Wisper 905SE Brakes

[ElephantsGerald]

I've noticed a couple of postings about the front and rear brakes on the Wisper 905SE:

Originally Posted by Phil the drill

I found the brake cables very stretchy, and had to replace those. The braking improvement was dramatic. I improved this further by replacing the promax front disc with an Avid BB07 (they're the business!)

Originally Posted by Aldby

I badly want to replace the Promax rear V brake on my Wisper 905se. I find it virtually impossible to get them evenly adjusted, and when I do, they soon revert to one side touching the rim and the otherside miles off

I too have found the brake cables spongy, and needing regular adjustment. How easy is it to replace the cables? (I had a look this morning and the brake, gear and electric cables all seem to be bound together in cable tidies).

Also, whats the advantage of the Avid BB07 Disk Brake? It costs £45 @ Wiggle, so its not an insignificant purchase.

My front disk brake has developed a bit of a judder when braking hard, and I've no expereience with disk brakes - I've tightened up the control cable, which hasn't helped. Theres a red plastic wheel beside the brake assembly, but I can't figure out what it does (and therefore how to adjust it).

Has anyone else had problems with the rear brakes? Mine seem fine as long as I keep tightening up the control cable regularly.

Any clues?

Regards,

Elephants

[Phil the drill]

Originally Posted by ElephantsGerald

I've noticed a couple of postings about the front and rear brakes on the Wisper 905SE:



I too have found the brake cables spongy, and needing regular adjustment. How easy is it to replace the cables? (I had a look this morning and the brake, gear and electric cables all seem to be bound together in cable tidies).

Also, whats the advantage of the Avid BB07 Disk Brake? It costs £45 @ Wiggle, so its not an insignificant purchase.

My front disk brake has developed a bit of a judder when braking hard, and I've no expereience with disk brakes - I've tightened up the control cable, which hasn't helped. Theres a red plastic wheel beside the brake assembly, but I can't figure out what it does (and therefore how to adjust it).

Has anyone else had problems with the rear brakes? Mine seem fine as long as I keep tightening up the control cable regularly.

Any clues?

Regards,

Elephants

Hi Elephants

Replacing the brake cables is really very easy, but you will need a decent pair of cable cutters/crimpers to do the job properly. For a one off job they probably don't warrant the investment. Replacing just the cable inners with decent ones will help very considerably, but replacing the outers as well with a good set will also give a little more improvement. If you can't borrow a set of cutters, then just go to a local bike shop and let them do it for you. They shouldn't charge you much just to redo a cable. The cable ties are easily unwound and rewound again at the end.
The Promax front disc unit has (justifiably) gained some degree of notoriety. It is a right royal pain in the wotsits to adjust, and to keep in adjustment. It works OK if well adjusted, but those adjustments.......The red disc is to centre the pads either side of the wheel, but it is not quite as simple as it seems, and relies on the disc pads being absolutely true and flat to the disc surface to work. Since most disc mounts are not welded with sufficent precision to guarantee this, the disc caliper often requires shimming carefully when fitted to the forks. This is virtually never done before leaving the factory (or at the dealers), and requires a some experience, and a lot of patience to get right.
Enter the Avid BB07... this unit has a mounting system unique amongst cable operated disc brakes, which allows the caliper to very easily mounted true to the disc, without shims. The whole thing is several orders of magnitude easier to set up correctly than the Promax unit, and combined with decent cables gives an awesome stopping performance. Grab a handful of these carelessly on a fast downhill and you'll do a forward roll so fast you won't know what's hit you... However, don't let that put you off, they have a very progressive feel to them, (not just on/off) and it is very easy to control the braking with them. If you look on the mountain biking forums you will find that this particular unit is held in very high regard, and is probably the only one almost universally regarded as a match for many hydraulic units.
Avid single digit V brakes are not that expensive, are easy to fit and also completely outclass their Promax counterparts (I fitted these on the rear of my bike also). It is a bit of an outlay in total, but after spending £1200 on the bike it is not such a huge percentage extra - just a pity they weren't fitted in the first place (which would have been at a proprtionately much lower cost). In fact fitting a decent V brake and compatible forks on the front would have been a big improvement on the Promax disc, in my personal view.
Hope this helps. Cheers, Phil

[the_killjoy]

I am surprised that you got more of an improvement by changeing the inner rather than the outer. I would have expected more compression of the outer than stretching of the inner.

[Phil the drill]

Originally Posted by the_killjoy

I am surprised that you got more of an improvement by changeing the inner rather than the outer. I would have expected more compression of the outer than stretching of the inner.

I actually changed both at the same time, so I didn't try them out individually. You're right though, I'm sure there is a contribution from both elements.

