaturing loctite on a disc rotor before attempting to remove the fastener. The thin beam torch concentrates the heat down through the fastener and into loctite on its way to heat sink surrounding it. Another little tip is to set a torque wrench to fastener value but in the undo position. Heat fasteners with butane torch and take to temp.... think hot baking tray in an oven doing the roast... thats about the temp! Count seconds to heat it ...say 40 secs, then apply torque. If unsuccessful up torque by 5% and the heat time by 20%... and go again.... Eventually the method should undo the fastener with the LEAST risk of stripping the fastener.... its just applied in a methodical and controlled way to give you the best chance of success. Good luck! Mags Thanks for taking the time to reply, I've heated the studs until they are a dull red, I've tried heating the boss from inside the hub with a welding torch on a soft flame. I've got the hub in a lathe chuck and made a bar which picks up on 2 studs and jams onto the lathe bed to prevent rotation. I'm using a large breaker bar and applying as much force as I dare but they are stuck fast. I keep thinking they must be cast in, but logic says they can't be as the surface the sprocket sits on is machined !!!!! Surely not a left hand thread? I've applied some force this way but they still won't budge. Thanks again, Simon.

Thanks for the reply, I'm sure most of the liquid 'loctite' products disintegrate with heat. Perhaps I'm not getting the hub hot enough but I fear that the studs may have a boss which is cast in. I will try it a little bit hotter and give it a bit more force. I know dis-similar metals corrode but I've not ever had anything this seized/tight before. Thanks again, Simon.

Hi Guys, I'm trying to remove the 5 10mm studs that secure the sprocket to the hub on what I thinks is a 242 rear hub. I believe this hub is common to the 200 & 247. Sprocket 1 side, brake plate on the other. I've welded nuts to the studs and gently heated the boss inside the hub but they won't budge. Before I try more heat and more force I just thought I would ask on hear if anyone has ever removed them Thanks in advance, Simon.