Page 2 of 2

Re: Pedal extenders ( to stop boots rubbing crank arm ) ?? Any experience ?

Posted: 14 Feb 2020, 12:41pm
by Brucey
pedal extenders are available down to ~15mm length and are not expensive eg

https://www.ebay.co.uk/itm/Bicycle-Pedal-Extenders-for-9-16-Inch-Cranksets-15mm-Spacers-Bike-31g-70g-1-Pair-/273468096609

so you could suck it and see.

Taping up the cranks is a good idea, but it looks like it is too late to save the paint on your cranks.

Whatever you do, I'd suggest that you cover the worn areas; they may start to corrode and this greatly increases the chances of breakage.

cheers

Re: Pedal extenders ( to stop boots rubbing crank arm ) ?? Any experience ?

Posted: 14 Feb 2020, 1:20pm
by simonhill
Brucey, did you see my point re the distance from pedal to pedal. Is there a standard or does it vary by much from bike to bike?

Re: Pedal extenders ( to stop boots rubbing crank arm ) ?? Any experience ?

Posted: 14 Feb 2020, 7:58pm
by Brucey
most of them are 'about the same' but there are small variations in pedals. For example all shimano SPD pedals (using the small cleats) have the same measurement apart from the 7400 and 6500 road models, which give you ~5mm reduction in 'Q' value. This difference is quite sufficient to provoke rubbing with some riders/shoes in use.

Best to check and see if you are sailing a bit close to wind, but if you are making marks like the OP's then you need more than a few mm.

cheers

Re: Pedal extenders ( to stop boots rubbing crank arm ) ?? Any experience ?

Posted: 15 Feb 2020, 12:10am
by simonhill
Thanks, I don't have a problem, was asking on behalf of OP and out of general interest.

However, the OP's question was will my legs have a problem if I attach my pedals further out. In other words, his legs will be more open while pedalling. No one has answered that.

Maybe we need a physiologist not a cyclist to answer it.

Re: Pedal extenders ( to stop boots rubbing crank arm ) ?? Any experience ?

Posted: 15 Feb 2020, 11:10am
by Brucey
I think that is a 'suck it and see' one. My instinct is that it won't be a big problem, else there would be a lot of riders who are very happy on a road bike, but can't ride a MTB at all.

The reason I say this is that the Q value of the latter is often ~40mm more than the former; I really don't like riding most MTB triple chainsets at all because of this but the reality is that on most MTBs this value can't realistically be reduced to a value much less than midway between road and MTB values, what with chainline, chainstays etc to consider. I therefore put up with the larger Q value on MTBs for the most part, but this does mean that I will not use most of my MTBs for anything other than offroading. It doesn't cause me intense pain to ride with higher Q, it is just less comfortable as well as feeling less efficient.


Obviously this is not a view held by all; there is a trend for fitting 1x MTB setups to road-ish bikes, enough for this to have acquired a name; 'Mullet gearing'

https://bikeretrogrouch.blogspot.com/2020/02/mullet-gearing.html

Most 1x MTB chainsets have lower Q than MTB triples, but they are still fairly high Q.

cheers

Re: Pedal extenders ( to stop boots rubbing crank arm ) ?? Any experience ?

Posted: 15 Feb 2020, 3:21pm
by TrevA
I use 20mm pedal extenders, because I like to have my heels close to the cranks to ease knee pain. They do increase the Q factor, but I don’t find this a problem. MTBs have a higher Q factor than road bikes anyway so if you can ride an MTB without problems you should be OK with the increased Q factor. Q factor is the distance between the left and right pedal when fitted.

Pedal extenders do help to give greater clearance for overshoes and prevent rubbing on your cranks. Pedal extenders need you to have a shoulder on the pedal axle - SPD SL are mostly fine in this respect, but Look pedals can’t be used with them, as they use Allen key to fit them to the cranks and have no shoulder. There are some copies of Look style pedals that can be used (that have the necessary shoulder for a pedal spanner). I got some from Decathlon and I think that Boardman do some too.

Re: Pedal extenders ( to stop boots rubbing crank arm ) ?? Any experience ?

Posted: 15 Feb 2020, 3:53pm
by woodworm
Thank you all for your input. I have another road bike with a mountain bike XT crank which I ride regularly and haven’t really noticed any difference. I wasn’t aware of the increased Q factor so thanks for that. I think I will just try some 15mm extenders and see how it goes.

Re: Pedal extenders ( to stop boots rubbing crank arm ) ?? Any experience ?

Posted: 16 Feb 2020, 12:03am
by simonhill
....and I too now know about the Q factor.

If at first..........

Re: Pedal extenders ( to stop boots rubbing crank arm ) ?? Any experience ?

Posted: 16 Feb 2020, 7:47am
by Brucey
woodworm wrote:Thank you all for your input. I have another road bike with a mountain bike XT crank which I ride regularly and haven’t really noticed any difference. I wasn’t aware of the increased Q factor so thanks for that. I think I will just try some 15mm extenders and see how it goes.


that is much the best thing to do. FWIW you can compare the Q values of your MTB and road bike by measuring the offset of the crank faces from the seat tube, allowing for any difference in seat tube diameter when comparing. You should measure both sides; very often the left crank is offset differently from the right side.

cheers

Re: Pedal extenders ( to stop boots rubbing crank arm ) ?? Any experience ?

Posted: 16 Feb 2020, 8:08am
by pwa
thatsnotmyname wrote:The point is, that there shouldn’t be any rubbing though.

OP - did you check cleat position?

The rubbing seems to be something experienced only with certain winter footwear, with its extra bulk. I had a similar issue with some bulky neoprene overshoes once. A bit of tape protection on the cranks in winter, then take it off when the offending footwear gets put to the back of the cupboard in Spring. Total cost? About 20p and a bit of an attack on one's aesthetic sensibilities. And what is saved? Any risk of knee damage by extending the pedal axles. But the OP has made a choice.

Re: Pedal extenders ( to stop boots rubbing crank arm ) ?? Any experience ?

Posted: 16 Feb 2020, 9:31pm
by nez
I had pedal extenders for a while. If you have ten to two feet they help a bit, but you need to watch in if you lean over a lot cornering because they make it much more likely you'll clout the ground - a bit like riding a Brompton. Fine if you've expecting it but can be a bit of a surprise the first time it happens.

Re: Pedal extenders ( to stop boots rubbing crank arm ) ?? Any experience ?

Posted: 17 Feb 2020, 10:54am
by irc
With size 12 feet that naturally angle out slightly I always get crank rub. I just accept it. One pair of shoes I had to modify. The sole was flared out at the heel and I needed to slice a bit off the corner of the right shoe,s sole for those to be usable.

Pedal washers probably worth a try as I am loath to play about to much with a tried and tested riding position.