[big jus]

just a small note but on a £1200 bike that i am seriously thinking about buying should i be worried that small ( in my mind ) details like this haven't been thought about and fixed at source ? if multiple owners are reporting the same problems after a short period of owning the bike what else is going to crop up in the medium/long term ???
i understand that bikes are bikes and all riders have their own tastes as to the way they are set up , but i dont expect to pay what is the equivelent of a small family car then have to carry out what seems to be adjustments or upgrades just to make the bike stop safely !
i may be being a little dramatic here but surely this is a problem the guys at wisper should have noticed and corrected ?

cheers

big jus

[ElephantsGerald]

Originally Posted by big jus

just a small note but on a £1200 bike that i am seriously thinking about buying should i be worried that small ( in my mind ) details like this haven't been thought about and fixed at source ? if multiple owners are reporting the same problems after a short period of owning the bike what else is going to crop up in the medium/long term ???
i understand that bikes are bikes and all riders have their own tastes as to the way they are set up , but i dont expect to pay what is the equivelent of a small family car then have to carry out what seems to be adjustments or upgrades just to make the bike stop safely !
i may be being a little dramatic here but surely this is a problem the guys at wisper should have noticed and corrected ?

cheers

big jus

Being very new to eBikes, and having not really cycled for years, I believe I'm starting to suffer from the "Urge to Tinker". Worse perhaps is the "Urge to Discuss Tinkering with Other People". These are well known medical conditions which are sadly incurable.

I've recently found myself browsing through web sites like http://www.wiggle.co.uk looking longingly at bike related accessories, most of which I couldn't possibly need (Aero Bars, Bar Ends, Body Armour?!?).

Having to tighten the brake cables every few weeks is hardly a big chore, and I get the impression that all bikes need this sort of regular attention and maintenance (something to do with the thin, light-weight, flexible components I think - by comparison the components on a car are more robust and heavy duty; you wouldn't go near a car that needed its brakes adjusted every couple of weeks ).

Personally I can understand the mechanics of a bicycle, and I can see how I could take it to bits using very simple tools (most of which I already have). By comparison the components of a car (to me a least) are conceptually simple, but baffling in reality, requiring all sorts of specialist tools to work on them.

I'm sure that the simplicity of a bicycle encourages folk to think "If I just changed that bit, fiddled with that thing, and added one of those, then it'd make the bike perfect!". The reality is that you could tinker and fiddle endlessly (and spend loads of money in the process) and still not achieve perfection.

I'm sure WEVCO could make all sorts of improvements to this, that, and the other, but the price would slowly creep up, and its already an expensive bike (although to be fair to WEVCO, most of the expense is down to having to pay our beloved government a shed load in import duties).

Doug and Dave have already improved the bike in many ways based on feedback from this forum (e.g. binning the front wheel quick release mechanism because the forces exerted by disk brakes can make the front wheel pop out of the drop-outs with a quick release), and I'm sure they'll continue to make improvements.

Don't get me wrong, the standard Wisper 905SE is an excellent bike, and I'm very happy with it. I've made no modifications (so far), and theres no real need to, but the "Urge to Tinker" strong in me, and its possible I won't be able to resist much longer

Regards,

Elephants

[Wisper Bikes]

Hi everyone!

The problem is simply the travel on the brake lever is not enough to operate the disk brakes to everyones satisfaction. The fulcrum of the lever is only about 15mm from the cable. We have now changed the brake lever to give over twice as much cable travel and this has cured the problem.

We have upgraded the whole braking system on the latest models.

If anyone needs a new brake lever let me know and I will put some spares on the next container.

Best regards David

[ElephantsGerald]

Originally Posted by Wisper Bikes

Hi everyone!

The problem is simply the travel on the brake lever is not enough to operate the disk brakes to everyones satisfaction. The fulcrum of the lever is only about 15mm from the cable. We have now changed the brake lever to give over twice as much cable travel and this has cured the problem.

We have upgraded the whole braking system on the latest models.

If anyone needs a new brake lever let me know and I will put some spares on the next container.

Best regards David

Thanks for the info David (P.S. I've PM'd you about the brake lever).

I'd be interested to know what upgrades you've made.

Is there any possibility of posting a description (with pretty pictures ) of how to adjust the front disk brake - I'm still a bit mystified as to whether I need to tighten the brake cable, twiddle the red knob, or do both.

Regards,

Elephants

[Wisper Bikes]

Hi Elephants

We have simply bought better (more expensive) brakes. The old ones are fine but the new ones are easier to source pads for.

I have asked Doug to put together instructions (with Pretty pictures) for you.

Best regards David

[moon]

Hi, my brakes constantly need adjusting too, I have adjusted them myself but have asked the electric transport shop in London to have a look at them too, but they said they would have to charge me as I had adjusted them myself and they cant be sure that i haven't done any damage to the bike because of this
I was under the impression that I would get a free service after about a month of owning the bike...

If the problem is the levers and not the cable stretching or slipping then I too would like some new levers...plus instructions on fitting them ..